The document discusses nanocomposite flame retardants (Nanoflam). Nanoflam uses nanoparticles that can reduce polymer flammability by decreasing heat release rate and increasing flame-out ability. It produces textile coatings and membranes that provide fire retardation through hydrophobic or thermal barrier coatings. The document describes different nanocomposite structures including immiscible, intercalated, and exfoliated, and techniques to characterize them including TEM, XRD, and NMR. It shows heat release rate is lower for nanocomposites containing iron compared to pure polystyrene, indicating better flame retardation. Past halogen flame retardants caused environmental issues but nanocomposites provide an alternative while significantly improving fire safety
Facile Synthesis and Characterization of Pyrolusite, β-MnO2, Nano Crystal wit...Editor IJCATR
MnO2 nanoparticles have been synthesized by a simple combustion method using MnSO4.4H2O. The crystalline phase, morphology, optical property and magnetic property of the as prepared nanoparticle were characterized using XRD, FT-IR, FT-Raman, SEM, UV-Vis, PL and VSM respectively. Structural studies by XRD indicate that the synthesized material as tetragonal rutile crystal structure. FT-IR and FT-Raman analysis revealed the stretching vibrations of metal ions in tetrahedral co-ordination confirming the crystal structure. The PL and UV analysis having an emission band at 390 nm, showed a prominent blue peak at 453 nm as well as a green emission lines at 553 nm with band gap energy of 3.2eV. Magnetic measurements indicate that the Néel temperature of the β-MnO2 structures is 92.5K for Hc = 100 Oe which showed antiferromagnetic behaviour.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Nanomaterials in the Ecosystem: Should we worry?Periodic Tables
Nanotechnology has the enormous potential to change our society. New advances in medicine, energy production, environmental cleanup and better access to clean water are just a few of the many possibilities. According to the Project on Emerging Nanotechnologies, the number of products that use nanomaterials has increased almost 380% since 2006. But, is it the same special properties that make nanoscale materials so useful that also pose potential risks to humans and the environment? Dr. Emily Bernhardt from the Center for the Environmental Implications of NanoTechnology discussed with us the fate of nanomaterials in our environment and why you should care.
PPT on "Functionalization of Nanoparticles and Nanoplatelets" by Deepak rawalDeepak Rawal
Presentation on Functionalization of nanoparticles, magnetic nanoparticles, chemical funtionalization, funtionalization of carbon nanotubes and their applications. Introduction about graphite nanoplatelets.
Metallic nanoparticles (MNPs) is a type of nanoparticle which have a metal core composed of inorganic metal or metal oxide that is usually covered with a shell made up of organic or inorganic material or metal oxide.
Facile Synthesis and Characterization of Pyrolusite, β-MnO2, Nano Crystal wit...Editor IJCATR
MnO2 nanoparticles have been synthesized by a simple combustion method using MnSO4.4H2O. The crystalline phase, morphology, optical property and magnetic property of the as prepared nanoparticle were characterized using XRD, FT-IR, FT-Raman, SEM, UV-Vis, PL and VSM respectively. Structural studies by XRD indicate that the synthesized material as tetragonal rutile crystal structure. FT-IR and FT-Raman analysis revealed the stretching vibrations of metal ions in tetrahedral co-ordination confirming the crystal structure. The PL and UV analysis having an emission band at 390 nm, showed a prominent blue peak at 453 nm as well as a green emission lines at 553 nm with band gap energy of 3.2eV. Magnetic measurements indicate that the Néel temperature of the β-MnO2 structures is 92.5K for Hc = 100 Oe which showed antiferromagnetic behaviour.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Nanomaterials in the Ecosystem: Should we worry?Periodic Tables
Nanotechnology has the enormous potential to change our society. New advances in medicine, energy production, environmental cleanup and better access to clean water are just a few of the many possibilities. According to the Project on Emerging Nanotechnologies, the number of products that use nanomaterials has increased almost 380% since 2006. But, is it the same special properties that make nanoscale materials so useful that also pose potential risks to humans and the environment? Dr. Emily Bernhardt from the Center for the Environmental Implications of NanoTechnology discussed with us the fate of nanomaterials in our environment and why you should care.
PPT on "Functionalization of Nanoparticles and Nanoplatelets" by Deepak rawalDeepak Rawal
Presentation on Functionalization of nanoparticles, magnetic nanoparticles, chemical funtionalization, funtionalization of carbon nanotubes and their applications. Introduction about graphite nanoplatelets.
Metallic nanoparticles (MNPs) is a type of nanoparticle which have a metal core composed of inorganic metal or metal oxide that is usually covered with a shell made up of organic or inorganic material or metal oxide.
Nanoparticles are solid colloidal particles ranging in size from 10 to 1000 nm.
Nanoparticles are made of a macromolecular material which can be of synthetic or natural origin.
This presentation dives into the deep realms of nano-chemistry starting from the very basics to a sufficient advanced level. Nano-chemistry has always been a very intriguing topic for most of us as we see it in movies more than frequently. If not, we at least hear some explanation about a curious event that relates directly to nano-chemistry.
Diving into the depths of those explanations related to nano-chemistry and revealing the actual facts about nano-chemistry and its related topics. We have formulated this presentation to become a crucial source of information regarding nano-chemistry and its other related terms.
It is also a study material for Basics of Chemistry subject taught during the 1st or 2nd semesters during B.E. / B.Tech degree courses.
Introduction to nanoscience and nanotechnologyaimanmukhtar1
Introduction of nanoscience/nanotechnology ,properties/potential applications of nanomaterials and electrodeposition of metal single component and alloy nanowires in AAO template
Nanocomposite materials based on metal nanoparticles, metal oxide nanoparticles and magnetic nanoparticles have been discussed in this presentation. Hope the presentation is useful, you can request for download if you find the content useful.
Analytical Spectroscopic systems
Mass Spectrometry
Atomic mass to charge ratio
Laser Raman
Spectroscopy
Molecular vibrational modes
Laser Induced
Breakdown
Spectroscopy
Atomic emission
Visible Reflectance
Spectroscopy
Reflected color
Nano Material
Introduction and Synthesis
Nanomaterials describe, in principle, materials of which a single unit is sized (in at least one dimension) between 1 and 1000 nanometres (10−9 meter) but is usually 1—100 nm (the usual definition of nanoscale[1]).
Nanomaterials research takes a materials science-based approach to nanotechnology, leveraging advances in materials metrology and synthesis which have been developed in support of microfabrication research. Materials with structure at the nanoscale often have unique optical, electronic, or mechanical properties.
Nanomaterials are slowly becoming commercialized[2] and beginning to emerge as commodities.[3]
Synthesis of ZnO Nanoparticles using wet chemical method and its characteriza...Govind Soni
This is very intersting power point on ZnO NPs synthesized by me GOVIND SONI and my lab partnes KAUSHAL ,SANEHA & DINESH under the guidance of our PhD scholar Mr.SAHIL & Ms.KIRTI in the CYRSTAL LAB of DR.BINAY KUMAR in Department of Physics & Astrophysics .This presentation basically covers the Introduction to Nanoscience and Nanotechnology and synthesis of Zinc oxide nanoparticles using wet chemical method . its characterization has been done in Msc finals Nanoscience lab using X-Ray Diffraction and Particle size Analyzer.This presentation also contains an advance topic on introduction to Spintronics which is basically the study of internsic spin of electronics and its magnetic moment.I hope it will be an important tool to know about Nanoworld .
Similar to Flash presentation inorganic nanoflam (2) (20)
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
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We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
1. NANOCOMPOSITE AS A
FLAME RETARDANT
(NANOFLAM)
• In this nanocomposite the nanoparticles can reduce the
flammability of polymers because of the reduction in heat
release rate, the increase in flame-out and their ability to auto-
extinguish.
• It can produce a wide variety of textile coatings which can
promote fire retardation.
• It can be used in different ways of protection via either, a
hydrophobic coating or a thermal barrier coating.
• Nanoflam produces membranes and coatings which are
used in this manufacture.
2. DESCRIBING
NANOCOMPOSITES:
• Nanocomposites may be described as either
immiscible (aggregated), intercalated or
exfoliated (also called delaminated); another
possible description is an end tethered structure
4. INTERCALATED
NANOCOMPOSITE
STRUCTURE:
• Intercalated structures are formed when a
single (or more) extended polymer chain is
intercalated between the layers of clay.
• The result is a well-ordered multilayer structure
of alternating polymeric and inorganic layers,
with a repeat distance between them;
intercalation causes about 2-3nm separation
between the platelets
6. NANOCOMPOSITE DESCRIPTION CONTINUED
• In an intercalated structure, registry is maintained between the clay layers while registry
is lost in an exfoliated structure, because they have higher phase homogeneity than the
intercalated counterpart, the exfoliated structure is more desirable in enhancing the
properties of the nanocomposites.
• The exfoliated configuration maximizes the polymer-clay interactions making the entire
surface of layers available for the polymer, which should lead to the most significant
changes in mechanical and physical properties.
• However, it is not easy to achieve complete exfoliation of clays and, indeed with few
exceptions, most of the polymer nanocomposites reported were found to have intercalated
nanostructures.
7. OUR 3 INSTRUMENTAL TECHNIQUES CHOSEN:
• Instrumental techniques to characterize nanoflam include Transmission Electron Microscope
(TEM), X-Ray Diffractometer (XRD) and Nuclear magnetic resonance (NMR) spectroscopy:
Complementary to XRD, TEM is the most popularly employed technique to determine
nanocomposite morphology; using TEM can image the nanocomposite structure.
In general, you collect several images at high and low magnification and at several positions
in the nanocomposite sample. Both a low magnification image, to show the global
dispersion of the additives in the polymer, and a higher magnification image, to evaluate
the registry of additives are needed.
1) Transmission Electron Microscope
(TEM):
8. HOW DOES
TEM WORK?
• It uses beams of electrons
which have been
accelerated and pass
through a very thin piece of
specimen, where it interacts
with it and generates a
projection image.
• It gives a higher resolution
image than a light
microscope
Transmission
electron
microscope
Light
microscope
9. EXAMPLE OF TEM:
Figure 1. PS/MMT
(montmorillonite)
nanocomposite TEM
micrographs
a) Shows TEM at low magnification
b) Shows TEM at higher magnifications
10. • It is well known that only materials ordered enough to diffract X-ray can be detected; disordered
materials will show no pattern with the X-ray technique.
• An intercalated nanocomposite results in an increase in basal spacing in the XRD pattern, while
the formation of an exfoliated nanocomposite leads to the complete loss of registry between the
layers and so no peak can be observed.
• A strong peak at lower values of 2θ = intercalated structure
• A broad peak at any 2θ = the possibility of disorder;
this disorder could be caused by exfoliation or it could be a simple composite which is disordered
• However, XRD is insufficient to characterise the nanocomposites structure, SO analytical techniques
must be utilized to confirm the morphology of material and explain the meaning of the XRD signal
2) X-RAY DIFFRACTOMETER (XRD):
11. HOW DOES XRD
WORK?
• XRD works by irradiating a material with
incident X-rays and then measuring the
intensities and scattering angles of the X-rays
that leave the material.
• Once the X-ray beam is focused on the
specimen it is diffracted by the specimen’s
crystalline phases according to Bragg’s law
A = 2d sinθ
• The Diffracted X-rays intensity is then
measured and as stated in previous slide, the
orientation of the specimen will be determined
by the peak present at the value of the 2θ.
Single-crystal X-ray diffraction
12. EXAMPLE OF XRD:
In this figure we are shown XRD patterns of
Zn2Al-X (X= CO3
2-, Cl-, NO3- and SO4
2-)
Layered double hydroxides (LDHs) washed
with acetone.
In this XRD example we can see that the
XRD patterns for all LDH samples exhibit
the typical patterns of hydrotalcite-like
materials, which is a doubled layered
hydroxide of general formula Mg 6Al 2CO
3(OH).4H2O
13. 3) NUCLEAR MAGNETIC RESONANCE (NMR):
• The interpretation of TEM images tends to be very subjective; the person who has made
the system almost always sees more exfoliation than others may see.
• The NMR technique offers an opportunity to quantify, in a way, the type of dispersion.
• The main objective in solid-state NMR measurement is to connect the measured
longitudinal relaxation times, T1Hs, of proton with the quality of clay dispersion; the
extent and the homogeneity of the dispersion of the silicate layers within the polymer
matrix are very important for determining physical properties.1
14. HOW DOES NMR WORK?
• When molecules are placed in a strong magnetic
field, the nuclei of some atoms will begin to behave
like small magnets.
• The resonant frequencies of the nuclei are then
measured and converted into an NMR spectrum that
displays all of the right frequencies as peaks on a
graph.
• The height of each peak represents the number of
nuclei that resonates at each specific frequency.
This is known as the intensity of signal. The more
resonating nuclei, the higher the intensity.
NMR machine
15. COMPARING THE RATE OF HEAT RELEASE OF NANOCOMPOSITE
FLAME RETARDANTS VS NORMAL FLAME RETARDANTS:
Heat release rate plots for polystyrene, and a polystyrene
nanocomposite containing iron (MMT) and one in which iron is absent
(SMM).
As you can see from the Heat release rate
plot, the polystyrene has the highest heat
release, showing that it is a poor flame
retardant compared to the others shown.
The best is the polystyrene
nanocomposite containing iron (MMT) as
its heat release rate is far lower than
polystyrene.
16. HISTORY OF
FLAME
RETARDANTS
• Halogenated flame retardants (HFRs) have been
used since the 60s mainly because they’re significantly
more compatible with many polymeric materials and
much better at causing charring and reducing smoke
allowing more time for escape.
• Fire retardants used to be compounds such as
Antimony Bromide or compounds containing
Chlorine. Hundreds of brominated and chlorinated
flame retardants have been developed and are being
detected in the environment.2
17. ISSUE WITH THIS:
• Using halogen chemicals can cause
environmental damage by destroying
the ozone layer in the stratosphere. 1
chlorine atom can destroy over 100,000
ozone molecules before it is removed
from the stratosphere!
• This is important to note as the Ozone
can be destroyed more quickly than it is
naturally created.
18. • Other minerals and compounds used as flame retardants include Aluminium Hydroxide,
Magnesium Hydroxide and compounds that have been heavily brominated.
ISSUES WITH THIS:
• The main issue with these certain compounds is that they can be expensive
EXAMPLES OF FLAME RETARDANTS:
19. SYNTHESIS OF NANOFLAM:
The methods of making flame-retardant PLA (polylactic acid) can be mainly divided into two
categories: incorporating inorganic or organic flame-retardant additives into PLA
through melt or solution blending, and copolymerization of reactive comonomers with
PLA. The flame-retardant additives include inorganic fillers (aluminium hydroxide,
hypo-phosphite salts, and expandable graphite) and organic additives (small-molecule
phosphates, oligomers/hyperbranched polymers).3
20. Conclusion:
• Nanocomposites as flame retardants are very beneficial compared to previously used flame
retardants, even though expensive in price they save the destruction of the ozone layer from
harsh halogen chemicals and significantly reduce the heat release rate of a fire which is a lot
more important to think about than just money.
THANK YOU FOR LISTENING TO OUR PRESENATATION ON OUR NANOCOMPOSITE
NANOFLAM, DOES ANYONE HAVE ANY QUESTIONS?
REFERENCES:
1 The Utility of Nanocomposites in Fire Retardancy
Linjiang Wang, Xuejun He, Charles A. Wilkie, Materials (Basel) 2010 Sep; 3(9): 4580–4606. Published online 2010 Sep 3. doi: 10.3390/ma3094580
2Frank L. Dorman, Eric j. Reiner, in Gas Chromatography, 2012, chapter 28.5 Halogenated Flame Retardants
3D.-Y.Wang, in Novel Fire retardant Polymers and Composite Materials, 2017