"Functionalized waste cellulose with antimicrobical activity"

Soybean hulls are one of the main by-products of soybean crushing and they are usually destined to become a putrescible waste. In a previous study, exhausted soybean hulls after the extraction of soybean peroxidase (an enzyme used for different applications) were employed as adsorbents of aqueous metal contaminants for water remediation [1]. In this work, such waste of soybean hulls were subjected to an acid-base treatment to isolate cellulose. The obtained material was functionalized with amino propyl groups [2] for the achievement of new sustainable materials with antimicrobial properties. For comparison purpose, analogous materials were synthesized starting from commercial cellulose. The amino-functionalization process resulted effective, since the antimicrobial activity of all the modified celluloses -tested by preliminary trials following the ASTM E 2149-2013 procedure- was outstanding against both Gram positive and Gram-negative bacteria. Particular attention was paid to the efficiency and sustainability of all the chemical processes with the use of waste materials, green solvents and sustainable procedures. The physical-chemical features of the samples were analyzed by several techniques such as electron scanning microscopy, infrared spectroscopy, thermogravimetry, differential scanning calorimetry. Preliminary results showed as the different synthetic procedures and the different starting cellulose samples influenced both the thermal stability and the microstructural order.