Surface Modification of Bacterial Cellulose Aerogels’ Web-like Skeleton for Oil/Water Separation

The cellulose nanofibers of bacterial cellulose aerogel (BCA) are modified only on their surfaces using a trimethylsilylation reaction with trimethyichlorosilane in liquid phase followed by freeze-drying. The obtained hydrophobic bacterial cellulose aerogels (HBCAs) exhibit low density (≤6.77 mg/cm³), high surface area (≥169.1 m²/g), and high porosity (≈ 99.6%), which are nearly the same as those of BCA owing to the low degrees of substitution (≤0.132). Because the surface energy of cellulose nanofibers decreased and the three-dimensional web-like microstructure, which was comprised of ultrathin (20–80 nm) cellulose nanofibers, is maintained during the trimethylsilylation process, the HBCAs have hydrophobic and oleophilic properties (water/air contact angle as high as 146.5°) that endow them with excellent selectivity for oil adsorption from water. The HBCAs are able to collect a wide range of organic solvents and oils with absorption capacities up to 185 g/g, which depends on the density of the liquids. Hence, the HBCAs are wonderful candidates for oil absorbents to clean oil spills in the marine environment. This work provides a different way to multifunctionalize cellulose aerogel blocks in addition to chemical vapor deposition method

Polyurea–Cellulose Composite Aerogel Fibers with Superior Strength, Hydrophobicity, and Thermal Insulation via a Secondary Molding Strategy

Aerogel materials, considered as the “miracle material that can change the world in the 21st century”, owe their transformative potential to their high specific surface area, porosity, and low density. In comparison to commercially available aerogel felt, aerogel particles, and aerogel powder, aerogel fibers not only possess the inherent advantages of aerogel materials but also exhibit exceptional flexibility and design versatility. Therefore, aerogel fibers are expected to be processed into high-performance textiles and smart wearable fabrics to further expand the application field of aerogel materials. However, the aerogel fibers suffer from poor mechanical properties and intricate, time-consuming preparation processes. Herein, a simple and efficient method for crafting polyurea–cellulose composite aerogel fibers (CAFs) with superior mechanical properties is presented. The dried bacterial cellulose (BC) matrix was immersed in a polyurea sol, and the aerogel fibers were prepared via secondary molding, followed by CO2 supercritical drying. In a representative case, the CAFs obtained via secondary molding demonstrate outstanding hydrophobicity with a contact angle of 126°, along with remarkable flexibility. Significantly, the CAFs exhibit excellent mechanical properties, including a tensile strength of 6.4 MPa. Moreover, the CAFs demonstrate superior thermal insulation capabilities, withstanding temperatures ranging from 180 to −40 °C. In conclusion, with the successful fabrication of polyurea–cellulose CAFs, this study introduces a magic approach for producing aerogel fibers endowed with exceptional mechanical properties and thermal insulation. This advancement contributes to the development and application of aerogel materials in various fields

Polyurea–Cellulose Composite Aerogel Fibers with Superior Strength, Hydrophobicity, and Thermal Insulation via a Secondary Molding Strategy

Aerogel materials, considered as the “miracle material that can change the world in the 21st century”, owe their transformative potential to their high specific surface area, porosity, and low density. In comparison to commercially available aerogel felt, aerogel particles, and aerogel powder, aerogel fibers not only possess the inherent advantages of aerogel materials but also exhibit exceptional flexibility and design versatility. Therefore, aerogel fibers are expected to be processed into high-performance textiles and smart wearable fabrics to further expand the application field of aerogel materials. However, the aerogel fibers suffer from poor mechanical properties and intricate, time-consuming preparation processes. Herein, a simple and efficient method for crafting polyurea–cellulose composite aerogel fibers (CAFs) with superior mechanical properties is presented. The dried bacterial cellulose (BC) matrix was immersed in a polyurea sol, and the aerogel fibers were prepared via secondary molding, followed by CO2 supercritical drying. In a representative case, the CAFs obtained via secondary molding demonstrate outstanding hydrophobicity with a contact angle of 126°, along with remarkable flexibility. Significantly, the CAFs exhibit excellent mechanical properties, including a tensile strength of 6.4 MPa. Moreover, the CAFs demonstrate superior thermal insulation capabilities, withstanding temperatures ranging from 180 to −40 °C. In conclusion, with the successful fabrication of polyurea–cellulose CAFs, this study introduces a magic approach for producing aerogel fibers endowed with exceptional mechanical properties and thermal insulation. This advancement contributes to the development and application of aerogel materials in various fields

Polyurea–Cellulose Composite Aerogel Fibers with Superior Strength, Hydrophobicity, and Thermal Insulation via a Secondary Molding Strategy

Aerogel materials, considered as the “miracle material that can change the world in the 21st century”, owe their transformative potential to their high specific surface area, porosity, and low density. In comparison to commercially available aerogel felt, aerogel particles, and aerogel powder, aerogel fibers not only possess the inherent advantages of aerogel materials but also exhibit exceptional flexibility and design versatility. Therefore, aerogel fibers are expected to be processed into high-performance textiles and smart wearable fabrics to further expand the application field of aerogel materials. However, the aerogel fibers suffer from poor mechanical properties and intricate, time-consuming preparation processes. Herein, a simple and efficient method for crafting polyurea–cellulose composite aerogel fibers (CAFs) with superior mechanical properties is presented. The dried bacterial cellulose (BC) matrix was immersed in a polyurea sol, and the aerogel fibers were prepared via secondary molding, followed by CO2 supercritical drying. In a representative case, the CAFs obtained via secondary molding demonstrate outstanding hydrophobicity with a contact angle of 126°, along with remarkable flexibility. Significantly, the CAFs exhibit excellent mechanical properties, including a tensile strength of 6.4 MPa. Moreover, the CAFs demonstrate superior thermal insulation capabilities, withstanding temperatures ranging from 180 to −40 °C. In conclusion, with the successful fabrication of polyurea–cellulose CAFs, this study introduces a magic approach for producing aerogel fibers endowed with exceptional mechanical properties and thermal insulation. This advancement contributes to the development and application of aerogel materials in various fields

Polyurea–Cellulose Composite Aerogel Fibers with Superior Strength, Hydrophobicity, and Thermal Insulation via a Secondary Molding Strategy

Aerogel materials, considered as the “miracle material that can change the world in the 21st century”, owe their transformative potential to their high specific surface area, porosity, and low density. In comparison to commercially available aerogel felt, aerogel particles, and aerogel powder, aerogel fibers not only possess the inherent advantages of aerogel materials but also exhibit exceptional flexibility and design versatility. Therefore, aerogel fibers are expected to be processed into high-performance textiles and smart wearable fabrics to further expand the application field of aerogel materials. However, the aerogel fibers suffer from poor mechanical properties and intricate, time-consuming preparation processes. Herein, a simple and efficient method for crafting polyurea–cellulose composite aerogel fibers (CAFs) with superior mechanical properties is presented. The dried bacterial cellulose (BC) matrix was immersed in a polyurea sol, and the aerogel fibers were prepared via secondary molding, followed by CO2 supercritical drying. In a representative case, the CAFs obtained via secondary molding demonstrate outstanding hydrophobicity with a contact angle of 126°, along with remarkable flexibility. Significantly, the CAFs exhibit excellent mechanical properties, including a tensile strength of 6.4 MPa. Moreover, the CAFs demonstrate superior thermal insulation capabilities, withstanding temperatures ranging from 180 to −40 °C. In conclusion, with the successful fabrication of polyurea–cellulose CAFs, this study introduces a magic approach for producing aerogel fibers endowed with exceptional mechanical properties and thermal insulation. This advancement contributes to the development and application of aerogel materials in various fields

The Role of the Liquid–Liquid Interface in the Synthesis of Nonequilibrium Crystalline Wurtzite ZnS at Room Temperature

In this research, the role that the organic–inorganic liquid interface plays in the synthesis of nonequilibrium crystalline materials is investigated. A hierarchical nanocrystalline film of wurtzite ZnS, the high-temperature stable phase, is successfully prepared at room temperature by an interfacial in situ fabrication process. The organic–inorganic liquid interface constructed by n-hexane and water acts as the reaction zone for the synthesis of ZnS nanocrystalline film. A series of experimental results have proved that the liquid–liquid interface is the key factor for wurtzite ZnS formation at room temperature without any additive. The ZnS film consists of core–shell subunits characterized by ZnS nanoparticles around an organic core. Between the liquid–liquid interface, the core–shell subunits are coupled onto the surface of a SAM-modified substrate by terminal amino groups, so that the ZnS nanocrystalline film is formed by a layer-by-layer mode. This research brings forward a feasible route for synthesizing wurtzite ZnS in one-step process at room temperature and provides some beneficial information for studying the structural kinetics of nonequilibrium crystalline synthesis

Elastic Agarose Nanowire Aerogels for Oil–Water Separation and Thermal Insulation

Problems resulting from the emission of crude oil, toxic organic solvents, and petroleum products, as well as massive heat dissipation from industrial pipes, have threatened ecosystems, human health, and industrial production. Eco-friendly and biodegradable natural materials are considered as the most promising absorbents or thermal insulation materials for oil–water separation and thermal insulation. In this work, agarose nanowire aerogels (ANAs) prepared from agarose (AG) solution were synthesized without any chemical reaction or chemical crosslinking agents to form AG hydrogels followed by supercritical CO2 (SC-CO2) drying. Then, hydrophobic agarose nanowire aerogels (HANAs) were obtained through a simple chemical vapor deposition (CVD) approach using methyltrimethoxysilane and methyltrichlorosilane. The gel skeleton of the HANAs after CVD was isometrically covered by a rigid silica coating with methyl on the ANA surface to improve flexibility, resulting in not only excellent self-cleaning and hydrophobicity with a water contact angle of 142° but also outstanding elasticity. Furthermore, the as-synthesized HANAs exhibited low density (≤0.09 g/cm3), a large specific surface area (≥210.5 m2/g), and high porosity (94.9–98.7%). Hence, the HANAs displayed high absorption capacities (approximately 48.2 g/g of chloroform absorption capacity) and selectivity of oils and organic solvents. In addition, they also exhibited excellent thermal insulation performance under both hot and cold conditions. The designed HANAs are expected to provide a highly efficient method for oil–water separation and thermal insulation

Elastic Agarose Nanowire Aerogels for Oil–Water Separation and Thermal Insulation

Problems resulting from the emission of crude oil, toxic organic solvents, and petroleum products, as well as massive heat dissipation from industrial pipes, have threatened ecosystems, human health, and industrial production. Eco-friendly and biodegradable natural materials are considered as the most promising absorbents or thermal insulation materials for oil–water separation and thermal insulation. In this work, agarose nanowire aerogels (ANAs) prepared from agarose (AG) solution were synthesized without any chemical reaction or chemical crosslinking agents to form AG hydrogels followed by supercritical CO2 (SC-CO2) drying. Then, hydrophobic agarose nanowire aerogels (HANAs) were obtained through a simple chemical vapor deposition (CVD) approach using methyltrimethoxysilane and methyltrichlorosilane. The gel skeleton of the HANAs after CVD was isometrically covered by a rigid silica coating with methyl on the ANA surface to improve flexibility, resulting in not only excellent self-cleaning and hydrophobicity with a water contact angle of 142° but also outstanding elasticity. Furthermore, the as-synthesized HANAs exhibited low density (≤0.09 g/cm3), a large specific surface area (≥210.5 m2/g), and high porosity (94.9–98.7%). Hence, the HANAs displayed high absorption capacities (approximately 48.2 g/g of chloroform absorption capacity) and selectivity of oils and organic solvents. In addition, they also exhibited excellent thermal insulation performance under both hot and cold conditions. The designed HANAs are expected to provide a highly efficient method for oil–water separation and thermal insulation

Elastic Agarose Nanowire Aerogels for Oil–Water Separation and Thermal Insulation

Problems resulting from the emission of crude oil, toxic organic solvents, and petroleum products, as well as massive heat dissipation from industrial pipes, have threatened ecosystems, human health, and industrial production. Eco-friendly and biodegradable natural materials are considered as the most promising absorbents or thermal insulation materials for oil–water separation and thermal insulation. In this work, agarose nanowire aerogels (ANAs) prepared from agarose (AG) solution were synthesized without any chemical reaction or chemical crosslinking agents to form AG hydrogels followed by supercritical CO2 (SC-CO2) drying. Then, hydrophobic agarose nanowire aerogels (HANAs) were obtained through a simple chemical vapor deposition (CVD) approach using methyltrimethoxysilane and methyltrichlorosilane. The gel skeleton of the HANAs after CVD was isometrically covered by a rigid silica coating with methyl on the ANA surface to improve flexibility, resulting in not only excellent self-cleaning and hydrophobicity with a water contact angle of 142° but also outstanding elasticity. Furthermore, the as-synthesized HANAs exhibited low density (≤0.09 g/cm3), a large specific surface area (≥210.5 m2/g), and high porosity (94.9–98.7%). Hence, the HANAs displayed high absorption capacities (approximately 48.2 g/g of chloroform absorption capacity) and selectivity of oils and organic solvents. In addition, they also exhibited excellent thermal insulation performance under both hot and cold conditions. The designed HANAs are expected to provide a highly efficient method for oil–water separation and thermal insulation

Elastic Agarose Nanowire Aerogels for Oil–Water Separation and Thermal Insulation

Problems resulting from the emission of crude oil, toxic organic solvents, and petroleum products, as well as massive heat dissipation from industrial pipes, have threatened ecosystems, human health, and industrial production. Eco-friendly and biodegradable natural materials are considered as the most promising absorbents or thermal insulation materials for oil–water separation and thermal insulation. In this work, agarose nanowire aerogels (ANAs) prepared from agarose (AG) solution were synthesized without any chemical reaction or chemical crosslinking agents to form AG hydrogels followed by supercritical CO2 (SC-CO2) drying. Then, hydrophobic agarose nanowire aerogels (HANAs) were obtained through a simple chemical vapor deposition (CVD) approach using methyltrimethoxysilane and methyltrichlorosilane. The gel skeleton of the HANAs after CVD was isometrically covered by a rigid silica coating with methyl on the ANA surface to improve flexibility, resulting in not only excellent self-cleaning and hydrophobicity with a water contact angle of 142° but also outstanding elasticity. Furthermore, the as-synthesized HANAs exhibited low density (≤0.09 g/cm3), a large specific surface area (≥210.5 m2/g), and high porosity (94.9–98.7%). Hence, the HANAs displayed high absorption capacities (approximately 48.2 g/g of chloroform absorption capacity) and selectivity of oils and organic solvents. In addition, they also exhibited excellent thermal insulation performance under both hot and cold conditions. The designed HANAs are expected to provide a highly efficient method for oil–water separation and thermal insulation