Kiran Meghwal

Synthesis and Characterization of Functionalized Polyaniline Having Methyl Violet as Pendant Groups

Methyl violet–substituted polyaniline is prepared by oxidative polymerization of aniline in an aqueous acidic media using tosic acid as dopant and ammonium persulphate as oxidant. Substitution of methyl violet (dye moieties) on polyaniline backbone takes place in the presence of butyl lithium. The structures of methyl violet–substituted polyanilinewas elucidated by Fourier transform infrared (FT-IR), fluorescence spectra, XRD and differential scanning calorimetery (DSC). Molecular weight is determined by gel permeation chromatography (GPC) and viscosity method. Conductivity and band gap of methyl violet–substituted polyaniline was computed by a two-probe conductometer.

Synthesis of dye-substituted polyanilines and study of their conducting and antimicrobial behavior

Abstract Conducting and antimicrobial properties of chemically synthesized polyanilines was found to be affective by varying the dye moieties. The temperature dependence of AC conductivity was studied by two-probe method to learn about the conduction behavior of the synthesized compounds. The conductivity of the dye-substituted polyanilines was found to be in the range of 10−3 S/cm. For the study of antimicrobial behavior of the synthesized dye-substituted polyanilines, different micro-organisms, namely, the bacteria Escherichia coli (MTCC 442), Pseudomonas aeruginosa (MTCC 441), Staphylococcus aureus (MTCC 96), and Staphylococcus pyogenus (MTCC 443) and fungal strains Candida albicans (MTCC 227), Aspergillus niger (MTCC 282), and Aspergillus clavatus (MTCC 1323), were chosen based on their clinical and pharmacological importance. Antimicrobial properties of dye-substituted polyanilines show very good results as compared to polyanilines and dyes individually.

Synthesis of ascorbic acid-doped oligoaniline, its drug composites and study of their antibacterial behavior

Oligoaniline (OANI) was prepared using chemical oxidative method using ascorbic acid as a dopant and ammonium persulfate as an oxidant. As-synthesized OANI was subjected for the preparation of various drug composites. All the synthesized compounds were characterized by FTIR, 1HNMR, TGA, GPC, etc. The thermal stability of the compounds was determined by TGA. The molecular weight was determined by GPC. Antibacterial studies of the synthesized compounds were investigated against four Gram-positive (Staphylococcus aureus MTCC 96, Streptococcus pyogenes MTCC 442, B. subtilis MTCC 441 and S. mutans MTCC 890) and four Gram-negative (Escherichia coli MTCC 443, Pseudomonas aeruginosa MTCC 1688, KL. pneumoniae MTCC 109 and S. typhi MTCC 98) bacteria based on their clinical and pharmacological importance. Some of the synthesized compounds showed excellent antibacterial activity as compared to individual bacterial activity of OANI and drugs to be used for preparation of composites.

Chapter 6 – Polyaniline-Based Blends: Natural Rubber and Synthetic Rubber

Abstract Polyaniline possesses unique properties and are widely used in many fields due to its light weight, low cost, and excellent electrical conductivity. The electrical and optical properties of conducting polymers make them potential candidates for applications in batteries, electrochromic displays, field-effect transistors, electrochemical sensors, and solar cells. The reason behind the extensive investigation of composites is to improve processibility and the mechanical properties of the conducting polymers. In this context, the present article discusses blends and composites obtained in the form of films and fibers, with a variety of polymers such as low-density polyethylene, polypropylene, acrylonitrile–butadiene–styrene, styrene–ethylene/butylene–styrene, polystyrene (PS), and styrene–butylene–styrene copolymers; nylons; poly(ethylene terephthalate), poly(vinyl chloride), and conducting polymers.