Antifungal activity and humidity sensitivity of quaternized cellulose synthesized in NaOH/urea aqueous solution

Abstract

In this work we report the fabrication of cellulose-based humidity responsive material with antifungal activity. The quaternized cellulose (QC) derivatives with low degree of substitution (DS) values of 0.08-0.37 were synthesized in NaOH/urea aqueous solution. Water insoluble QC membranes (c-QCM) were prepared by casting from QC aqueous solutions, followed by crosslinking with glutaraldehyde. The c-QCMs were disintegrated in acid solutions, but were able to keep membrane shape in neutral and mild basic solutions with pH value of 7.2 and 9.7. The equilibrium water adsorption ratios of c-QCMs were in the range of 66-98%, depending on the DS values of quaternary ammonium groups and the pH value of the aqueous solutions. The antifungal activity of QC was evaluated and found that QC could effectively inhibit the reproduction of Rhizopus stolonifer, Aspergillus flavus and Penicillium digitatum, with minimum inhibitory concentration of 5, 10, and 7.5 mg/mL, respectively. The resistivity of the c-QCM changed for about 65-134 times corresponding to the change of environmental relative humidity from 20 to 99%; and the performance of c-QCM as a resistive-type humidity responsive material was consistent in the cycling of relative humidity.

New supramolecular metallo-terpyridine carboxymethyl cellulose derivatives with antimicrobial properties

“…The reason for the high MIC values than those usually reported for antimicrobial agents could be attributed to the polymeric nature of prepared cellulose derivative and the DS values of the CMC used and the prepared CMC-terpyridine derivative. However, such high values are not uncommon for antimicrobial cellulose modified derivatives (Jebali et al, 2013;Zhang et al, 2012).…”

Synthesis of new cellulose ethers using Suzuki–Miyaura reactions

“…Most of these derivatives are water-soluble and low concentrations are required to greatly modify the formulation rheology. The most commercially important cellulose ethers are carboxymethylcellulose (CMC; Thielking & Schmidt, 2000) and alkyl cellulose such as methyl cellulose (MC; Majewicz & Podlas, 2000) and ethyl cellulose (EC; Koch, 1937) but some derivatives bearing hydroxyl (hydroxyethylcellulose, HEC; Bert & Wagenknecht, 2008), carboxyl (Liebert & Heinze, 1998) or amino (Zhang et al, 2012) moieties have also been developed. These compounds are generally synthesized in two steps.…”

Synthesis, Characterization and Antibacterial Activity of Novel β-cyclodextrin Polyurethane Materials

“…Samples after quaternization appeared a notable weight loss at a higher temperature of 300-310. It reflects that the thermal stability of QAS-β-CDPU is better than β-CDPU[36].…”