A study of the characteristics of polymer deposition by electrospraying

The electrospinning process is capable of producing fibres in the submicron range. Electrospinning has gained much attention in the last decade not only due to its versatility in spinning a wide variety of polymeric fibres, but also due to its consistency in producing nanofibres. Instead of producing fibres if charged droplets are formed then the process is called electrospraying or electrostatic spraying.<br><br>In this research, it has been attempted to apply electrostatic spraying in the textile field for the coating of specialised textile surfaces. This process overcomes the disadvantages of the standard coating techniques. In the standard coating process, the polymers are impregnated into the interstices of the fibres/yarns, which results in alteration of the original properties of the textile substrate. Also, coating thickness cannot be achieved at submicron level, which increases the stiffness of the substrate. In electrospraying, the polymer droplets are deposited at the submicron level, which facilitates a thinner coating on substrates. <br><br>Therefore, it is of interest to develop an understanding of spraying characteristics while a polymer solution is subjected to electrospraying. This research study investigated the effect of process parameters on polymer droplet diameter and its aggregation during electrospraying. Response surface methodology was utilised to design the experiments and evaluate the significance of process parameters on polymer aggregation. Applied voltage, solution flow rate, nozzle-collector distance and polymer concentration significantly affected the polymer aggregation and droplet diameter. Minimum polymer aggregation and smaller droplet diameter were observed at higher applied voltage, higher field strength and lower nozzle-collector distance. In addition, the development of a bicomponent polymer droplet deposition technique was successfully demonstrated in this research study; this technique can impart dual functionality to the textile substrate. This research contributes to the knowledge established in the field of electrostatic spraying which leads to coating of polymers at the submicron range on the textile substrate.