Liquid Crystals on paper (and cellulose nanofibres)

This work describes the surface initiated atom transfer radical polymerisation (SI-ATRP) of liquid crystalline monomers from cellulose fibres (paper) to yield side-chain liquid crystal polymers (SCLCPs) attached to the surface of cellulose (paper) biofibres, utilising recent developments in ATRP chemistry. Developments in ATRP have been utilised to provide robust conditions for the grafting. SCLCP grafts with varied mesogenic units have been achieved. A new mixing protocol has been developed to allow for the polymerisations in the presence of homogenous substrates. Covalent attachment has been confirmed for both smectic and nematic SCLCPs to cellulose, with graft-from polymerisations evidenced for both types of mesogenic units. All graftings were confirmed by FT-IR, with special attention given to the carbonyl peak at ∼ 1730 cm-1. The cellulose surfaces were characterised by Scanning Electron Microscopy and Polarising Optical Microscopy (POM). Sacrificial initiator was used to monitor the extent of surface grafting, and characterisation of the sacrificial polymers produced was carried out by gel permeation chromatography, 1H NMR and POM.