Page 473 - Demo

SECTION II. APPLIED BIOTECHNOLOGY IN THE PHARMACEUTICAL INDUSTRY... 477Figure 2. Effect of GO concentration on methylene blue adsorption capacity The incorporation of graphene oxide (GO) into hydrogel materials enhances both adsorption capacity and adsorption efficiency. This improvement was attributed to the structural changes induced by increased GO content, which results in a hydrogel matrix with a more porous structure and an expanded specific surface area%u2014key factors contributing to the enhanced adsorption performance. In addition, the presence of hydroxyl and carboxyl functional groups in the GO structure facilitates electrostatic interactions and weak hydrogen bonding with methylene blue (MB) to take place. Furthermore, strong %u03c0-%u03c0 interactions between the aromatic regions of GO and MB molecules further augment the adsorption process. However, when the GO content exceeds 300 mg/L, a decline in adsorption capacity and efficiency was observed, likely due to the aggregation of GO at higher concentrations. The aggregation reduces the availability of active sites and disrupts the uniformity