Starch and cellulose are naturally abundant biodegradable polymers. Starch has disadvantages such as weak barrier properties against water and poor thermal properties. Polyvinyl Alcohol (PVA) is anticipated to be a good candidate for incorporation into these natural polymers. Also PVA shows high resistance to solvents and good barrier properties to oxygen. Because of their weak barrier properties of Starch or carboxymethyl cellulose and PVA polymeric blend other approach is needed. Making nanocomposites by adding nanoclay to improve barrier properties of these films is a new way. In this research, nanocomposites of carboxymethyl cellulose/Polyvinyl Alcohol/clay and starch/Polyvinyl Alcohol/clay at three different weight percentage of PVA (15, 30, and 45) and two nanoclay level (5 and 10) were prepared and their films were made after drying. Optical and thermal properties of the nanocomposites were investigated using UV-Vis spectrophotometry, thermogravimetry analysis (TGA/DTG). The energy gap of the samples was calculated using the graph (α hν )2 against hν and tauc equation. The results showed that addition of PVA and nanoclay increased the thermal resistance of nanocomposite. The energy gap of the nanocomposites films is obtained less than the 5 eV, indicating that these nanocomposites has the potential to use in electronic components such as diodes.

Due to the expansion and importance of nano fibers in the field of pharmaceutical sciences and the ability to use them as skin patches, in this study, nanofibers carrying clindamycin was obtained from adding pure clindamycin to poly(vinyl Alcohol) and poly(vinyl pyrrolidone) polymers fallowed by electrospinning of polymeric solution. The obtained nanofibers were analyzed by Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM), scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDS), Element Mapping (EMPA), and contact angle analysis. The nature of the bond between clindamycin drug and poly(vinyl Alcohol)/poly(vinyl pyrrolidone) substrate was investigated using the quantum theory of atoms in molecules (QTAIM). Antibacterial effects of non-electrospun polymer solution and obtained nanofibers mats were investigated on standard strains of Pseudomonas aeruginosa, Acinetobacter and Staphylococcus aureus bacteria. According to the obtained results, Pseudomonas aeruginosa bacteria was resistant to non-electrospun polymer solution and clindamycin nanofibrous mats. Acinetobacter bacteria was resistant to polymer solution, but clindamycin nanofiber had moderate effect on it. Clindamycin nanofibers mats and non-electrospun polymer solution were very effective against Staphylococcus aureus bacteria. Therefore, clindamycin nanofibrous mats can be used as transdermal patches to treat infections caused by Staphylococcus aureus and Acinetobacter bacteria. In addition, the polymer solution can be useful as a medicinal solution in the transdermal treatment of Staphylococcus aureus bacterial infections.

Hydrogels were produced from mixtures of Polyvinyl Alcohol (PVA), Polyvinyl pyrrolidone (PVP), and acrylic acid (AAc) using γ,-radiation at doses of 3, 7, and 10 kGy and the effect of the variation in concentration of AAc within 0%–, 3% (w/v) on the gelation, swelling, crosslinking, thermal properties, crystallinity, mechanical properties, and surface morphology of the hydrogels were characterized and their adsorptive removal properties for methylene blue (MB) was investigated. The swelling trend was pH-dependent which was dictated by the dominance of two competing factors namely, crosslink density and hydrophilicity. Although thermal analysis showed that the presence of AAc decreased the thermal stability of the hydrogels, SEM images exhibited gradual morphological changes establishing the role of AAc as a crosslinker, and thus increasing the elastic moduli, toughness, and crystallinity of the hydrogels. However, correlation between the characterization results revealed that, in spite of AAc occupying some of the crosslinking sites within PVA–, PVP networks, at low concentration (1% w/v), it could not polymerize enough to contribute to the crosslinks. FTIR spectral analysis revealed a possible gelation mechanism along with the points of interaction among the gel-components. MB adsorption capacity of the hydrogels reached a maximum of 117 mg/g following pseudo-second-order kinetics through film diffusion mechanism while the adsorption isotherm resembled most with that of Langmuir.

AHaake viscometer was used for viscosity measurements of aqueous Polyvinyl Alcohol mixtures at temperatures of 288, 298, and 308 K. It was observed that at low concentration of Polyvinyl Alcohol, variations of the measured shear stress (τ) versus shear rate (γ) were linear and therefore, the Newtonian behaviour of the studied mixtures is considered. The modified Eyring viscosity model previously proposed by the authors was used to test the measured data for aqueous Polyvinyl Alcohol mixtures. It was shown that the model is well capable to fit the data and the parameters, of the modle are evaluated.

In this study, foaming process of Polyvinyl Alcohol with the addition of some compounds was investigated using the batch foaming technique. The reason for the crystalline structure in Polyvinyl Alcohol is presence of strong hydrogen bonds between its chains. By adding some plasticizers and additives, these strong bonds can be broken and new bonds can be formed. Studies show that the foamability of semi-crystalline Polyvinyl Alcohol biopolymer was improved significantly after adding softener and nanoparticles as nucleating agent. Various analyzes showed that suitable intermolecular interactions occur in Polyvinyl Alcohol and its blends in turn expand the processability window of Polyvinyl Alcohol. Polyvinyl Alcohol is a very suitable option for tissue engineering applications due to its non-toxicity and high biocompatibility. Considering this case, it is very important to examine the morphology of the produced sponges using a scanning electron microscope and study the cell structures of the resulting foam. It was found that by changing the operational variables and adding different polymer compounds, a significant change in the structure and cell density of polymer foams was observed. Also, the cell size distribution, cell density and porosity of the produced foams can be controlled by adding certain amount of additives and changing pressure and temperature.