Robust Flower‐Like TiO₂@Cotton Fabrics with Special Wettability for Effective Self‐Cleaning and Versatile Oil/Water Separation

Abstract

Inspired by the hierarchical structure of the mastoid on the micrometer and nanometer scale and the waxy crystals of the mastoid on natural lotus surfaces, a facile one-step hydrothermal strategy is developed to coat fl ower-like hierarchical TiO 2 micro/nanoparticles onto cotton fabric substrates (TiO 2 @ Cotton). Furthermore, robust superhydrophobic TiO 2 @Cotton surfaces are constructed by the combination of hierarchical structure creation and low surface energy material modifi cation, which allows versatility for self-cleaning, laundering durability, and oil/water separation. Compared with hydrophobic cotton fabric, the TiO 2 @Cotton exhibits a superior antiwetting and selfcleaning property with a contact angle (CA) lager than 160° and a sliding angle lower than 5°. The superhydrophobic TiO 2 @Cotton shows excellent laundering durability against mechanical abrasion without an apparent reduction of the water contact angle. Moreover, the micro/nanoscale hierarchical structured cotton fabrics with special wettability are demonstrated to selectively collect oil from oil/water mixtures effi ciently under various conditions (e.g., fl oating oil layer or underwater oil droplet or even oil/water mixtures). In addition, it is expected that this facile strategy can be widely used to construct multifunctional fabrics with excellent self-cleaning, laundering durability, and oil/water separation. The work would also be helpful to design and develop new underwater superoleophobic/superoleophilic materials and microfl uidic management devices.

Reduced graphene oxide-coated cotton as an efficient absorbent in oil-water separation

“…It is worthy to mention that rGO@cotton showed excellent absorption capacity for engine oil, pump oil, acetone, propanol, DMF, and NMP compare to previously reported data found in the literature. The sorption capacity of rGO@cotton is comparable to that of robust and durable cotton fabrics [40], flower-like TiO 2 @cotton [61], and superhydrophobic cotton [6].…”

Durable antibacterial and UV-protective Ag/TiO₂@fabrics for sustainable biomedical application

“…39 Briefly, 0.75 g (2 mM) of potassium titanium oxalate was dissolved in deionized water (15 mL), then sonicated for 5 min in an ultrasonic cleaning machine (KQ100E; Kunshan Ultrasonic Instrument Co., Ltd., Kunshan City, People's Republic of China) with a frequency of 40 kHz, followed by adding diethylene glycol (20 mL) under vigorous magnetic stirring. After stirring for 20 min, the mixed solution was transferred into a teflon-lined stainless steel vessel (100 mL).…”

Designing durable and flexible superhydrophobic coatings and its application in oil purification

“…Durable superhydrophobic coatings have been reported recently, 26 such as acrylic polyurethane based coating, 27 textured surface obtained by chemical etching, 28,29 surfaces template from innately microstructured hydrogel matrix, 30 block-copolymer-based thin-film patterning, 31 combination of rodlike palygorskite and organosilanes via spray-coating, 32 fluorine-free polysiloxane/multiwalled carbon nanotubes, 33 titanium dioxide materials with special wettability, 34 or various coatings fabricated on fabrics/sponges/cotton. [35][36][37][38][39][40] However, most of the reported surfaces are not durable enough, as they can only resist abrasion against wipes, 28 fine sandpaper (e.g., 800, 1000, 2000 grid), mild droplets/sand impinging, 30,31 or were easily disabled after a short distance (i.e., less than 5 m) of abrasion. 27,29,[41][42][43] Besides, the mechanical stability may be simply due to the fact that the coating thickness is too thick to be worn out completely to expose the substrate surface underneath the superhydrophobic coating.…”