Gelation of cellulose nanocrystal suspensions in glycerol

Recent Advances in Chiral Nematic Structure and Iridescent Color of Cellulose Nanocrystal Films

“…However, the formation of stable gels from CNC suspensions may be desirable for some applications. For example, thixotropic gels of CNC in glycerol were prepared by careful evaporation of water from dilute glycerol-water suspensions of acid-form CNC [16]. The much lower volatility of glycerol compared to water facilitated the evaporation of water and the increased concentration in glycerol.…”

Supramolecular Nanofibrillar Polymer Hydrogels

“…Different cellulose sources such as wood or algae yield CNCs with different dimensions, even under similar preparation conditions [146]. For example, cotton and wood yield highly crystalline CNCs with narrow size distribution, whereas tunicin and algae generate CNCs with larger dispersities and lengths that range from 100 nm to several micrometers [147]. During hydrolysis, sulfuric acid reacts with surface hydroxyl groups on CNCs leading to the functionalization of the surface of the CNC with sulfate ester groups.…”

“…For example, shear thinning (thixotropic) CNC hydrogels were obtained by desulfation of CNCs with glycerol [147]. Alternatively, the addition of NaCl can be used to control the rheological behavior of CNC suspensions in the isotropic, chiral nematic and gel states over a range of CNC and NaCl concentrations [156].…”

Ion-Mediated Gelation of Aqueous Suspensions of Cellulose Nanocrystals

“…Desulphation of the CNC surface by heating their suspension in the presence of glycerol led to a decrease in CNC stability and favoured attraction between them, thereby yielding thixotropic CNC hydrogels. 15 In this process, however, the replacement of water with glycerol may limit the range of bio-related applications of the CNC hydrogels. An alternative method relies on increasing the ionic strength of CNC suspensions by adding salts.…”