Thermal and morphological studies of poly (vinyl alcohol)/poly (vinyl pyrrolidone)/organoclay nanocomposites containing L-leucine moiety

Abstract

This work is devoted to the synthesis and characterization of poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP)/organoclay (OC) (PPOC) hybrid and comparison between PPOC, PVA/PVP matrix, and PVA/OC (POC) nanocomposite (NC). The PPOC NCs were prepared by mixing a colloidal swelled solution consisting of OC with a water solution of PVA and PVP in the 3:1 weight ratio of PVA to PVP. L-Leucine ammonium ion-exchanged clay was utilized as the nanofiller.

The surface modification of CuO nanoparticles with a flame retardant coupling agent and their influence on the thermal stability of poly(amide-imide)/CuO nanocomposites

Abstract

The present work reports the fabrication and characterization of the thermally stable poly(amide–imide)/CuO nanocomposites. For this purpose, a biodegradable and optically active poly(amide–imide) was synthesized through polycondensation reaction under green media. Subsequently, the surface of CuO nanoparticles was modified with 2,3,4,5-tetrabromo-6-[(4-hydroxyphenyl) carbamoyl] benzoic acid as a new coupling agent to increase their dispersity. The modified nanoparticles were characterized by different methods.

Effect of Starch-MWCNT@ Valine Nanocomposite on the Optical, Morphological, Thermal, and Adsorption Properties of Chitosan

Abstract

The overall goal of this research was to develop a practical method for improving chitosan (Chit) properties using Starch-MWCNT@Valine (SMV) nanocomposite (NC) as a new filler. To prevent aggregation and also improve the dispersion of MWCNTs into the chit matrix, first the surface of MWCNTs was covalently modified by valine as a natural amino acid. Then modified MWCNT was embedded into starch matrix for the preparation of SMV NC.

Mechanical, thermal and optical properties of nanocomposite films prepared by solution mixing of poly(vinyl alcohol) with titania nanoparticles modified with citric acid and vitamin C

Abstract

The aim of this work was to fabricate the nanocomposite films based on poly(vinyl alcohol) and investigate their thermal stability, mechanical and optical properties of nanocomposite films. For this purpose, first, the titanium dioxide nanoparticles surface was modified simultaneously with biocompatible citric acid and vitamin C to prevent their agglomeration in the poly(vinyl alcohol)matrix. Afterward, the modified titanium dioxide nanoparticles were embedded into the poly(vinyl alcohol)matrix via solution casting along with ultrasonic method.

Surface functionalization of carbon nanotubes: fabrication and applications

Abstract

Carbon nanotubes (CNT)s show exceptional one-dimensional π-electron conjugation, mechanical strength, high chemical and thermal stability, which make them very attractive for use in many applications. CNTs intrinsically tend to hold together as ropes and bundles due to van der Waals interactions. The prevention of such behavior has been investigated by testing a variety of surface modification methods. The functionalized CNTs present enhanced properties enabling facile production of novel nanomaterials and nanodevices.

Chemical adsorption of D-sucrose on MWCNTs for compatibility improvement with alanine-based poly(amide-imide) matrix: morphology examination and thermal stability study

Abstract

A simple and fast method has been developed for the covalently functionalized multi-walled carbon nanotubes (MWCNTs) with d-sucrose carbohydrate (MWCNT-Suc) in an aqueous solution. Fourier transform infrared technique confirmed the ester linkage between the MWCNTs and sucrose. Good water solubilization of MWCNTs was obtained. Nanotube-reinforced poly(amide-imide) (PAI) nanocomposites (NCs) were prepared by mixing MWCNT-Suc with alanine amino acid-based PAI matrix.