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cellulose aerogel

Victor V Revin, Nikolay A Pestov, Michael V Shchankin, Vladimir M Mishkin, Vladimir I Platonov, Dmitriy A Uglanov
Aerogels with a density of 4.2-22.8 kg/m3 were obtained from bacterial cellulose synthesized in static and dynamic cultivation conditions on a molasses medium. The strength properties and porous structure of the aerogels strongly depended on their density. With a 22.8 kg/m3 aerogel density, the modulus of elasticity at 80% compression of the sample was 0.1 MPa. The decrease in the density of aerogels led to an increase in the pore sizes ranging from 20 µm to 1000 µm and a decrease in the modulus of elasticity...
February 15, 2019: Biomacromolecules
Yingzhan Li, Liqian Zhu, Nathan Grishkewich, Kam C Tam, Jinying Yuan, Zhiping Mao, Xiaofeng Sui
Cellulose nanofibers (CNFs) aerogels with controllable surface wettability were prepared by grafting poly (N, N-dimethylamino-2-ethyl methacrylate) (PDMAEMA) polymer brushes via surface-initiated atom transfer radical polymerization (SI-ATRP). After grafting PDMAEMA polymer, the surface of the aerogel was hydrophobic. While in the presence of CO2, the surface of the aerogel gradually changes from hydrophobic to hydrophilic. The porous structure and CO2-responsiveness of PDMAEMA brushes within the CNFs aerogels allowed for the on-off switching in the oil-water mixture separation process...
February 8, 2019: ACS Applied Materials & Interfaces
Daniel A Osorio, Bryan E J Lee, Jacek M Kwiecien, Xiaoyue Wang, Iflah Shahid, Ariana L Hurley, Emily D Cranston, Kathryn Grandfield
Chemically cross-linked cellulose nanocrystal (CNC) aerogels possess many properties beneficial for bone tissue scaffolding applications. CNCs were extracted using sulfuric acid or phosphoric acid, to produce CNCs with sulfate and phosphate half-ester surface groups, respectively. Hydrazone cross-linked aerogels fabricated from the two types of CNCs were investigated using scanning electron microscopy, X-ray micro-computed tomography, X-ray photoelectron spectroscopy, nitrogen sorption isotherms, and compression testing...
January 30, 2019: Acta Biomaterialia
Hong Wei Koh, Duyen K Le, Gek Nian Ng, Xiwen Zhang, Nhan Phan-Thien, Umeyr Kureemun, Hai M Duong
This work presents for the first time, a simple, practical and scalable approach to fabricating recycled polyethylene terephthalate (rPET) aerogels for thermal and acoustic insulation applications. The rPET aerogels were successfully developed from recycled PET fibers and polyvinyl alcohol (PVA) and glutaraldehyde (GA) cross-linkers using a freeze-drying process. The effects of various PET fiber concentrations (0.5, 1.0 and 2.0 by wt.%), fiber deniers (3D, 7D and 15D) and fiber lengths (32 mm and 64 mm) on the rPET aerogel structures and multi-properties were comprehensively investigated...
May 17, 2018: Gels
Juntao Tang, Yang Song, Feiping Zhao, Stewart Spinney, Juliana da Silva Bernardes, Kam Chiu Tam
A sustainable nanomaterial, cellulose nanofibril (CNF) was used to prepare aerogel sorbents to remove various contaminants in wastewater. A mussel-inspired coating strategy was used to introduce polydopamine onto the surface of CNFs, which were cross-linked with polyethylenimine (PEI) to form the aerogels. The synthetic procedure was optimized to achieve a minimal consumption of raw materials to produce a robust porous structure. The aerogels possessed a low density (25.0 mg/cm3 ), high porosity (98.5%) and shape recovery in air and water...
March 15, 2019: Carbohydrate Polymers
Xuexia Zhang, Minghui Liu, Hankun Wang, Ning Yan, Zhiyong Cai, Yan Yu
Cellulose aerogels have shown outstanding potential as renewable functional materials; however, their practical applications are still limited by inherent hydrophilicity and weak mechanical properties. To overcome hydrophilicity and fragility issues of aerogels, in this study, silylated bamboo-derived cellulose nanofibrils (CNF) aerogels with aligned porous structures were achieved by directionally freeze-casting a mixture of CNF suspension and methyltrimethoxysilane sol. The silylated CNF aerogels exhibited distinct aligned lamellar structures and significantly anisotropic mechanical properties...
March 15, 2019: Carbohydrate Polymers
Xu Xu, Fuhao Dong, Xinxin Yang, He Liu, Lizhen Guo, Yuehan Qian, Aiting Wang, Shifa Wang, Jinyue Luo
The absorbent materials synthesized from bio-sources with low cost and high selectivity for oils and organic solvents have attracted increasing attention in the field of oil spillage and discharge of organic chemicals. We developed a convenient surface-grafting method to prepare efficient and recyclable bio-based aerogels from epoxidized soybean oil (ESO)-modified cellulose at room temperature. The porous network-like structure of the cellulose aerogel was still fully retained after undergoing hydrophobic modification with ESO...
January 2, 2019: Journal of Agricultural and Food Chemistry
Wenbin Hu, Lingbin Lu, Zhanying Li, Lin Shao
Bulk Al-doped carboxymethyl cellulose aerogels were obtained via a facile slow-gel method and freeze-drying technology. In this method, the cross-linker Al3+ was released slowly and completely with enough d-(+)-gluconic acid δ-lactone as a sustained-release agent. Depended on controlled releasing of Al3+ , the reaction speed between Al3+ and carboxyl groups was controlled and Al3+ was well-distributed in the aerogels. The coordination type between Al3+ and carboxymethyl cellulose was the bidentate bridging coordination...
March 1, 2019: Carbohydrate Polymers
Marina Voronova, Natalia Rubleva, Nataliya Kochkina, Andrei Afineevskii, Anatoly Zakharov, Oleg Surov
Composite films and aerogels of polyvinylpyrrolidone/cellulose nanocrystals (PVP/CNC) were prepared by solution casting and freeze-drying, respectively. Investigations into the PVP/CNC composite films and aerogels over a wide composition range were conducted. Thermal stability, morphology, and the resulting reinforcing effect on the PVP matrix were explored. FTIR, TGA, DSC, X-ray diffraction, SEM, and tensile testing were used to examine the properties of the composites. It was revealed PVP-assisted CNC self-assembly that produces uniform CNC aggregates with a high aspect ratio (length/width)...
December 5, 2018: Nanomaterials
Hosein Bidgoli, Yadollah Mortazavi, Abbas Ali Khodadadi
A new synthesis strategy was adopted to convert cellulose to a biodegradable sorbent with properties of very high oil absorption and retention capacities, excellent oil-water selectivity, good mechanical strength and recycling ability. The sorbent in form of a hydrophobic/oleophilic nano-structured aerogel was prepared through functionalizing cotton cellulose with low surface energy moieties followed by dissolving and chemically cross-linking the product in an organic medium (DMSO), and freeze-drying. High absorption capacities of 40...
November 23, 2018: Journal of Hazardous Materials
Hao-Yang Mi, Xin Jing, Zhiyong Cai, Yuejun Liu, Lih-Sheng Turng, Shaoqin Gong
Boosting power generation performance while employing economical and biocompatible materials is an ongoing direction in the field of triboelectric nanogenerators (TENGs). Here, highly porous, biocompatible, cellulose nanofibril (CNF) composite-based TENGs are developed through an environmentally friendly freeze-drying approach. High tribopositivity materials, including silica fiber, human hair, and rabbit fur, are used as fillers in composite TENG fabrication for the first time to enhance the triboelectric output performance...
December 5, 2018: Nanoscale
Mingjie Wang, Fu Liu, Yao Chen, Jianmin Gao
The biomorphic Silicon Carbide (BioSiC) ceramic with highly interconnected porous three-dimensional (3D) structure was fabricated by utilizing balsa wood cellulose nanofibers aerogel as the biotemplate and polycarbosilane (PCS) as the preceramic precursor. Evolution of morphology, composition, and pore properties from untreated wood to porous BioSiC was investigated systemically. The shrinkage and weight gain during pyrolysis was discussed. It was found that the structure of as-synthesized BioSiC was related to the microstructure of wood aerogel template and the concentration of PCS precursor...
November 30, 2018: Materials
Amir Sheikhi, Joel Hayashi, James Eichenbaum, Mark Gutin, Nicole Kuntjoro, Danial Khorsandi, Ali Khademhosseini
The recent decade has witnessed a growing demand to substitute synthetic materials with naturally-derived platforms for minimizing their undesirable footprints in biomedicine, environment, and ecosystems. Among the natural materials, cellulose, the most abundant biopolymer in the world with key properties, such as biocompatibility, biorenewability, and sustainability has drawn significant attention. The hierarchical structure of cellulose fibers, one of the main constituents of plant cell walls, has been nanoengineered and broken down to nanoscale building blocks, providing an infrastructure for nanomedicine...
November 27, 2018: Journal of Controlled Release: Official Journal of the Controlled Release Society
Jean Paulo de Oliveira, Graziella Pinheiro Bruni, Shanise Lisie Mello El Halal, Fabiano Cleber Bertoldi, Alvaro Renato Guerra Dias, Elessandra da Rosa Zavareze
This study describes the valorization of rice and oat husks by obtaining cellulose nanocrystals for the production of aerogels for food packaging applications. Commercial cellulose was used as a control sample. Nanocrystals from cellulose were obtained by enzymatic hydrolysis and mechanical treatment at high pressure. The morphology, particle size, functional groups, crystallinity, and thermal properties of the cellulose nanocrystals were analyzed. The morphology, functional groups, crystallinity, water absorption capability, and zeta potential of aerogels were also analyzed...
November 21, 2018: International Journal of Biological Macromolecules
Chao Lei, Junkuo Gao, Wenjing Ren, Yuanbo Xie, Somia Yassin Hussain Abdalkarim, Shunli Wang, Qingqing Ni, Juming Yao
In the present work, we develop novel method of loading metal-organic frameworks (UiO-66 and UiO-66-NH2 ) on the flexible cellulose aerogels as metal-organic frameworks@cellulose aerogels composite materials by using in situ growth procedure at room temperature. The as prepared metal-organic frameworks@cellulose aerogels composite materials were well characterized via SEM, XRD, atomic absorption spectrometer, and TG analysis, besides the adsorption of Pb2+ and Cu2+ in metal-organic frameworks@cellulose aerogels composite materials was investigated...
February 1, 2019: Carbohydrate Polymers
Beini Zeng, Xungai Wang, Nolene Byrne
Cellulose aerogels with orientated micron-sized pore structure were obtained from denim waste utilizing ionic liquid solvents through dissolution, regeneration and drying. The pore structure of denim-derived aerogels was comprised of a mixture of micron-sized vertically aligned pores and a nanoporous fibrous network. The size and distribution of vertically aligned pores and the nanopores were influenced by the choice of ionic liquid solvent, amount of denim used and drying method employed. A detailed study on the morphology of the cellulose aerogels produced from waste denim is provided...
February 1, 2019: Carbohydrate Polymers
Kathirvel Ganesan, Tatiana Budtova, Lorenz Ratke, Pavel Gurikov, Victor Baudron, Imke Preibisch, Philipp Niemeyer, Irina Smirnova, Barbara Milow
A detailed study of the production of polysaccharide aerogel (bio-aerogel) particles from lab to pilot scale is surveyed in this article. An introduction to various droplets techniques available in the market is given and compared with the lab scale production of droplets using pipettes and syringes. An overview of the mechanisms of gelation of polysaccharide solutions together with non-solvent induced phase separation option is then discussed in the view of making wet particles. The main steps of particle recovery and solvent exchange are briefly described in order to pass through the final drying process...
October 31, 2018: Materials
Hongyuan Zhang, Shangyun Lyu, Xiaomin Zhou, Hongbo Gu, Chao Ma, Chunhui Wang, Tao Ding, Qian Shao, Hu Liu, Zhanhu Guo
In this work, the concentration effect of both nanocellulose and sodium dodecylsulfate (SDS) on the fabrication of a super light 3D hierarchical framework adsorbent nanocellulose aerogel foam (NAF) is exploited through a high speed mechanical foaming and solvent-free method by adding SDS. The results show that the optimal concentration of nanocellulose and SDS for preparation of this 3D NAF/SDS is 0.4 and 0.2 wt%, accordingly. By utilizing unique gridding framework of NAF/SDS, a low density of 1.50 mg cm-3 and high adsorption capacity of 206...
February 15, 2019: Journal of Colloid and Interface Science
Chaoji Chen, Liangbing Hu
Cellulose is the most abundant biopolymer on Earth and has long been used as a sustainable building block of conventional paper. Note that nanocellulose accounts for nearly 40% of wood's weight and can be extracted using well-developed methods. Due to its appealing mechanical and electrochemical properties, including high specific modulus (∼100 GPa/(g/cm3 )), excellent stability in most solvents, and stability over a wide electrochemical window, nanocellulose has been widely used as a separator, electrolyte, binder, and substrate material for energy storage...
October 9, 2018: Accounts of Chemical Research
Hao Guan, Zhiyong Cheng, Xiaoqing Wang
Aerogels derived from nanocellulose have emerged as attractive absorbents for cleaning up oil spills and organic pollutants due to their lightweight, exceptional absorption capacity, and sustainability. However, the majority of the nanocellulose aerogels based on the bottom-up fabrication process still lack sufficient mechanical robustness because of their disordered architecture with randomly assembled cellulose nanofibrils, which is an obstacle to their practical application as oil absorbents. Herein, we report an effective strategy to create anisotropic cellulose-based wood sponges with a special spring-like lamellar structure directly from natural balsa wood...
October 3, 2018: ACS Nano
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