Alfassi Gilad, Rein Dmitry M, Shpigelman Avi, Cohen Yachin
Department of Biotechnology Engineering, ORT Braude College, Karmiel 2161002, Israel.
Faculty of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Polymers (Basel). 2019 Oct 23;11(11):1734. doi: 10.3390/polym11111734.
Cellulose acetate is one of the most important cellulose derivatives. The use of ionic liquids in cellulose processing was recently found to act both as a solvent and also as a reagent. A recent study showed that cellulose dissolution in the ionic liquid 1-ethyl-3-methylimidazoliumacetate (EMIMAc) mixed with dichloromethane (DCM) resulted in controlled homogenous cellulose acetylation; yielding water-soluble cellulose acetate (WSCA). This research investigated the properties of cellulose acetate prepared in this manner, in an aqueous solution. The results revealed that WSCA fully dissolves in water, with no significant sign of molecular aggregation. Its conformation in aqueous solution exhibited a very large persistence length, estimated as over 10 nm. The WSCA exhibited surface activity, significantly reducing the surface tension of water. Because of the molecular dissolution of WSCA in water, augmented by its amphiphilicity, aqueous solutions of WSCA exhibited an overwhelmingly high rate of enzymatic hydrolysis.
醋酸纤维素是最重要的纤维素衍生物之一。最近发现离子液体在纤维素加工中既作为溶剂又作为试剂。最近的一项研究表明，纤维素溶解于与二氯甲烷（DCM）混合的离子液体1-乙基-3-甲基咪唑醋酸盐（EMIMAc）中会导致可控的均相纤维素乙酰化；生成水溶性醋酸纤维素（WSCA）。本研究调查了以这种方式制备的醋酸纤维素在水溶液中的性质。结果表明，WSCA完全溶解于水中，没有明显的分子聚集迹象。其在水溶液中的构象表现出非常大的持久长度，估计超过10纳米。WSCA表现出表面活性，显著降低了水的表面张力。由于WSCA在水中的分子溶解，加上其两亲性，WSCA的水溶液表现出极高的酶促水解速率。
