A model HA-type polymer of para-benzoquinone synthetic humic acid (SHA) and its complexes with copper, iron and manganese metal ions were studied using atomic force microscopy (AFM). Natural humic acids (HA) and synthetic humic acids (SHA) were examined by fluorescence spectroscopy, which indicated similarity of SHA and HA spectra. The AFM images of SHA and its complexes revealed variable morphologies, such as small spheres, aggregates and a sponge-like structure. The SHA complexes displayed morphologies similar to those of natural HA. The presence of copper, iron and manganese ions led to the formation of aggregate-type structures in an apparent arrangement of smaller SHA particles.
synthesis and characterization of hydrazone ligand and their metal complexesMUBASHIRA M
This slide mainly contain the synthesis, characterization of a few hydrazine based heterocyclic ligand such as hydralazone and phenyl hydralazone and also their metal complexes. so in this work, my aim is to synthesise the ligands; 2-thiophenecarboxylaldehydehydralazone and 2,3-butanedionephenylhydrazone. also to characterized the synthesised hydrazones by different physiochemical techniques.
Removal of Heavy Metals from Aqueous Solutions by Modified Activated Carbon f...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Synthesis and Application of C-Phenylcalix[4]resorcinarene in Adsorption of C...Jacsonline.Org
Synthesis and Application of C-Phenylcalix[4]resorcinarene in Adsorption of Cr(III) and Pb(II), for more information visit our website http://jacsonline.org/
The problem of environmental pollution is more expressed and more present by the development of the industry and the growth of the human population. Pollution of natural and wastewater is most often due to the release of heavy metals into watercourses. The greatest challenge for researchers is choosing the right biomass from a large number of low-cost biomaterials, and availability and price are very important selection factors. Microbial biomass, forestry waste and agroindustrial complexes are most frequently examined, as well as various macromolecules of natural origin. In this paper, barley straw that arises as agricultural waste product in barley production in Bosnia and Herzegovina, was used as a biosorbent. In the experimental part, physical and chemical characterization of barley straw was performed, after which the efficiency of removing Cd(II) and Ni(II) from aqueous solutions, using barley straw, and the influence of process parameters (pH value of aqueous solution, biosorbent size, interaction of metal ions) on the biosorption capacity were tested. It can be concluded that barley straw has good adsoption characteristics for the use as a low-cost natural sorbent for the removal of heavy metals from water.
Chelating ion exchange and antimicrobial studiesIJECSJournal
The Copolymer (p-HBTF-I) was synthesized by condensation of p-hydroxybenzoicacid and thiosemicarbazide with formaldehyde in the presence of 2M HCL as a catalyst at 126 ± 2 0C for 5 hrs. with molar proportion of reactants. The copolymer (p-HBTF-I) was characterized by elemental analysis, FT-IR, UV-Visible 1H-NMR Spectroscopy. The chelating ion-exchange property of this polymer was studied for five metal ions viz. Cu (II), Ni (II), Co (II), Zn (II), and Pb (II) ions. The chelating ion-exchange study was carried out over a wide range of pH, shaking time and in mediaof various ionic strengths. The copolymer possesses antimicrobial activity for certain bacteria such as B. Subtilis, ,E.Coli, S. Typhi .
synthesis and characterization of hydrazone ligand and their metal complexesMUBASHIRA M
This slide mainly contain the synthesis, characterization of a few hydrazine based heterocyclic ligand such as hydralazone and phenyl hydralazone and also their metal complexes. so in this work, my aim is to synthesise the ligands; 2-thiophenecarboxylaldehydehydralazone and 2,3-butanedionephenylhydrazone. also to characterized the synthesised hydrazones by different physiochemical techniques.
Removal of Heavy Metals from Aqueous Solutions by Modified Activated Carbon f...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Synthesis and Application of C-Phenylcalix[4]resorcinarene in Adsorption of C...Jacsonline.Org
Synthesis and Application of C-Phenylcalix[4]resorcinarene in Adsorption of Cr(III) and Pb(II), for more information visit our website http://jacsonline.org/
The problem of environmental pollution is more expressed and more present by the development of the industry and the growth of the human population. Pollution of natural and wastewater is most often due to the release of heavy metals into watercourses. The greatest challenge for researchers is choosing the right biomass from a large number of low-cost biomaterials, and availability and price are very important selection factors. Microbial biomass, forestry waste and agroindustrial complexes are most frequently examined, as well as various macromolecules of natural origin. In this paper, barley straw that arises as agricultural waste product in barley production in Bosnia and Herzegovina, was used as a biosorbent. In the experimental part, physical and chemical characterization of barley straw was performed, after which the efficiency of removing Cd(II) and Ni(II) from aqueous solutions, using barley straw, and the influence of process parameters (pH value of aqueous solution, biosorbent size, interaction of metal ions) on the biosorption capacity were tested. It can be concluded that barley straw has good adsoption characteristics for the use as a low-cost natural sorbent for the removal of heavy metals from water.
Chelating ion exchange and antimicrobial studiesIJECSJournal
The Copolymer (p-HBTF-I) was synthesized by condensation of p-hydroxybenzoicacid and thiosemicarbazide with formaldehyde in the presence of 2M HCL as a catalyst at 126 ± 2 0C for 5 hrs. with molar proportion of reactants. The copolymer (p-HBTF-I) was characterized by elemental analysis, FT-IR, UV-Visible 1H-NMR Spectroscopy. The chelating ion-exchange property of this polymer was studied for five metal ions viz. Cu (II), Ni (II), Co (II), Zn (II), and Pb (II) ions. The chelating ion-exchange study was carried out over a wide range of pH, shaking time and in mediaof various ionic strengths. The copolymer possesses antimicrobial activity for certain bacteria such as B. Subtilis, ,E.Coli, S. Typhi .
A new Schiff base 4-chlorophenyl)methanimine
(6R,7R)-3-methyl-8-oxo-7-(2-phenylpropanamido)-5-thia-1-
azabicyclo[4.2.0]oct-2-ene-2-carboxylate= (HL)= C23H20
ClN3O4S) has been synthesized from β-lactam antibiotic
(cephalexin mono hydrate(CephH)=(C16H19N3O5S.H2O) and 4-
chlorobenzaldehyde . Figure(1) Metal mixed ligand complexes
of the Schiff base were prepared from chloride salt of
Fe(II),Co(II),Ni(II),Cu(II),Zn(II) and Cd (II), in 50% (v/v)
ethanol –water medium (SacH ) .in aqueous ethanol(1:1)
containing and Saccharin(C7H5NO3S) = sodium hydroxide.
Several physical tools in particular; IR, CHN, 1H NMR, 13C
NMR for ligand and melting point molar conductance, magnetic
moment. and determination the percentage of the metal in the
complexes by flame(AAS). The ligands and there metal
complexes were screened for their antimicrobial activity against
four bacteria (gram + ve) and (gram -ve) {Escherichia coli,
Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus}.
The proposed structure of the complexes using program, Chem
office 3D(2006). The general formula have been given for the
prepared mixed ligand complexes Na2[M(Sac)3(L)], M(II) = Fe
(II), Co(II) , Ni(II), Cu (II), Zn(II) , and Cd(II).
HL= C29H24 ClN3O4S, L= C29H23 ClN3O4S -.
Kinetics of Ruthenium(III) Catalyzed and Uncatalyzed Oxidation of Monoethanol...Ratnakaram Venkata Nadh
Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide
(NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate
and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS,
a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate
concentration and decreased with an increase in the perchloric acid concentration. This indicates that free
amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate,
which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the
medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher
oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A
suitable mechanism consistent with the observations has been proposed and a rate law has been derived to
explain the kinetic orders.
Examination of Adsorption Abilities of Natural and Acid Activated Bentonite f...AnuragSingh1049
The effect of the initial concentration of Cr, Co, Cu, Ni, and Pb metal ions from multicomponent solutions on the sorption capacity of natural and acid activated bentonite was examined in this paper. The acid activation was performed by using hydrochloric and sulfuric acid at different concentrations. The results of adsorption research have shown that bentonite can be effectively used as an adsorbent for the removal of metal ions from multicomponent solutions. Acid activation of bentonite changes the structure and content of individual oxides, increases the porosity and the number of available spots for the adsorption process. For this reason, the bentonite removal efficiency increased after acid activation for all heavy metals tested. With increased acid concentration, the degree of bentonite adsorption increased, and sulfuric acid rather than chloric acid showed better results in removal efficiency.
SYNTHESIS AND CHARACTERIZATION OF KAOLINITE COATED WITH CU-OXIDE AND ITS EFFE...Premier Publishers
In this paper, a novel copper oxide coated kaolinite was prepared as an adsorbent of Hg(II) ions from aqueous media. The materials used for this study were synthesized, characterised and the product tested for mercury ion removal using standard laboratory procedures. Reactivity and removal kinetic models derived from Freundlich isotherm were used to investigate contact time and pH effects on the coefficient of protonation and rate of mass transfer of Hg(II) ions to the reactive sites, Proton coefficient of 0.89 indicated a decrease in proton consumption function when compared with uncoated kaolinite. At the 12th h reaction time, a maximum adsorption capacity of 85% was achieved. Mass transfer rates of 0.9359h-1 and 0.0748h-1 for the first and second reaction phases indicated a reduction when compared with uncoated kaolinite. These changes may be ascribed to masking of reaction sites and exposed surface area of the Cu-Oxide coated kaolinite.
Vibrational Characterization and Antioxidant Activity of Newly Synthesized Ga...peertechzpublication
The gallium(III) complex of orotic acid (HOA) was synthesized and its structure was determined
by means of analytical and spectral analyses. Detailed vibrational analysis of HOA, sodium salt of HOA
(NaOA) and Ga(III)-OA systems based on both the calculated and experimental spectra confi rmed the
suggested metal-ligand binding mode. Signifi cant differences in the IR and Raman spectra of the complex
were observed as compared to the spectra of the ligand and confi rmed the suggested metal-ligand
binding mode.
Eco-friendly method for the estimation of cobalt (II) in real samples using 1...Innspub Net
An easy and quick spectrophotometric method is developed for the investigation of cobalt at trace level using 1-(2-Thiazolylazo)-2-naphthol (TAN) in presence of surfactant cetyltrimethylammonium bromide (CTAB) aqueous micellar solution. The cobalt forms bis [1-(2-Thiazolylazo)-2-naphthol] cobalt complex reacting with 1-(2-Thiazolylazo)-2-naphthol. Proposed method is of great importance because use of micellar system instead of solvent extraction steps that were toxic, expensive and time consuming. The method shows improved sensitivity, selectivity and molar absorption. The coefficient of molar absorption and Sandell’s sensitivity was found to be ε 1.89 × 104L mol-1 cm-1 and 3.1ngcm-2 at λmax 572.7nm. Graph of Linear concentration calibration was obtained in the range 0.02-9.0μgmL-1; stoichiometric metal ligand ratio was found 1:2 for the complex Co-[TAN]2 formation. The proposed method was applied for the investigation of cobalt from different alloys, biological, environmental and pharmaceutical samples. Full articles at https://lnkd.in/fbEHTJ6
Synthesis and Characterization of Schiff Base from Aromatic Amine and Aromati...ijtsrd
The synthesis of Schiff base From Aromatic Amine And Aromatic P Nitro benzaldehyde was performed by a novel method of stirring followed by the addition of p nitro benzaldehydeandm nitro aniline 0.02M . Characterization of the synthesized compounds, determination of purity and identity of the compounds using following spectroscopic and chromatographic techniques Solubility, Thin Layer Chromatographic studies, Ultra Violet studied rotational and vibrational studies FT IR studies. The compounds were investigated for their Antimicrobial activity by cup plate method. Compound1 nitro 4 1 imino,4 nitrophenyl benzene was found to be the most active according to pharmacological evaluation exhibited antimicrobial. Ms. Chetana D. Patil | Mr. Digamber N. Bhosale | Ms. Smita P. Bedis "Synthesis and Characterization of Schiff Base from Aromatic Amine and Aromatic P-Nitro Benzaldehyde" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26401.pdfPaper URL: https://www.ijtsrd.com/pharmacy/medicinal-chemistry/26401/synthesis-and-characterization-of-schiff-base-from-aromatic-amine-and-aromatic-p-nitro-benzaldehyde/ms-chetana-d-patil
Kinetic, thermodynamic and equilibrium studies on removal of hexavalent chrom...Ratnakaram Venkata Nadh
Removal of Cr(VI) by biosorption on two agro waste materials, casuarinas fruit powder (CFP) and sorghum
stem powder (SSP), has been investigated. The prepared adsorbent materials were characterized by SEM, EDX,
FTIR and BET. These biomaterials effectively removed Cr(VI) with a maximum removal of 93.35% and 63.75% using
15 gL−1 and 5 gL−1 of CFP and SSP, respectively, at 60 oC with 20mgL−1 initial Cr(VI) concentration in solution. In both
cases of adsorbents, kinetic data of adsorption fitted well in pseudo-second-order in terms of correlation coefficient
(R2). This helps in proposing the process of adsorption as chemical coordination, which is correlated with the thermodynamic
study results conducted at different values of temperature. Langmuir, Freundlich and D-R models were evaluated
for description of metal sorption isotherms. Values of coefficients of intra-particle diffusion and mass transfer have
also been determined at different values of temperature.
Visible Light Photocatalytic Degradation of Methylene Blue and Malachite Gree...IJEAB
A facile solid state metathesis synthesis of barium tungstate (BaWO4) followed by ball milling and subsequent preparation of barium tungstate-graphene oxide (BaWO4–GO) nano composite using a colloidal blending process and its application as a visible light photocatalyst for the degradation of Malachite green and Methylene blue dyes. The morphology and composition of barium tungstate (BaWO4) nano composite have been characterized using X-Ray Diffraction (XRD), UV–Visible Diffuse Reflectance Spectra (UV-DRS), Raman Spectra, Field Emission Scanning Electron Microscopy (FESEM) – EDAX and UV Visible Spectroscopy. This composite material is found to be a wide band gap semiconductor with band gap of 4.3 eV. The sample shows poor transmittance in ultraviolet region while it has maximum transmittance in visible-near infrared regions. It shows an increase in range and intensity of light absorption and the reduction of electron–hole pair recombination in BaWO4 with the introducing of GO on to it.
Spectral studies of 5-({4-amino-2-[(Z)-(2-hydroxybenzylidene) amino] pyrimidi...IOSR Journals
Some transition metal ions Complexes with 5-({4-amino-2-[(Z)-(2-hydroxybenzylidene) amino]
pyrimidin-5-yl} methyl)-2,3,4-trimethoxybenzene were prepared and characterized by elemental analyses,
Infrared , magnetic moment, electronic spectra , mass spectra, X-ray powder diffraction, molar conductance
and thermal analysis (TGA). The complexes have general formulae [ML2.2H2O] {where M = Mn (II), Co (II), Ni
(II), Cu (II), Zn (II), Pd (II) and Pt (II). The coordination behavior of the metal ions towards to the investigated
Schiff base takes place through –C=N,-NH2 and –OH groups. The obtained C, H and N elemental analysis data
showed the Metal: Ligand ratio is 1:2 [M: L] ratio. The molar conductance data reveal that all the metal
complexes are non-electrolytic in nature. From the magnetic moments the complexes are paramagnetic except
Zn metal ion complexes have octahedral geometry with coordination number eight. The thermal behavior of
these complexes shows that, the hydrated complexes have loses two water molecules and immediately followed
by decomposition of the anions and ligand molecules in the second and third stage. The Schiff bases and metal
complexes show good activity against some bacteria. The antimicrobial results indicate that, the metal
complexes have better antimicrobial activity as compared to the prepared Schiff base.
Complexation, Spectroscopic, Thermal, Magnetic And Conductimetric Studies On ...IOSR Journals
7-hydroxy-4-methyl-8-(phenylazo) coumarin (L1)and 7-hydroxy-4-methyl-8-(o-carboxyphenylazo) coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and Mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and the complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and studied by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass spectra and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn metal ions and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
A new Schiff base 4-chlorophenyl)methanimine
(6R,7R)-3-methyl-8-oxo-7-(2-phenylpropanamido)-5-thia-1-
azabicyclo[4.2.0]oct-2-ene-2-carboxylate= (HL)= C23H20
ClN3O4S) has been synthesized from β-lactam antibiotic
(cephalexin mono hydrate(CephH)=(C16H19N3O5S.H2O) and 4-
chlorobenzaldehyde . Figure(1) Metal mixed ligand complexes
of the Schiff base were prepared from chloride salt of
Fe(II),Co(II),Ni(II),Cu(II),Zn(II) and Cd (II), in 50% (v/v)
ethanol –water medium (SacH ) .in aqueous ethanol(1:1)
containing and Saccharin(C7H5NO3S) = sodium hydroxide.
Several physical tools in particular; IR, CHN, 1H NMR, 13C
NMR for ligand and melting point molar conductance, magnetic
moment. and determination the percentage of the metal in the
complexes by flame(AAS). The ligands and there metal
complexes were screened for their antimicrobial activity against
four bacteria (gram + ve) and (gram -ve) {Escherichia coli,
Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus}.
The proposed structure of the complexes using program, Chem
office 3D(2006). The general formula have been given for the
prepared mixed ligand complexes Na2[M(Sac)3(L)], M(II) = Fe
(II), Co(II) , Ni(II), Cu (II), Zn(II) , and Cd(II).
HL= C29H24 ClN3O4S, L= C29H23 ClN3O4S -.
Kinetics of Ruthenium(III) Catalyzed and Uncatalyzed Oxidation of Monoethanol...Ratnakaram Venkata Nadh
Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide
(NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate
and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS,
a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate
concentration and decreased with an increase in the perchloric acid concentration. This indicates that free
amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate,
which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the
medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher
oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A
suitable mechanism consistent with the observations has been proposed and a rate law has been derived to
explain the kinetic orders.
Examination of Adsorption Abilities of Natural and Acid Activated Bentonite f...AnuragSingh1049
The effect of the initial concentration of Cr, Co, Cu, Ni, and Pb metal ions from multicomponent solutions on the sorption capacity of natural and acid activated bentonite was examined in this paper. The acid activation was performed by using hydrochloric and sulfuric acid at different concentrations. The results of adsorption research have shown that bentonite can be effectively used as an adsorbent for the removal of metal ions from multicomponent solutions. Acid activation of bentonite changes the structure and content of individual oxides, increases the porosity and the number of available spots for the adsorption process. For this reason, the bentonite removal efficiency increased after acid activation for all heavy metals tested. With increased acid concentration, the degree of bentonite adsorption increased, and sulfuric acid rather than chloric acid showed better results in removal efficiency.
SYNTHESIS AND CHARACTERIZATION OF KAOLINITE COATED WITH CU-OXIDE AND ITS EFFE...Premier Publishers
In this paper, a novel copper oxide coated kaolinite was prepared as an adsorbent of Hg(II) ions from aqueous media. The materials used for this study were synthesized, characterised and the product tested for mercury ion removal using standard laboratory procedures. Reactivity and removal kinetic models derived from Freundlich isotherm were used to investigate contact time and pH effects on the coefficient of protonation and rate of mass transfer of Hg(II) ions to the reactive sites, Proton coefficient of 0.89 indicated a decrease in proton consumption function when compared with uncoated kaolinite. At the 12th h reaction time, a maximum adsorption capacity of 85% was achieved. Mass transfer rates of 0.9359h-1 and 0.0748h-1 for the first and second reaction phases indicated a reduction when compared with uncoated kaolinite. These changes may be ascribed to masking of reaction sites and exposed surface area of the Cu-Oxide coated kaolinite.
Vibrational Characterization and Antioxidant Activity of Newly Synthesized Ga...peertechzpublication
The gallium(III) complex of orotic acid (HOA) was synthesized and its structure was determined
by means of analytical and spectral analyses. Detailed vibrational analysis of HOA, sodium salt of HOA
(NaOA) and Ga(III)-OA systems based on both the calculated and experimental spectra confi rmed the
suggested metal-ligand binding mode. Signifi cant differences in the IR and Raman spectra of the complex
were observed as compared to the spectra of the ligand and confi rmed the suggested metal-ligand
binding mode.
Eco-friendly method for the estimation of cobalt (II) in real samples using 1...Innspub Net
An easy and quick spectrophotometric method is developed for the investigation of cobalt at trace level using 1-(2-Thiazolylazo)-2-naphthol (TAN) in presence of surfactant cetyltrimethylammonium bromide (CTAB) aqueous micellar solution. The cobalt forms bis [1-(2-Thiazolylazo)-2-naphthol] cobalt complex reacting with 1-(2-Thiazolylazo)-2-naphthol. Proposed method is of great importance because use of micellar system instead of solvent extraction steps that were toxic, expensive and time consuming. The method shows improved sensitivity, selectivity and molar absorption. The coefficient of molar absorption and Sandell’s sensitivity was found to be ε 1.89 × 104L mol-1 cm-1 and 3.1ngcm-2 at λmax 572.7nm. Graph of Linear concentration calibration was obtained in the range 0.02-9.0μgmL-1; stoichiometric metal ligand ratio was found 1:2 for the complex Co-[TAN]2 formation. The proposed method was applied for the investigation of cobalt from different alloys, biological, environmental and pharmaceutical samples. Full articles at https://lnkd.in/fbEHTJ6
Synthesis and Characterization of Schiff Base from Aromatic Amine and Aromati...ijtsrd
The synthesis of Schiff base From Aromatic Amine And Aromatic P Nitro benzaldehyde was performed by a novel method of stirring followed by the addition of p nitro benzaldehydeandm nitro aniline 0.02M . Characterization of the synthesized compounds, determination of purity and identity of the compounds using following spectroscopic and chromatographic techniques Solubility, Thin Layer Chromatographic studies, Ultra Violet studied rotational and vibrational studies FT IR studies. The compounds were investigated for their Antimicrobial activity by cup plate method. Compound1 nitro 4 1 imino,4 nitrophenyl benzene was found to be the most active according to pharmacological evaluation exhibited antimicrobial. Ms. Chetana D. Patil | Mr. Digamber N. Bhosale | Ms. Smita P. Bedis "Synthesis and Characterization of Schiff Base from Aromatic Amine and Aromatic P-Nitro Benzaldehyde" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26401.pdfPaper URL: https://www.ijtsrd.com/pharmacy/medicinal-chemistry/26401/synthesis-and-characterization-of-schiff-base-from-aromatic-amine-and-aromatic-p-nitro-benzaldehyde/ms-chetana-d-patil
Kinetic, thermodynamic and equilibrium studies on removal of hexavalent chrom...Ratnakaram Venkata Nadh
Removal of Cr(VI) by biosorption on two agro waste materials, casuarinas fruit powder (CFP) and sorghum
stem powder (SSP), has been investigated. The prepared adsorbent materials were characterized by SEM, EDX,
FTIR and BET. These biomaterials effectively removed Cr(VI) with a maximum removal of 93.35% and 63.75% using
15 gL−1 and 5 gL−1 of CFP and SSP, respectively, at 60 oC with 20mgL−1 initial Cr(VI) concentration in solution. In both
cases of adsorbents, kinetic data of adsorption fitted well in pseudo-second-order in terms of correlation coefficient
(R2). This helps in proposing the process of adsorption as chemical coordination, which is correlated with the thermodynamic
study results conducted at different values of temperature. Langmuir, Freundlich and D-R models were evaluated
for description of metal sorption isotherms. Values of coefficients of intra-particle diffusion and mass transfer have
also been determined at different values of temperature.
Visible Light Photocatalytic Degradation of Methylene Blue and Malachite Gree...IJEAB
A facile solid state metathesis synthesis of barium tungstate (BaWO4) followed by ball milling and subsequent preparation of barium tungstate-graphene oxide (BaWO4–GO) nano composite using a colloidal blending process and its application as a visible light photocatalyst for the degradation of Malachite green and Methylene blue dyes. The morphology and composition of barium tungstate (BaWO4) nano composite have been characterized using X-Ray Diffraction (XRD), UV–Visible Diffuse Reflectance Spectra (UV-DRS), Raman Spectra, Field Emission Scanning Electron Microscopy (FESEM) – EDAX and UV Visible Spectroscopy. This composite material is found to be a wide band gap semiconductor with band gap of 4.3 eV. The sample shows poor transmittance in ultraviolet region while it has maximum transmittance in visible-near infrared regions. It shows an increase in range and intensity of light absorption and the reduction of electron–hole pair recombination in BaWO4 with the introducing of GO on to it.
Spectral studies of 5-({4-amino-2-[(Z)-(2-hydroxybenzylidene) amino] pyrimidi...IOSR Journals
Some transition metal ions Complexes with 5-({4-amino-2-[(Z)-(2-hydroxybenzylidene) amino]
pyrimidin-5-yl} methyl)-2,3,4-trimethoxybenzene were prepared and characterized by elemental analyses,
Infrared , magnetic moment, electronic spectra , mass spectra, X-ray powder diffraction, molar conductance
and thermal analysis (TGA). The complexes have general formulae [ML2.2H2O] {where M = Mn (II), Co (II), Ni
(II), Cu (II), Zn (II), Pd (II) and Pt (II). The coordination behavior of the metal ions towards to the investigated
Schiff base takes place through –C=N,-NH2 and –OH groups. The obtained C, H and N elemental analysis data
showed the Metal: Ligand ratio is 1:2 [M: L] ratio. The molar conductance data reveal that all the metal
complexes are non-electrolytic in nature. From the magnetic moments the complexes are paramagnetic except
Zn metal ion complexes have octahedral geometry with coordination number eight. The thermal behavior of
these complexes shows that, the hydrated complexes have loses two water molecules and immediately followed
by decomposition of the anions and ligand molecules in the second and third stage. The Schiff bases and metal
complexes show good activity against some bacteria. The antimicrobial results indicate that, the metal
complexes have better antimicrobial activity as compared to the prepared Schiff base.
Complexation, Spectroscopic, Thermal, Magnetic And Conductimetric Studies On ...IOSR Journals
7-hydroxy-4-methyl-8-(phenylazo) coumarin (L1)and 7-hydroxy-4-methyl-8-(o-carboxyphenylazo) coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and Mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and the complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and studied by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass spectra and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn metal ions and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
A dual functional colorimetric and fluorescence chemosensor based on benzo[f]fluorescein dye derivatives for copper ions and pH; kinetics and thermodynamic study
Experimental and theoretical investigations of some pyrazolo-pyrimidine deriv...Al Baha University
The anticorrosion performance of three pyrazolo-pyrimidine derivatives, namely, 4-amino pyrazolo-pyrimidine
(APP), 4-hydroxy pyrazolo-pyrimidine (HPP), and 4-mercapto pyrazolo-pyrimidine (MPP) on copper in 0.5M
H2SO4 solution have been investigated using electrochemical, surface analysis, as well as theoretical techniques.
The results indicate that these inhibitors have largely inhibited the corrosion of copper and the inhibition efficiency
increased with increasing concentration. Moreover, the inhibitors adsorb on copper surface following
Langmuir adsorption isotherm. XPS analysis were performed for describing the bonding characteristics between
inhibitors and copper substrate. Furthermore, DFT and molecular dynamics simulation calculations were applied
to further explain the anti-corrosion mechanism.
Spectroscopic, Thermal, Magnetic and conductimetric studies on some 7-hydroxy...IOSR Journals
7-hydroxy-4-methyl-8-(p-methylphenylazo)coumarin (L1) and 7-hydroxy-4-methyl-8-(p-methoxyphenylazo)coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and characterized by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn divalent metal ions with the investigated ligands 1:1 and 1:2 complexes and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
SYNTHESIS AND CHARACTERIZATION OF THERMAL ANALYSIS OF La (II) MACROCYCLIC COM...inventionjournals
The macrocyclic complex compounds of La(II) containing a ligand having tetraoxotetrahydrazin moity are synthesized by template condensation of malonodihydrazide (C3H8N4O2) with different aldehydes. The complexes are characterized on the basis of elemental analysis, UV-visible & IR spectroscopy, magnetic moment and conductance measurement and other physical properties.Antibacterial activity of the derived complex compounds, as well as already used standard compound kanamycin, was tested on fourteen pathogenic bacteria. Given results were then compared to the efficacy of the Antibacterial activity of standard compound kanamycin used for control of these pathogenic bacteria.
V mn-mcm-41 catalyst for the vapor phase oxidation of o-xylenesunitha81
The role of V and Mn incorporated mesoporous molecular sieves was
investigated for the vapor phase oxidation of o-xylene. Mesoporous monometallic
V-MCM-41 (Si/V = 25, 50, 75 and 100), Mn-MCM-41 (Si/Mn = 50) and bimetallic
V-Mn-MCM-41 (Si/(V ? Mn) = 100) molecular sieves were synthesized by
a direct hydrothermal (DHT) process and characterized by various techniques such
as X-ray diffraction, DRUV-Vis spectroscopy, EPR, and transmission electron
microscopy (TEM). From the DRUV-Vis and EPR spectral study, it was found that
most of the V species are present as vanadyl ions (VO2?) in the as-synthesized
catalysts and as highly dispersed V5? ions in tetrahedral coordination in the calcined
catalysts. The activity of the catalysts was measured and compared with each other
for the gas phase oxidation of o-xylene in the presence of atmospheric air as an
oxidant at 573 K. Among the various catalysts, V-MCM-41 with Si/V = 50
exhibited high activity towards production of phthalic anhydride under the experimental
condition. The correlation between the phthalic anhydride selectivity and
the physico-chemical characteristics of the catalyst was found. It is concluded that
V5? species present in the MCM-41 silica matrix are the active sites responsible for
the selective formation of phthalic anhydride during the vapor phase oxidation of
o-xylene.
Synthesis and Characterization of Thermal Analysis of La (Ii) Macrocyclic Com...inventionjournals
The macrocyclic complex compounds of La(II) containing a ligand having tetraoxotetrahydrazin moity are synthesized by template condensation of malonodihydrazide (C3H8N4O2) with different aldehydes. The complexes are characterized on the basis of elemental analysis, UV-visible & IR spectroscopy, magnetic moment and conductance measurement and other physical properties.Antibacterial activity of the derived complex compounds, as well as already used standard compound kanamycin, was tested on fourteen pathogenic bacteria. Given results were then compared to the efficacy of the Antibacterial activity of standard compound kanamycin used for control of these pathogenic bacteria.
The study of intermolecular interactions at interfaces is essential for a number of applications, in addition
to the understanding of mechanisms involved in sensing and biosensing with liquid samples. There are,
however, only a few methods to probe such interfacial phenomena, one of which is the atomic force
spectroscopy (AFS) where the force between an atomic force microscope tip and the sample surface is
measured. In this study, we used AFS to estimate adhesion forces for a nanostructured film of poly(oethoxyaniline)
(POEA) doped with various acids, in measurements performed in air. The adhesion force
was lower for POEA doped with inorganic acids, such as HCl and H2SO4, than with organic acids, because
the counterions were screened by the ethoxy groups. Significantly, the morphology of POEA both in the
film and in solution depends on the doping acid. Using small-angle X-ray scattering (SAXS) we observed
that POEA dissolved in amixture of dimethyl acetamide exhibits a more extended coil-like conformation,
with smaller radius of gyration, than for POEA in water, as in the latter POEA solubility is lower. In AFS
measurements in a liquid cell, the force curves for a POEA layer displayed an attractive region for pH 5
due to van der Waals interactions, with no contribution from a double-layer since POEA was dedoped. In
contrast, for pH 3, POEA was doped and the repulsive double-layer force dominated. With AFS one is
therefore able to correlate molecular-level interactions with doping and morphology of semiconducting
polymers.
assessment of biomass of leaves of water hyacinth (eichhornia crassipes)IJAEMSJORNAL
Green chemistry methods for nanoparticles synthesis have implemented the valorization of renewable waste that reduces the use of chemicals and sub-products to minimize the environmental impact. Herein, we report a method to synthesize Ag and Au nanoparticles (AgNPs, AuNPs) using one of the world´s worst aquatic weeds, water hyacinth. From a reaction between a solution of AgNO3 or HAuCl4 and controlling the pH, the nanoparticles were synthesized. The optimum pH value to obtained uniform quantum dots was found to be acidic for AgNPs and neutral for AuNPs. The size was highly dependent on pH for AgNPs, a smaller size was for acidic pH, and the larger size was for basic pH, and cubic and hexagonal are the predominant structures, no dependent was observed in AuNPs, and orthorhombic is the most common form. This method was sustainable because water hyacinth is a renewable resource in all world, and their use is not being exploited in any process. The bioreduction process using water hyacinth promotes the metallic nanoparticles formation and applied standard conditions for temperature and pressure. Also, the rate of synthesis is fast.
Si-Imidazole-HSO4 Functionalized Magnetic Fe3O4 Nanoparticles as an Efficient...Iranian Chemical Society
An efficient and simple method for the preparation of Si-Imidazole-HSO4 functionalized magnetic Fe3O4 nanoparticles (Si-Im-HSO4 MNPs) and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. This catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. Compared to the classical ring opening of epoxides, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity.
Similar to Study of a model humic acid type polymer by fluorescence spectroscopy and atomic force microscopy (20)
The accurate knowledge of the size distribution of
the soil clay particles (φ ≤ 2 μm) can improve the
understanding of the soil surface chemical processes,
which, in their turn, occur mainly in this smallest
sized fraction. However, there are few available
techniques for particle size evaluation at the
nanoscale.
In this work, the synthetic Hydroxyapatite (HAP)
was studied using different preparation routes to
decrease the crystal size and was studied the
temperature effect on the nano-sized hydroxyapatite
crystallization. X-ray diffraction (XRD) analysis
indicated the all samples were composed by a
crystalline HAP phase and another amorphous part.
A low-cost sensor array system for banana ripeness monitoring is presented. The sensors are constructed by employing a graphite line-patterning technique (LPT) to print interdigitated graphite electrodes on tracing paper and then coating the printed area with a thin film of polyaniline (PANI) by in-situ polymerization as the gas-sensitive layer. The PANI layers were used for the detection of volatile organic compounds (VOCs), including ethylene, emitted during ripening. The influence of the various acid dopants, hydrochloric acid (HCl), methanesulfonic acid (MSA), p-toluenesulfonic acid (TSA) and camphorsulfonic acid (CSA), on the electrical properties of the thin film of PANI adsorbed on the electrodes was also studied. The extent of doping of the films was investigated by UV-Vis absorption spectroscopy and tests showed that the type of dopant plays an important role in the performance of these low-cost sensors. The array of three sensors, without the PANI-HCl sensor, was able to produce a distinct pattern of signals, taken as a signature (fingerprint) that can be used to characterize bananas ripeness.
Nanobiosensors can be built via functionalization of atomic force microscopy (AFM) tips with
biomolecules capable of interacting with the analyte on a substrate, and the detection being
performed by measuring the force between the immobilized biomolecule and the analyte.
The optimization of such sensors may require multiple experiments to determine suitable
experimental conditions for the immobilization and detection. In this study we employ molecular
modeling techniques to assist in the design of nanobiosensors to detect herbicides. As a proof
of principle, the properties of acetyl co-enzyme A carboxylase (ACC) were obtained with
molecular dynamics simulations, from which the dimeric form in an aqueous solution was
found to be more suitable for immobilization owing to a smaller structural fluctuation than
the monomeric form. Upon solving the nonlinear Poisson–Boltzmann equation using a
finite-difference procedure, we found that the active sites of ACC exhibited a positive surface
potential while the remainder of the ACC surface was negatively charged. Therefore, optimized
biosensors should be prepared with electrostatic adsorption of ACC onto an AFM tip
functionalized with positively charged groups, leaving the active sites exposed to the analyte.
The preferential orientation for the herbicides diclofop and atrazine with the ACC active site
was determined by molecular docking calculations which displayed an inhibition coefficient
of 0.168 mM for diclofop, and 44.11 mM for atrazine. This binding selectivity for the herbicide
family of diclofop was confirmed by semiempirical PM6 quantum chemical calculations which
revealed that ACC interacts more strongly with the herbicide diclofop than with atrazine,
showing binding energies of 119.04 and +8.40 kcal mol1, respectively.
Atomic force spectroscopy, a technique derived from Atomic Force Microscopy (AFM), allowed us to distinguish nonspecific and specific interactions between the acetolactate synthase enzyme (ALS) and anti-atrazine antibody biomolecules and the herbicides imazaquin, metsulfuron-methyl and atrazine. The presence of specific interactions increased the adhesion force (Fadh) between the AFM tip and the herbicides, which made the modified tip a powerful biosensor. Increases of approximately 132% and 145% in the Fadh values were observed when a tip functionalized with ALS was used to detect imazaquin and metsulfuron-methyl, respectively. The presence of specific interactions between the atrazine and the anti-atrazine antibody also caused an increase in the Fadh values (approximately 175%) compared to those observed when using an unfunctionalized tip. The molecular modeling results obtained with the ALS enzyme suggest that the orientation of the biomolecule on the tip surface could be suitable for allowing interaction with the herbicides imazaquin and metsulfuron-methyl
Emeraldine-salt polyaniline form (ES-PANI) was chemically synthesized using hydrochloric acid at time
synthesis ranging from 0.5 to 48 h and characterized by X-ray diffraction (XRD), LeBail fit, Small-angle
X-ray diffraction (SAXD), Small-angle X-ray Scattering (SAXS) and Scanning Electron Microscopy
(SEM). Crystallinity and crystal data (a = 5.7122, b = 17.8393, c = 22.8027, a = 83.1575, b = 84.6971 and
c = 88.4419) were obtained by XRD and showed that the crystallinity did not vary with the time
synthesis. LeBail fit revealed that the crystallites were very small lamellae with global average size
around 39 Å. By SAXS it was obtained the particle Radius of Giration (Rg) of 320 Å. The maximum particle
size (Dmax) of 650 Å was obtained from the pair-distance distribution function (p(r)). SEM images showed
a fiber morphology formed by interconnected non homogeneous nanospheres. Electrical conductivity of
the samples was in 1.84 104 S/cm.
The use of agrochemicals has increased considerably in recent years, and consequently, there has been increased exposure of ecosystems and human populations to these highly toxic compounds. The study and development of methodologies to detect these substances with greater sensitivity has become extremely relevant. This article describes, for the first time, the use of atomic force spectroscopy (AFS) in the detection of enzyme-inhibiting herbicides. A nanobiosensor based on an atomic force microscopy (AFM) tip functionalised with the acetolactate synthase (ALS) enzyme was developed and characterised. The herbicide metsulfuron-methyl, an ALS inhibitor, was successfully detected through the acquisition of force curves using this biosensor. The adhesion force values were considerably higher when the biosensor was used. An increase of ~250% was achieved relative to the adhesion force using an unfunctionalised AFM tip. This considerable increase was the result of a specific interaction between the enzyme and the herbicide, which was primarily responsible for the efficiency of the nanobiosensor. These results indicate that this methodology is promising for the detection of herbicides, pesticides, and other environmental contaminants.
The immobilization of enzymes on atomic force microscope tip (AFM tip) surface is a crucial step in thedevelopment of nanobiosensors to be used in detection process. In this work, an atomistic modeling ofthe attachment of the acetyl coenzyme A carboxylase (ACC enzyme) on a functionalized AFM tip surface isproposed. Using electrostatic considerations, suitable enzyme–surface orientations with the active sitesof the ACC enzyme available for interactions with bulk molecules were found. A 50 ns molecular dynamicstrajectory in aqueous solution was obtained and surface contact area, hydrogen bonding and proteinstability were analyzed. The enzyme–surface model proposed here with minor adjustment can be appliedto study antigen–antibody interactions as well as enzyme immobilization on silica for chromatographyapplications.
In this work, the synthetic hydroxyapatite (HAP) was studied using different preparation routes to decrease the crystal size and to study the temperature effect on the HAP nano-sized hydroxyapatite crystallization. X-ray diffraction (XRD) analysis indicated that all samples were composed by crystalline and amorphous phases . The sample with greater quantity of amorphous phase (40% of total mass) was studied. The nano-sized hydroxyapatite powder was heated and studied at 300, 500, 700, 900 and 1150 °C. All samples were characterized by XRD and their XRD patterns refined using the Rietveld method. The crystallites presented an anisotropic form, being larger in the [001] direction. It was observed that the crystallite size increased continuously with the heating temperature and the eccentricity of the ellipsoidal shape changed from 2.75 at 300 °C to 1.94, 1.43, 1.04 and 1.00 respectively at 500, 700, 900 and 1150 °C. In order to better characterize the morphology of the HAP the samples were also examined using atomic force microscopy (AFM), infrared spectrometry (IR) and thermogravimetric analysis (TGA).
The present paper describes the influence of the chemical structure of two aminoalkoxysilanes: 3-
aminopropyltriethoxysilane (APTS) and N-(3-(trimethoxysilyl)-propyl)-ethylenediamine (TSPEN) on the
morphology of thin layer hybrid films with phosphotungstic acid (HPW), a Keggin heteropolyanion. X-ray
photoelectron spectroscopy analyses indicated that both silane films showed protonated amine species interacting
with the heteropolyanion by electrostatic forces as well as the presence of secondary carbamate anions.
The hybrid films have different surface morphology according to atomic force microscopy analyses.
The hybrid film with TSPEN forms flatter surfaces than the hybrid film with APTS. This effect is ascribed to
higher flexibility and chelating ability of the TSPEN on adsorbed molecules. Ultrasonication effect on surface
morphology of the hybrid film with APTS plays a fundamental role on surface roughness delivering enough
energy to promote surface diffusion of the HPW heteropolyanions. This diffusion results in agglomerate formation,
which corroborates with the assumption of electrostatic bonding between the HPW heteropolyanions
and the protonated amine surface. These hybrid films could be used for electrochemical sensor
design or to build photochromic and electrochromic multilayers.
The increasing importance of studies on soft matter and their impact on new
technologies, including those associated with nanotechnology, has brought intermolecular
and surface forces to the forefront of physics and materials science, for these are the
prevailing forces in micro and nanosystems. With experimental methods such as the atomic
force spectroscopy (AFS), it is now possible to measure these forces accurately, in addition
to providing information on local material properties such as elasticity, hardness and
adhesion. This review provides the theoretical and experimental background of AFS,
adhesion forces, intermolecular interactions and surface forces in air, vacuum and in solution
In this work, is presented the thermal behavior of polyaniline (PANI) and its derivatives poly(oethoxyaniline)
(POEA) and poly(o-methoxyaniline) (POMA), which were studied by using differential
scanning calorimetry (DSC), modulated DSC (TMDSC), respectively, and thermal gravimetric analysis
(TGA). The results from diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and thermal
analysis showed the formation of crosslinking isomerization reaction during the heating process. The
results showed that the maximum weight loss and the crystallinity degree depend on the type of the
aromatic ring substituent group, i.e. hydrogen, ethoxy or methoxy.
Suspensions of white and colored nanofibers
were obtained by the acid hydrolysis of white
and naturally colored cotton fibers. Possible differences
among them in morphology and other characteristics
were investigated. The original fibers were
subjected to chemical analysis (cellulose, lignin and
hemicellulose content), X-ray diffraction (XRD)
analysis, and scanning electron microscopy (SEM).
The nanofibers were analyzed with respect to yield,
elemental composition (to assess the presence of
sulfur), zeta potential, morphology (by scanning
transmission electron microscopy (STEM)) and
atomic force microscopy (AFM), crystallinity
(XRD) and thermal stability by thermogravimetric
analysis in air under dynamic and isothermal temperature
conditions. Morphological study of several
cotton nanofibers showed a length of 85–225 nm and
diameter of 6–18 nm. The micrographs also indicated
that there were no significant morphological differences
among the nanostructures from different cotton
fibers. The main differences found were the slightly
higher yield, sulfonation effectiveness and thermal
stability under dynamic temperature conditions of the
white nanofiber. On the other hand, in isothermal
conditions at 180 C, the colored nanofibers showed
a better thermal stability than the white.
This paper reports on the adsorption of an ultrathin chitosan layer on spin-coated films of cellulose,
where efficient attachment was induced by oxidizing cellulose which provided anionic sites for electrostatic
interaction with the positively charged chitosan. Both the cellulose oxidation and the chitosan
adsorption were confirmed with Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron
spectroscopy (XPS) measurements. The molecular-level interaction between chitosan and cellulose
involved the NAH groups, as inferred from the disappearance caused by chitosan adsorption of the amide
band at 1667 cm1 in the FTIR spectrum of cellulose. The XPS data confirmed a significant increase in the
atomic concentration of nitrogen groups, from 2.16% to 4.73% when chitosan was adsorbed on the oxidized
cellulose film, which also led to rougher films as illustrated by atomic force microscopy images.
One may now envisage applications in which the bactericide action of chitosan is combined with the biocompatibility
of cellulose
The interaction between poly(o-ethoxyaniline) (POEA) adsorbed onto solid substrates and humic substances
(HS) and Cu2+ ions has been investigated using UV–vis spectroscopy and atomic force microscopy
(AFM). Both HS and Cu2+ are able to dope POEA and change film morphology. This interaction was
exploited in a sensor array made with nanostructured films of POEA, sulfonated lignin and HS, which
could detect small concentrations of HS and Cu2+ in water.
In this study, the layer-by-layer technique is used to deposit nanostructured films exhibiting electrical
conductivity and magnetic behavior, from poly(o-ethoxyaniline) (POEA), sulfonated polystyrene (PSS) and
positively-charged maghemite nanoparticles. In order to incorporate the nanoparticles into the films,
maghemite nanoparticles, in the form of magnetic fluid, were added to POEA solutions, and the resulting
suspensions were used for film deposition. UV–Vis spectroscopy and atomic force microscopy images reveal
that POEA remains doped in the films, even in the presence of the maghemite nanoparticles, and its typical
globular morphology is also present. Electrical measurements show that a POEA/PSS film prepared from
POEA solution containing 800 μL of the magnetic fluid exhibits a similar conductivity to that of the control
film and, additionally, magnetic measurements indicated that nanosized maghemite phase was incorporated
within the polymeric film.
The existence of conducting islands in polyaniline
films has long been proposed in the literature, which
would be consistent with conducting mechanisms based on
hopping. Obtaining direct evidence of conducting islands,
however, is not straightforward. In this paper, conducting
islands were visualized in poly(o-ethoxyaniline) (POEA)
films prepared at low pH, using Transmission Electron Microscopy
(TEM) and atomic force spectroscopy (AFS). The
size of the islands varied between 67 and 470 Å for a
pH = 3.0, with a larger average being obtained with AFS,
probably due to the finite size effect of the atomic force microscopy
tip. In AFS, the conducting islands were denoted
by regions with repulsive forces due to the double-layer
forces. On the basis of X-ray diffraction (XRD) patterns for
POEA in the powder form, we infer that the conducting islands
are crystalline, and therefore a POEA film is believed
to consist of conducting islands dispersed in an insulating,
amorphous matrix. From conductivity measurements we inferred the charge transport to be governed by a typical quasione dimensional variable range hopping (VRH) mechanism.
Chemical sensors made from nanostructured films of poly(o-ethoxyaniline) POEA and poly(sodium 4-styrene sulfonate) PSS are produced and
used to detect and distinguish 4 chemicals in solution at 20 mM, including sucrose, NaCl, HCl, and caffeine. These substances are used in order to
mimic the 4 basic tastes recognized by humans, namely sweet, salty, sour, and bitter, respectively. The sensors are produced by the deposition of
POEA/PSS films at the top of interdigitated microelectrodes via the layer-by-layer technique, using POEA solutions containing different dopant
acids. Besides the different characteristics of the POEA/PSS films investigated by UV–Vis and Raman spectroscopies, and by atomic force
microscopy, it is observed that their electrical response to the different chemicals in liquid media is very fast, in the order of seconds, systematical,
reproducible, and extremely dependent on the type of acid used for film fabrication. The responses of the as-prepared sensors are reproducible and
repetitive after many cycles of operation. Furthermore, the use of an “electronic tongue” composed by an array of these sensors and principal component analysis as pattern recognition tool allows one to reasonably distinguish test solutions according to their chemical composition.
Atomic force spectroscopy ~AFS! was used to measure interaction forces between the tip and nanostructured layers of poly~o-ethoxyaniline! ~POEA! in pure water and CuSO4 solutions. When the tip approach and retraction were carried out at low speeds, POEA chains could be physisorbed onto the Si3N4 tip
via nonspecific interactions.We conjecture that while detaching, POEA chains were stretched and the estimated
chain lengths were consistent with the expected values from the measured POEA molecular weight. The effects
from POEA doping could be investigated directly by performing AFS measurements in a liquid cell, with the
POEA film exposed to liquids of distinct pH values. For pH 6.0, the force curves normally displayed an
attractive region for POEA, but at lower pH values—where POEA is protonated—the repulsive double-layer
forces dominated. Measurements in the liquid cell could be further exploited to investigate how the film
morphology and the force curve are affected when impurities are deliberately introduced in the liquid. The
shape of the force curves and the film morphology depended on the concentration of heavy metal in the liquid
cell. AFS may therefore be used to study the interaction between film and analyte, with important implications
for the understanding of mechanisms governing the sensing ability of taste sensors.
More from Grupo de Pesquisa em Nanoneurobiofisica (20)
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.