Anti-Bacterial Microgel Synthesis: Sonochemical Modification of Carbopol for Hygienic Applications

The volume of studies conducted on biopolymeric materials emphasizes the high-consumption of polymers in biomaterial fields, especially in cosmetics industry which must be resistant to different kinds of microorganisms and bacteria. Polymers in this category include acrylate polymers, which are generally made by precipitation polymerization. Carbopol is a brand of acrylic polymer, based on poly(acrylic acid). This polymer is highly used as thickening and gelling agents for its rheological features. By chemically induced antimicrobial agents into the carbopol structure, microgels of inherently antimicrobial properties are obtained with effective applications in personal and public health applications, including combating and controlling corona epidemics (Covid 19).

In this study, it has been tried to improve the antibacterial nature of Carbopol by its bonding and surface modification with different amounts of cationic monomer acryloyl oxyethyl trimethyl ammonium chloride (A.Etac). In this work, for the first time, we attempted to modify the surface of carbopol by ultrasound. We also studied the swelling rate of the sample before and after surface modification in aqueous, alcoholic and salt solutions. Infrared spectroscopy (IR), scanning electron microscopy (SEM) with energy dispersive X-Ray analysis (SEM-EDX), antibacterial, rheometry and swelling tests were used to evaluate the chemical surface modification of Carbopol microparticles to achieve the stated goals. Antibacterial properties of the samples were evaluated by gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureu) by plate count agar method.

Experimental results showed that the modified carbopol was significantly resistant to the bacteria. It should be noted that the samples showed more resistance to gram-positive bacteria than gram-negative bacteria. The results of rheological analysis also showed that the gel strength significantly increased after surface chemical modification. In addition, modified samples showed higher swelling in water and biological media (0.9% brine)