Cooperative crosslinking in polyvinyl alcohol organogels.

Abstract

Manipulating and optimizing the properties of gels is important for practical applications but can be both synthetically difficult and expensive. In this work, we report an easily tunable polyvinyl alcohol (PVA) organogel formed with boric acid (BA) and 1,4-benzenediboronic acid (1,4-BDBA) as crosslinkers. While PVA and BA alone form weak aggregations in DMSO, adding small amounts of 1,4-BDBA dramatically improves the material properties and gelation. PVA organogels made with mixtures of BA and 1,4-BDBA have improved thermal properties, lower CGCs, and higher G' than those with either crosslinker alone. We propose that these enhanced material properties are the result of cooperative PVA crosslinking between 1,4-BDBA and BA. As the properties of this system can be improved by simply varying the ratio of crosslinkers, these organogels are highly adjustable and are a practical alternative to PVA hydrogels.