Waterproof Coatings Research Articles

Strong, tough self-healing multi-functional sodium alginate-based edible composite coating for banana preservation

Edible coatings are a new green technology for preventing the rotting of fruits and extending their shelf lives. However, during storage, respiratory processes can generate large amounts of water, causing the dissolution of these coating. Furthermore, these coating can be mechanically damaged. Therefore, the development of strong, tough, waterproof and self-healing edible coatings is highly desirable. Herein, gluconolactone was slowly oxidized to generate gluconic acid, which was further used to protonate amino groups in wheat gluten (WG), forming strong electrostatic interactions, hydrogen bonds and ester bonds between soy hull nanocellulose (SHNC) and sodium alginate (SA). The introduction of WG and SHNC improved the mechanical strength, hydrophobicity and water retention of the composite film from 28 MPa, 33.2° ± 1.18° and 19.43° ± 0.83° to 60 MPa, 45.13° ± 1.53° and 41.47° ± 0.96°, respectively. Further, the composite film exhibited excellent self-healing, UV resistance and gas-barrier properties. Banana preservation experiments showed that at 25 °C and 50 % RH, the composite coating effectively slowed the mass loss and softening of bananas, delayed the browning of banana peels and ripening of fruit pulp, and extended the shelf life of bananas to 7 days. Therefore, this study provides a new perspective for the preparation of a new, strong, tough, waterproof and self-healing multi-functional edible coating with high potential for the preservation of perishable fruits.

Evaluation of the permeability of ultrathin parylene AF4 films to determine minimum closed thickness for nanoscale packaging

This study investigated the permeability of parylene AF4 films of varying thickness to determine the minimum closed thickness for nanoscale packaging coatings. In particular, films with thicknesses of 15, 20, and 25 nm were deposited using 1 g of dimer and by adjusting the coating machine’s chamber height. Closeness analysis and electrochemical impedance spectroscopy (EIS) were employed to determine the minimum closed thickness. The closeness analysis results revealed a resistance of 1.35 MΩ (below the 20 MΩ threshold) for the 15 nm film, indicating a nonclosed film; conversely, the 20 and 25 nm films exhibited resistance values of 66.1 and 111.7 MΩ (above the threshold), respectively, indicating closed films. The EIS results indicated that the failure soaking times of the 15, 20, and 25 nm films were approximately <10, 20, and 50 min, respectively. These results indicate that the 20 nm film exhibited the lowest minimum closed thickness and was effective for waterproofing. These findings contribute valuable data toward developing nanoscale waterproof coatings for packaging applications.

Preparation and Characterization of Fluorinated Acrylate and Epoxy Co-Modified Waterborne Polyurethane.

Conventional waterborne polyurethane (WPU) has poor water resistance and poor overall performance, which limits its application in outdoor coatings. A solution to this problem is urgently needed. The introduction of fluorine-containing groups can effectively improve the water resistance of WPU. In this study, a new fluorinated chain extender (HFBMA-HPA) synthesized by free radical copolymerization and epoxy resin (E-44) were used to co-modify WPU, and five waterborne fluorinated polyurethane (WFPU) emulsions with different fluorine contents were prepared by the self-emulsification method. The effects of HFBMA-HPA content on the emulsion particle properties, coating surface properties, mechanical properties, water resistance, thermal stability, and corrosion resistance were investigated. The results showed that the WFPU coating had excellent thermal stability, corrosion resistance, and mechanical properties. As the content of HFBMA-HPA increased from 0 wt% to 14 wt%, the water resistance of the WFPU coating gradually increased, the water contact angle (WCA) increased from 73° to 98°, the water absorption decreased from 7.847% to 3.062%, and the surface energy decreased from 32.8 mN/m to 22.6 mN/m. The coatings also showed impressive performances in the adhesion and flexibility tests in extreme conditions. This study provides a waterborne fluorinated polyurethane material with excellent comprehensive performance that has potential application value in the field of outdoor waterproof and anticorrosion coatings.

Functionalized flattened bamboo board: In-situ immersion assembly of flame-retardant, waterproof and anti-mold composite coatings

The flattened bamboo board (FB) represents a promising innovation in the bamboo industry. To address the challenges of flammability and hygroscopicity, composite coatings consisting of melamine (MEL), phytic acid (PA), cerium ions (Ce3+), and sodium laurate (La) are assembled on the FB surface through an in-situ impregnation strategy. The resulting MEL/PA-Ce3+@La FB exhibits exceptional flame retardancy. It achieves a V-0 rating in the vertical burning test (UL-94) and boasts a high limiting oxygen index (LOI) value of 38.5 %. The coated FB exhibits superhydrophobicity, evidenced by a water contact angle of 156.5°, which can be attributed to the in-situ growth of PA-Ce3+ complexes (for constructing micro/nanoscale coarse structures) and the modification with La (for reducing surface energy).This superhydrophobic surface imparts both self-cleaning and anti-mold properties to the coated FB. Moreover, the coated FB exhibits excellent mechanical stability, withstanding 36 cycles of sandpaper abrasion and tape peeling without losing its hydrophobicity. In summary, this work provides an innovative strategy for the bamboo processing industry to produce flattened bamboo boards with combined flame retardancy, superhydrophobic and anti-mold properties. Such versatility holds significant potential to facilitate the utilization of flattened bamboo boards in the construction and decorative materials industries.

Study on Antibacterial Durability of Waterproof Coatings with Different Base Materials

Microbial corrosion of waterproof coatings causes structural damage to buildings and renovation materials and severely threatens human health. In practical applications, coatings with different base materials show different durabilities to external environmental influences. There is little literature on the antimicrobial durability performance of waterproof coatings. Therefore, this paper selected four standard waterproofing coatings, including polyurethane coatings, cement-based coatings, asphalt-modified polymer coatings, and polymer emulsion coatings, as the main body of this study. Their antimicrobial abilities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, Candida albicans, and mold were tested after experiencing three kinds of harsh environments: Ultraviolet ray (UV), water immersion, and low temperature. The results show that the extreme climates significantly reduced the ability of the four coatings to resist mold, and the highest growth rate of bacteria was 54.64%. Under UV conditions, the polymer emulsion coatings were significantly more resistant to Candida albicans, and the optical density of the bacterial liquid showed a negative growth trend. The microstructural integrity of the polymer emulsion coatings was found to be damaged by Scanning Electron Microscope (SEM) observation. This work improves the durability application research on these coatings and provides a valuable reference for developing new environmentally friendly, antibacterial, and anticorrosive waterproof coatings.

A polyurethane elastomer combining high strength and excellent self‐healing properties for waterproofing coatings

AbstractSelf‐healing materials have not been able to solve the problem of the coexistence of mechanical strength and self‐healing function. Despite years of research, high‐strength self‐healing materials still require external factors to accelerate their self‐healing process. For this reason, in this study, two kinds of chain extenders were inserted into the hard segment to design the molecular structure of polyurethane. The introduction of two chain extenders not only provided multiple binding modes for hydrogen bond recombination, but also formed more types of hydrogen bonds. Based on the design, a polyurethane elastomer PUGI‐D3B2 with high strength and excellent self‐healing properties was synthesized. Data such as FTIR and 1H NMR spectra clearly demonstrate the successful synthesis of PUGI‐D3B2. The mechanical strength of PUGI‐D3B2 is 15.34 MPa, and its surface scratches can completely disappear after self‐healing at 60°C for 10 h，and 98.02% of the mechanical strength is restored after 12 h of heal. Therefore, combining the excellent self‐healing properties of PUGI‐D3B2, we prepared a multifunctional superhydrophobic material (SHN‐SiO2/PUGI‐D3B2). It can be used in a wide range of applications such as waterproof coatings, biomedicine and flexible electronics, which provides a new idea for the future direction of multifunctional materials.

Comparison between Waterproofing Sheets Membrane and Polyurea Waterproofing Coating Methods

This research aims to compare between Waterproofing Sheets Membrane and Polyurea Waterproofing Coating Methods, and know the waterproofing methods applying time, cost, weight, materials durability, and the waterproofing methods materials fire resistance properties. The research used qualitative analysis techniques to compare the two waterproofing methods objectively, Through lab testing, researchers found that: the polyurea waterproofing coating method usually takes between 1 to 2 working days to apply while the traditional sheet membrane waterproofing method takes between 5 to 7 working days applying time, and the polyurea waterproofing coating method can be more expensive than the traditional waterproofing sheet membranes method. Applying polyurea requires specialized equipment and trained personnel for proper handling and application, Both methods' materials weight are considered relatively light but the polyurea coating method materials are lighter, the polyurea waterproofing coating system lasts up to 30 years. Rather than the traditional system which durability is up to 20 years, the polyurea waterproofing coating system is considered a good fire resistance system rather than traditional sheet membrane system. It is recommended to clean and clear the surface before the commence of the waterproofing process. and the surface needs to be tested for at least 3 full days to confirm that the waterproofing system was applied successfully and without missing any openings.

Castor oil‐based paper packaging coating with water resistance and degradability obtained by thiol‐ene click reaction

AbstractWith the implementation of plastic restrictions and the increasingly serious problem of environmental pollution, paper with green and recyclable characteristics is gradually becoming a substitute for packaging materials. However, the rich cellulose structure in the paper, which contains hydroxyl groups leading to its hydrophilicity, allows water molecules to penetrate the paper and disrupt the hydrogen bonds between cellulose, resulting in a decrease in mechanical properties. Therefore, waterproof coatings are crucial for paper‐based materials to be used in many applications. Based on this, the paper surface was chemically modified with castor oil‐based resin (CO‐590) monomer prepared by coupling agent and castor oil (CO). The results indicated that the modified paper with the contact angle (CA) of 114° had excellent waterproof performance and had a reduction by 40.3% in water vapor transmission rate (WVTR), but also its mechanical increased to 26.9 MPa and the decomposition temperature to 410.5°C. In addition, the coating on its surface could be removed in an alkaline solution and had a possibility to recycle blank paper in the future for manufacturing sustainable production. This work not only provides a method for preparing modified packaging paper, but also expands the application fields of materials.

Waterproofing a Thermally Actuated Vibrational MEMS Viscosity Sensor

An efficient and inexpensive post-process method to waterproof an electrically actuated microtransducer has been studied. The electrical signals of microtransducers operating in electrically conductive fluids must be effectively isolated from the surrounding environment while remaining in contact for sensing purposes. A thermally actuated MEMS viscosity sensor uses electrical signals for both actuation and sensing. Three post-processing materials, (1) Parylene-C, (2) flouroacrylate-based polymer, and (3) nitrocellulose-based polymer, were coated as thin layers of waterproofing materials on different sensors. All three coating materials provided adequate protection when tested under normal operating conditions. Although the vibration response of the sensors was slightly modified, it did not affect their functionality in a significant way when measuring conductive fluids based on glycerol–water mixtures. All the treated sensors lasted over 1.2 million actuations without any decay in performance or failures. When the test bias conditions were increased by 5x to accelerate failures, the flouroacrylate-based polymer samples lasted 2x longer than the others. Visual analysis of the failures indicates that the edge of the diaphragm, which undergoes the most significant stress and strain values during actuation, was the location of the mechanical failure. This work guides post-processed waterproofing coatings for microscale actuators operating in harsh and damaging environments.

Exploring Al2O3 blister evolution through cathodoluminescence and attenuated total reflectance infrared analyses

This work focuses on the morphological and optical evolution of Al2O3 thick films grown by atomic layer deposition on Si-SiO2 substrates. Blister formation has been the subject of extensive research in the literature; our work fills a crucial gap in the optical characterization of areas inside and outside blisters. Morphological studies were carried out by scanning electron microscopy; we found a reciprocal relationship between the density of the blisters and their diameter. The thickness and refractive index were studied by ellipsometry, revealing a systematic increase in the refractive index with increasing annealing temperature. In addition, we observed the hydrophobic behavior in all films using the water contact angle technique, which suggests that even with blisters, this material can be used in waterproof coatings. Using Auger spectroscopy, we confirmed that delamination occurs completely once the blisters are broken. In this work, we perform cathodoluminescence measurements outside and inside the ampoules. In the area outside the blisters, we observe emissions attributed to the F centers, and the change from the main peaks of 2.8 and 3.4 eV for the as-deposited film to the dominance of emissions centered at 3.4 and 3.7 eV is clearly observed. Furthermore, we observed a strong increase in the cathodoluminescence signal at higher annealing temperatures. On the other hand, we also observed the evolution of the blisters through the cathodoluminescence spectra; in that area, we observed the radical change in the spectrum once the blister is broken, giving rise to the SiO2 signals. We also observed this rupture through a new absorption band in the attenuated total reflectance IR spectra.

Facile fabrication of waterborne polyurethane coatings with good hydrophobicity and antifouling properties by leveraging fluorinated polysiloxane

The unsatisfactory water and fouling resistance of waterborne polyurethane (WPU) coatings have significantly hampered their practical applications. Herein, a simple strategy to prepare a novel industrial WPU hydrophobicity and antifouling coating (FSiWPU) was employed. The FSiWPU coating was prepared by a facile polycondensation reaction to introduce hydroxyl-terminated siloxane fluoride (HTFSi) into polyether-type WPU. The study demonstrated that the coating material exhibited excellent hydrophobicity (with a water contact angle of 107.9°), water resistance (with a water absorption of 8.7 %) and considerable mechanical strength (35.6 MPa). More importantly, due to the surface enrichment of low-surface-energy HTFSi chain segments, the coating exhibited excellent antifouling and substrate shielding protection against various contaminating liquids and corrosive chemicals. The approach provided a promising candidate for the large-scale production and practical application of waterproof and anti-fouling waterborne polyurethane coatings.

Impact of long-term dust accumulation on photovoltaic module performance - a comprehensive review.

This paper reviews the impact dust accumulation for long-term on the performance of photovoltaic (PV) modules. It examines accumulation impact on the PV efficiency, their solar energy production, and their lifetime. The paper also discusses the various strategies for preventing dust accumulation, such as waterproof coatings, hydrophobic coatings, and anti-static coatings. Finally, the paper provides a comprehensive review in dust control and highlights potential future research directions. This review provides an in-depth analysis of PV behavior and its effect by dust accumulation and provides useful information for researchers and practitioners in the solar industry.

Waterproof and Flame-Retardant Fabric Coating with Nail-Tie Structure was Constructed by Janus Particles with Strong Mechanical, Physical, and Chemical Durability.

Oil spills are one of the most dangerous sources that cause serious environmental pollution and fire and explosion. In this work, multifunctional separator silica@polydivinylbenzene/poly 2,6-dimethyl-1, 4-phenyl ether (silica@PDVB/PPE) Janus particles were fabricated via seed emulsion polymerization, causing phase segregation as well as selective modification. The epoxy modified silica is partially covalently bonded to the fabric substrate surface by simple spraying to achieve a strong composite coating. The low surface energy PDVB/PPE forms a micronano rough layered surface, which can achieve a super hydrophobic and lipophile surface (WCA = 155°) and obtain a high flux separation of water and oil at 32,700 L·m-2·h-1. At the same time, the Janus composite fabric coating has the advantages of high heat resistance and flame retardant, which is realized by halogen-free flame-retardant unsaturated polyphosphate (PPE), making Janus fabric have potential value in separating oil-water mixtures and fire protection applications. In addition, the coating shows excellent chemical durability. After soaking in various aqueous solvents and organic solvents for 30 h, it can still maintain superhydrophobicity and flame retardant. The coating still has water repellency and flame retardant after 50 washings and mechanical wear and has good mechanical durability.

Mechanochemically robust hydrophobic fabric using an aqueous emulsion of amine-terminated polydimethylsiloxane

Polydimethylsiloxane (PDMS) is a highly reliable thermosetting polymer with exceptional chemical and mechanical resistance, as well as remarkable water repellency and adhesive performance. Its unique features make it the preferred choice for fluorine-free hydrophobic coatings. However, the use of PDMS requires organic solvents that are toxic and environmentally hazardous. In this study, an emulsion composed of amine-terminated polydimethylsiloxane (PDMS-NH2) in an environmentally friendly solvent, water, was prepared. Subsequently, glutaraldehyde (GA) was added and crosslinked to generate a hydrophobic PDMS–GA emulsion. The PDMS–GA emulsion is a low-viscosity solution that can infiltrate different types of fabrics (cotton, nylon, and polyester) or paper with numerous intertwined fibers. After dipping the fabrics and paper into the prepared PDMS–GA emulsion, they were washed in an aqueous solution containing dispersed kaolin particles and dried to yield a rough structure. As a result, a hydrophobic surface with a water contact angle of 151.2° was achieved. Furthermore, after exposure to strongly acidic or alkaline solutions (pH 1–13) and washing six times with water, the hydrophobic fabric remained chemically stable. Additionally, it withstood ten tape peeling tests, proving its mechanical durability. Crucially, the hydrophobic treatment method does not involve fluorine and uses eco-friendly water as the solvent. Therefore, this is a convenient way to apply waterproof coatings to functional textiles that require water resistance and are expected to have great industrial applications.

Sustainable Bio-Based Epoxy Resins with Tunable Thermal and Mechanic Properties and Superior Anti-Corrosion Performance.

Bio-based epoxy thermoset resins have been developed from epoxidized soybean oil (ESO) cured with tannic acid (TA). These two substances of vegetable origin have been gathering attention due to their accessibility, favorable economic conditions, and convenient chemical functionalization. TA's suitable high phenolic functionalization has been used to crosslink ESO by adjusting the -OH (from TA):epoxy (from ESO) molar ratio from 0.5:1 to 2.5:1. By means of Fourier-transform infrared spectroscopy, resulting in thermosets that evidenced optimal curing properties under moderate conditions (150-160 °C). The thermogravimetric analysis of the cured resins showed thermal stability up to 261 °C, with modulable mechanical and thermal properties determined by differential scanning calorimetry, dynamical mechanical thermal analysis, and tensile testing. Water contact angle measurements (83-87°) and water absorption tests (0.6-4.5 initial weight% intake) were performed to assess the suitability of the resins as waterproof coatings. Electrochemical impedance spectroscopy measurements were performed to characterize the anti-corrosive capability of these coatings on carbon steel substrates. Excellent barrier properties have been demonstrated due to the high electrical isolation and water impermeability of these oil-based coatings, without signs of deterioration over 6 months of immersion in a 3.5 wt.% NaCl solution. These results demonstrate the suitability of the developed materials as anti-corrosion coatings for specific applications.

Exploration of functionalizing graphene and the subsequent impact on PFAS adsorption capabilities via molecular dynamics

Per- and polyfluoroalkyl substances (PFAS) are extremely stable compounds due to their strong C–F bonds. They are used in water and stain proof coatings, aqueous film forming foams for fire suppression, cosmetics, paints, adhesives, etc. PFAS have been found in soils and waterways around the world due to their widespread usage and recalcitrance to degradation. Development of selective adsorbent materials is necessary to effectively capture a vast family of PFAS structures in order to remediate PFAS contamination in the environment. The work herein is focused on extracting design principles from molecular dynamics simulations of PFAS with functionalized graphene materials. Simulations examined how PFBA, PFOA, and PFOS interact with graphene, graphene oxide, nitrogen group-functionalized graphene oxide, partially fluorinated graphene flakes, and fully fluorinated flakes. Five flakes were used in each simulation to examine how interactions between flakes may lead to competitive interactions with respect to PFAS or formation of pores. Our study revealed that both the clustering mechanisms of the flakes and functional groups on the flake play a role in PFAS adsorption. The most effective functionalizations for PFAS adsorption are as follows: pristine graphene ≈ fully fluorinated > graphene oxide ≈ partially fluorinated > amine and amide functionalized graphene oxide flake. Long chain PFAS and sulfonate PFAS had higher propensity to adsorb to the materials compared to short chain PFAS and carboxylic head groups.

Hydration behaviour of cement in polymer cement waterproof coating and its effect on the macroscopic performance

In polymer-cement waterproof coating systems, the polymer emulsion influences the hydration behaviour of the cement component, which in turn affects the macroscopic performance of the coating. In this study, the effects of styrene–acrylate (SA), vinyl acetate copolymer emulsion (VAE), and styrene–butadiene (SB) emulsions on the hydration behaviour of cement and macroscopic properties of waterproofing coatings were investigated through chemical binding water testing; thermogravimetric, X-ray diffraction X-ray photoelectron spectroscopy, and Fourier transform infrared microscopic analyses; and macroscopic property characterisation. Moreover, the mechanism of the chemical reaction between the emulsion and cement was clarified. The degree of cement hydration is the least and most affected by the SB and VAE emulsions, respectively. When the cement proportion in the inorganic phase is 50%, the hydration degree of cement in cases involving SA, VAE, and SB emulsions is 24.87%, 19.57%, and 28.61%, respectively. As the cement proportion in the powder phase increases, the tensile strength and bond strength of the polymer cement waterproof coating increase and the elongation at break decreases. The rate of increase of the tensile strength and rate of decrease of the elongation at break both decrease after the cement content becomes 50%. The SA emulsion complexes with the calcium ions in the hydrated environment, which enhances the interfacial bonding between the organic and inorganic phases and results in excellent macroscopic performance of SA waterproof coatings. The SB emulsion waterproof coating has the best mechanical properties and highest water resistance owing to the highest degree of hydration of cement under the action of SB emulsion and hydrophobicity of the emulsion. The VAE emulsion generates hydrophilic polyvinyl-vinyl alcohol and small molecule products that easily dissolve in alkaline hydration environments, leading to low water resistance of the corresponding waterproof coating.

Nonporous water-proof coatings with resistance to harsh water environments and spontaneous dewetting

The superhydrophobic surfaces in harsh water environments (such as deep sea or extreme rainstorms) often suffer from irreversible air layer collapse or structural damage. However, the rough micro/nano-structures dominating superhydrophobicity are usually loose and fragile, which generate insufficient anti-wetting capillary pressure to deal with harsh water environments. Here, an electrostatic-field-assisted aerosolization deposition (EFAAD) method was proposed to fabricate a densified superhydrophobic surface featuring nonporous microlevel protrusion with nanoscale secondary modification. The mechanism of controllable deposition was investigated and spraying parameter configuration was optimized. The EFAAD coating showed exciting tolerance of high-speed jet impact (85.4 m/s, Weber number of 202588), ultrasonic micro jet impact (25 min), and hydrostatic pressure (5 MPa) for the coordinated structural robustness and air layer stability. Even though the superhydrophobicity of EFAAD coating was compromised under extreme conditions, the water film could dewet spontaneously induced by any bubble with radium than 130 μm. Moreover, the EFAAD coating has also proved comprehensive tolerance to tape peeling (more than 400 cycles), UV irradiation, and severe solution corrosion, exhibiting particularly promising for various high-water-pressure applications.

Cedar leaf-like bifunctional coating with excellent contact electrical conductivity and waterproofness

Traditional electrically conductive coatings applied to the field of connectors would cause electrical signal crosstalk or even short circuits due to their excellent electrical conductivity. Meanwhile, the traditional waterproof coatings were difficult to achieve excellent electrical conductivity due to their high contact resistance. Therefore, there was a long-standing contradiction between electrical conductivity and waterproofing in the field of connectors. Based on the conductive effect of electronic tunnel, a new design concept of electrically conductive and waterproof coating was proposed. An ultra-thin and highly cross-linked hydrophobic coating was manufactured onto a dense electrically conductive coating so as to create a bifunctional coating. Simultaneously, the hydrophobic coating was thin enough so that it did not destroy the conductive response of electronic tunnel. Concretely, the electrically conductive coating (polyaniline) was in-situ polymerized on the substrate by plasma initiation, and then another ultra-thin hydrophobic coating (polysiloxane) was also polymerized onto the initial conductive coating by a similar method. The contact conductivity of the bifunctional coating was up to 2.08 × 107S/m. The plasma firstly initiated the dissociation of reactive monomers, and then polymerization. Consequently, these two monomers with different polarity (aniline and hexamethyldisiloxane) can sequentially polymerize to form a dense coating. Importantly, the interface between the conductive coating and hydrophobic coating were connected by chemical bond without delamination failure. Interestingly, the surface of the bifunctional coating exhibited a protrusion like structure of cedar leaves, resulting in the water contact angle to reach 133.3°. This work provided clear guidance and a strong impetus for the development of contact electrical conductivity and waterproofness for the connector field.

An eco-friendly and facile method to prepare waterborne polyurethane based fire-resistant & waterproof coatings for wood protection

The fire-resistant & waterproof coatings for wood protection are highly demanded to reduce fire risk and save lives because wooden furniture and in-house decorations are widely used in our daily life. Herein, an eco-friendly and facile method was proposed to prepare such coatings, where a waterborne polyurethane (WPU) with non-volatility was blended with commercial flame retardants. A coating of ∼250 μm could generate charcoal of ∼10 mm that the painted plywood could withstand burning for ∼20 min. For the purpose to turn the hydrophilic WPU into water-repellent coating, hydrophobic nano-SiO2 were sprayed onto the surface to assemble into hierarchical structure. Consequently, the coating showed strong water repellency and the water contact angle arose from ∼89° to ∼157°. This method is conducive to the industrial production of fire-resistant and waterproof coatings due to its green and easy-to-scale up features, which will benefit thousands of households.