20180323 electrospinning and polymer nanofibersTianyu Liu
The slides for a guest lecture of a graduate course (Chem 6564) offered by the Department of Chemistry, Virginia Polytechnic Institute and State University.
PDC Analysis of LLDPE-NR Nanocomposite for Effect of Moisture Absorption IJECEIAES
The properties of insulation have been improved by many research and the ability of nanocomposite material that composes the characteristic of improving electrical performance due to the addition of nanofiller into the based material gets serious attention. Polarization and Depolarization Current (PDC) measurement that has the ability to assess the condition of HV insulations with the initial periods after a DC step voltage application was favoured compared to other non-destructive monitoring techniques. This paper presents the works on moisture absorption in LLDPE-NR nanocomposite with different amount and percentage of nanofillers. The study of PDC level of the LLDPE-NR compound, filled with different amount of SiO 2 , TiO and MMT nanofiller using Polarization and Depolarization Current (PDC) measurement technique is the main objective of this research. These results show that sample A1 has the lowest polarization current value and sample B5 has the lowest depolarization current value.
20180323 electrospinning and polymer nanofibersTianyu Liu
The slides for a guest lecture of a graduate course (Chem 6564) offered by the Department of Chemistry, Virginia Polytechnic Institute and State University.
PDC Analysis of LLDPE-NR Nanocomposite for Effect of Moisture Absorption IJECEIAES
The properties of insulation have been improved by many research and the ability of nanocomposite material that composes the characteristic of improving electrical performance due to the addition of nanofiller into the based material gets serious attention. Polarization and Depolarization Current (PDC) measurement that has the ability to assess the condition of HV insulations with the initial periods after a DC step voltage application was favoured compared to other non-destructive monitoring techniques. This paper presents the works on moisture absorption in LLDPE-NR nanocomposite with different amount and percentage of nanofillers. The study of PDC level of the LLDPE-NR compound, filled with different amount of SiO 2 , TiO and MMT nanofiller using Polarization and Depolarization Current (PDC) measurement technique is the main objective of this research. These results show that sample A1 has the lowest polarization current value and sample B5 has the lowest depolarization current value.
Effect of Chemical Treatment on the Morphology and Mechanical Properties of P...IOSRJAC
Natural fiber extracted from Plantain (Musa paradisiaca) fibers were treated with alkaline and potassium permanganate (KMnO4) —acetone solution at various concentrations for different soaking time. In order to identify the effect of this chemical modification on the mechanical properties and surface morphology of the fiber, Instron testing machine and Scanning Electron Microscope (SEM) was used. Mechanical properties test results reveals that chemical treatment substantially improve the strength of treated fiber and increase it bulk density. Optimum tensile strength of 690Mpa was obtained after treatment; while Scanning Electron Microscope (SEM) micrographs indicate enhance surface roughness of treated fibres. Treated Fibres with 0.05% KMnO4-acetone solution for 3min (05K3) was found to the highest tensile strength, enhance uniform surface roughness, and bulk density.
XRD Studies of Some Cellulose Fibers at Different Temperaturesijceronline
The X-ray diffractogram of raw ginger (Zingiber officinale), turmeric (Curcuma longa) and eri (Samia cynthia ricini) fibers are taken at different temperatures ( 313, 353, 393, 433 and 473 K) in an X-ray powder diffractometer (Phillips X’Pert Pro) with high temperature attachment (Anton Paar, HTK-16). It is found that the percentage of degree of crystalinity first increases from its value at 313K to the value at 353K, and then decreases at higher temperature for all the experimented raw fibers. The degree of crystallinity finds to be maximum at temperature 353K. The degree of crystallinity of chemically treated ginger fibers also finds to decrease with the rise of temperature with maximum at 353K. The degree of crystallinity of ginger fiber finds to increase due to degumming at a certain temperature.
Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries.
Influence of Thickness on Electrical and Structural Properties of Zinc Oxide ...paperpublications3
Abstract: Zinc Oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 1500C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 〖34.31^0-34.35〗^0with hkl (002). Other parameters calculated include the stress ( ) and the grain size (D).
Influence of uv coating process parameters on optical parameters of boardsdchidrewar
This is the project report which highlights the Influence of uv coating process parameters on optical parameters of boards. Optical properties includes Delta E, Brightness and Gloss. Several UV process parameters were studied which includes Belt Speed, Coating Thickness and lamp intensity.
Needleless electrospun nanofibers containing microcapsules: a methodology for...IJERA Editor
The present paper investigates the facile production of electrospun polyvinyl alcohol (PVA) nanofibers containing either micro-sized polymer or hybrid capsules, using a needleless electrospinning system. Oilcontaining microcapsules with diameters of around 3 or 10 µm, respectively, were produced via an oil-in-water miniemulsion and mixed with a PVA solution. Appropriate adjustment of electrospinning parameters enabled a controlled assembly of PVA nanofibers into a network containing microcapsules, without damaging their integrity. The PVA nanofibers have diameters in a range of 200-300 nm and showed good homogeneity. The introduction of microcapsules caused an increase in the PVA nanofiber diameters probably due to an increase in the solution viscosity. The production of such self-supported and loaded microcontainers could be of high interest for various applications.
Abstract— The aim of this study has been devoted to the study of electrospun polymeric nanofiber mats that can be potentially used in active packaging. A previous characterization of the PVA solutions was carried out. Thus, density, electrical conductivity and viscosity have been measured as a function of PVA concentration (0, 4, 7 and 10% w/w). Subsequently, a standard electrospinning process was carried out. The fibber diameter was determined by analyzing high-resolution images from Scanning Electron Microscopy (SEM) using Image J software. Moreover, a characterization of tensile properties (by means of DMA) and vapour sorption capacity of PVA-based nanofiber mats was performed. In addition, water-soluble compounds were incorporated into electrospun nanofiber mats. Although they may induce marked changes in morphology, their incorporation may lead to marked improvements in techno-functional properties. Thus, addition of Sodium Carbonate (SC) involves occurrence of beads, due to the increase in electrostatic charges, whereas Citric Acid (CA) induce an increase in fibber size, related to a loss of solvent evaporation efficiency. However, both compounds significantly enhance water vapour absorption capacity.
STUDY OF ABSORPTION IN CARBON NANOTUBE COMPOSITES FROM 1HZ TO 40GHZjmicro
Absorption performances in High Density Polyethylene (HDPE) and polycarbonate (PC) polymer matrices
containing various loads of carbon nanotubes were analysed. It depends on electrical conductivity,
dielectric constant and thickness of the polymer composites. These parameters can be easily controlled.
Significant absorption, which can reach between 60 and 90%, hence occurs at particular combinations of
these last parameters (in a frequency range from 1Hz to GHz). These new results are really useful in
various applications, and are considered in low scale systems as a major technological solution against
electromagnetic interferences.
In these work, new nano and micro thermoplastic based composite is prepared with zeolite filler, The method involves using zeolite in powder form, the preparation of zeolite powder from ores by crushing it into small - sized granules. The characteristics of the zeolite powder are determined. The physical properties and chemical composition (XRD) are evaluated before impeding it into the thermoplastic. Thermoplastics powder are added to the zeolite powder as granules in different sizes, The particles sizes ranging from the size of a millimeter to nanometer. The manufacturing quality parameters are optimized at volume percentages of filler in the range 20 to 25 % , composite material is formed into molds. New Composite material is characterized by easy deformation into different shapes beside machine ability. The characteristics of new composite such as SEM, EDX,FTIR in absorption and transmission mode are evaluated and compared with the standard characteristics of Zeolite ores. The performance and characteristics of the new composite are completely different. The new composite is hard, solid and does not absorb water. The work end with list of recommendation about the new field and expected application of Zeolite when using it as filler in thermoplastic based micro and nano composites.
Effect of Chemical Treatment on the Morphology and Mechanical Properties of P...IOSRJAC
Natural fiber extracted from Plantain (Musa paradisiaca) fibers were treated with alkaline and potassium permanganate (KMnO4) —acetone solution at various concentrations for different soaking time. In order to identify the effect of this chemical modification on the mechanical properties and surface morphology of the fiber, Instron testing machine and Scanning Electron Microscope (SEM) was used. Mechanical properties test results reveals that chemical treatment substantially improve the strength of treated fiber and increase it bulk density. Optimum tensile strength of 690Mpa was obtained after treatment; while Scanning Electron Microscope (SEM) micrographs indicate enhance surface roughness of treated fibres. Treated Fibres with 0.05% KMnO4-acetone solution for 3min (05K3) was found to the highest tensile strength, enhance uniform surface roughness, and bulk density.
XRD Studies of Some Cellulose Fibers at Different Temperaturesijceronline
The X-ray diffractogram of raw ginger (Zingiber officinale), turmeric (Curcuma longa) and eri (Samia cynthia ricini) fibers are taken at different temperatures ( 313, 353, 393, 433 and 473 K) in an X-ray powder diffractometer (Phillips X’Pert Pro) with high temperature attachment (Anton Paar, HTK-16). It is found that the percentage of degree of crystalinity first increases from its value at 313K to the value at 353K, and then decreases at higher temperature for all the experimented raw fibers. The degree of crystallinity finds to be maximum at temperature 353K. The degree of crystallinity of chemically treated ginger fibers also finds to decrease with the rise of temperature with maximum at 353K. The degree of crystallinity of ginger fiber finds to increase due to degumming at a certain temperature.
Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries.
Influence of Thickness on Electrical and Structural Properties of Zinc Oxide ...paperpublications3
Abstract: Zinc Oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 1500C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 〖34.31^0-34.35〗^0with hkl (002). Other parameters calculated include the stress ( ) and the grain size (D).
Influence of uv coating process parameters on optical parameters of boardsdchidrewar
This is the project report which highlights the Influence of uv coating process parameters on optical parameters of boards. Optical properties includes Delta E, Brightness and Gloss. Several UV process parameters were studied which includes Belt Speed, Coating Thickness and lamp intensity.
Needleless electrospun nanofibers containing microcapsules: a methodology for...IJERA Editor
The present paper investigates the facile production of electrospun polyvinyl alcohol (PVA) nanofibers containing either micro-sized polymer or hybrid capsules, using a needleless electrospinning system. Oilcontaining microcapsules with diameters of around 3 or 10 µm, respectively, were produced via an oil-in-water miniemulsion and mixed with a PVA solution. Appropriate adjustment of electrospinning parameters enabled a controlled assembly of PVA nanofibers into a network containing microcapsules, without damaging their integrity. The PVA nanofibers have diameters in a range of 200-300 nm and showed good homogeneity. The introduction of microcapsules caused an increase in the PVA nanofiber diameters probably due to an increase in the solution viscosity. The production of such self-supported and loaded microcontainers could be of high interest for various applications.
Abstract— The aim of this study has been devoted to the study of electrospun polymeric nanofiber mats that can be potentially used in active packaging. A previous characterization of the PVA solutions was carried out. Thus, density, electrical conductivity and viscosity have been measured as a function of PVA concentration (0, 4, 7 and 10% w/w). Subsequently, a standard electrospinning process was carried out. The fibber diameter was determined by analyzing high-resolution images from Scanning Electron Microscopy (SEM) using Image J software. Moreover, a characterization of tensile properties (by means of DMA) and vapour sorption capacity of PVA-based nanofiber mats was performed. In addition, water-soluble compounds were incorporated into electrospun nanofiber mats. Although they may induce marked changes in morphology, their incorporation may lead to marked improvements in techno-functional properties. Thus, addition of Sodium Carbonate (SC) involves occurrence of beads, due to the increase in electrostatic charges, whereas Citric Acid (CA) induce an increase in fibber size, related to a loss of solvent evaporation efficiency. However, both compounds significantly enhance water vapour absorption capacity.
STUDY OF ABSORPTION IN CARBON NANOTUBE COMPOSITES FROM 1HZ TO 40GHZjmicro
Absorption performances in High Density Polyethylene (HDPE) and polycarbonate (PC) polymer matrices
containing various loads of carbon nanotubes were analysed. It depends on electrical conductivity,
dielectric constant and thickness of the polymer composites. These parameters can be easily controlled.
Significant absorption, which can reach between 60 and 90%, hence occurs at particular combinations of
these last parameters (in a frequency range from 1Hz to GHz). These new results are really useful in
various applications, and are considered in low scale systems as a major technological solution against
electromagnetic interferences.
In these work, new nano and micro thermoplastic based composite is prepared with zeolite filler, The method involves using zeolite in powder form, the preparation of zeolite powder from ores by crushing it into small - sized granules. The characteristics of the zeolite powder are determined. The physical properties and chemical composition (XRD) are evaluated before impeding it into the thermoplastic. Thermoplastics powder are added to the zeolite powder as granules in different sizes, The particles sizes ranging from the size of a millimeter to nanometer. The manufacturing quality parameters are optimized at volume percentages of filler in the range 20 to 25 % , composite material is formed into molds. New Composite material is characterized by easy deformation into different shapes beside machine ability. The characteristics of new composite such as SEM, EDX,FTIR in absorption and transmission mode are evaluated and compared with the standard characteristics of Zeolite ores. The performance and characteristics of the new composite are completely different. The new composite is hard, solid and does not absorb water. The work end with list of recommendation about the new field and expected application of Zeolite when using it as filler in thermoplastic based micro and nano composites.
Polyacrylonitrile and polylactic acid blend nanofibre spinning using needlele...OUTR, Bhubaneswar
Polyacrylonitrile and polylactic acid blend nanofibre spinning using needleless electrospinning technique, Keywords, Introduction, Materials and Methods, Spinning Solution Preparation, PAN with DMF, PAN and PLA Blend with DMF, PAN and PLA Blend with DMF and Acetone, Electrospinning, Analysis of Fibre Surface Morphology, Pore Size Analysis, Results and Discussion, Effect of PAN Concentration on Fibre Diameter, Effect of Potential Difference between Electrodes on Fibre Diameter, Effect of Distance between Two Electrodes, Effect of Relative Humidity on Fibre Diameter, Effect of Blending of PLA with PAN and DMF on Fibre Quality, Effect of Acetone on Spinnability and Fibre Diameter of PAN/PLA Blend, Pore Size Analysis of Nanofibre Mat Spun at Standardised Parameters, Conclusion, References.
Characterization of Electrospun Nafion-Poly Acrylic Acid Membranes, Breakthro...drboon
Problem statement: In this paper we focus on discussing the mechanical properties of electrospun Nafion-PAA membranes. Approach: We prepared solutions of varying composition ratios of Nafion and PAA in order to create the membranes using the electrospinning process. After the confection of the membranes they were studied using SEM Microscopy and various methods of mechanical properties determination. Results: Results have determined that the 80%Nafion/20%PAA heat treated post compacted membranes have the best water uptake. Conclusion: The membranes produced are superior to those commercially produced in regards to water uptake, especially those of Order 1.
NANOFIBER SPINNING OF PAN AND PLA BLEND USING NEEDLELESS ELECTROSPINNING TECH...OUTR, Bhubaneswar
NANOFIBER SPINNING OF PAN AND PLA BLEND USING NEEDLELESS ELECTROSPINNING TECHNIQUE
INTRODUCTION, OBJECTIVES, MATERIALS & METHODS, RESULTS & DISCUSSION, CONCLUSION, REFERENCES
To explore the possibility of replacing hazardous DMF used during spinning with eco-friendly acetone.
To standardise the process parameters to obtain the nanofiber with least possible diameter.
To evaluate the pore size of the Nano fibrous mat prepared at standardised parameter.
To combine the properties of PAN and PLA polymers and prepare a PAN & PLA blend nanofiber.
In this research in order to produce blood sugar biosensor, an appropriate
membrane for glucose oxidase immobilization by using nanofibers created from
polymers of polyacrylic acid and starch are studied. They are biocompatible and
biodegradable respectively and were prepared by electro-spinning method for
nanofiber fabrication. Dimethylformamide and distilled water were used as solvent for
PAA and starch respectively to get a homogeneous solution. Because nanofibers made
of polyacrylic acid-starch face with enzymes, due to its extremely high hydrophilic
‘OH’ groups may lose their cohesion, crosslinking as chemical surface modification
and for better enzyme immobilization, non-thermal plasma surface modification using
atmospheric pressure Dielectric Barrier Discharge (DBD) were used. Crosslinking was
carried out by APTMS and Glutaraldehyde (GA). The effect of electro-spinning process
variables on morphology of nanofibers was examined by Scanning Electron
Microscopy (SEM). Nanofibers structure and chemical composition to demonstrate
the successful linking and immobilization of enzymes in the composite membrane was
obtained by Fourier Transform Infrared spectroscopy (FTIR) and improved thermal
stability of nanofibers in presence of enzyme and surface modifications was
determined by Thermal Gravimetric Analysis (TGA).
Design and Development of Polyaniline-coated Fabric Strain Sensor for Goniome...Editor IJCATR
In the last few years, the smart textile area has become increasingly widespread, leading to developments in new wearable
sensing systems. As conventional sensor techniques often cause problems for long term patient monitoring (e.g. skin irritation,
hampering wires), elegant solutions are explored to integrate sensors in clothing. By using the textile material itself as a sensor, the
integration is increased resulting in even more patient friendliness.
In this paper, a flexible fabric strain sensor with high sensitivity, good stability and large deformation is reported. It is
fabricated by in-situ polymerization of polyaniline on the fabric substrate at low temperature. Thickness and morphology of the
conducting thin film on the surface of the fibers were examined by scanning electron microscopy (SEM). The resistivity of the PANi
coated fabric was measured using standard two probe apparatus.
The measurement of the conductivity change with strain shows that the fabrics so prepared exhibits a high strain sensitivity
while its good stability is indicated by a small loss of conductivity after the thermal and humidity aging tests, and supported by the
slight change in conductivity over storage of 90 days. The developed flexible strain sensor can be used in the preparation of smart
garment for goniometry applications.
Synthesis and Characterization of Cellulose Nanofibers From Coconut Coir FibersIOSR Journals
Cellulose nanofibers were isolated from coconut coir fibers by chemical treatment using alkaline, mineral acids and inorganic salts, followed by mechanical treatment and disintegration methods like sonication, cryo crushing and dissolution. The size and morphology of cellulose nanofibers were investigated by using the Field Emission Scanning Electron Microscope (FESEM). The width of synthesized cellulose nanofibers investigated by the FESEM was around 30 nm to 90 nm and few microns in length. Elemental analysis of cellulose nano fibers were confirmed with the Energy Dispersive Analysis (EDS) results. XRD study was conducted for the crystalline property of cellulose nanofibers synthesized from coconut coir fibers using standard microcrystalline cellulose as reference. FT-IR spectra confirmed the presence of hydroxyl groups, C-H bond and the C-O-C groups in the synthesized cellulose nanofibers. The cellulose nano fibers were successfully utilized in the preparation of transparent thin film, filtration and water treatment.
The impact of flow rate and bed height on the adsorption behavior of methylene blue, Bismarck brown y, and indigo dyes on to Cedrus libani was investigated. The biomass was characterized by scanning electron microscopy as well as Fourier transformed infrared spectroscopy before and after adsorption to ascertain the functional groups responsible for the adsorption. The amount of dye adsorbed per unit mass of the biomass (qe) was calculated and was found to be dependent on the variables investigated within the experimental range. It was discovered that increase in bed height and flow rate increased the value of the dye adsorbed on to the biomass. The results obtained show that methylene blue dye adsorbed more onto the biomass, while indigo dye adsorbed at the least level.
Antibacterial ethylene propylene rubber impregnated with silver nanopowder: A...Iranian Chemical Society
Following our interest in reaching for a molded rubber article with possible detergent contact applications, durable silver nanopowder (AgNP) is synthesized by arc discharge, then mixed with varying ratios of ethylene propylene rubber (EPR), affording novel AgNP@EPR nanocomposites. X-ray diffraction (XRD) patterns of AgNP as well as AgNP@EPR show no trace of impurity, while scanning electron microscopy (SEM) indicates an average diameter of 50 nm for the former. Transmission electron microscopy (TEM) images while confirm the SEM results, show quite a few 5 nm AgNP particles lying beside some micro crumbs. Our DC arc discharge technique involves explosion of movable silver anode and static cathode by a current pulse between 5 to 10 A cm-2. A solution blending method is employed for preparation of AgNP@EPR nanocomposites. The AgNP is first dispersed in toluene using an ultrasonic homogenizer, and then thoroughly mixed with EPR in the same solvent whose removal gives nanocomposites of 2, 4, 6 and 8 vol% AgNP in EPR, showing strong antibacterial activity against both Escherichia coli and Staphylococcus aureus.
What are the main advantages of using HR recruiter services.pdfHumanResourceDimensi1
HR recruiter services offer top talents to companies according to their specific needs. They handle all recruitment tasks from job posting to onboarding and help companies concentrate on their business growth. With their expertise and years of experience, they streamline the hiring process and save time and resources for the company.
Personal Brand Statement:
As an Army veteran dedicated to lifelong learning, I bring a disciplined, strategic mindset to my pursuits. I am constantly expanding my knowledge to innovate and lead effectively. My journey is driven by a commitment to excellence, and to make a meaningful impact in the world.
Putting the SPARK into Virtual Training.pptxCynthia Clay
This 60-minute webinar, sponsored by Adobe, was delivered for the Training Mag Network. It explored the five elements of SPARK: Storytelling, Purpose, Action, Relationships, and Kudos. Knowing how to tell a well-structured story is key to building long-term memory. Stating a clear purpose that doesn't take away from the discovery learning process is critical. Ensuring that people move from theory to practical application is imperative. Creating strong social learning is the key to commitment and engagement. Validating and affirming participants' comments is the way to create a positive learning environment.
Affordable Stationery Printing Services in Jaipur | Navpack n PrintNavpack & Print
Looking for professional printing services in Jaipur? Navpack n Print offers high-quality and affordable stationery printing for all your business needs. Stand out with custom stationery designs and fast turnaround times. Contact us today for a quote!
RMD24 | Debunking the non-endemic revenue myth Marvin Vacquier Droop | First ...BBPMedia1
Marvin neemt je in deze presentatie mee in de voordelen van non-endemic advertising op retail media netwerken. Hij brengt ook de uitdagingen in beeld die de markt op dit moment heeft op het gebied van retail media voor niet-leveranciers.
Retail media wordt gezien als het nieuwe advertising-medium en ook mediabureaus richten massaal retail media-afdelingen op. Merken die niet in de betreffende winkel liggen staan ook nog niet in de rij om op de retail media netwerken te adverteren. Marvin belicht de uitdagingen die er zijn om echt aansluiting te vinden op die markt van non-endemic advertising.
Taurus Zodiac Sign_ Personality Traits and Sign Dates.pptxmy Pandit
Explore the world of the Taurus zodiac sign. Learn about their stability, determination, and appreciation for beauty. Discover how Taureans' grounded nature and hardworking mindset define their unique personality.
Cracking the Workplace Discipline Code Main.pptxWorkforce Group
Cultivating and maintaining discipline within teams is a critical differentiator for successful organisations.
Forward-thinking leaders and business managers understand the impact that discipline has on organisational success. A disciplined workforce operates with clarity, focus, and a shared understanding of expectations, ultimately driving better results, optimising productivity, and facilitating seamless collaboration.
Although discipline is not a one-size-fits-all approach, it can help create a work environment that encourages personal growth and accountability rather than solely relying on punitive measures.
In this deck, you will learn the significance of workplace discipline for organisational success. You’ll also learn
• Four (4) workplace discipline methods you should consider
• The best and most practical approach to implementing workplace discipline.
• Three (3) key tips to maintain a disciplined workplace.
3.0 Project 2_ Developing My Brand Identity Kit.pptxtanyjahb
A personal brand exploration presentation summarizes an individual's unique qualities and goals, covering strengths, values, passions, and target audience. It helps individuals understand what makes them stand out, their desired image, and how they aim to achieve it.
Accpac to QuickBooks Conversion Navigating the Transition with Online Account...PaulBryant58
This article provides a comprehensive guide on how to
effectively manage the convert Accpac to QuickBooks , with a particular focus on utilizing online accounting services to streamline the process.
RMD24 | Retail media: hoe zet je dit in als je geen AH of Unilever bent? Heid...BBPMedia1
Grote partijen zijn al een tijdje onderweg met retail media. Ondertussen worden in dit domein ook de kansen zichtbaar voor andere spelers in de markt. Maar met die kansen ontstaan ook vragen: Zelf retail media worden of erop adverteren? In welke fase van de funnel past het en hoe integreer je het in een mediaplan? Wat is nu precies het verschil met marketplaces en Programmatic ads? In dit half uur beslechten we de dilemma's en krijg je antwoorden op wanneer het voor jou tijd is om de volgende stap te zetten.
Falcon stands out as a top-tier P2P Invoice Discounting platform in India, bridging esteemed blue-chip companies and eager investors. Our goal is to transform the investment landscape in India by establishing a comprehensive destination for borrowers and investors with diverse profiles and needs, all while minimizing risk. What sets Falcon apart is the elimination of intermediaries such as commercial banks and depository institutions, allowing investors to enjoy higher yields.
1. The International Istanbul Textile Congress 2013
May 30th to June 1th 2013, Istanbul, Turkey
1
INCORPORATION ANTIBACTERIAL NANOFIBROUS LAYER IN SPROT
CLOTHING
Mina. Bayat tork1
, Elmira. Hadipour Goudarzi2
, Maryam Yousefzadeh2
, and Masoud. Latifi2
1,2
Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran
mina-bayat77@aut.ac.ir
Abstract: In this study antibacterial PVA electrospun nanofibers have been successfully prepared applying
different effective electrospinning techniques. For improving the antibacterial properties of the cloth, the
nano-silver particles (AGNPS) have been used and applied to cotton fabric. The effect of applied voltage,
solution feed rate, distance and concentration on the morphology and diameter of nanofibers were
investigated in order to obtain optimum electrospinning conditions. The three different electrospinning
methods that were used, are conventional electrospinning, Co-electrospinning and Core-Shell one. The
antibacterial activity of cotton fabrics that were coated with nanofibrous mats were evaluated against Gram-
negative bacteria Escherichia coli. It was concluded that prepared nanocomposites nanofibrous cloth, due to
large surface area, excellent antibacterial properties, porosity and flexibility have potential for any
antibacterial applications such as sport-textile, bio-textile, wound healing, underwear clothing, and so many
others.
Keywords: PVA Nanofibers, Antibacterial Clothing, Core-Shell Electrospinning, Co-Electrospinning
1. Introduction
Electrospinning is an effective process, utilizing electrostatic forces for fabrication non-woven fibrous mats.
Electrospinning process due to its uniqe properties, is widely used in many fields such as protective clothing,
biomedical clothing, tissue engineering, drug delivery and etc.
A typical electrospinning setup include syring pump, high voltage source and a grounded collector. in this
method fibers in micro or nano scale were obtained by applying electrical charge to a polymer solution.
various parameters influence characteristics of electrospun nanofibers such as solution concentration,
applied voltage, feed rate, solvent properties(surface tention,viscosity), distance between capillary tip and
collector [1].
In recent years, the design of antibacterial clothing has attracted much interest. Textile fabrics especially
sport clothing and biomedical clothing due to large surface areas and the ability to retain moisture make
them convenient for bacterial growth. therefore many research have been done for preparation antibacterial
textile material. Because electrospun nanofibers have high porosity and a very small pore size, they have a
larger specific surface area [2]. Non-woven mats made of such electrospun fibers show great potential for
antibacterial application.
Many studies have been done in filed of electrospinning of PVA with nanoparticles especially silver nano
particles. The PVA/Ag composite nanofibrous wound dressing material was successfully prepared by
electrospinning a PVA/AgNO3 aqueous solution into nonwoven web[3]. Nano-fibrous mats have been
successfully prepared by electrospinning of the blend solutions of cationic cellulose derivatives (PQ-4) and
polyvinyl alcohol (PVA)[2].
It is well known,that silver nanoparticles posses antibacterial properties to control infections. they are widely
used due to their uniqe properties as antibacterial agent against microorganism. Textile materials containing
silver nanoparticles have recently found many applications in different fields such as biomedical, sport
clothing, wound dressing and etc [4,5].
Current research is mainly focused on investigating some of the methods of electrospinning technique, which
have the ability to incorporate the Silver nanoparticles into nanofibrous mat and therefore in sport clothing.
2. The International Istanbul Textile Congress 2013
May 30th to June 1th 2013, Istanbul, Turkey
2
2. Experimental
2.1 Materials and preparation
PVA, (Mw 72,000) was purchased from Merck chemical Co, emulsion solution of silver nanoparticles
(4,000ppm particle size of about 50nm)was obtained from Nanofanavaran e kasra company, to prepare the
polymer solutions, distilled water was used as a solvent and all of the solutions applied on the knit weave
cotton fabrics
.
2.2 Electrospinning PVA solutions and optimization
In this study, two PVA solution concentrations (6% and 12% w/v) were prepared. To Prepare 6% and 12%
PVA composite solution concentrations; 1.2 gr and 0.6 gr of PVA powder were dissolved in the solvent
consist of 7.5 cc silver nanoparticles solution and 2.5 cc distilled water, respectively.
2.3 Electrospinning conditions
To received to optimum conditions and prepare nanofibers with out any defects; it was necessary to be done
studies in different electrospinning conditions And therefore, solution concentration, applied voltage, distance
and solution feed rate were found in the optimum conditions..
2.4 Different methods of producing nanofibers containing silver nanoparticles
In this study, three different methods were used for preparing nanofibers. These methods consist of: the
conventional electrospinning, co-electrospinning and core-shell one.
At the first method, 12% PVA solution concentration consist of silver nanoparticles was electrospuned
conventionaly.
The second method was similar to the first method except that emulsion silver nanoparticles solution was
sprayed on the fabric in front of electrospinning of the composite solution. At the third method, with use of the
6% and 12% composite polymer solution as the shell and core respectively, core-shell electrospinning was
done to produce the core-shell nanofibers.
2.5 Measurment and characterization
To determine the optimal producing conditions nanofiber, SEM images were taken from the samples and
nanofiber diameter of each samples was measured with Image J software.
After the preparation of the samples according to the three mentioned methods; antibacterial test was
performed . In this investigation, AATCC100 standard that is a quantitative method was used.
3. Results & Discussion
In our experiment the electrospun PVA/Ag nano particles(AgNPs) fiber webs were prepared by three
different methods. At First in order to obtain optimum electrospinning conditions, the effects of concentration,
applied voltage ,distance and feed rate on the morphology and diameter of the electrospun PVA/AgNPs
were investigated.
Table (1) shows the different conditions that applied for prepration of electrospun fiber webs. it is observed
that the average diameter of nanofibers increased with increasing concentration of solution from 12% to
15%.
Table 1. different electrospinning conditions
Voltage(Kv)Distance (cm)
Feed rate
(ml/h)
concentration
(%w/v)
12, 16, 208, 14, 200.13
12
12, 16, 208, 14, 200.25
12, 16, 208, 14, 200.13
15
12, 16, 208, 14, 200.25
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3.1 Concentartion
Concentration of solution is an important and critical parameter in the electrospinning process because some
characteristics of solution is related to concentration of solution. Surface tention and viscosity of the
polymeric solution are a function of solution concentration. high or low concentration of solution causes the
process to be faced with problem. Therefore an optimum value should be selected [1].
Based on reports, around optimum concentration of the solution, the diameter of nanofibers increases with
increasing concentration of solution [1]. in this study, the finer fibers were obtained at concentration of 12%.
3.2 Voltage
To examine the effect of voltage on diameter of electrospun fiber, different voltages 12, 16, 20 Kv were
applied.
under similar conditions, the impact of voltage on the diameter of electrospun fiber was not clear. but it is
observed that the average diameter of fibers in 16 Kv was less than other applied voltage. according to work
carried out by others, it is obvious optimal voltage for a certain polymer is required for generation nanofibers
without defects[1].
3.3 Distance
the distance between capillary tip and collector can also effect the morphology and fiber diameter. the effect
of distance between capillary tip and collector on the diameter of nanofiberous is not regular. in this work,
electrospinning at three distances (8,14,20 cm) were carried out. The results showed that fibers with smaller
diameters are achieved at 8cm.
3.4 feed rate
feed rate determine amount of solution that removed from syring. fiber diameter increase with increasing
feed rate. in addition, with increasing feed rate, there is possibility to see defects such as bead.
according to what mentioned ,12%, 16 Kv, 8 cm, 0.13 ml/h were selected as optimum conditions for
electrospinning.
Figure (1) shows the the scanning electron microscope images of the PVA/AgNps electrospun fibers.
Figure 1. solution concentration:12%, applyed voltage: 16 Kv, feed rate:0.13 ml/h and left to right distance equal 14 ,8,
20 cm respectively
3.5 The antibacterial efficacy of treated cotton fabrics
In this study,the antibacterial properties of cotton fabrics that were coated with PVA/AgNPs nanofibrous
mats against gram negative bacteria, Escherichia-coli were evaluated by the standard quantitatively testing
method (AATCC 100)[6].
rectangular pieces of fabric (4*2 cm) of treated cotton fabric and control sample( without AgNPs ) were
prepared and they were sterilized in the autoclave. bacteria were cultured in nutrient broth and heat for 24 h
in 37 ̊c.E coli suspension was added to each fabric-containing petri dishese. After incubation, add 100 ml of
neutralizing solution to petridishes containing untreated control samples and to petri dishese containing
treated test samples. then incubate all plates for 48 h at 37 ̊c.after that the colonies grown on the plates
were counted.
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Therefore the percentage reduction of bacteria was calculated by equation(1).
R=100(B-A)/B (1)
Where:
R=% reduction
A=the number of bacteria recovered from the inoculated treated test specimen swatches over the desired
contact period.
B=the number of bacteria recovered from the inoculated treated test specimen swatches immediately after
inoculation. (at “0” contact time)
Picture of plates shows antibacterial property of coated cotton fabrics with nanofibrous mats.
4. Conclusion
In this study antibacterial PVA/silver nanoparticles nanofibers have been successfully prepared using three
different methods. results indicated With increasing the solution concentration, distance and feed rate,
average nanofiber diameter was increased. While the changes in voltage did not lead to specific trend in the
nanofiber diameter.
Optimum conditions for preparing finer nanofiber with out any defect were as follows: solution concentration,
distance, applyed voltag and feed rate equaled 12%, 8cm, 16 Kv and 0.13 ml/h respectively.
for all of the samples Antibacterial test result, showed antibacterial property.
5. Referencing
[1] Travis J, Sill; Horst A, von Recum.: Electrospinning: Applications in drug delivery and tissue engineerin,
Biomaterials, 29. (2008) 1989e2006
[2] Baoquan, Jia.; Jinping, Zhou.; Lina, Zhang.: Electrospun nano-fiber mats containing cationic cellulose
derivatives and poly (vinyl alcohol) with antibacterial activity, Carbohydrate Research, 346. (2011) 1337–
1341
[3] Kyung Hwa Hong.: Preparation and Properties of Electrospun Poly(vinyl alcohol)/Silver Fiber Web as
Wound Dressings, Published online in Wiley InterScience (www.interscience.wiley.com)
[4] Messaouda, M and etal.: Photocatalytic generation of silver nanoparticles and application to the
antibacterial functionalization of textile fabrics, Journal of Photochemistry and Photobiology A: Chemistry,
215. (2010) 147–156
[5] Singh, M; and etal.: Nanomater. Bios, 3. (2008) 115
[6] American Association of Textile Chemists and Colorists.: AATCC Test Method 100-2004
Antibacterial Finishes on Textile Materials, N.C., USA, 2011