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Enhanced barrier performance of cellulosic wood fiber/filler network

University of British Columbia

Cellulose is an abundant material, which is widely used in papermaking. It is both a biodegradable and sustainable material. However, its hydrophilic nature may limit its applications in specific and novel areas such as waterproof packaging and paper based microfluidics. In this thesis, three different routes are followed to render the surface of the paper superhydrophobic. First, chemical vapor-phase silanization is done on handsheets made from wood pulp with untreated kaolin clay and precipitated calcium carbonate (PCC) as fillers. The effect of fiber length, filler’s type, size, and concentration on the barrier performance of handsheets is shown. Secondly, mircofibrillated cellulose (MFC), which serves as reinforcement agent in paper, is employed as an additive to change the hydrophilic property of paper. MFC is silanized to obtain hydrophobicity before being dispersed into the pulp suspension. Then the resulting paper undergoes an additional silanization (post-treatment). The third approach involves depositing Janus clay particles on untreated paper. A Janus particle has a hydrophobic and a hydrophilic surface. Because clay particles are hydrophilic, they are treated to obtain hydrophobicity on one side, while the other side remains hydrophilic. An efficient method to obtain these types of particles is the formation of a Pickering emulsion. The study here, focuses on the determining the barrier properties of the prepared superhydrophobic or hydrophobic papers: wettability, water vapor transmission rate (WVTR), and air permeability. The handsheets with shorter fiber length, precipitated calcium carbonate, smaller filler size and lower filler content, were found to exhibit lower WVTR values. The water contact angle of handsheets loaded with fillers, Janus clay particles and hydrophobic MFC, was found to be 120~130°, 141° and 134~144° respectively.

Text

2016-07-27

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/58543

Chemical and Biological Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/