Surfaces with Sustainable Superhydrophobicity upon Mechanical Abrasion

Surfaces with sustainable superhydrophobicity have drawn much attention in recent years for improved durability in practical applications. In this study, hollow mesoporous silica nanoparticles (HMSNs) were prepared and used as reservoirs to load dodecyltrimethoxysilane (DDTMS). Then superhydrophobic surfaces were fabricated by spray coating HMSNs with DDTMS as particle stacking structure and polydimethylsiloxane (PDMS) as hydrophobic interconnection. The mechanical durability of the obtained superhydrophobic surface was evaluated by a cyclic sand abrasion. It was found that once the surface was mechanically damaged, new roughening structures made of the cavity of the HMSNs would expose and maintain suitable hierarchical roughness surrounded by PDMS and DDTMS, favoring sustainable superhydrphobicity of the coating. The surfaces could sustain superhydrophobicity even after 1000 cycles of sand abrasion. This facile strategy may pave the way to the development of robust superhydrophobic surfaces in practical applications

Surfaces with Sustainable Superhydrophobicity upon Mechanical Abrasion

Surfaces with sustainable superhydrophobicity have drawn much attention in recent years for improved durability in practical applications. In this study, hollow mesoporous silica nanoparticles (HMSNs) were prepared and used as reservoirs to load dodecyltrimethoxysilane (DDTMS). Then superhydrophobic surfaces were fabricated by spray coating HMSNs with DDTMS as particle stacking structure and polydimethylsiloxane (PDMS) as hydrophobic interconnection. The mechanical durability of the obtained superhydrophobic surface was evaluated by a cyclic sand abrasion. It was found that once the surface was mechanically damaged, new roughening structures made of the cavity of the HMSNs would expose and maintain suitable hierarchical roughness surrounded by PDMS and DDTMS, favoring sustainable superhydrphobicity of the coating. The surfaces could sustain superhydrophobicity even after 1000 cycles of sand abrasion. This facile strategy may pave the way to the development of robust superhydrophobic surfaces in practical applications

Washable and Wear-Resistant Superhydrophobic Surfaces with Self-Cleaning Property by Chemical Etching of Fibers and Hydrophobization

Superhydrophobic poly­(ethylene terephthalate) (PET) textile surfaces with a self-cleaning property were fabricated by treating the microscale fibers with alkali followed by coating with polydimethylsiloxane (PDMS). Scanning electron microscopy analysis showed that alkali treatment etched the PET and resulted in nanoscale pits on the fiber surfaces, making the textiles have hierarchical structures. Coating of PDMS on the etched fibers affected little the roughening structures while lowered the surface energy of the fibers, thus making the textiles show slippery superhydrophobicity with a self-cleaning effect. Wettability tests showed that the superhydrophobic textiles were robust to acid/alkaline etching, UV irradiation, and long-time laundering. Importantly, the textiles maintained superhydrophobicity even when the textiles are ruptured by severe abrasion. Also colorful images could be imparted to the superhydrophobic textiles by a conventional transfer printing without affecting the superhydrophobicity

Flexible Superamphiphobic Film with a 3D Conductive Network for Wearable Strain Sensors in Humid Conditions

A three-dimensional (3D) conductive network with high sensitivity and a wide response range is applicable for wearable strain sensors. However, structural deformation of the 3D network under mechanical stimuli gives rise to mass pores, which are easily soaked by rain, sweat, oil, and so on, thus affecting the sensitivity of the sensors. Herein, a stretchable film with outstanding superhydrophobicity is proposed for reliable strain sensors based on a 3D conductive network. First, superconductive carbon black (SCB) nanoparticles are assembled on electrospun fibers of thermoplastic polyurethane (TPU) to form a TPU/SCB conductive film. Then, a dispersion of carbon nanotubes (CNTs) and fluorinated silica (F-SiO2) is sprayed on the TPU/SCB film to form a conductive TPU/SCB@CNTs/F-SiO2 composite film. After immersion of the composite film in a mixed solution of poly­(dimethylsiloxane) (PDMS) and perfluorodecyltrichlorosilane (PFDTS) and drying, a flexible conductive superamphiphobic film was obtained. When the film was used as a strain sensor, it showed superior sensitivity (12.05–60.42), a wide strain range (0–100%), a fast response time (75–100 ms), and good stability in stretching–relaxing cycles. Benefiting from the favorable superamphiphobicity, the obtained strain sensor could be effectively utilized to display stable electrical signals underwater and monitor human motions under dry/sweat exposure, showing significant potential in practical wearable sensors for stretchable, breathable, and reliable human behavior monitoring

Flexible Superamphiphobic Film with a 3D Conductive Network for Wearable Strain Sensors in Humid Conditions

A three-dimensional (3D) conductive network with high sensitivity and a wide response range is applicable for wearable strain sensors. However, structural deformation of the 3D network under mechanical stimuli gives rise to mass pores, which are easily soaked by rain, sweat, oil, and so on, thus affecting the sensitivity of the sensors. Herein, a stretchable film with outstanding superhydrophobicity is proposed for reliable strain sensors based on a 3D conductive network. First, superconductive carbon black (SCB) nanoparticles are assembled on electrospun fibers of thermoplastic polyurethane (TPU) to form a TPU/SCB conductive film. Then, a dispersion of carbon nanotubes (CNTs) and fluorinated silica (F-SiO2) is sprayed on the TPU/SCB film to form a conductive TPU/SCB@CNTs/F-SiO2 composite film. After immersion of the composite film in a mixed solution of poly­(dimethylsiloxane) (PDMS) and perfluorodecyltrichlorosilane (PFDTS) and drying, a flexible conductive superamphiphobic film was obtained. When the film was used as a strain sensor, it showed superior sensitivity (12.05–60.42), a wide strain range (0–100%), a fast response time (75–100 ms), and good stability in stretching–relaxing cycles. Benefiting from the favorable superamphiphobicity, the obtained strain sensor could be effectively utilized to display stable electrical signals underwater and monitor human motions under dry/sweat exposure, showing significant potential in practical wearable sensors for stretchable, breathable, and reliable human behavior monitoring

Flexible Superamphiphobic Film with a 3D Conductive Network for Wearable Strain Sensors in Humid Conditions

A three-dimensional (3D) conductive network with high sensitivity and a wide response range is applicable for wearable strain sensors. However, structural deformation of the 3D network under mechanical stimuli gives rise to mass pores, which are easily soaked by rain, sweat, oil, and so on, thus affecting the sensitivity of the sensors. Herein, a stretchable film with outstanding superhydrophobicity is proposed for reliable strain sensors based on a 3D conductive network. First, superconductive carbon black (SCB) nanoparticles are assembled on electrospun fibers of thermoplastic polyurethane (TPU) to form a TPU/SCB conductive film. Then, a dispersion of carbon nanotubes (CNTs) and fluorinated silica (F-SiO2) is sprayed on the TPU/SCB film to form a conductive TPU/SCB@CNTs/F-SiO2 composite film. After immersion of the composite film in a mixed solution of poly­(dimethylsiloxane) (PDMS) and perfluorodecyltrichlorosilane (PFDTS) and drying, a flexible conductive superamphiphobic film was obtained. When the film was used as a strain sensor, it showed superior sensitivity (12.05–60.42), a wide strain range (0–100%), a fast response time (75–100 ms), and good stability in stretching–relaxing cycles. Benefiting from the favorable superamphiphobicity, the obtained strain sensor could be effectively utilized to display stable electrical signals underwater and monitor human motions under dry/sweat exposure, showing significant potential in practical wearable sensors for stretchable, breathable, and reliable human behavior monitoring

Thermally Conductive, Superhydrophobic, and Flexible Composite Membrane of Polyurethane and Boron Nitride Nanosheets by Ultrasonic Assembly for Thermal Management

Thermal management is of significance for modern electronic products, and it remains challenging to keep the cooling performance of thermal management materials in multi-environment applications from being unaffected by external contamination. Herein, we constructed thermally conductive, superhydrophobic, and flexible composites using thermoplastic polyurethane electrospun membrane as a nano-fibrous substrate, hexagonal boron nitride nanosheets as a conducting filler, and polydimethylsiloxane/SiO2 nanoparticles for hydrophobization. The composite membrane demonstrated outstanding thermal management performance with an ultrahigh thermal conductivity (TC) of 7.193 W/m K. The membrane is flexible with durable TC even after 500 bending and stretching cycles and possesses superhydrophobicity with a water contact angle greater than 165° and a slide angle lower than 2.7°, which prevents the surface from being stained and protects its excellent TC for long-term applications, favoring thermal management of modern electronic products