Synthesis and Characterization of Polyaniline and its Composites for Opto Electrical Sensing Applications

Abstract

newline quotAmmonia (NH3) is a widely used chemical in various chemical production, industrial, newlineagriculture (fertilizers), and refrigeration. The need for ammonia sensors arises from newlinethe toxic, corrosive, and environmentally damaging properties of NH3. Reliable and newlineefficient ammonia sensors are vital for maintaining safe workplaces, protecting the newlineenvironment, and complying with safety and environmental regulations. Traditionally, newlinepure organic ammonia sensors (e.g., Polyaniline, Polypyrrole) are advantageous for newlineapplications requiring room temperature operation, flexibility and low-cost fabrication, newlinebut they are limited by lower stability, slower response, and poor selectivity. Pure newlineinorganic ammonia sensors (e.g., Metal Oxides: ZnO, SnO2) offer high sensitivity, fast newlineresponse times, and stability in harsh conditions but require high temperatures, making newlinethem less suitable for portable, low-power applications and limiting their mechanical newlineflexibility. These drawbacks drive the need for organic-inorganic hybrid sensors, which newlinecan combine the best properties of both material types-addressing limitations like poor newlineselectivity, slow response, and environmental instability while providing the higher newlinesensitivity and more stable performance. newlineThis thesis investigates the synthesis of pure polyaniline and its composites with newlineZnO, SnO2, and rGO for improvements in structural, optical, electrical, and gas sensing newlineproperties. Polyaniline and its composites with ZnO, SnO2, and rGO offer significant newlineimprovements in the sensitivity, response time, and stability of ammonia sensors. These newlinematerials are highly desirable for developing reliable and efficient ammonia sensors newlinefor industrial, environmental, and safety applications. Polyaniline- based composites newlineshow great potential for addressing the limitations of traditional sensors, providing a newlinepromising solution for real-time ammonia monitoring. quot