No abstract

No abstract

In this work, we report the preparation of poly(vinylidene fluoride)/poly methylmethacrylate (PVDF/PMMA)/graphene polymer blend nanocomposites via synthesis of PMMA/graphene as a masterbatch through in situ polymerization. The PMMA/graphene masterbatch compounded with PVDF by solution mixing in different ratios. The compounding was followed by solution casting to form polymer blend nanocomposites. Solution cast films were subjected to thermal treatments at three different temperatures. The crystalline structure of thermally treated samples was studied with X‐ray diffraction spectroscopy and Differential Scanning Calorimetric (DSC) analysis. Results indicated PMMA chains persuade the β crystalline form in PVDF but cannot stabilize them in elevated temperature; however, graphene sheets due to restricting effect on TT conformation chains are able to stabilize them. DSC data revealed the graphene sheets can increase the crystallinity of PVDF and also act as nucleating agents. Transmission Electron Microscopy demonstrated coexistence of the different stacking orders of graphene sheets in both masterbatch and polymer blend nanocomposite. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

This work has been undertaken to study the cell behavior of L929 fibroblasts on the laser irradiated polyethylene terephthalate (PET) surface. To modify the surface properties of the PET, CO2 pulsed laser at the wavelength of 9.25 microm and KrF excimer laser at 248 nm with various number of pulses were used. Laser irradiation caused some changes in the chemical and physical properties of the laser-treated film surfaces, which were evaluated using different techniques. These changes may affect the cell adhesion and growth on the laser-treated PET. Therefore, cell attachment and spreading were investigated on the laser-treated PET in vitro. The data from in vitro assays showed the fibroblast cells were attached and proliferated extensively on the CO2 and KrF laser-treated films in comparison with the unmodified PET. The results obtained from the cell behavior studies revealed that surface morphology and wettability affected cell adhesion and spreading on the laser-treated PET.

Polystyrene latex particles in an emulsifierfree emulsion were prepared by purified styrene (St) as monomer and 2,2Ј-azobis (2-amidino propane) dihydrochloride (ABA, 2HCl) as initiator. The optimized condition of polymerization of styrene was obtained by using the various parameters such as different amounts of monomer (0.009, 0.051, and 0.071 mol styrene/mol Water), different amounts of initiator (6.02, 4.62, 2.41, and 1.00 weight percent of initiator relative to styrene), and pH (range 1-7). Quantitative and qualitative analyses of prepared polymer were performed by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Gel Permeation Chromatography (GPC), and 1 H-NMR and FT-IR spectroscopy, that were used, respectively, to show the morphology of particles, the glass transition temperature (T g ), the average molecular weight, and the structure of the prepared polymer.