Radical–Polar Crossover Reactions: Oxidative Coupling of 1,3-Dioxolanes with Electron-Deficient Alkenes and Vinylarenes Based on a Radical Addition and Kornblum–DeLaMare Rearrangement

A new radical-polar crossover reaction has been developed involving the combination of a tandem radical reaction and Kornblum–DeLaMare rearrangement in a one-pot process. This simple methodology allows for the construction of polyfunctionalized carbonyl compounds via the oxidative coupling of 1,3-dioxolanes with electron-deficient alkenes and vinylarenes in the presence of Co­(salen) and TBHP under mild conditions. This reaction also exhibited high functional group tolerance, wide substrate scope, and operational simplicity

Bu₄NI-Catalyzed Cross-Coupling between Sulfonyl Hydrazides and Diazo Compounds To Construct β‑Carbonyl Sulfones Using Molecular Oxygen

A new cross-coupling reaction between sulfonyl hydrazides and diazo compounds has been established, leading to a variety of β-carbonyl sulfones in good yields. This methodology was distinguished by simple manipulation, easily available starting materials, and wide substrate scope. A plausible mechanism involving a radical process was proposed based upon the experimental observations and literature

Design of Eu³⁺-Doped Fluoride Phosphor with Zero Thermal Quenching Property Based on Density Functional Theory

Although being applied in various fields, white light emitting diodes (WLEDs) still have drawbacks that urgently need to be conquered: the luminescent intensity of commercial phosphors sharply decreases at working temperature. In this study, we calculated the forming energy of defects and confirmed that the VNa defect state can stably exist in β-NaGdF4, by density functional theory (DFT) calculation. Furthermore, we predicted that the VNa vacancies would provide a zero thermal quenching (ZTQ) property for the β-NaGdF4-based red-light phosphor. Then, a series of β-NaGdF4:xEu3+ and β-NaGdF4:0.25Eu3+,yYb3+ red-light phosphors were synthesized by the hydrothermal method. We found that β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+ phosphors possess ZTQ properties at a temperature range between 303–483 K and 303–523 K, respectively. The thermoluminescence (TL) spectra were employed to calculate the depth and density of the VNa vacancies in β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+. Combining the DFT calculation with characterization results of TL spectra, it is concluded that electrons stored in VNa vacancies are excited to the exited state of Eu3+ to compensate for the loss of Eu3+ luminescent intensity. This will lead to an increase of luminescent intensity at high temperatures and facilitate the samples to improve ZTQ properties. WLEDs were obtained with CRI = 83.0, 81.6 and CCT = 5393, 5149 K, respectively, when phosphors of β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+ were utilized as the red-light source. These results indicate that these two phosphors may become reliable red-light sources with high antithermal quenching properties for WLEDs

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

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