Directed Discovery of Greener Cosolvents: New Cosolvents for Use in Ionic Liquid Based Organic Electrolyte Solutions for Cellulose Dissolution
Directed Discovery of Greener Cosolvents: New Cosolvents for Use in Ionic Liquid Based Organic Electrolyte Solutions for Cellulose Dissolution
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DOI：
10.1021/acssuschemeng.6b02020
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发表时间：
2016-11-01
影响因子：
8.4
通讯作者：
Scott, Janet L.
中科院分区：
文献类型：
--
作者：
Gale, Ella;Wirawan, Remigius H.;Scott, Janet L.
纤维素是一种丰富的、廉价的、可再生的、但顽固的材料，如果溶解，可能会形成各种材料、复合材料和混合物。最近，离子液体和一些溶剂(所谓的有机电解质溶液，OESS)的混合物被用作有效的纤维素溶解溶剂，但许多使用的助溶剂缺乏绿色证书，这是一个长期存在的问题，其中偶极非质子溶剂是选择的溶剂。我们提出了一种合理的方法，基于最近发表的数据库中收集的溶剂参数范围的定义，为OES的形成寻找更绿色的助溶剂。因此，伽马-丁内酯被确定为适合于溶解微晶纤维素的OES前体，而基于生物的伽马-戊内酯作为一种效率稍低但明显更安全的替代品。助溶剂效率的比较表明，以前使用的溶解纤维素的质量或浓度的测量可能掩盖了1-甲基咪唑、二甲基亚砜(DMSO)、N，N-二甲基甲酰胺、N-N‘-二甲基咪唑烷酮、N，N-二甲基乙酰胺、N-甲基吡咯烷酮和环丁舒烷(很少考虑)之间的相似之处，而摩尔基础上的比较表明，溶剂的摩尔体积是一个重要因素。DMSO/1-乙基-3-甲基咪唑乙酸酯的参考相互作用中心模型(RISM)计算表明，DMSO与乙酸乙酯阴离子之间存在竞争，纤维素被离子液体优先溶剂化。
Cellulose is an abundant, cheap, renewable, yet recalcitrant, material, which, if dissolved, may be formed into a wide range of materials, composites, and mixtures. Much attention has recently been focused on the use of mixtures of ionic liquids and some solvents (so-called organic electrolyte solutions, OESs) as efficient cellulose dissolution solvents, but many of the cosolvents used lack green credentials a perennial problem where dipolar aprotic solvents are the solvents of choice. We present a rational approach, based on definition of ranges of solvent parameters gathered together in recently published databases, to find "greener" cosolvents for OES formation. Thus, gamma-butyrolactone is identified as a suitable OES former for dissolution of microcrystalline cellulose and biobased gamma-valerolactone as a marginally less efficient, but significantly safer, alternative. Comparison of cosolvent efficiency reveals that previous use of measures of mass, or concentration, of cellulose dissolved may have masked the similarities between 1-methylimidazole, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, N-N'-dimethylimidazolidinone, NN-dimethylacetamide, N-methylpyrrolidinone, and sulfolane (seldom considered), while comparison on a molar basis reveals that the molar volume of the solvent is an important factor. Reference-interaction site model (RISM) calculations for the DMSO/1-ethyl-3-methylimidazolium acetate OES suggest competition between DMSO and the acetate anion and preferential solvation of cellulose by the ionic liquid.