Preparation of Transparent Cellulose/PMMA Composite Sheet from Cellulose Aerogel

In this work, wet cellulose aerogel sheet was prepared via NaOH/urea dissolution system followed by multiple solvent exchanges. Firstly, hyacinth cellulose solution was prepared and then cast into plastic mold. The casting solution was left standing to become solid hydrogel. Then, multiple solvent exchanges by water was carried out in order to remove NaOH and urea completely to obtain wet hydrogel. Then, transparent cellulose sheet was successfully prepared by backfilling the nano/micro sized aerogel channel with a refractive index matching polymer which was PMMA emulsion in this study. The transparent cellulose sheet exhibited 80-90 percent transparency. In contrast, cellulose aerogel exhibited relatively low percent transmittance only 8.24%. In addition, the coefficient of thermal expansion (CTE) of transparent cellulose sheet with a thickness of 0.5 mm (10.45 ppmK -1 ) was significantly lower that pure PMMA sheet (79.70 ppmK -1 ), indicating that aerogel based transparent cellulose exhibited lower thermal expansion than neat plastic.