Preparation of Food Grade Superhydrophobic Coatings Based on Attapulgite Nanorods

Abstract

The superhydrophobic coating is a promising strategy to avoid liquid foods adhesion on the packages and thus significantly reduce their waste and environmental pollution. However, food-grade superhydrophobic coatings are yet limited, especially those with excellent performances. Herein, we report the preparation of food-grade superhydrophobic coatings by the combination of attapulgite (APT) natural nanorods, stearic acid (STA), and hydroxypropyl distarch phosphate (HDP) adhesive. First, a stock suspension was prepared by an esterification reaction between APT and STA. Then, the edible HDP primer and the STA@APT suspension were sequentially spray-coated onto substrates to form the HDP/STA@APT superhydrophobic coatings. The influences of the STA and APT concentrations on the wettability and morphology of the coatings were studied. Due to the hierarchical structure and low surface energy of the coatings assembled by APT and STA, the coatings show excellent static and dynamic superhydrophobicity and self-cleaning performance. In addition, the coatings exhibit good environmental stability and excellent antiadhesive properties toward various liquid foods and are also applicable to various frequently used food packing materials. Thus, we believe that superhydrophobic coatings have a broad application prospect for food packing.

Design of Mineral Oil/Stearic Acid Hybrid Coatings for Reducing Hygroscopicity of Ammonium Nitrate

“…It is worth noting that the peak of the NH 4 + cations in the FT-IR spectrum of AN particles at 3032 cm –1 was weakened and shifted to 3014 cm –1 in the spectrum of the MO/SA@AN particles, indicating the chemical interaction between the MO/SA hybrid coating and NH 4 + in the AN molecule. Compared with SA, the −COOH peaks at 1704 and 1472 cm –1 are significantly weakened on the spectrum of MO/SA@AN, , further indicating chemical interaction between the MO/SA hybrid coating and the AN molecule. These results are also confirmed by a shift of the −OH peak from 3420 to 3395 cm –1 . − …”

Attapulgite-Based Stable Superhydrophobic Coatings for Preventing Rain Attenuation of 5G Radomes

“…The main reason for the poor mechanical stability of superhydrophobic coatings is that their fragile micro/nanostructures are easily damaged by mechanical abrasion. , To date, there has been significant progress in improving the mechanical stability of superhydrophobic coatings. , Designing self-similar micro/nanostructures, , introducing adhesives, , introducing elastic materials − and endowing self-healing functions − are considered to be helpful to improve mechanical stability of superhydrophobic coatings. Among these strategies, the introduction of adhesives is widely favored by researchers, as it is often simple and low-cost .…”

Degradable Superhydrophobic Coatings Using the Solid–Liquid Transition of a Multilayer Structure near Body Temperature

“…For example, in drug delivery, contents are released in response to pH, temperature, light, and redox . Recent advances have led to edible smart surfaces with hydrophobic natural waxes, which are approved by the U.S. Food and Drug Administration, and the brittleness of these coatings has been decreased , with a diatom shell, chitosan, cellulose, ectin, oils, and attapulgite. , Although these coatings would be useful as protective films for drug delivery and edible electronics, , their wax materials have high melting points, e.g., approximately 61–65 °C for beeswax, and cannot be dissolved in the body. Thus, what is needed is a film designed to be degradable in the body.…”