D.S. Patil

Development of advanced antimicrobial and sterilized plasma polypropylene grafted muga (Antheraea assama) silk as suture biomaterial.

Surface modification of silk fibroin (SF) materials using environmentally friendly and non-hazardous process to tailor them for specific application as biomaterials has drawn a great deal of interest in the field of biomedical research. To further explore this area of research, in this report, polypropylene (PP) grafted muga (Antheraea assama) SF (PP-AASF) suture is developed using plasma treatment and plasma graft polymerization process. For this purpose, AASF is first sterilized in argon (Ar) plasma treatment followed by grafting PP onto its surface. AASF is a non-mulberry variety having superior qualities to mulberry SF and is still unexplored in the context of suture biomaterial. AASF, Ar plasma treated AASF (AASFAr) and PP-AASF are subjected to various characterization techniques for better comparison and the results are attempted to correlate with their observed properties. Excellent mechanical strength, hydrophobicity, antibacterial behavior, and remarkable wound healing activity of PP-AASF over AASF and AASFAr make it a promising candidate for application as sterilized suture biomaterial.

Radio-frequency Ar plasma treatment on muga silk fiber: correlation between physicochemical and surface morphology

Radio-frequency (RF) Ar plasma treatment is carried out on natural muga silk fibers in a capacitively coupled plasma reactor. The physical and thermal properties of the muga fibers are investigated at an RF power of 20 W and in the treatment time range of 5 to 20 min. The virgin and plasma-treated muga fibers are characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The effect of Ar plasma treatment can be observed only on the outermost layer of the muga fibers without any significant variation in their bulk and thermal properties, as supported by differential scanning calorimetry and thermogravimetric analysis. Improvement in tensile strength and hydrophobicity of the plasma-treated muga fibers is observed at lower treatment time and RF power. Attempts are made to correlate the properties of the plasma-treated muga fibers with their surface chemistry and surface morphologies.

Fabrication of a heterostructure device with Au/PPani?TiO2/ITO configuration and study of device parameters including current conduction mechanism

Polyaniline based composites incorporating titanium dioxide have been synthesized by an alternative pathway using reactive magnetron sputtering of titanium and plasma polymerization of aniline monomer. Structural, optical and morphological characterizations of plasma polymerized aniline (PPani) and titanium dioxide (TiO2) composites (PPani‐TiO2) reveal the evidence for the incorporation of TiO2 in the PPani matrix. A hybrid heterostructure device having PPani‐TiO2 composite with a top gold (Au) layer and bottom indium-tin oxide (ITO) layer is fabricated. The developed heterostructure device exhibits rectifying behaviour indicating the formation of a Schottky contact between Au and PPani‐TiO2. The detailed electrical measurement of the device is performed under different temperatures. The ideality factor (n) and barrier height (φB) of the heterojunction diode at room temperature (300K) are found to be 1.28 and 0.43eV, respectively. Possible conduction mechanisms are examined using various plotting and curve fitting methods for space charge limited conduction mechanism (SCLC), Schottky emission mechanism and Poole‐Frenkel (PF) emission mechanism. The heterostructure device shows best fit of SCLC process as compared to the other mechanisms including Schottky emission and PF emission. (Some figures may appear in colour only in the online journal)

Synthesis and characterization of plasma polymerized styrene films by rf discharge

The deposition of polystyrene films by capacitively coupled rf plasma on bell metal was investigated. Argon/styrene gas mixture was used for coating in the pressure range (7-16) × 10-2 mbar at different rf powers (40-150 Watt). The structure and composition of these polystyrene films were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. The deposition condition of these films was optimized for good adhesive and corrosion resistance behaviours. The results showed the possible application of polystyrene films as corrosion resistance coating on bell metal.