The Effect of Clay Content on PMMA-Clay Nanocomposite Foams

2005 ◽  
Vol 24 (2) ◽  
pp. 49-70 ◽  
Author(s):  
Allan R. Manninen ◽  
Hani E. Naguib ◽  
A. Victoria Nawaby ◽  
Xia Liao ◽  
Michael Day
Keyword(s):  
High Pressure ◽  
Clay Content ◽  
Polymer Chains ◽  
Nanocomposite Films ◽  
Compression Moulding ◽  
Clay Particles ◽  
Nanocomposite Foams ◽  
Cell Structures ◽  
Nanoclay Content ◽  
Co Precipitation

In this study the CO2 sorption at 45 °C in PMMA nanocomposite films containing 2 wt.% of nanoclay has been measured using an in-situ gravimetric technique. The films examined were prepared by compression moulding material obtained by dry-blend and solvent co-precipitation techniques. The CO2 diffusion coefficients were found to be higher for the dry-blended nanocomposite due to the larger agglomerations of the organoclay agglomerations, which prevented the polymer chains from fully wetting and intercalating the clay particles. The Tg-p profile for PMMA nanocomposite containing 2 wt.% nanoclay in the presence of CO2 was also measured using high-pressure DSC. The glass transition phase envelope was shifted vertically by approximately 10 °C when compared to the value reported in the literature for neat PMMA. This result suggests that the nanoclay affects the plasticization behaviour of PMMA under high-pressure CO2 conditions. The cellular morphologies obtained for these PMMA nanocomposite foams produced by batch processing with subcritical CO2 are strongly dependent upon the clay content and the dispersion of the nanoclay in the material. In the case of intercalated nanocomposites, most clay particles exist as agglomerated stacks of silicate sheets. On foaming the cells tend to form around the clay particles causing either irregular-shaped cells or layers to be produced. As a result, the cell density increases and the mean cell size decreases in the foamed nanocomposite on increasing the nanoclay content. Accordingly, the resulting cell structures are highly non-uniform and show large variations in cellular morphologies throughout the foam.

Formulation and Evaluation of Chitosan-Polyaniline Nanocomposites for Controlled Release of Anticancer Drug Doxorubicin

2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Dillip Kumar Behera ◽  
Kampal Mishra ◽  
Padmolochan Nayak
Keyword(s):  
Tensile Strength ◽  
Drug Release ◽  
Nanocomposite Films ◽  
Casting Method ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Clay Particles ◽  
Solution Casting Method ◽  
Nanoclay Content

In this present work, chitosan (CS) crosslink with polyaniline (PANI) with montmorilonite (MMT) called as (CSPANI/MMT) and CS crosslink with PANI without MMT called as (CS-PANI) were prepared by employing the solution casting method. Further the formation of nanocomposites CS-PANI/MMT and CS-PANI were investigated using XRD, FTIR, SEM and tensile strength. Water uptake and swelling ratio of the CS-PANI and CS-PANI/MMT were found to decrease with increase in concentration of clay. Mechanical properties of the CS-PANI and CS-PANI/MMT were assessed in terms of tensile strength and extensibility using texture analyzer. Increase in tensile strength and reduction in extensibility was reported with increase in the nanoclay content. In vitro drug release study on CS-PANI and CS-PANI/MMT indicated pronounced sustained release of doxorubicin by the incorporation of clay particles in the CS polymer matrix. Overall CSPANI/MMT nanocomposite films exhibited improved mechanical and sustained drug release properties than CS-PANI.

scholarly journals FORMULATION AND EVALUATION OF CHITOSAN-POLYPYRROLE NANOCOMPOSITES FOR CONTROLLED RELEASE OF ANTICANCER DRUG DOXORUBICIN

2019 ◽  
pp. 247-253
Author(s):  
DILLIP KUMAR BEHERA ◽  
KAMPAL MISHRA
Keyword(s):  
Tensile Strength ◽  
Controlled Release ◽  
Drug Release ◽  
Anticancer Drug ◽  
Nanocomposite Films ◽  
Sustained Drug Release ◽  
Clay Particles ◽  
Materials Used ◽  
Nanoclay Content

Objective: The purpose of the present study was a characterization of chitosan (CS)-polypyrrole (PPY) nanocomposites for controlled release of anticancer drug doxorubicin (DOX). Methods: Chitosan crosslink with PPY with montmorillonite (MMT) called as (CS-PPY/MMT) were formulated using the solvent casting method. The prepared nanocomposites were characterized by X-Ray Diffraction Analysis (XRD), tensile strength, scanning electronic microscope (SEM). Results: The XRD result confirmed that the CS-PPY/MMT possessed crystal structure. The nanocomposites CS-PPY/MMT-4 were showed a homogenous morphology. The Water uptake and swelling ratio of the CS-PPY and CS-PPY/MMT were found to decrease with increase in the concentration of clay. Mechanical properties of the CS-PPY and CS-PPY/MMT were assessed in terms of tensile strength and extensibility using texture analyzer. Increase in tensile strength and reduction in extensibility was reported with an increase in the nanoclay content. In vitro drug release study on CS-PPY and CS-PPY/MMT indicated pronounced sustained release of doxorubicin by the incorporation of clay particles in CS-PPY/MMT. It was observed that during the first 60 min of the dissolution study, the CS-PPY/MMT-4 film showed just 79.32±0.56% drug release as while the CS-PPY-1, CS-PPY/MMT-2 and CS-PPY/MMT-3 films showed a release of 53.79±1.23%, 63.51±1.24% and 68.15±2.38% respectively. Conclusion: CS-PPY/MMT nanocomposite films exhibited improved mechanical and sustained drug release properties than CS-PPY. The combination of biodegradable polymeric chains and clay reinforcement can be applied to achieve the desired combination of properties of materials used as a biosensor for diverse biomedical applications.

Elastomer nanocomposites based on NBR/BR/nanoclay: morphology and mechanical properties

2013 ◽  
Vol 33 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Shohreh Tolooei ◽  
Ghasem Naderi ◽  
Shirin Shokoohi ◽  
Sedigheh Soltani
Keyword(s):  
Mechanical Properties ◽  
Polymer Chains ◽  
Butadiene Rubber ◽  
Cure Characteristics ◽  
Fluid Uptake ◽  
Roll Mill ◽  
Dispersion State ◽  
Cure Time ◽  
Diffraction Patterns ◽  
Nanoclay Content

Abstract Ternary elastomer nanocomposites based on acrylonitrile butadiene rubber (NBR), polybutadiene rubber (BR) and two types of nanoclay (Cloisite 15A and Cloisite 30B) were prepared using a laboratory scale two-roll mill. The effects of nanoclay composition on the cure characteristics, mechanical properties and morphology of NBR/BR (50/50) nanocomposite samples containing 3, 5, 7 and 10 wt% nanoclay were investigated. According to the cure characteristics both types of nanoclay caused a reduction in the scorch time and optimum cure time of the nanocomposite compound. X-ray diffraction patterns of all samples suggested the intercalation of polymer chains into the silicate layers. This was confirmed by transmission electron microscopy (TEM) micrographs. Dynamic mechanical thermal analysis (DMTA) was utilized to study the dispersion state of nanoclay within the elastomer blend matrix. The results showed the development of mechanical properties with the establishment of interactions between nanoclay and polymer chains. Antiknock and brake fluid uptake were also reduced with increasing the nanoclay content.

Preparation and Properties of Fe3O4/PMMA Nanocomposite Films

2009 ◽  
Vol 79-82 ◽  
pp. 505-508
Author(s):  
Li Li ◽  
H. Zhao ◽  
Wei Wang ◽  
F.F. Nie
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Chemical Structure ◽  
Silane Coupling Agent ◽  
Blood Compatibility ◽  
Nanocomposite Films ◽  
Precipitation Process ◽  
Silane Coupling ◽  
Magnetic Fe3o4 Nanoparticles ◽  
Co Precipitation ◽  
Magnetic Fe3o4

The magnetic Fe3O4 nanoparticles had been synthesized by co-precipitation process and surface treatment by silane coupling agent (KH570). The magnetic Fe3O4/PMMA nanocomposite films were prepared by blend method, and the chemical structure, mechanical properties, surface morphology and the biocompatibility of the nanocomposite films were studied in this work. The magnetic Fe3O4 nanoparticles were well dispersed in the Fe3O4/PMMA nanocomposite films. The strength of the nanocomposite films, as well as the strain, decreased first and then increased with the increasing of the nanoparticles. The hemolytic ratio indicated that the nanocomposite films had a better blood compatibility.

Preparation of Cellulose Nanofibrils by High-Pressure Homogenizer and Zein Composite Films

2013 ◽  
Vol 829 ◽  
pp. 534-538 ◽  
Author(s):  
Alireza Shakeri ◽  
Sattar Radmanesh
Keyword(s):  
Atomic Force Microscopy ◽  
High Pressure ◽  
Food Packaging ◽  
Cellulose Nanofibrils ◽  
Composite Films ◽  
Average Diameter ◽  
Nanocomposite Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Pressure Homogenizer

Cellulose nanofibrils ( NF ) have several advantages such as biodegradability and safety toward human health. Zein is a biodegradable polymer with potential use in food packaging applications. It appears that polymer nanocomposites are one of the most promising applications of zein films. Cellulose NF were prepared from starting material Microcrystalline cellulose (MCC) by an application of a high-pressure homogenizer at 20,000 psi and treatment consisting of 15 passes. Methods such as atomic force microscopy were used for confirmation of nanoscale size production of cellulose. The average diameter 45 nm were observed. Zeincellulose NF nanocomposite films were prepared by casting ethanol suspensions of Zein with different amounts of cellulose NF in the 0% to 5%wt. The nanocomposites were characterized by using Fourier transform infrared spectroscopy ( FTIR ), Atomic force microscopy ( AFM ) and X-ray diffraction ( XRD ) analysis. From the FTIR spectra the various groups present in the Zein blend were monitored. The homogeneity, morphology and crystallinity of the blends were ascertained from the AFM and XRD data, respectively. The thermal resistant of the zein nanocomposite films improved as the nanocellulose content increased. These obtained materials are transparent, flexible and present significantly better physical properties than the corresponding unfilled Zein films.

Electromagnetic interference shielding study in microwave and NIR regions by highly efficient Ag/ZnS and polyaniline-Ag/ZnS particles

2021 ◽  
pp. 089270572110649
Author(s):  
Muhammad Zahid ◽  
HM Fayzan Shakir ◽  
Zulfiqar Ahmad Rehan
Keyword(s):  
Electromagnetic Interference ◽  
Near Infrared ◽  
Oxidative Polymerization ◽  
Composite Films ◽  
Nir Spectroscopy ◽  
Infrared Region ◽  
Nanocomposite Films ◽  
Emi Shielding ◽  
Zns Nanoparticles ◽  
Co Precipitation

The chemical oxidative polymerization and co-precipitation methods were employed for the preparations of polyaniline (PANI) and silver-doped zinc sulfide (ZnS) nanoparticles to be used for electromagnetic interference (EMI) shielding. PVC-based composite films were fabricated by the incorporation of Ag/ZnS and PANI-Ag/ZnS nanoparticles. These nanoparticles were first analyzed by X-ray diffraction and zetasizer for their crystal structure and particle size. Prepared nanocomposite films were then analyzed for various properties like electrical conductivity, transmission in the near-infrared region (700 nm to 2500 nm), and EMI shielding efficiency in the microwave region (0.1 GHz to 20 GHz). These parameters were characterized by DC Conductivity, NIR spectroscopy, and vector network analyzer. It was found that with the addition of the concentration of nanoparticles, both values of conductivity and shielding efficiency improved. The highest attenuation value in 0.1 to 20 GHz reached 52.5 dB in 0.1 to 20 GHz frequency for 20 wt% PANI-Ag/ZnS and < 0.5% transmission was evaluated in the NIR region.

Morphology, Crystalline Structure and Isothermal Crystallization Kinetics of Polybutylene Terephthalate/Montmorillonite Nanocomposites

2005 ◽  
Vol 13 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Defeng Wu ◽  
Chixing Zhou ◽  
Xie Fan ◽  
Dalian Mao ◽  
Zhang Bian
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Polymer Chains ◽  
Isothermal Crystallization Kinetics ◽  
Clay Particles ◽  
Nucleation Sites ◽  
Kinetics Of ◽  
Montmorillonite Nanocomposites

The melt intercalation method was employed to prepare poly(butylene terepathalate)/montmorillonite nanocomposites, and their microstructure was characterized by wide angle X-ray diffraction and transmission electron microscopy. The XRD results showed that the crystalline plane such as (010), (111), (100) was smaller than that of pristine PBT, which indicates that the crystallite size of PBT in the nanocomposites could be diminished by adding clay. Moreover, the isothermal crystallization kinetics of PBT and PBT/MMT nanocomposites was investigated by differential scanning calorimetry (DSC). During isothermal crystallization, the development of crystallinity with time was analysed by the Avrami equation. The results show that very small amounts of clay dramatically increased the rate of crystallization and high clay concentrations reduced the rate of crystallization at the low crystallization temperatures. At low concentrations of clay, the distance between dispersed platelets was large so it was relatively easy for the additional nucleation sites to incorporate surrounding polymer, and the crystal nucleus was formatted easily. However, at high concentrations of clay, the diffusion of polymer chains to the growing crystallites was hindered by large clay particles, despite the formation of additional nucleation sites by the clay layers. At the higher crystallization temperature, the crystallization of the nanocomposites was slower than that of the pure PBT under the experimental conditions, which means that with the increase in chains mobility at the high crystallization temperature, the crystal nuclei are harder to format, and the hindering effect of clay particles on the polymer chains was stronger than the nucleating effect of the layers. In addition, the activation energies of crystallization for PBT and its nanocomposites were calculated by the Arrhenius relationship, and the results showed that the nanocomposites with a low clay content had the lower activation energy values than PBT, while high amounts of clay increased the activation energy of PBT.

scholarly journals Ionic Liquids as Delaminating Agents of Layered Double Hydroxide during In-Situ Synthesis of Poly (Butylene Adipate-co-Terephthalate) Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 618 ◽  
Author(s):  
Hynek Beneš ◽  
Jana Kredatusová ◽  
Jakub Peter ◽  
Sébastien Livi ◽  
Sonia Bujok ◽  
...  
Keyword(s):  
Food Packaging ◽  
Water Vapor Permeability ◽  
Nanocomposite Films ◽  
Precipitation Method ◽  
Vapor Permeability ◽  
Inorganic Particles ◽  
In Situ Preparation ◽  
End Use ◽  
Co Precipitation

Currently, highly demanded biodegradable or bio-sourced plastics exhibit inherent drawbacks due to their limited processability and end-use properties (barrier, mechanical, etc.). To overcome all of these shortcomings, the incorporation of lamellar inorganic particles, such as layered double hydroxides (LDH) seems to be appropriate. However, LDH delamination and homogenous dispersion in a polymer matrix without use of harmful solvents, remains a challenging issue, which explains why LDH-based polymer nanocomposites have not been scaled-up yet. In this work, LDH with intercalated ionic liquid (IL) anions were synthesized by a direct co-precipitation method in the presence of phosphonium IL and subsequently used as functional nanofillers for in-situ preparation of poly (butylene adipate-co-terephthalate) (PBAT) nanocomposites. The intercalated IL-anions promoted LDH swelling in monomers and LDH delamination during the course of in-situ polycondensation, which led to the production of PBAT/LDH nanocomposites with intercalated and exfoliated morphology containing well-dispersed LDH nanoplatelets. The prepared nanocomposite films showed improved water vapor permeability and mechanical properties and slightly increased crystallization degree and therefore can be considered excellent candidates for food packaging applications.

Fabricaton Of Granular Materials by High-Pressure Sputitering

1990 ◽  
Vol 195 ◽  
Author(s):  
G.M. Chow ◽  
R.L. Holtz ◽  
C.L. Chien ◽  
A.S. Edelstein
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
Granular Materials ◽  
Thermal Gradient ◽  
High Pressures ◽  
Processing Parameters ◽  
Nanocomposite Films ◽  
Nanoscale Particles ◽  
20 Nm ◽  
Al Matrix

ABSTRACTA brief study of the fabrication of granular materials by high-pressure sputtering is presented. This method utilizes sputtering at high pressures (p > 100 mTorr) in a thermal gradient to produce nanoscale particles, which are then embedded in a matrix by normal sputtering (p ∼ a few mTorr). The shape, size and the degree of aggregationof these nanoscale crystals can be changed by varying such processing parameters as the sputtering gas pressure and the target voltage. Examples are presented of nanocomposite films containing Mo nanocrystals (grain size ranging from 3 to 20 nm ) in an Al matrix.

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