Cellulose functionalization with the use of chemical pretreatments can be regarded as potential route to both promote nanocellulose fabrication and increase the product value by its adjustable surface properties. Sequential regioselective periodate oxidation and consecutive chlorite oxidation or reductive amination combined with high-shear homogenization were used to produce anionic cellulose nanofibers (CNF) or amino-modified amphiphilic cellulose nanocrystals (CNCs), respectively. Periodate oxidation was regarded as a key element to control the formation of reactive aldehyde groups and govern the individualization of either CNF or CNCs. The hydrophobicity of the CNCs was affected by the proper selection of amines with divergent chain lengths, which were attached to cellulose backbone with reductive amination. Highly anionic dicarboxylic acid cellulose (DCC) nanofibers were investigated for their potential to function as a selective thin-film composite membrane for ultrafiltration (UF) applications. Based on the preliminary tests, results comparable to commercial UF membrane were achieved when industrial process waters were purified. In addition pore-size of the nanoporous DCC-nanofiber layer of the composite membrane was found to be tunable by employing divergent cross-linkers. The amino-functionalization of cellulosic fibers was among the first attempts to fabricate CNCs with an acid-free methodology. As a result CNCs with uniform width and length were obtained after mechanical homogenization. The characteristics of barrier films fabricated solely from amino-functionalized CNCs was investigated. According to the results good mechanical strength and high resistance to permeation of oxygen even at elevated relative humidity was obtained. The use of amino-functionalized CNCs should be further investigated for its compatibility and potential as reinforcing additive in composite structures.

Functionalized nanocelluloses and their use in barrier and membrane thin films

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.