Bacterial Cellulose Aerogels: From Lightweight Dietary Food to Functional Materials

Author(s):  
Falk Liebner ◽  
Nikita Aigner ◽  
Christian Schimper ◽  
Antje Potthast ◽  
Thomas Rosenau
Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1422
Author(s):  
Viktor V. Revin ◽  
Alexander V. Dolganov ◽  
Elena V. Liyaskina ◽  
Natalia B. Nazarova ◽  
Anastasia V. Balandina ◽  
...  

Currently, there is an increased demand for biodegradable materials in society due to growing environmental problems. Special attention is paid to bacterial cellulose, which, due to its unique properties, has great prospects for obtaining functional materials for a wide range of applications, including adsorbents. In this regard, the aim of this study was to obtain a biocomposite material with adsorption properties in relation to fluoride ions based on bacterial cellulose using a highly productive strain of Komagataeibacter sucrofermentans H-110 on molasses medium. Films of bacterial cellulose were obtained. Their structure and properties were investigated by FTIR spectroscopy, NMR, atomic force microscopy, scanning electron microscopy, and X-ray structural analysis. The results show that the fiber thickness of the bacterial cellulose formed by the K. sucrofermentans H-110 strain on molasses medium was 60–90 nm. The degree of crystallinity of bacterial cellulose formed on the medium was higher than on standard Hestrin and Schramm medium and amounted to 83.02%. A new biocomposite material was obtained based on bacterial cellulose chemically immobilized on its surface using atomic-layer deposition of nanosized aluminum oxide films. The composite material has high sorption ability to remove fluoride ions from an aqueous medium. The maximum adsorption capacity of the composite is 80.1 mg/g (F/composite). The obtained composite material has the highest adsorption capacity of fluoride from water in comparison with other sorbents. The results prove the potential of bacterial cellulose-based biocomposites as highly effective sorbents for fluoride.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2218
Author(s):  
Binbin Wu ◽  
Yikai Sun ◽  
Qiujin Fan ◽  
Jiahui Chen ◽  
Weizheng Fang ◽  
...  

In this report, phthalocyanine (Pc)/reduced graphene (rG)/bacterial cellulose (BC) ternary nanocomposite, Pc-rGBC, was developed through the immobilization of Pc onto a reduced graphene–bacterial cellulose (rGBC) nanohybrid after the reduction of biosynthesized graphene oxide-bacterial cellulose (GOBC) with N2H4. Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to monitor all of the functionalization processes. The Pc-rGBC nanocomposite was applied for the treatment of phenol wastewater. Thanks to the synergistic effect of BC and rG, Pc-rGBC had good adsorption capacity to phenol molecules, and the equilibrium adsorption data fitted well with the Freundlich model. When H2O2 was presented as an oxidant, phenol could rapidly be catalytically decomposed by the Pc-rGBC nanocomposite; the phenol degradation ratio was more than 90% within 90 min of catalytic oxidation, and the recycling experiment showed that the Pc-rGBC nanocomposite had excellent recycling performance in the consecutive treatment of phenol wastewater. The HPLC result showed that several organic acids, such as oxalic acid, maleic acid, fumaric acid, glutaric acid, and adipic acid, were formed during the reaction. The chemical oxygen demand (COD) result indicated that the formed organic acids could be further mineralized to CO2 and H2O, and the mineralization ratio was more than 80% when the catalytic reaction time was prolonged to 4 h. This work is of vital importance, in terms of both academic research and industrial practice, to the design of Pc-based functional materials and their application in environmental purification.


2018 ◽  
Vol 16 (1_suppl) ◽  
pp. 163-169 ◽  
Author(s):  
Xinhua Liu ◽  
Yong Li ◽  
Zhaoyang Chu ◽  
Yinchun Fang ◽  
Hongliang Zheng

Introduction: Bacterial cellulose (BC) aerogels have received more and more attention due to their renewability, biodegradability and other excellent properties in recent years. Modification of BC aerogels using different methods would expand their applications. However, many problems exist for these modifications, such as a low grafting ratio, the larger dosage of metal catalyst required and so on. Activator regeneration by electron transfer (ARGET) for atom transfer radical polymerization (ATRP) is a novel ATRP method which could significantly reduce the amount of metal catalyst required and achieve a high grafting ratio. Methods: Novel nanostructured BC aerogels containing epoxy groups were prepared by the ARGET ATRP method. BC aerogels were functionalized with initiating sites by reaction with 2-bromoisobutyryl bromide (BiBBr), and followed by ARGET ATRP reaction with glycidyl methacrylate (GMA) which was catalyzed by copper(II) bromide (CuBr2) and N,N,N',N,'N"-pentamethyldiethylenetriamine (PMDETA), and then reduced by vitamin C. BC aerogels containing epoxy groups (BC-g-PGMA) were obtained after freeze-drying. The influence factors of the solvent ratio of N,N-dimethyl formamide (DMF)/toluene, monomer concentration, the concentration of CuBr2, the molar ratio of vitamin C (Vc)/CuBr2,reaction temperature and time on the grafting ratio were investigated. Results: The results showed that the optimal DMF and toluene volume ratio was 2:1, the optimal monomer and CuBr2 concentration were 2 mol/l and 1.5 mmol/l. The optimal molar ratio of PMDETA/CuBr2 and Vc/CuBr2 were 4:1 and 1:1. The optimal reaction temperature and time were 60°C and 9 h. Scanning electron microscopy (SEM) images showed that GMA was strongly adhered onto the surface and inside of the BC pellicle. Conclusions: GMA was self-grown on the BC surface and achieved the high grafting ratio of 1052.7% under optimal conditions. The BC-g-PGMA aerogels containing the epoxy groups will provide wider application prospects in drug release, enzyme fixed, functional materials and other fields.


Author(s):  
Yoichi Ishida ◽  
Hideki Ichinose ◽  
Yutaka Takahashi ◽  
Jin-yeh Wang

Layered materials draw attention in recent years in response to the world-wide drive to discover new functional materials. High-Tc superconducting oxide is one example. Internal interfaces in such layered materials differ significantly from those of cubic metals. They are often parallel to the layer of the neighboring crystals in sintered samples(layer plane boundary), while periodically ordered interfaces with the two neighboring crystals in mirror symmetry to each other are relatively rare. Consequently, the atomistic features of the interface differ significantly from those of cubic metals. In this paper grain boundaries in sintered high-Tc superconducting oxides, joined interfaces between engineering ceramics with metals, and polytype interfaces in vapor-deposited bicrystal are examined to collect atomic information of the interfaces in layered materials. The analysis proved that they are not neccessarily more complicated than that of simple grain boundaries in cubic metals. The interfaces are majorly layer plane type which is parallel to the compound layer. Secondly, chemical information is often available, which helps the interpretation of the interface atomic structure.


2020 ◽  
Vol 11 (48) ◽  
pp. 7603-7624
Author(s):  
Ismail Altinbasak ◽  
Mehmet Arslan ◽  
Rana Sanyal ◽  
Amitav Sanyal

This review provides an overview of synthetic approaches utilized to incorporate the thiol-reactive pyridyl-disulfide motif into various polymeric materials, and briefly highlights its utilization to obtain functional materials.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
SH Kim ◽  
MJ Lee ◽  
J Han ◽  
CE Lee

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