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Chlorinated poly(vinyl chloride) (CPVC)/calcium carbonate nanocomposites were successfully prepared by the incorporation of calcium carbonate (CaCO3) nanoparticles into the CPVC matrix. The compatibility between the two phases was obtained by surface modification of the CaCO3 nanoparticles with stearic acid, leading to improved material performance. The effects of the addition of different amounts of CaCO3 nanoparticles to the CPVC on the thermal, mechanical, and morphological characteristics of the CPVC/CaCO3 nanocomposites were investigated. The thermal stability of the CPVC/CaCO3 nanocomposites was evaluated by thermogravimetric analysis and differential scanning calorimetry. In addition, the surface texture of the CPVC and the dispersion of the CaCO3 were evaluated using scanning electron microscopy. Important enhancements in the thermal and mechanical properties of the modified CPVC/CaCO3 nanocomposites were obtained by incorporating different amounts (2.00%, 3.75%, and 5.75%) of surfacemodified CaCO3 nanoparticles within the CPVC polymer matrix. The results reveal that 3.75% of CaCO3 was the optimum amount, where the CPVC/CaCO3 nanocomposite shows the highest impact strength, the highest tensile strength, the highest thermal stability, and the lowest elongation percentage: Replacement of the commercial impact modifier used in industry with the prepared surface-modified CaCO3 nanoparticles for the development of CPVC was successfully achieved. [ABSTRACT FROM AUTHOR]

Modified composites based on cellulose filled with nano-particles of sodium silicate forming cellulose/polypyrrole-TiO2/ sodium silicate nanocomposite were prepared by combining a colloidal sol–gel technique and in-situ oxidative chemical polymerization. The effect of polypyrrole content, processing and the coating by the sodium silicate nanoparticles on the morphology and structure of the prepared composites were studied. The method of processing used was proven to be efficient to uniformly disperse the nano-particles within the polymeric matrix. The dielectric properties, including dielectric constant, ε ′ (ω) , dielectric loss, ε ′′ (ω) , tan δ and ac conductivity, σac, of the obtained composites were studied. [ABSTRACT FROM AUTHOR]

A new type of synthesis route for the preparation of conducting chelating polymer composites (CCPCs) based on waste polystyrene grafted with acrylic (AA) and maleic (MA) acids in the presence of montmorillonite clay was investigated. The prepared composites were characterized using various techniques including Fourier-transform infrared spectroscopy, thermogravimetric analysis, light microscopy and x-ray diffraction analysis. The prepared composites of different AA and MA weight percentage (wt%) have been used as adsorbents for removal of toxic copper ions from their aqueous solutions. The copper uptake by the CCPC grafted with AA was found to be much higher than that of the CCPCs grafted with MA. The key parameters that can affect copper ion uptake such as time and pH were also investigated, and it was found that the increase in pH highly enhanced the copper uptake. The study was further extended to measure the alternating current (AC) conductivities of the prepared composites and their copper complexes which proved that the AC conductivities of the copper-free composites are higher than the AC conductivities of the composites complexed with copper ions. [ABSTRACT FROM PUBLISHER]

Objective: This work deals with the preparation, characterization and in vitro release study of IBU-loaded gel graft copolymer nanoparticles. Method: Gelatin (Gel) graft copolymer nanoparticles were prepared using styrene (Sty) and/or 2-hydroxyethyl methacrylate (HEMA) monomers in the presence of potassium persulfate and glutaraldehyde as an initiator and cross-linker, respectively. The prepared nanoparticles as sustained release drug carriers were investigated using the nonsteriodal anti-inflammatory model drug, ibuprofen (IBU). Results: The prepared nanoparticles as sustained release drug carriers were investigated using the nonsteriodal anti-inflammatory model drug, IBU. The prepared Gel/HEMA and Gel/Sty nanoparticles exhibited particles size ranging from 15 to 17 nm and from 0.42 to 5 mm, respectively. The dissolution of IBU in phosphate buffer, pH 7.4, at 37°C from the prepared nanoparticles was evaluated using UV spectroscopy. In addition, the prepared nanoparticles were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), transmitting electron microscope (TEM) and zeta potential/particle size analyzer. In vitro dissolution study showed that the dissolution rates of the crosslinked nanoparticles were retarded relative to the uncrosslinked ones. Moreover, the released amount constantly decreases with increasing gluteraldehyde content in the gel nanoparticles. Conclusion: Crosslinked gel-based graft copolymers exhibited slow IBU release within six hours. Furthermore, results from different characterization techniques such as TEM, particles size and zeta potential measurements confirmed the formation of pH-responsive gel-graft copolymer nanoparticles. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate new materials to be carried out as scaffolds using breast cancer cells MCF-7. These new nanocomposites were prepared through blending of gelatin with poly ( DL-lactide- co-glycolide) (PLG) in presence of titanium nanowires (TiO2) and cartilage powder (CP). The prepared nanomaterials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and transmitting electron microscope. Moreover, the MCF-7 cells were in vitro tested with apoptosis/necrosis assay, micronucleus test, and DNA fragmentation and MMT assay. TiO2 nanowires and CP particles have diameters around 28-128 and 17-20 nm, respectively. These were coated with gelatin matrix. Seeding of MCF-7 cells with the prepared nanomaterials revealed high cell attachment to their surfaces and they were viable after 72 h. It has been shown that the prepared nanocomposites did not induce necrotic effects on MCF-7 cells; however, they induced a significant DNA fragmentation in comparison with the nontreated control cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]