Superhydrophobic and Conductive Foams with Antifouling and Oil-Water Separation Properties

Magnetic Hyperporous Elastic Material with Excellent Fatigue Resistance and Oil Retention for Oil-Water Separation

Oily wastewater has caused serious threats to the environment; thus, high-performance absorbing materials for effective oil-water separation technology have attracted increasing attention. Herein, we develop a magnetic, hydrophobic, and lipophilic hyperporous elastic material (HEM) templated by high internal phase emulsions (HIPE), in which free-radical polymerization of butyl acrylate (BA) and divinylbenzene (DVB) is employed in the presence of poly(dimethylsiloxane) (PDMS), lecithin surfactant, and modified Fe3O4 nanoparticles. The adoption of the emulsion template with nanoparticles as both stabilizers and cross-linkers endows the HEM with biomimetic hierarchical open-cell micropores and elastic cross-linked networks, generating an oil absorbent with outstanding mechanical stability. Compressive fatigue resistance of the HEM is demonstrated to endure 2000 mechanical cycles without plastic deformation or strength degradation. By exploiting the synergistic effect of hierarchical structures and low-surface-energy components, the resulting HEM also possesses excellent and robust hydrophobicity (water contact angle of 164°) and good oil absorption capacity, in which Fe3O4 nanoparticles lead to convenient magnetically controlled oil recyclability as well. Notably, the unique biomimetic microporous structure demonstrates superior oil retention capacity (>95% at 1000 rpm and >60% at 10,000 rpm) over the state-of-the-art porous materials for a diverse variety of oils to reduce the risk of secondary oil leakage, along with good recoverability by squeezing owing to the excellent compression resilience. These excellent performances of our HEM provide broad prospects for practical applications in oil-water separation, energy conversion, and smart soft robotics.

The antifouling mechanism and application of bio-inspired superwetting surfaces with effective antifouling performance

With the rapid development of industries, the issue of pollution on Earth has become increasingly severe. This has led to the deterioration of various surfaces, rendering them ineffective for their intended purposes. Examples of such surfaces include oil rigs, seawater intakes, and more. A variety of functional surface techniques have been created to address these issues, including superwetting surfaces, antifouling coatings, nano-polymer composite materials, etc. They primarily exploit the membrane's surface properties and hydration layer to improve the antifouling property. In recent years, biomimetic superwetting surfaces with non-toxic and environmental characteristics have garnered massive attention, greatly aiding in solving the problem of pollution. In this work, a detailed presentation of antifouling superwetting materials was made, including superhydrophobic surface, superhydrophilic surface, and superhydrophilic/underwater superoleophobic surface, along with the antifouling mechanisms. Then, the applications of the superwetting antifouling materials in antifouling domain were addressed in depth.

Metal and Metal Oxide Nanoparticle Incorporation in Polyurethane Foams: A Solution for Future Antimicrobial Materials?

With the technological developments witnessed in recent decades, nanotechnology and nanomaterials have found uses in several common applications and products we encounter daily. On the other hand, polyurethane (PU) foams represent an extremely versatile material, being widely recognized for their extensive application possibilities and possessing a multitude of fundamental attributes that enhance their broad usability across various application fields. By combining the versatility of PU with the antimicrobial properties of nanoparticles, this emerging field holds promise for addressing the urgent need for effective antimicrobial materials in various applications. In this comprehensive review, we explore the synthesis methods, properties and applications of these nanocomposite materials, shedding light on their potential role in safeguarding public health and environmental sustainability. The main focus is on PU foams containing metal and metal oxide nanoparticles, but a brief presentation of the progress documented in the last few years regarding other antimicrobial nanomaterials incorporated into such foams is also given within this review in order to obtain a larger image of the possibilities to develop improved PU foams.

Flexible Puncture-Resistant Composites for Antistabbing Applications: Silica and Silicon Carbide Nanoparticle-/TPU-Coated Aramid Fabrics

In harsh environments, it is crucial to design personal protective materials that possess both puncture/cut resistance and chemical resistance. In order to fulfill these requirements, this study introduces an innovative approach that combines hydrophobically modified rigid nanoparticles with thermoplastic polyurethane elastomers. These materials are then laminated with high-performance aramid fabrics through a scraping process, resulting in a multifunctional composite with puncture/cut resistance, superhydrophobicity, self-cleaning properties, and acid/alkali resistance. The quasi-static puncture tests conducted reveal the remarkable performance of the composite. The maximum spike puncture resistance reaches 267.62 N, which is 17.14 times higher than that of the pure fabric (15.61 N). Similarly, the maximum knife puncture resistance reaches 115.02 N, exhibiting a 5.01 times increase compared to that of the pure aramid fabric (22.97 N). Furthermore, the results obtained from the yarn pull-out, fabric burst strength, and tearing experiments demonstrate that the incorporation of rigid nanoparticles significantly enhances the friction between the yarns, enabling a greater number of yarns to participate in the dissipation of impact energy. As a result, the puncture resistance of the fabric is greatly improved. Significantly, the composite exhibits sustained superhydrophobicity even after exposure to harsh chemicals such as concentrated sulfuric acid and sodium hydroxide as well as undergoing cyclic mechanical wear. These findings highlight the composite's exceptional durability and resistance to corrosion. Overall, this study offers insights and methods for the development of multifunctional flexible puncture-resistant equipment for individuals.

Advances in the research of carbon-, silicon-, and polymer-based superhydrophobic nanomaterials: Synthesis and potential application

With the rapid development of science and technology, superhydrophobic nanomaterials have become one of the hot topics from various subjects. Due to their distinct properties, such as superhydrophobicity, anti-icing and corrosion resistance, superhydrophobic nanomaterials are widely used in industry, agriculture, defense, medicine and other fields. Hence, the development of superhydrophobic materials with superior performance, economical, practical features, and environment-friendly properties are extremely important for industrial development and environmental protection. Aimed to provide a scientific and theoretical basis for the subsequent study on the preparation of composite superhydrophobic nanomaterials, this paper reviewed the latest progress in the research of superhydrophobic surface wettability and the theory of superhydrophobicity, summarized and analyzed the latest development of carbon-based, silicon-based and polymer-based superhydrophobic nanomaterials in terms of their synthesis, modification, properties and structure sizes (diameters), discussed the problems and unique application prospects of carbon-based, silicon-based and polymer-based superhydrophobic nanomaterials.

A Single-Step Route to Robust and Fluorine-Free Superhydrophobic Coatings via Aerosol-Assisted Chemical Vapor Deposition

Robust fluorine-free superhydrophobic films were produced from a mixture of two fatty acids (stearic acid and palmitic acid), SiO₂ nanoparticles, and polydimethylsiloxane. These simple and nontoxic compounds were deposited via aerosol-assisted chemical vapor deposition to provide the rough topography required for superhydrophobicity, formed through island growth of the aggregates. The optimum conditions for well-adhered superhydrophobic films produced films with a highly textured morphology, which possessed a water contact angle of 162 ± 2° and a sliding angle of <5°. Superhydrophobicity was maintained after ultraviolet exposure (14 days at 365 nm), heat treatment (5 h at 300 °C and 5 h at 400 °C), 300 tape peel cycles, and exposure to ethanol and toluene (5 h each).