H. Somashekarappa

Polymeric degradation of water soluble chitosan/HPMC films using WAXS data

Abstract Films of cationic chitosan and non-ionic hydroxypropyl methyl cellulose (HPMC) have been prepared by solvent casting method, using glycerol as a plasticiser, from aqueous lactic acid medium. Here, an attempt is made to compare the degradation effect of neutral HPMC and chitosan on water uptake and flexibility in terms of microstructural parameters obtained from X-ray line profile analysis. The intension of this study is to investigate properties for the potential use of chitosan/HPMC films to improve flexibility for packaging, solubility of drug, drug release and biodegradability. Fractured surfaces of the films were examined through wide angle X-ray diffraction and the intensity profiles were used to determine the microstructural parameters. Chitosan and HPMC films have more water retentiveness property compared to other blends studied here.

Microstructural Parameters of HPMC/PVP Polymer Blends Using Wide Angle X-Ray Technique

Hydroxypropylemethylecellulose (HPMC) and Polyvinylpyrrolidone (PVP) polymer virgin and blend films were prepared and investigated using wide angle X-ray scattering method. Microstructural parameters like lattice strain (g %), the crystallite size for individual the Braggs reflection (hkl) have been computed using line profile analysis and hence by whole pattern fitting method. The X-ray diffraction study reveals that the blending of PVP decreases the crystallanity of HPMC up to 5:4 concentration and then increases. Measured tensile strength decreases, Youngs Modulus decreases, and % elongation increases as the concentration of PVP increases. The surface morphology investigated using scanning electron microscope, shows that the two polymers were miscible in all concentration range.

Microstructural and electrical properties of PVA/PVP polymer blend films doped with cupric sulphate

A series of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) polymer blends added with different concentrations of cupric sulphate (CuSO4) were prepared by solution casting method and were subjected to X-ray diffraction (XRD) and Ac conductance measurements. An attempt has been made to study the changes in crystal imperfection parameters in PVA/PVP blend films with the increase in concentration of CuSO4. Results show that decrease in micro crystalline parameter values is accompanied with increase in the amorphous content in the film which is the reason for film to have more flexibility, biodegradability and good ionic conductivity. AC conductance measurements in these films show that the conductivity increases as the concentration of CuSO4 increases. These films were suitable for electro chemical applications.

Variation of crystallite size of Al1-xInxN for different values of x and band gap

By using wide angle X-ray scattering (WAXS) technique, we have characterized the epitaxial Al1-xInxN films (thickness, 150 nm) with 0 <x < 1 grown by plasma source molecular beam epitaxy on sapphire (0001) at the low substrate temperature of 375°C, by computing the crystallite size in these samples. We observe that the crystallite size decreases with increase in the concentration of indium and that the band gap in these samples has a direct correlation with the crystallite size.

Effect of NiCuZnFe2O4 on the microcrystalline properties of PVA/CMC polymer blends

A series of PVA/CMC polymer composite films with different amounts of NiCuZnFe2O4 (nickel–copper–zinc–ferrite) was prepared by means of solution-casting technique. These films were characterised using various techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–visible) and AC electrical conductivity measurements. Recorded XRD pattern at room temperature shows an increase in amorphousity of the matrix with concentration of NiCuZnFe2O4 nanoferrite. Microstructural parameters were computed using an in-house program employing XRD data. UV–visible spectra show that the optical absorption of the PVA/CMC nanocomposite films in the UV region is quite high. FTIR spectra show the stretching of the major vibration bands associated with organic–inorganic chemical groups present in the nanoferrite-doped polymer blends. Measured AC electrical conductivity of prepared samples shows that the added nanoferrite does increase the ionic conductivity at lower concentrations.

Spectroscopic analysis of PVA/CMC: NiCuZnFe2O4 polymer nanocomposites

Nickel copper zinc ferrite nanoparticle doped PVA/CMC nanocomposites are synthesized by solution casting method. Wide angle X-ray scattering technique has been used to characterize these nanocomposites. Using Williamson-Hall plot we have determined the microcrystalline parameters like crystallite size and lattice strain for theses samples for various concentration of nanoparticles. We find significant changes in the microstructural parameters with the concentration of nanoparticles. The prepared films are analyzed using FTIR.

Characterization of montmorillonite doped PVA/SA blends using X-ray diffraction

PVA films doped with Montmorillonite was prepared by slow evaporation technique. These films have been used to record X-ray patterns at room temperature. Correlation lengths and microstructural parameters were computed using in-house program employing X-ray data. Results show that correlation lengths as well as crystallite size increases with increase in the concentration of Montmorillonite which is inconformity with the conductivity studies.

Structure-property relation in HPMC polymer films plasticized with Sorbitol

A correlation study on physical and mechanical properties of Hydroxy propyl-methylcellulose (HPMC) polymer films plasticized with different weight ratio of Sorbitol, prepared using solution casting method, was carried out using wide angle X-ray technique and universal testing machine. It is found that the crystallanity decreases as the concentration of Sorbitol increases up to a certain concentration and there afterwards increases. Measured Physical Properties like tensile strength decreases and elongation (%) increases indicating increase in the flexibility of the films. These observations confirm the correlation between microstructal parameters and mechanical properties of films. These films are suitable for packaging food products.

Characterization of HPMC/PVP polymer blend films using WAXS technique

Hydroxy propyl methyl cellulose (HPMC) and Poly vinyl pyrrolidone (PVP) polymer blend films were prepared and investigated using X-ray line profile analysis method. Here an attempt has been made to study the changes in the crystallite size and lattice strain in HPMC with the increase in concentration of PVP. Decrease in these microcrystalline parameters implies increase in the amorphous nature of the film giving more flexibility, degradability and good miscibility. Micro structural parameters reveals that the blend films have more amorphous nature than virgin HPMC. This further justified by SEM images which indicate better miscibility of the two polymers in the blend matrix.