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cellulose aerogel

Xiao Wei, Ting Huang, Jun Nie, Jing-Hui Yang, Xiao-Dong Qi, Zuo-Wan Zhou, Yong Wang
As one of the materials from natural resources, the functionalization and application of cellulose attract increasing concerns. In this work, we reported a facile method to prepare the bio-inspired functionalization of microcrystalline cellulose (MCC) aerogel through polydopamine (PDA) coating, which was realized via the self-polymerization of dopamine in the MCC/LiBr solution followed by the freeze-drying technology. The morphological characterization showed that the pore morphologies of the compounded aerogel were influenced by the content of PDA...
October 15, 2018: Carbohydrate Polymers
Jian Zhou, You-Lo Hsieh
Strong and highly conductive aerogels have been assembled from cellulose nanofibrils (CNFs) protonated with conductive poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) complex at equal mass or less. Protonating CNF surface carboxylates and hydrogen-bonding CNF surface carboxyls with PSS in PEDOT/PSS generated PEDOT/PSS/CNF aerogels that were up to ten times stronger while as conductive as neat PEDOT/PSS aerogel, attributed to the transformation of PEDOT benzoid structure to the more electron transfer-preferred quinoid structure...
August 9, 2018: ACS Applied Materials & Interfaces
Fang Ren, Zhen Li, Wen-Zhen Tan, Xiao-Hui Liu, Zhen-Feng Sun, Peng-Gang Ren, Ding-Xiang Yan
Composite aerogels consisting of graphene oxide (GO) and regenerated cellulose (RCE) were prepared via a solution mixing-regeneration and freeze-drying process. The prepared RCE/GO composites aerogel exhibited 3D network thin-walled pore structure with large specific surface area, also favorable compression recovery capability, outstanding dye elimination efficiency and reusability after the addition of GO. With addition of only 0.5 wt% GO, the methylene blue (MB) elimination efficiency of RCE/GO aerogel reached 99...
July 27, 2018: Journal of Colloid and Interface Science
K Srasri, M Thongroj, P Chaijiraaree, S Thiangtham, H Manuspiya, P Pisitsak, S Ummartyotin
In this study, we have attempted to extract cellulose fiber from newspaper waste for circular economy project. Cellulose was successfully extracted from newspaper waste with high purity. It was further developed as a composite with Fe3 O4 powder. 10-30 wt% of Fe3 O4 was synthesized from conventional synthetic route and it was uniformly distributed into cellulose suspension. The composite was prepared by freeze-dry technique in order to remove water and create the porosity. X-ray diffraction and thermogravimetric analysis were employed to characterize the structural and thermal properties of composite...
July 21, 2018: International Journal of Biological Macromolecules
Muhammad Farooq, Mika H Sipponen, Ari Seppälä, Monika Österberg
Cellulose nanofiber (CNF) aerogels offer excellent thermal insulation properties, but high flammability restricts their application. In this study, CNF aerogels were prepared by incorporating sodium bicarbonate (SBC), which effectively improved the fire retardancy without compromising the thermal conductivity of the aerogels, which was only 28 mW m-1 K-1 . The minimum burning velocity of flame-retardant aerogels was 0.20 cm s-1 at 40 wt % of SBC, which is significantly lower compared to 5.84 cm s-1 of pure CNF aerogels...
August 2, 2018: ACS Applied Materials & Interfaces
J Vincent Edwards, Krystal R Fontenot, Falk Liebner, Brian D Condon
The growing incidence of chronic wounds in the world population has prompted increased interest in chronic wound dressings with protease-modulating activity and protease point of care sensors to treat and enable monitoring of elevated protease-based wound pathology. However, the overall design features needed for the combination of a chronic wound dressing that lowers protease activity along with protease detection capability as a single platform for semi-occlusive dressings has scarcely been addressed. The interface of dressing and sensor specific properties (porosity, permeability, moisture uptake properties, specific surface area, surface charge, and detection) relative to sensor bioactivity and protease sequestrant performance is explored here...
July 18, 2018: Sensors
Xuesong Ge, Youna Shan, Lin Wu, Xindong Mu, Hui Peng, Yijun Jiang
Composite aerogels with excellent mechanical properties were prepared by using carboxymethyl cellulose (CMC) as raw materials, 2D graphene oxide (GO) nanosheets as reinforcement, boric acid (BA) as cross-linker. By controlling the heat transfer rate, composite aerogels with isotropy and anisotropy structure were prepared, the mechanical and heat insulation properties were studied. The isotropy composite aerogel had compression strength of 110 kPa at 60% compression, which was 5 times of the axial and 14 times of the radial of anisotropy structure composite aerogels, and thermal conductivity was also lower than those of two directions of anisotropy composite aerogel...
October 1, 2018: Carbohydrate Polymers
Hongjuan Geng
This work reported a facile approach to make cellulose-based aerogels in NaOH/urea aqueous solution via freeze-drying hydrogels, which were obtained by mixing N,N'-methylene bisacrylamide (MBA) with cellulose solution at room temperature. The cellulose solution showed pronounced MBA-induced gelation behaviors. The obtained cellulose aerogels possessed a three dimensional network with macroporous structure (20-600 μm), low density (0.0820-0.0083 g/cm3 ), high porosity (90.3%-99.02%), moderate thermal stability (275 °C) and certain absorbency to Cu (II) (85 mg/g) and methylene blue (MB) (115 mg/g)...
June 30, 2018: International Journal of Biological Macromolecules
Yixi Wang, Linyan Zhao, Juan Hou, Huili Peng, Jianning Wu, Zhiyong Liu, Xuhong Guo
In this study, a highly efficient and eco-friendly porous cellulose-based aerogel was synthesized by grafting polyethyleneimine onto quaternized cellulose (PQC) to remove the anionic dye Congo Red (CR). The prepared aerogel had a good flexibility and formability. The adsorbents were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and elemental analysis. The results showed that there were many amino groups on CE/PQC aerogel and the structure was porous, which increased the adsorption capacity...
June 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Jian Li, Keman Zuo, Weibing Wu, Zhaoyang Xu, Yonggang Yi, Yi Jing, Hongqi Dai, Guigan Fang
This study describes the preparation of an aerogel adsorbent based on nanofibrillated cellulose(NFC) and polyethyleneimine(PEI) via electrostatic combination without chemical crosslinking. Purely physical crosslinking between NFC and PEI was confirmed by attenuated total refraction-Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). The NFC/PEI hybrid aerogels exhibited good structural stability and shape recovery in water. Absorption experiment shows that the hybrid aerogels are excellent adsorbents for the removal of heavy metal ions owing to the highly porous structure and the existence of plenty of amine groups...
September 15, 2018: Carbohydrate Polymers
Hongjuan Geng
Cellulose/N,N'-methylene bisacrylamide/graphene oxide hydrogels were prepared by mixing cellulose with N,N'-methylene bisacrylamide (MBA) and graphene oxide (GO) in NaOH/urea aqueous solution. Two states of hydrogels, i.e. the freshly prepared hydrogels and the hydrogels at swelling equilibrium state in deionized water, were prepared. The gelation time, mechanical properties, transparency, texture properties and water retention ratio of the hydrogels were investigated. Results showed that the cellulose solution showed obvious MBA and GO induced gelation behaviors...
September 15, 2018: Carbohydrate Polymers
Hanwei Wang, Yipeng Chen, Baokang Dang, Xiaoping Shen, Chunde Jin, Qingfeng Sun, Jianchuan Pei
The serious agglomeration phenomenon of ultrafine nanoparticles is widespread, resulting in low utilization and poor performance of adsorbents in the scavenging of toxic ions. Herein, ultrafine MnFe2 O4 (8-13 nm) are uniformly anchored onto the cellulose framework by fast hydrothermal and freeze-drying processes. The as-prepared super-hydrophilic MnFe2 O4 /cellulose aerogel (MCA) had a three-dimensional (3D) network structure with interconnected and forked fibrils, developed porous structure and high surface area...
September 15, 2018: Carbohydrate Polymers
Fred J Burpo, Alexander N Mitropoulos, Enoch A Nagelli, Jesse L Palmer, Lauren A Morris, Madeline Y Ryu, J Kenneth Wickiser
Noble metal aerogels offer a wide range of catalytic applications due to their high surface area and tunable porosity. Control over monolith shape, pore size, and nanofiber diameter is desired in order to optimize electronic conductivity and mechanical integrity for device applications. However, common aerogel synthesis techniques such as solvent mediated aggregation, linker molecules, sol⁻gel, hydrothermal, and carbothermal reduction are limited when using noble metal salts. Here, we present the synthesis of palladium aerogels using carboxymethyl cellulose nanofiber (CNF) biotemplates that provide control over aerogel shape, pore size, and conductivity...
June 9, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Duanchao Wang, Houyong Yu, Xuemeng Fan, Jiping Gu, Shounuan Ye, Juming Yao, Qingqing Ni
Charged nanocellulose (NC) with a high aspect ratio (larger than 100) extracted from animal or bacterial cellulose and chemical cross-linked NC aerogels have great promising applicability in material science, but facile fabrication of such NC aerogels from plant cellulose by physical cross-linking still remains a major challenge. In this work, carboxylated cellulose nanofiber (CNF) with the highest aspect ratio of 144 was extracted from wasted ginger fibers by a simple one-step acid hydrolysis. Our approach could easily make the carboxylated CNF assemble into robust bulk aerogels with tunable densities and desirable shapes on a large scale (3D macropores to mesopores) by hydrogen bonds...
June 20, 2018: ACS Applied Materials & Interfaces
Wenwen Guo, Xin Wang, Ping Zhang, Jiajia Liu, Lei Song, Yuan Hu
Thermally insulating materials made from renewable resources are desirable for energy efficient buildings. Traditional petroleum-derived insulating materials such as rigid polyurethane foam and expanded polystyrene display poor flame retardancy and inorganic insulating materials such as silica aerogel are fragile. Herein, we reported a facile approach to prepare cellulose nanofiber (CNF)-hydroxyapatite (HAP) composite foam by a simple freeze-drying process. The resultant HAP-CNF composite foams showed a thermal conductivity in the range of 38...
September 1, 2018: Carbohydrate Polymers
Yu Wu, Yang Zhang, Nanqing Chen, Sheng Dai, Hua Jiang, Siqun Wang
In this work, cellulose nanofibrils (CNFs) were used to develop novel amine-based aerogels that can be applied as adsorbents for CO2 . Elemental analysis indicated that there was an increase in the C and N content when the concentration of aminosilane was higher. Moreover, Fourier transform infrared spectroscopy confirmed that the aminosilane had been grafted on the CNF. Thermal analysis and X-ray diffraction revealed that the thermal stability of the aerogel decreased after the modification, and the crystallinity decreased...
August 15, 2018: Carbohydrate Polymers
Zhen-Yu Wu, Hai-Wei Liang, Bi-Cheng Hu, Shu-Hong Yu
Carbon aerogels that are typically prepared using sol-gel chemistry have unique three dimensional networks of interconnected nanometer-sized particles and thus exhibit many fascinating physical properties and great application potentials in widespread fields. To boost the practical applications, it is urgent to develop efficient and low-cost methods to produce high-performance carbon aerogels in large-scale, preferably in a sustainable way. In 2012, two new classes of aerogels consisting of carbon nanofiber (CNF) networks were prepared from biomass-derived precursor by chemosynthesis (i...
May 16, 2018: Angewandte Chemie
Zhaoyang Xu, Xiangdong Jiang, Sicong Tan, Weibing Wu, Jiangtao Shi, Huan Zhou, Peng Chen
In recent years, carbon aerogels have attracted much attention in basic research and as potential applications in many fields. Herein, the authors report a novel approach using bamboo powder as raw material to fabricate cellulose nanofibers (CNFs)/multi-walled carbon nanotubes (MWCNTs) carbon aerogels by a simple dipping and carbonisation process. The developed material exhibits many exciting properties including low density (0.056 g cm-3 ), high porosity (95%), efficient capability for separation of oily droplets from water, and high adsorption capacity for a variety of oils and organic solvents by up to 110 times its own weight...
June 2018: IET Nanobiotechnology
Chunhui Wang, Xiong Chen, Bin Wang, Ming Huang, Bo Wang, Yi Jiang, Rodney S Ruoff
We report the assembly of graphene oxide (G-O) building blocks into a vertical and radially aligned structure by a bidirectional freeze-casting approach. The crystallization of water to ice assembles the G-O sheets into a structure, a G-O aerogel whose local structure mimics turbine blades. The centimeter-scale radiating structure in this aerogel has many channels whose width increases with distance from the center. This was achieved by controlling the formation of the ice crystals in the aqueous G-O dispersion that grew radially in the shape of lamellae during freezing...
May 14, 2018: ACS Nano
Luting Zhu, Lu Zong, Xiaochen Wu, Mingjie Li, Haisong Wang, Jun You, Chaoxu Li
Conventional metal-organic framework (MOF) powders have periodic micro/mesoporous crystalline architectures tuned by their three-dimensional coordination of metal nodes and organic linkers. To add practical macroscopic shapeability and extrinsic hierarchical porosity, fibrous MOF aerogels were produced by synthesizing MOF crystals on the template of TEMPO-cellulose nanofibrils. Cellulose nanofibrils not only offered extrinsic porosities and mechanical flexibility for the resultant MOF aerogels, but also shifted the balance of nucleation and growth for synthesizing smaller MOF crystals, and further decreased their aggregation possibilities...
May 22, 2018: ACS Nano
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