Surface modification of cellulose-based paper, which displays roll-off properties for water and oils (surface tension ≥23.8 mN·m) and good repellency toward n-heptane (20.1 mN·m), is reported. Droplets of water, diiodomethane, motor oil, hexadecane, and decane all "bead up", i.e., exhibit high contact angles, and roll off the treated surface under the influence of gravity. Unlike widely used approaches that rely on the deposition of nanoparticles or electrospun nanofibers to create superamphiphobic surfaces, our method generates a hierarchical structure as an inherent property of the substrate and displays good adhesion between the film and substrate. The two-step combination of plasma etching and vapor deposition used in this study enables fine-tuning of the nanoscale roughness and thereby facilitates enhanced fundamental understanding of the effect of micro- and nanoscale roughness on the paper wetting properties. The surfaces maintain their "roll-off" properties after dynamic impact tests, demonstrating their mechanical robustness. Furthermore, the superamphiphobic paper has high gas permeability due to pore-volume enhancement by plasma etching but maintains the mechanical flexibility and strength of untreated paper, despite the presence of nanostructures. The unique combination of the chemical and physical properties of the resulting superamphiphobic paper is of practical interest for a range of applications such as breathable and disposable medical apparel, antifouling biomedical devices, antifingerprint paper, liquid packaging, microfluidic devices, and medical testing strips through a simple surface etching plus coating process.

No abstract

No abstract

No abstract

Hydrophilic-oleophobic surfaces have attracted significant attention recently due to their potential use in technologies ranging from oil-water separation to self-cleaning surfaces. However, existing methods rely heavily on fluorinated coating materials, which are harmful to the environment. In this manuscript, a simple, solution based method to fabricate oleophobic paper with tunable hydrophilicity using a non-fluorinated material is reported for the first time. Wetting control is achieved by paper surface modification using a thin film of hydrolyzed methyltrimethoxysilane (MTMS). Hydrophilicity is tuned by adjusting the sonication time during MTMS hydrolysis. 29 Si NMR and ATR-FTIR analyses reveal that the change in hydrophilicity is caused by varying the concentration of polar silanol groups in the MTMS solution and, ultimately, on the film surface. The modified paper displays wetting behavior ranging from superhydrophilic/oleophobic (immediate water absorption; motor oil contact angle, 64.2°±1.4 o ) to amphiphobic (water contact angle 85.2°±3.4°; motor oil contact angle 61.2°±2.5°) as a function of hydrolysis time. For all surface-modified samples, no absorption of motor oil is observed for several weeks, indicating stable oil resistance. Based upon results from SEM, optical profilometry, and air permeability, the intrinsic porosity of paper is also largely retained after coating. 9, 29, 30 fluorinated polymer brushes, 10, 11, 30-32 fluoroalkylated flipflop-type silane coupling agents, 33 fluorinated block copolymers 33 and blends of fluorinated and non-fluorinated polymers.