Flame-retardant polyvinyl alcohol/cellulose nanofibers hybrid carbon aerogel by freeze drying with ultra-low phosphorus

Under the current situation of frequent oil spills, the development of green and recyclable high-efficiency oil-absorbing aerogel materials has attracted wide attention from researchers. In this study, we report a high-strength, three-dimensional hydrophobic cellulose nanofiber (CNF)/polyvinyl alcohol (PVA)/graphene oxide (GO) composite aerogel with an anisotropic porous structure, which was fabricated by directional freeze-drying technology using anisotropically grown ice crystals as a template, followed by hydrophobic treatment with a simple dip coating process. The prepared composite aerogel presented anisotropic multi-level pore microstructures, low density (17.95 mg/cm3) and high porosity (98.8%), good hydrophobicity (water contact angle of 142°) and great adsorption capacity (oil absorption reaching 96 times its own weight). More importantly, the oriented aerogel had high strength, whose compressive stress at 80% strain reached 0.22 MPa and could bear more than 22,123 times its own weight without deformation. Therefore, the CNF/PVA/GO composite aerogel prepared by a simple and easy-to-operate directional freeze-drying method is a promising absorbent for oil-water separation.

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Novel Cellulose Nanofibers/Polyvinyl Alcohol/Polyethyleneimine Nanoparticle for Cu2+ Removal in Water

10.21203/rs.3.rs-485817/v1 ◽

2021 ◽

Author(s):

Rongrong Si ◽

Chaojun Wu ◽

Dongmei Yu ◽

Qijun Ding ◽

Ronggang Li

Keyword(s):

Polyvinyl Alcohol ◽

Freeze Drying ◽

Removal Rate ◽

Cellulose Nanofibers ◽

Drying Method ◽

Order Model ◽

Bending Vibration ◽

Pseudo Second Order ◽

Kinetics Of ◽

Structurally Stable

Abstract In this study, environmentally friendly CNF/PVA/PEI nanoparticle was obtained by assembling PEI (polyethyleneimine) into CNF/PVA aerogels, which were prepared by freeze-drying method with the help of glutaraldehyde. FTIR results showed that PEI likely assembled into the CNF/PVA aerogel due to appearances of bending vibration of the CNF/PVA/PEI nanoparticle at 1615cm− 1. BET results further demonstrated that PEI have successfully assembled into aerogel since the specific surface area (22.93m2/g) of CNF/PVA/PEI nanoparticle was lower than that (56.37m2/g) of CNF/PVA aerogel. SEM results also showed that PEI could obviously regulate the morphology of CNF/PVA aerogel. TGA indicated that CNF/PVA/PEI nanoparticle was structurally stable at 216.4°C. The adsorption kinetics of the CNF/PVA/PEI nanoparticle for Cu2+ removal presented good correlations with the Pseudo-second-order model. The adsorption and desorption results showed that the removal rate of 2g/L CNF/PVA/PEI nanoparticle for Cu2+in water could reach more than 93% when the concentration of Cu2+ ranged from 20 to 80mg/L in one hour, and it could still retain more than 80% after 3 cycles.

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Core–shell expandable graphite @ layered double hydroxide as a flame retardant for polyvinyl alcohol

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-021-10843-x ◽

2021 ◽

Author(s):

Haozhe Ning ◽

Zhongying Ma ◽

Zhihao Zhang ◽

Dan Zhang ◽

Yuhua Wang

Keyword(s):

Polyvinyl Alcohol ◽

Flame Retardant ◽

Layered Double Hydroxide ◽

Expandable Graphite ◽

Core Shell ◽

Double Hydroxide

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Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

Nano-Micro Letters ◽

10.1007/s40820-021-00635-1 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Weihua Gu ◽

Jiaqi Sheng ◽

Qianqian Huang ◽

Gehuan Wang ◽

Jiabin Chen ◽

...

Keyword(s):

Microwave Absorption ◽

Thermal Insulation ◽

Freeze Drying ◽

Thermal Infrared ◽

Carbon Aerogel ◽

Carbon Aerogels ◽

List Type ◽

Drying Method ◽

Cross Sectional ◽

Compression Resistance

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

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Structural analysis of α-zirconium phosphate/cerium phosphate/graphene oxide nanocomposites with flame-retardant properties in polyvinyl alcohol

New Journal of Chemistry ◽

10.1039/c9nj06253j ◽

2020 ◽

Vol 44 (11) ◽

pp. 4568-4577 ◽

Cited By ~ 2

Author(s):

Qian Leng ◽

Junyi Li ◽

Yuhua Wang

Keyword(s):

Graphene Oxide ◽

Structural Analysis ◽

Polyvinyl Alcohol ◽

Flame Retardant ◽

Zirconium Phosphate ◽

Cerium Phosphate ◽

Ternary Nanocomposite ◽

Flame Retardant Properties ◽

Synergistic Flame Retardant

A ternary nanocomposite was developed, which exhibits novel synergistic flame-retardant effect with APP-containing PVA.

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Cellulose Nanofibers Derived Carbon Aerogel with 3D Multiscale Pore Architecture for High-Performance Supercapacitors

Nanoscale ◽

10.1039/d1nr04838d ◽

2021 ◽

Author(s):

Lumin Chen ◽

Hou-Yong Yu ◽

Ziheng Li ◽

Xiang Chen ◽

Wenlong Zhou

Keyword(s):

High Performance ◽

Electrode Materials ◽

Carbon Materials ◽

Cellulose Nanofibers ◽

Rate Capability ◽

Carbon Aerogel ◽

Large Specific Surface Area ◽

Hierarchical Porous Structure ◽

Pore Architecture ◽

Hierarchical Porous

Carbon materials are highly promising electrode materials for supercapacitors, due to their hierarchical porous structure and large specific surface area. However, the limited specific capacitance and inferior rate capability significantly...

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