Cellulosic wood fibres find increasing use in new applications in addition to traditional use as a papermaking raw material. This trend is to a large extent motivated by the biodegradable nature of the material and the fact that is derived form a from a renewable resource. On the other hand, a suspension of cellulosic fibres or microfibers offers the opportunity to create surfaces with desired optical, wettability, mechanical and barrier properties. In this work we demonstrate two methods to manipulate the cellulosic fibre or microfibre suspension. First, the incorporation of Janus silica and titanium dioxide fillers in wood fibre networks (handsheets) by filtration and layer-by-layer (LBL) deposition is demonstrated. The effect of filler’s dual functionality on the wettability and water vapour transmission rate of handsheets loaded with the Janus fillers was investigated. Without silanization, the handsheets with silica filler are hydrophilic except when prepared by LBL and 40% Janus silica filler. It was also found that silanization of the handsheets in conjunction with Janus fillers results in the formation of superhydrophobic handsheets with minimal liquid water absorption. Only the silanized handsheets prepared at 40% Janus TiO filler loading were found to be hydrophobic. In the second method, ffilms were prepared by from microfiber suspensions on hydrophobic and hydrophilic containers at temperature and relative humidity. It was found that when the suspension from a container with a hydrophilic surface leads to the formation of opaque films whereas a hydrophobic container leads to translucent films. It is noted that this self-assembly process provides films from microfibers with physical and mechanical properties of the films were found to be comparable to those of nano fibrillated and micro fibrillated cellulose films.

Cellulosic wood fibre paper with mineral Janus fillers and cellulosic films by evaporative self-assembly

ACS Spring 2022

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