Superhydrophobic Cotton Fabrics Research Articles

Fabrication and characterization of a novel superhydrophobic cotton fabric with integrated 3D graphene-Ag/TiO2 aerogel for superior antibacterial performance, oil-water separation, and enhanced durability

This research delineates the pioneering development of a superhydrophobic cotton textile, ingeniously integrated with a three-dimensional graphene-Ag/TiO2 aerogel. The study meticulously details the fabrication process, structural characterization, and diverse industrial applications of this advanced textile. The fabric demonstrates exceptional hydrophobicity, evidenced by a water contact angle (WCA) of 161.8°. Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Raman spectra, and Fourier Transform Infrared Spectroscopy (FTIR) substantiate the micromorphological and chemical alterations of the cotton surface, highlighting the successful reduction of graphene oxide (GO) and incorporation of polydimethylsiloxane (PDMS), TiO2, and Ag nanoparticles. The fabric’s antibacterial efficacy is rigorously established, boasting an impressive antibacterial rate that surpasses 99.99% against E. coli and S. aureus. Additionally, the fabric demonstrates its capability to discern between oil and water with remarkable finesse, showcasing a separation efficiency that exceeds 98%, even under extreme chemical conditions. The textile also exhibits excellent self-cleaning, washing, and chemical durability, alongside robust antistatic properties. Despite a marginal decrease in air permeability relative to raw cotton, the fabric’s multifunctional capabilities significantly compensate for this trade-off. The unique three-dimensional architecture of the hybrid graphene-Ag/TiO2 aerogel (AT-HGA) modified cotton marks a substantial advancement in bio-based material science, with broad potential applications in functional garments, medical textiles, and various industrial sectors.

Durable superhydrophobic cotton fabrics with electromagnetic wave absorption based on MoS2/RGO composites

Durable superhydrophobic cotton fabrics with electromagnetic wave absorption based on MoS2/RGO composites

Fabrication of versatile and durable superhydrophobic cotton fabrics using PTA-Ala adhesive

In recent years, the preparation of functional textiles based on polyphenols adhesion has received extensive attention and research. However, polyphenols are prone to peroxidation during oxidative polymerization, which can compromise the interfacial adhesion of their monomers. Reintroducing reactive functional groups after oxidative polymerization of polyphenols may potentially compensate for the lost interfacial adhesion while increasing cohesion. In this paper, L-alanine (Ala) is introduced into poly (tannic acid) (PTA) solution to generate the PTA-Ala via Michael addition and Schiff base reaction. Original cotton fabrics are modified with PTA-Ala solution to enhance adhesion strength between the fabrics and subsequent functional modifiers. A silver nanowire network is then incorporated to increase the surface roughness through tannic acid reduction. Finally, polydimethylsiloxane is applied to reduce fabric surface energy, resulting in superhydrophobic multifunctional OH-PDMS/Ag/PTA-Ala/cotton fabrics. The finished cotton fabric exhibits a water contact angle of 166.7 ± 1.9° and a rolling angle of 5 ± 0.5°. Moreover, the fabric features diverse functionalities such as oil-water separation, photothermal conversion, antimicrobial properties, water collection, and anti-icing capabilities, alongside excellent durability and self-healing properties that extend its service life. This finished cotton fabric demonstrates promising applications in oil pollution control, outdoor clothing and medical protection, highlighting its broad across various industries.

Durable self-cleaning superhydrophobic cotton fabrics for wearable textiles

Cotton fabric is widely used in various industrial goods due to its ability to enhance aesthetic appeal, but preserving its shine and genuine appearance presents a significant challenge. In this work, a durable self-cleaning superhydrophobic surface suitable for wearable textiles was achieved on cotton fabrics by applying a composite coating of stearic acid-modified titanium oxide (TiO2) nanoparticles and polydimethylsiloxane (PDMS) through a simple dip/spray coating technique. The fabric surface displayed an exceptional water contact angle (WCA) of 165 ± 2° and a minimal slide angle (SA) of approximately 2°, demonstrating outstanding water repellency and sliding characteristics. The surface exhibited impressive self-cleaning abilities for both dust particles and muddy water. The coated cloth maintained its exceptional superhydrophobic properties even after being subjected to 40 abrasion cycles, 30 adhesive tape peels, nearly 60 min of ultrasound treatment, and 30 washing cycles. Additionally, the as-coated cotton showed excellent chemical stability, tensile strength, flexibility, air permeability and breathability. The model trials with a baby doll have proven the high possibility of commercializing self-cleaning clothing in this research.

Preparation and properties of sustainable superhydrophobic cotton fabrics modified with lignin nanoparticles, tannic acid and methyltrimethoxysilane

Functional superhydrophobic cotton fabrics find extensive applications in both textile and non-textile domains. Nonetheless, fabric treatment typically relies on fluorine-containing compounds, inorganic nanoparticles and potentially hazardous organic solvents, posing environmental risks during fabrication and disposal. To address this issue, endeavours are underway to develop environmentally sustainable and cost-effective methods and materials for imparting superhydrophobic properties to cotton fabric surfaces. Here, we prepared lignin nanoparticles (LNP) utilising deep eutectic solvents and facilitated their surface adhesion to cotton fabrics through the self-polymerisation of tannic acid (TA) under alkaline conditions for the construction of micro-/nanostructures on the fabric surface. Subsequently, methyltrimethoxysilane (MTMS) was employed to confer superhydrophobic properties to the fabrics using a combination of thermal chemical vapour deposition techniques, resulting in a contact angle of approximately 164.3° and a sliding angle of 8.52°. Owing to the combined effect of TA and LNP, the modified fabrics exhibited excellent ultraviolet (UV) shielding ability (UV transmittance < 1 %, UV protection factor = 50 + ) and photothermal conversion (54.2 °C in 150 s). In short, micro-/nanostructures with surface hydrophilicity were constructed on the surface of cotton fabrics using two hydrophilic biomaterials, i.e. TA, which is similar to polydopamine but lighter in colour and less expensive, and LNP as sustainable colloidal particles. Subsequently, their surface roughness was further enhanced, and superhydrophobic properties were imparted through modification with the low surface energy substance MTMS. This method not only promotes the high-value utilisation of lignin but also serves as a reference for constructing superhydrophobic structures using biomass hydrophilic materials on cellulose substrates. The prepared superhydrophobic fabric suggests potential applications in water and stain repellence, self-cleaning, outdoor UV protection and the management of marine oil spill pollution.

A Fluorine-Free Superhydrophobic Cotton Fabric Prepared by a Green and Energy-Saving Method Is Used for Long-Lasting and Efficient Oil-Water Separation.

Oil pollution poses a major threat to the ecosystem. Therefore, it is necessary to develop a material that can separate oil and water efficiently. Fabrics have a wide range of applications due to their economic simplicity and degradability. However, the existing methods of preparing superhydrophobic fabrics are complicated and energy-consuming, which are difficult to meet the concept of green and sustainable development. Moreover, various modified fabrics are less stable in harsh environments and do not have the ability to efficiently separate oil and water over a long period of time. In this paper, superhydrophobic zirconium dioxide (ZrO2) obtained from the modification of stearic acid was loaded onto the fabric surface using the adhesive properties of PDMS, resulting in the preparation of superhydrophobic/superoleophilic STA-ZrO2 fabrics. The fabric is made without involving time-consuming and energy-consuming heating, and it offers efficient oil-water separation, good stability and excellent recyclability. Truly in line with the concept of sustainable development.

Synthesis and Characterization of ZnO Nanoparticles and Their Application on Cotton Fabrics to Obtain Superhydrophobic Surfaces

حضرت جسيمات أوكسيد الزنك النانوية ZnO (NPs) بطريقة كيميائية رطبة عند درجتي حرارة مختلفتين (30-90) ̊C باستخدام كلوريد الزنك كبادئ في وسط مائي. تم توصيف جسيمات أوكسيد الزنك النانوي المحضر باستخدام المجهر الإلكتروني الماسح (SEM) ,حيود الأشعة السينية (XRD) ، وطيف الأشعة تحت الحمراء (FTIR) ، أشارت أنماط الأشعة السينية الى بنية سداسية (wurtizte) بمتوسط حجم بلوري (19.5-23nm) لجسيمات أوكسيد الزنك المحضرة عند درجتي الحرارة (30-90 ̊C)على التوالي. أظهرت صور المجهر الالكتروني الماسح أنه مع زيادة درجة الحرارة ، تغير شكل جسيمات أوكسيد الزنك النانوي من الأسلاك النانوية إلى االشكل الكروي . لتصنيع قماش قطني فائق المقاومة للماء. تم غمر القماش في محلول غروواني لأوكسيد الزنك بتركيز (1٪) ,ثم تعديله لاحقًا بحمض الشمع . تم توصيف القماش القطني المعالج باستخدام المجهر الإلكتروني الماسح (SEM) واختبار زاوية التماس (CA) .أظهرت نتائج المجهر الالكتروني الماسح أن جسيمات أوكسيد الزنك النانوي المحضر عند(90 ̊C) خلق خشونة على سطح القطن أفضل من جسيمات أكسيد الزنك النانوي المحضرعند (30 ̊C). أظهرت نتائج اختبار زاوية التماس CA خصائص فائقة الكره للماء لعينات أوكسيد الزنك النانوي المحضر عند(90 ̊C) ، بينما أظهرت عينات أوكسيد الزنك النانوي المحضر عند(30 ̊C) خصائص كارهة للماء فقط بعد التعديل بحمض الشمع. تم استخدام تراكيز مختلفة من حمض الشمع لجعل سطح أوكسيد الزنك كارهاً للماء. أظهرت نتائج زاوية التماس (CA) أن القماش القطني المعالج بأوكسيد الزنك النانوي المحضر عند الدرجة (90 ̊C) المعدل ب 1٪ وزناً من حمض الشمع أظهر سطحاً فائق الكره للماء بزاوية تماس (CA=154̊ ).

A facile method to fabricate superhydrophobic cotton fabrics finished using water-proof and antibacterial agent

Superhydrophobic emulsions (SHEs) based on fatty acids (stearic, palmitic, myristic and lauric acids)-melamine (FAMEs) was synthesized without emulsifier and applied on cotton fabric. The superhydrophobic compounds (FAME1, FAME2, FAME3 and FAME4) were successfully prepared on the basis of the reaction between fatty acid anhydrides and melamine. The chemical structures of the prepared FAME compounds were investigated using FTIR,1HNMR spectroscopy and elemental analysis. The cotton fabric samples were treated with the prepared emulsions using different concentrations in the range of 20 – 60 g/L. Hydrostatic pressure, water contact angle (WCA) and water permeability tests were performed on the treated samples. It was shown that super hydrophobicity of the fabric treated with stearic acid-melamine emulsion (60 g/L) recorded the best results due to the combined effect of surface roughness imparted by melamine and the low surface energy of stearic acid. Furthermore, antibacterial agent Biochrol WS1 in concentrations (2 and 8%) was simultaneously applied to the treated samples. The Kirby-Bauer disc diffusion method was used to estimate the biological activity of the treated cotton. Two strains of bacteria: Gram-positive (Bacillus subtilis - Staphylococcus aureus) and Gram-negative (Escherichia coli-Pseudomonas aeruginosa) were used for this purpose. The tensile strength of treated samples was measured as well. The results showed that the antibacterial and water-proof fabrics can be achieved by applying selected material without significant changes on their comfort properties.

Surface engineering toward self-cleaning and color-fastness photonic textiles

Structural coloration using photonic crystals (PCs) has emerged as a significant approach in the textile industry due to their environmental contributions. Cellulose nanocrystals (CNCs), crucial bio-PC with abundant resources and renewability, have shown great potential as photonic dyeing agents. However, due to the high water sensitivity, addressing the anti-washing performance and color fastness becomes important yet challenging. Here, we demonstrate a two-step approach for preparing superhydrophobic and iridescent cotton fabrics (SICFs). By co-assembling CNCs and poly (ethylene glycol) diacrylate under various sonication durations, flexible and tunable chiral nematic nanostructures are constructed on the cotton fabric surfaces. Additionally, surface superhydrophobicity and self-cleaning functions are imparted through the grafting of hyperbranched polyglycidol and 1H, 1H′, 2H, 2H′-perfluorodecyltrichlorosilane. Compared to hydrophilic structural-color counterparts, the resulting SICFs exhibit robust color fastness, surface anti-wettability, and water stability. The molecular design of this work provides new insights to development of eco-friendly textile industry.

All-weather self-healing superhydrophobic coating functionalized with the cauliflower-like PPy and TiN on cotton fabric for efficient oil-water separation

Superhydrophobic materials are currently undergoing rapid development in various industries, with increasing attention being paid to their service life. Herein, we report an all-weather self-healing superhydrophobic cotton fabric based on photothermal and Joule-heating effects, which can be used for efficient oil-water separation. With the assistance of Safranine T, unique cauliflower-like polypyrrole (PPy) was prepared. Subsequently, titanium nitride (TiN) was loaded to enhance the photothermal performance of the fabric, and polydimethylsiloxane (PDMS) was grafted onto surface to improve the water repellency of PPy@TiN/PDMS fabric. The fabric not only has strong light absorption in visible-near infrared region, but also has good Joule-heating effect, up to 116.3 °C (light intensity of 5 sun) and 128.5 °C (voltage of 8 V). Due to unique all-weather heating performance, the migration of low surface energy PDMS chains is accelerated, so that the PPy@TiN/PDMS fabric after air plasma etching and oxydation can quickly heal its water contact angle (WCA) to 156° under light or low voltage conditions. Additionally, the fabric demonstrates an outstanding performance for the separation of various oil-water mixtures and in multiple cycle separation experiments. This study presents a novel approach for extending the longevity of superhydrophobicity and addressing the issue of waste oil treatment.

Stable and Durable Superhydrophobic Cotton Fabrics Prepared via a Simple 1,4-Conjugate Addition Reaction for Ultrahigh Efficient Oil-Water Separation.

Superhydrophobic materials used for oil-water separation have received wide attention. However, the simple and low-cost strategy for making durable superhydrophobic materials remains a major challenge. Here, this work reports that stable and durable superhydrophobic cotton fabrics can be prepared using a simple two-step impregnation process. Silica nanoparticles are surface modified by hydrolysis condensation of 3-aminopropyltrimethoxysilane (APTMS). 1,4-conjugate addition reaction between the acrylic group of cross-linking agent pentaerythritol triacrylate (PETA) and the amino group of octadecylamine (ODA) forms a covalent cross-linked rough network structure. The long hydrophobic chain of ODA makes the cotton fabric exhibit excellent superhydrophobic properties, and the water contact angle (WCA) of the fabric surface reaches 158°. The modified cotton fabric has good physical and chemical stability, self-cleaning, and anti-fouling. At the same time, the modified fabric shows excellent oil/water separation efficiency (98.16% after 20 cycles) and ultrahigh separation flux (15413.63 L m-2 h-1) due to its superhydrophobicity, superoleophilicity, and inherent porous structure. The method provides a broad prospect in the future diversification applications of oil/water separation and oil spill cleaning.

A novel superhydrophobic cotton fabric constructed by rosin-based polymer and nano-hydroxyapatite for oil/water separation

The discharge of oily wastewater in daily life and industrial production has inflicted severe damage on the natural environment and human health. Therefore, it is urgent to separate oily wastewater. Herein, a rosin-based polymer (poly(DR-DMP)) was prepared by polymerization of double-bond functionalized rosin acid (DR) and diethyl(methacryloyloxymethyl)phosphonate (DMP). And a novel superhydrophobic cotton fabric was constructed by poly(DR-DMP) and nano-hydroxyapatite (HAP). The water contact angle (WCA) and sliding angle (SA) of poly(DR-DMP)@HAP fabric achieved values of 162° and 8°, respectively. Meanwhile, the poly(DR-DMP)@HAP fabric had excellent separation performance for several oil/water mixtures, with oil fluxes up to 8941.83 L·m−2·h−1 and separation efficiency (more than 95.35 %). Furthermore, the poly(DR-DMP)@HAP fabric exhibited excellent separation performance for various emulsions, and also had excellent superhydrophobicity and oil/water separation performance after mechanical and chemical treatment. Through the vertical flame test (VFT) and thermogravimetric analysis (TG), the results showed that poly(DR-DMP)@HAP fabric had a certain flame retardancy. Overall, poly(DR-DMP)@HAP fabric had excellent superhydrophobicity, self-cleaning, oil/water separation and flame retardancy, which had great application potential in oil/water separation.

Durable, multifunctional cotton fabrics with in situ deposited micro/nanomaterials for effective self–cleaning, oil–water separation and antibacterial activity

The facile modification of cotton fabrics for excellent self–cleaning, oil–water separation, and antibacterial activity is of great interest for multifunctional requirements. Herein, a durable, robust, fluorine–free multifunctional cotton fabric was fabricated via in-situ growing zeolitic imidazolate framework-67 (ZIF-67) on the cotton surface, followed by depositing hydrophobic SiO2 (H-SiO2) nanoparticles synthesized via an improved Stöber reaction. Meanwhile, the abundant hydroxyls of the cotton fabrics provided the necessary ion interaction sites for the uniform deposition of micro/nanomaterials, confirmed by the visualized Raman imaging technology. The resultant H-SiO2/ZIF-67@cotton fabric exhibited superhydrophobicity with a water contact angle of 159° and versatile self–cleaning, antifouling, oil–water separation, as well as prominent antibacterial activity against S. aureus and E. coli. At the same time, the superhydrophobic cotton fabric possessed excellent durability and stability against harsh environments, including abrasion, washing, acid, base, salt, and organic solvents. This facile technique can be applied for large-scale production of multifunctional superhydrophobic cotton fabrics due to its easy operation, low cost, and environmental friendliness.

Robust superhydrophobic cotton fabric based on dual-sized silica particles with self-healing nature

Improving the durability of wear-resistant superhydrophobic surfaces is crucial for their practical use. To tackle this, research is now delving into self-healing superhydrophobic surfaces. In our study, we developed superhydrophobic cotton fabrics by embedding nano-silica particles, micro-silica powder, and polydimethylsiloxane (PDMS) using a dipping method. This innovative design grants the SiO2/PDMS cotton fabric remarkable superhydrophobicity, reflected by a water contact angle of 155°. Moreover, the PDMS was stored in the amorphous areas of cellulose of cotton fabrics, attaching to the fiber surface and playing a role in connecting micro-blocks and nano-particles. This causes a self-diffusion of PDMS molecules in these fabrics, allowing the surface to regain its superhydrophobicity even after abrasion damage. Impressively, this self-healing property can be renewed at least 8 times, showcasing the fabric's resilience. Moreover, these superhydrophobic cotton fabrics exhibit outstanding self-cleaning abilities and repel various substances such as blood, milk, cola, and tea. This resilience, coupled with its simplicity, low cost-effectiveness, and eco-friendliness, makes this coating highly promising for applications across construction, chemical, and medical fields. Our study also delves into understanding the self-healing mechanism of the SiO2/PDMS cotton fabric, offering insights into their long-term performance and potential advancements in this field.

Facile fabrication of durable and breathable superhydrophobic cotton fabric for self-cleaning, UV-blocking, anti-icing, and photothermal de-icing

Facile fabrication of durable and breathable superhydrophobic cotton fabric for self-cleaning, UV-blocking, anti-icing, and photothermal de-icing

Durable superhydrophobic cotton fabrics based on fluorinated alternating copolymer and silica nanoparticle: Preparation and oil-water separation

The development of superhydrophobic materials has attracted great attention due to their promising potential in a variety of areas including oil–water separation. In this work, durable and robust superhydrophobic cotton fabrics based on fluorinated alternating copolymer and silica nanoparticle are prepared. Silica nanoparticles are in-situ produced and immobilized onto the surface of poly dopamine (PDA) wrapped cotton fabrics, then modified by fluorinated block copolymer (AB2)nA-b-PIPMSAm, followed by removing the iodine on the polymers, to prepare superhydrophobic cotton fabrics with water contact angle up to 160.8°. The prepared cotton fabrics are durable, displaying excellent resistance to varying organic solvents, acids, alkalis, hot water, sonication and mechanical abrasion. High separation efficiency (maximum 99.6 %) and satisfying reusability for continuous separation of oil/water mixtures are achieved. The separation efficiency for trichloromethane/water mixtures is still as high as 94 % even after 50 times of repetitive separation. In addition, water-in-oil emulsion can be also efficiently handled, displaying high practical application potential.

High‐potent trifunctional polybenzoxazines coatings for superhydrophobic cotton fabrics and mild steel corrosion protection applications

AbstractNew trifunctional polybenzoxazines were developed and utilized as a high‐potent coating material for superhydrophobic cotton fabrics and mild steel corrosion protection applications. New trifunctional benzoxazines resin have been synthesized using trihydroxytriphenylmethane (TTM) with dimethylaminopropylamine (dmapa), 1‐(3‐aminopropyl)imidazole (ipa) and aminoethoxyethanol (aee) as amine sources with paraformaldehyde through Mannich condensation. The structural confirmation of synthesized benzoxazines was ascertained by spectral studies. The ring opening polymerization of TTM‐Bzs was studied using DSC analysis. All the three TTM‐Bz monomers show curing temperature lower than 210°C. The thermo‐stability and water contact angle (WCA) of polybenzoxazines were studied using thermogravimetric analysis and goniometer, respectively. Among the TTM‐PBz studied, the poly(dmapa) exhibit better thermo‐stability and hydrophobic behavior when compared to rest of the synthesized polybenzoxazines. Poly(TTM‐dmapa)‐coated cotton fabric exhibits the superhydrophobic behavior and mild steel (MS)‐coated specimen possesses the higher charge transfer resistance value of 3.47 × 107 Ω cm2. It was also inferred that all the TTM‐PBz‐coated MS specimens exhibit higher corrosion protection behavior as well as good thermo‐stability and hydrophobic nature. Further, the obtained results suggested that these materials can be suitably exploited for hydrophobic anticorrosion applications with improved performance and enhanced longevity.

Superhydrophobic cotton fabric based on aqueous paint for passive daytime radiative cooling

Passive daytime radiative cooling (PDRC) is a technology that dissipates excess heat to outer space without any energy consumption. Numerous PDRC materials have been developed recently. However, hazardous organic solvents are often used in the fabrication process of these PDRC materials, and most PDRC materials are easily contaminated. In this study, a new scalable eco-friendly aqueous paint without volatile organic compounds (VOCs) was developed by combining fluoroacrylate copolymer with high-scattering polysilsesquioxane particles. The solar reflectivity and emissivity of the cotton fabric coated with the aqueous paint (PDRC@CF) are significantly enhanced (reach 92.2 % and 92.7 %, respectively) due to the synergistic effect of fluoroacrylate copolymer and polysilsesquioxane. The PDRC@CF has a remarkable radiative cooling effect with a surface temperature 5.7 °C lower than the ambient air and 16.1 °C lower than the pristine cotton fabric under direct sunlight exposure. Moreover, the aqueous paint endows the PDRC@CF with a washable superhydrophobic surface, whose water contact angle is 150.1°and sliding angle is 2.3°, possessing excellent self-cleaning performance. The PDRC@CF effectively combining the properties of anti-fouling and radiative cooling, can be applied to outdoor product protection and other energy-efficient cooling fields.

Silica-Based Superhydrophobic and Superoleophilic Cotton Fabric with Enhanced Self-Cleaning Properties for Oil-Water Separation and Methylene Blue Degradation.

Superhydrophobic textiles with multifunctional characteristics are highly desired and have attracted tremendous research attention. This research employs a simple dip-coating method to obtain a fluorine-free silica-based superhydrophobic and superoleophilic cotton fabric. Pristine cotton fabric is coated with SiO2 nanoparticles and octadecylamine. SiO2 nanoparticles are anchored on the cotton fabric to increase surface roughness, and octadecyl amine lowers the surface energy, turning the hydrophilic cotton fabric into superhydrophobic. The designed cotton fabric exhibits a water contact angle of 159° and a sliding angle of 7°. The prepared cotton fabric is characterized by attenuated total reflectance-fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. In addition, the coated fabric reveals excellent features, including mechanical and chemical stability, superhydrophobicity, superoleophilicity, and the self-cleaning ability. SiO2 nanoparticles and octadecylamine-coated cotton fabric demonstrate exceptional oil-water separation and wastewater remediation performance by degrading the methylene blue solution up to 89% under visible light. The oil-water separation ability is tested against five different oils with more than 90% separation efficiency. This strategy has the advantages of low-cost precursors, a simple and scalable coating method, enhanced superhydrophobicity and superoleophilicity, self-cleaning ability, efficient oil-water separation, and exceptional wastewater remediation performance.

Just Soaping Them: The Simplest Method for Converting Metal Organic Frameworks into Superhydrophobic Materials.

The incorporation of superhydrophobic properties into metal organic framework (MOF) materials is highly desirable to enhance their hydrolytic stability, gas capture selectivity in the presence of humidity and efficiency in oil-water separations, among others. The existing strategies for inducing superhydrophobicity into MOFs have several weaknesses, such as increased cost, utilization of toxic reagents and solvents, applicability for limited MOFs, etc. Here, we report the simplest, most eco-friendly, and cost-effective process to impart superhydrophobicity to MOFs, involving a rapid (90 min) treatment of MOF materials with solutions of sodium oleate, a main component of soap. The method can be applied to both hydrolytically stable and unstable MOFs, with the porosity of modified MOFs approaching, in most cases, that of the pristine materials. Interestingly, this approach was used to isolate superhydrophobic magnetic MOF composites, and one of these materials formed stable liquid marbles, whose motion could be easily guided using an external magnetic field. We also successfully fabricated superhydrophobic MOF-coated cotton fabric and fiber composites. These composites exhibited exceptional oil sorption properties achieving rapid removal of floating crude oil from water, as well as efficient purification of oil-in-water emulsions. They are also regenerable and reusable for multiple sorption processes. Overall, the results described here pave the way for an unprecedented expansion of the family of MOF-based superhydrophobic materials, as virtually any MOF could be converted into a superhydrophobic compound by applying the new synthetic approach.