Bio-based epoxy polymers consisting of cashew nut shell liquid (CNSL)-derived epoxy cardanol prepolymer (ECP) and phenalkamine were reinforced using two types of cellulose nanofibers (CNFs) with different hydrophobicity. The more hydrophobic CNF(A) chemically bonded with phenalkamine improved the mechanical and thermal properties of the composites. The composites at a CNF content of 2.0 wt% had the tensile strength and Young’s modulus of 85 and 500 MPa, respectively, which were 2.9 and 9.4 times greater than those of the base epoxy resin, respectively. Thus, CNSL-based epoxy composites effectively reinforced with hydrophobic CNFs promising high potential as a bio-based epoxy coating, film, and resin.

Hygroscopicity and lipophilicity are opposing properties, and the development of surfaces that exhibit both these properties on a variety of solid substrates and particles is expected to lead to the creation of new functional materials. We recently reported that polydialkylsiloxane, a well-known lipophilic organosilicon compound, can exhibit hydrophilic properties by introducing an ammonium salt group. Herein, we used linear polysiloxanes containing the ammonium salt as surface modifiers. The surface of the substrate was modified with polysiloxane via a photo-initiated thiol-ene reaction. Consequently, this substrate exhibited both hygroscopic and lipophilic surface properties. The surface patterning treatment was carried out under light irradiation using a photomask, and the patterned substrate exhibited unique surface wettability, retaining water only in the presence of the polymer. As this surface treatment procedure can be widely applied to materials containing hydroxy groups on their surfaces, it is expected that various types of functional materials can be created in the future, including the preparation of particles that can be dispersed in both water and oil, or unique fiber materials.

A treatment technique to confer the functions of scavenging and detecting nickel and cobalt ions upon cotton fabric was studied in order to prevent metal allergy symptoms. Cotton fabrics were treated with alizarin in combination with tamarind gum and polyethylene glycol diglycidyl ether. The chemically crosslinked tamarind gum worked as the fixing matrices of the indicator alizarin. The treated cotton fabrics showed colour change from reddish purple to bluish purple by immersed in aqueous solution containing Ni²⁺ or Co²⁺. The results indicated the possibility that the alizarin-treated cotton fabric scavenges hapten metal ions which cause allergies and the detection is indicated by the change in colour of the fabric. The colour changes are based on alizarin - metal complex formation.