Fabrication of highly amphiphobic paper using pulp debonder

As a biodegradable, inexpensive and universally accessible material, paper is used widely in many applications, including packaging, office supplies and household products. However, the hydrophilic and oleophilic nature of paper often limits its use in applications that involve direct contact with liquids. The main purpose of this study was to create highly amphiphobic paper for products such as low cost medical testing strips, liquid packaging, and breathable and disposable medical apparel. A three-step process was developed to create paper with contact angles greater than 150° for water and motor oil, and greater than 140° for n-hexadecane. First, a commercially available debonding agent was used to manipulate the dimensions of the fiber network through efficient fines removal and modification of inter-fiber hydrogen bonding. Then an oxygen plasma was used to create nano-scale roughness on the micrometer-sized fibers and to remove residual fines that were blocking the inter-fiber pores. Finally, the paper was immersed in a fluorosilane solution to obtain a thin, low surface energy coating. XPS, SEM, mercury porosimetry and profilometry were used to evaluate changes in the fiber network after each step. This study marks the first report that uses debonder agents specifically to modify the anti-wetting properties of paper substrates by controlling the topology of the fiber network. The processes used in this procedure are simple, cost effective and amenable to scale-up.