Transparent superhydrophilic cellulose-based coating with anti-fogging, anti-biofouling and oil/water separation properties

It is a huge challenge to design multifunctional superhydrophilic coatings by bio-based raw materials and low carbon emissions in full life cycle. As a green, hydrophilic, low-cost material, cellulose has irreplaceable advantages in the preparation of sustainable superhydrophilic coatings. Here, a novel and large-scale transparent saxifrages-biomimetic superhydrophilic cellulose-based coating (SES) was fabricated by one-step method through blending semi-wet maleic anhydride esterified cellulose (EC) modified cellulose with waterborne styrene-acrylate latex (SAL) and sodium dodecyl sulfate (SDS). The EC was chosen as fillers because of its smallest particle size and the best dispersion of cellulose in waterborne latex. With the addition of SDS, affected by polarity, the hydrophilic head group orientally arranges the cellulose to form a saxifrage-like structure on the surface of coating. The obtained superhydrophilic coating with a static water contact angle of 0° and a waterborne oil contact angle of 157.1°, and the coating remained in a superhydrophilic state after 600 times of wear resistance cycle test. The SES coatings have excellent performance in anti-fogging, biological anti-fouling and oil-water separation, this is due to the synergy effects of the micro-nano scale roughness, high surface energy and hydrophilic group of coating film. The life cycle assessment (LCA) analysis of saxifrages-biomimetic SES superhydrophilic coating proved that the cellulose-based coatings were low-cost, easily prepared, and non-pollution, reducing carbon emission.