Tungsten disulfide (WS2) doped polyacrylamide (PAAm) composites: Gelation and optical studies

Abstract

The organic Acrylamide (AAm) copolymerization in various contents of inorganic WS2 has been reported. The aim was to investigate the effect of the WS2 amount on the obtained morphology and the gelation process of the AAm composites. It was found that during gelation process the photon intensity of transmission decreased significantly above some critical time, called the gel point, tg. The decrease in the photon intensity of transmission was related to the increase in the intensity of scattered light from the gel attributable to the production of microgel that occurs while copolymerization held in AAm with Bis-Acrylamide (BIS). Gel points were found to be increased by increasing WS2 content. Time-dependent scattering of composites manifests the growth mechanism, the greater microgel particles, as in agreement with Rayleigh's equation of scattering. It is determined that concentration of microgels is inversely proportional to the WS2 content. The composite rate constants of gelation, kr were produced and observed that it is proportional to WS2 content. It is understood that inclusion of WS2 in AAm system during gelation delays the process at early times but then contributes to increase the gelation process by increasing the rate of polymerization. Besides less compact PAAm gels are produced in the presence of WS2 atoms. It is also shown that the microgel growth mechanism and gel point of PAAm composite incorporated with WS2 can be significantly tailored by the amount of WS2. Tunable growth mechanism and critical gelation point is crucial for flexible electronic applications.