Superhydrophobic SiC/CNTs Coatings with Photothermal Deicing and Passive Anti-Icing Properties

For faster and greener anti-icing/deicing, a new generation of anti-icing materials are expected to possess both passive anti-icing properties and active deicing properties. The photothermal effect of carbon nanotubes (CNTs) is used in the field of photothermal cancer therapy, while the application in anti-icing/deicing is seldom investigated. Superhydrophobic SiC/CNTs coatings with photothermal deicing and passive anti-icing properties were first prepared by a simple spray-coating method. The results of 3D profile and microstructure observed via scanning electron microscopy demonstrate that the micronanostructure combined with peaklike SiC microstructure and villiform CNTs nanostructure makes the coatings surface superhydrophobic, exhibiting a water contact angle of up to 161° and a roll angle as low as 2°. This micronanostructure can also reduce ice anchoring and ice adhesion strength. Utilizing the photothermal effect of CNTs, the surface temperature of the coatings is rapidly increased upon near-infrared light (808 nm) irradiation. The heat is transferred rapidly to the surroundings by highly thermal conductive CNTs. The light-to-heat conversion efficiency in deicing tests is approximately 50.94%, achieving a highly efficient remote deicing effect. This superhydrophobic coating combining photothermal deicing and passive anti-icing properties is expected to be further used in various practical applications and in development of a new generation of anti-icing/deicing coatings

Adopting Intrinsic Hydrophilic Thermoplastic Starch Composites to Fabricate Antifogging Sustainable Films with High Antibiosis and Transparency

Fogging on transparent surfaces such as goggles causes a series of hazards to users. To fabricate antifogging and low-haze transparent renewable polymer materials, intrinsic hydrophilicity with high water adsorption capability of thermoplastic starch (TPS) had been adopted. Strikingly, when benzoic acid (BA) was blended with thermoplastic starch (TPS-BA), the haze of TPS-BA was only 7.8% when it suffered the cold and warm method of antifogging measurement with 87% transmittance. Simultaneously, TPS-BA achieved an 18 mm inhibition zone for Staphylococcus aureus. To reveal the antifogging mechanism of TPS-BA films, the surficial and interior structure features were evaluated by three-dimensional optical scanner, scanning electron microscopy (SEM), contact angle testing, small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), temperature-dependent Fourier transform infrared (FTIR), dynamic mechanical analysis (DMA), and so on. The incorporation of BA resulted in the roughness (Rq), water contact angle (WCA), and crystallinity of the TPS-BA film decreasing from 6.5 to 0.68 μm, 65.1 to 39.9°, and 13.6 to 6.3%, respectively. The amorphous matrix and smooth surface reduced the scattered light, allowing the TPS-BA film to achieve low haze performance and high transmittance. Importantly, the diversified and weakened hydrogen bonds formed among starch, BA, and glycerol could inhibit the formation of starch crystalline regions and allowed hydroxyl groups to quickly bond with water. Thus, when TPS-BA is placed in a high-humidity surrounding, an “expressway” is constructed for water molecules diffusing into the TPS-BA matrix. This novel low-haze, antifogging, sustainable, and facilely fabricated TPS with antibacterial properties is a promising candidate in disposable medical goggles to fight against COVID-19

Biodegradable-Renewable Vitrimer Fabrication by Epoxidized Natural Rubber and Oxidized Starch with Robust Ductility and Elastic Recovery

Facilitating biobased epoxidized natural rubber (ENR) vitrimer with biodegradable-renewables and reprocessability is a facile strategy to reduce environmental pollution and the carbon emission evoked by waste vulcanized rubber. Herein, oxidized starch with 57% carboxyl content (OST-57) was fabricated by H2O2/Cu2+ oxidation and served as a bio-macromolecular cross-linking agent. When OST and ENR latex were mixed and subjected to thermal processing, the β-hydroxyl ester bonds between OST-57 and ENR were formed and covalent topology networks were constructed. Consequently, the cross-linking density dominated the comprehensive performance of this novel biobased ENR vitrimer, and enabled it to achieve a high elongation at break (1108%), elastic recovery (90%), shape fixed ratio (99.5%), and shape recovery ratio (95.6%) when the content of OST-57 was 30 phr. Meanwhile, due to the low activation energy (Ea) (80.3 kJ/mol) of transesterification, the ENR/OST-57 vitrimer exhibited sound thermo-activated reprocessability, and its loss in mechanical properties was lower than 12% even after being subjected to thermal reprocessing twice. Noteworthily, different from those of the presented vitrimer, ENR/OST-57 showed a distinctive biodegradable-renewable feature when α-amylase was adopted and destroyed the cross-linking network. As a result, the biodegradable ENR with residual β-hydroxyl ester bonds presented similar features as the neat ENR when diisopropylbenzene peroxide was utilized to form the chemical bond cross-linking topology networks. This novel strategy of fabricating biobased vitrimer will promote ENR for wide applications in the field of high ductility and recovery without environmental impact

Adopting Intrinsic Hydrophilic Thermoplastic Starch Composites to Fabricate Antifogging Sustainable Films with High Antibiosis and Transparency

Fogging on transparent surfaces such as goggles causes a series of hazards to users. To fabricate antifogging and low-haze transparent renewable polymer materials, intrinsic hydrophilicity with high water adsorption capability of thermoplastic starch (TPS) had been adopted. Strikingly, when benzoic acid (BA) was blended with thermoplastic starch (TPS-BA), the haze of TPS-BA was only 7.8% when it suffered the cold and warm method of antifogging measurement with 87% transmittance. Simultaneously, TPS-BA achieved an 18 mm inhibition zone for Staphylococcus aureus. To reveal the antifogging mechanism of TPS-BA films, the surficial and interior structure features were evaluated by three-dimensional optical scanner, scanning electron microscopy (SEM), contact angle testing, small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), temperature-dependent Fourier transform infrared (FTIR), dynamic mechanical analysis (DMA), and so on. The incorporation of BA resulted in the roughness (Rq), water contact angle (WCA), and crystallinity of the TPS-BA film decreasing from 6.5 to 0.68 μm, 65.1 to 39.9°, and 13.6 to 6.3%, respectively. The amorphous matrix and smooth surface reduced the scattered light, allowing the TPS-BA film to achieve low haze performance and high transmittance. Importantly, the diversified and weakened hydrogen bonds formed among starch, BA, and glycerol could inhibit the formation of starch crystalline regions and allowed hydroxyl groups to quickly bond with water. Thus, when TPS-BA is placed in a high-humidity surrounding, an “expressway” is constructed for water molecules diffusing into the TPS-BA matrix. This novel low-haze, antifogging, sustainable, and facilely fabricated TPS with antibacterial properties is a promising candidate in disposable medical goggles to fight against COVID-19

Superhydrophobic SiC/CNTs Coatings with Photothermal Deicing and Passive Anti-Icing Properties

For faster and greener anti-icing/deicing, a new generation of anti-icing materials are expected to possess both passive anti-icing properties and active deicing properties. The photothermal effect of carbon nanotubes (CNTs) is used in the field of photothermal cancer therapy, while the application in anti-icing/deicing is seldom investigated. Superhydrophobic SiC/CNTs coatings with photothermal deicing and passive anti-icing properties were first prepared by a simple spray-coating method. The results of 3D profile and microstructure observed via scanning electron microscopy demonstrate that the micronanostructure combined with peaklike SiC microstructure and villiform CNTs nanostructure makes the coatings surface superhydrophobic, exhibiting a water contact angle of up to 161° and a roll angle as low as 2°. This micronanostructure can also reduce ice anchoring and ice adhesion strength. Utilizing the photothermal effect of CNTs, the surface temperature of the coatings is rapidly increased upon near-infrared light (808 nm) irradiation. The heat is transferred rapidly to the surroundings by highly thermal conductive CNTs. The light-to-heat conversion efficiency in deicing tests is approximately 50.94%, achieving a highly efficient remote deicing effect. This superhydrophobic coating combining photothermal deicing and passive anti-icing properties is expected to be further used in various practical applications and in development of a new generation of anti-icing/deicing coatings

Stretch-Induced Robust Intrinsic Antibacterial Thermoplastic Gelatin Organohydrogel for a Thermoenhanced Supercapacitor and Mono-gauge-factor Sensor

Sustainable organohydrogel electronics have shown promise in resolving the electronic waste (e-waste) evoked by traditional chemical cross-linking hydrogels. Herein, thermoplastic-recycled gelatin/oxidized starch (OST)/glycerol/ZnCl2 organohydrogels (GOGZs) were fabricated by introducing the anionic polyelectrolyte OST and solvent exchange strategy to construct noncovalently cross-linking networks. Benefiting from the electrostatic interaction and hydrogen and coordination bonds, GOGZ possessed triple-supramolecular interactions and a continuous ion transport pathway, which resulted in excellent thermoplasticity and high ionic conductivities and mechanical and antibacterial properties. Because of the thermally induced phase transition of gelatin, GOGZ exhibited isotropic-ionic conductivity with a positive temperature coefficient and realized intrinsic affinity with the activated carbon electrode for fabricating a double-layer structure supercapacitor. These novel features significantly decreased the impedance (3.71 Ω) and facilitated the flexible supercapacitors to achieve thermoenhanced performance with 4.89 Wh kg–1 energy density and 49.2 F g–1 specific mass capacitance at 65 °C. Fantastically, the GOGZ-based stress sensor exhibited a monolinear gauge factor (R2 = 0.999) at its full-range strain (0 to 350%), and its sensitivity increased with the thermoplastic-recycled times. Consequently, this sustainable and temperature-sensitive sensor (−40 to 60 °C) could serve as health monitoring wearable devices with excellent reliability (R2 = 0.999) at tiny strain. Moreover, GOGZ could achieve efficient self-enhancement by stretch-induced alignment. The sustained weighted load, tensile strength, and elongation at break of the stretch-induced GOGZ were 6 kg/g, 2.37 MPa, and 300%, respectively. This self-enhanced feature indicated that GOGZ can be utilized as an artificial muscle. Eventually, GOGZ obtained high intrinsic antibiosis (Dinhibition circle > 25 mm) by a binding species (−COO–NH3+−) from COOH in OST and NH2 in gelatin, freezing resistance, and water retention. In summary, this study provided an effective strategy to fabricate thermoplastic-recycled organohydrogels for multifunctional sustainable electronics with novel performance

Preparation of Novel c‑6 Position Carboxyl Corn Starch by a Green Method and Its Application in Flame Retardance of Epoxy Resin

Novel c-6 position oxidized corn starch (OST) with high carboxyl content (26.3–54.5%) was prepared by a green method, using hydrogen peroxide as the oxidant. The as-obtained OSTs were then used as flame-retardant carbon sources with microencapsulated ammonium polyphosphate (MFAPP) in epoxy resin (EP). Compared to EP, the obtained EP/MFAPP/OST composites exhibit significantly enhanced flame retardancy. The introduction of only 6.25 wt % OSTs and 6.25 wt % MFAPP results in remarkably increased limiting oxygen index and decreased heat release rate, and all composites can reach UL94 V-0 rating. Thermogravimetric analyses and cone calorimetry results suggest both OSTs and MFAPP have good catalytic charring effects, and the increased carboxyl content benefits the char formation of the composites. Because of the formation of compact char on the sample surface during combustion, the transfer of oxygen, heat, and flammable gas products is inhibited; the flame retardancy of EP/MFAPP/OST composites is thus remarkably enhanced

Multifunction E‑Skin Based on MXene–PA–Hydrogel for Human Behavior Monitoring

Hydrogels have attracted significant attention in various fields, such as smart sensing, human–machine interaction, and biomedicines, due to their excellent flexibility and versatility. However, current hydrogel electronic skins are still limited in stretchability, and their sensing functionality is often single-purpose, making it difficult to meet the requirements of complex environments and multitasking. In this study, we developed an MXene nanoplatelet and phytic acid-coreinforced poly(vinyl alcohol) (PVA) composite, denoted as MXene–PA–PVA. The strong hydrogen bonds formed by the interaction of the different components and the enhancement of chain entanglement result in a significant improvement in the mechanical properties of the PVA/PA/MXene composite hydrogel. This improvement is reflected in an increase of 271.43% in the maximum tensile strain and 35.29% in the maximum fracture stress. Moreover, the composite hydrogel exhibits excellent adhesion, water retention, heat resistance, and conductivity properties. The PVA/PA composite material combined with MXene demonstrates great potential for use as multifunctional sensors for strain and temperature detection with a strain-sensing sensitivity of 3.23 and a resistance temperature coefficient of 8.67. By leveraging the multifunctional characteristics of this composite hydrogel, electronic skin can accurately monitor human behavior and physiological reactions. This advancement opens up new possibilities for flexible electronic devices and human–machine interactions in the future

Supplemental Material, Supporting_information - Synergetic effect of nanoclay and nano-CaCO₃ hybrid filler systems on the foaming properties and cellular structure of polystyrene nanocomposite foams using supercritical CO₂

Supplemental Material, Supporting_information for Synergetic effect of nanoclay and nano-CaCO3 hybrid filler systems on the foaming properties and cellular structure of polystyrene nanocomposite foams using supercritical CO2 by Xinghan Lian, Wenjie Mou, Tairong Kuang, Xianhu Liu, Shuidong Zhang, Fangfang Li, Tong Liu and Xiangfang Peng in Cellular Polymers</p