Design of photochemical materials for carbohydrate production via the immobilisation of whole plant cells into a porous silica matrix

2010 ◽  
Vol 20 (5) ◽  
pp. 929-936 ◽  
Author(s):  
Christophe F. Meunier ◽  
Joanna C. Rooke ◽  
Alexandre Léonard ◽  
Pierre Van Cutsem ◽  
Bao-Lian Su
Keyword(s):  
Porous Silica ◽  
Plant Cells ◽  
Silica Matrix ◽  
Whole Plant

Bioencapsulation in Sol-Gel Glasses

1998 ◽  
Vol 519 ◽  
Author(s):  
L. Bergogne ◽  
S. Fennouh ◽  
J. Livage ◽  
C. Roux
Keyword(s):  
Sol Gel ◽  
Porous Silica ◽  
Silica Matrix ◽  
Whole Cells ◽  
The Past ◽  
Wide Range ◽  
Activity Of Enzymes ◽  
Gel Glasses ◽  
Micro Organisms

AbstractBioencapsulation in sol-gel materials has been widely studied during the past decade. Trapped species appear to retain their bioactivity in the porous silica matrix. Small analytes can diffuse through the pores allowing bioreactions to be performed in-situ, inside the sol-gel glass. A wide range of biomolecules and micro-organisms have been encapsulated. The catalytic activity of enzymes is used for the realization of biosensors or bioreactors. Antibody-antigen recognition has been shown to be feasible within sol-gel matrices. Trapped antibodies bind specifically the corresponding haptens and can be used for the detection of traces of chemicals. Even whole cells are now encapsulated without any alteration of their cellular organization. They can be used for the production of chemicals or as antigens for immunoassays.

Controlled growth of ZnS:Mn nanophosphor in porous silica matrix

2004 ◽  
Vol 96 (11) ◽  
pp. 6700-6705 ◽  
Author(s):  
D. Haranath ◽  
Nitesh Bhalla ◽  
Harish Chander ◽  
Rashmi ◽  
Meenakshi Kar ◽  
...  
Keyword(s):  
Porous Silica ◽  
Silica Matrix ◽  
Controlled Growth

CeO2 nanodots embedded in a porous silica matrix as an active yet durable catalyst for HCl oxidation

2016 ◽  
Vol 6 (13) ◽  
pp. 5116-5123 ◽  
Author(s):  
Xian Chen ◽  
Xihua Xu ◽  
Zhaoyang Fei ◽  
Xingxing Xie ◽  
Jiawei Lou ◽  
...  
Keyword(s):  
Surface Defects ◽  
Porous Silica ◽  
Silica Matrix ◽  
Redox Ability

The nano-sized CeO2 particles (2–4 nm) with significantly rich surface defects and excellent redox ability uniformly embedded in the porous SiO2 matrix exhibit superior and durable activity (1.60 gCl2 gcat−1 h−1) with a time on stream of 100 h.

scholarly journals Bacterial Cyanuric Acid Hydrolase for Water Treatment

2015 ◽  
Vol 81 (19) ◽  
pp. 6660-6668 ◽  
Author(s):  
Sujin Yeom ◽  
Baris R. Mutlu ◽  
Alptekin Aksan ◽  
Lawrence P. Wackett
Keyword(s):  
Cyanuric Acid ◽  
Porous Silica ◽  
Silica Matrix ◽  
Water Disinfection ◽  
Significant Activity ◽  
Acid Hydrolase ◽  
Acid Hydrolases ◽  
Content Type ◽  
Silica Bead ◽  
Degradation Rates

ABSTRACTDi- and trichloroisocyanuric acids are widely used as water disinfection agents, but cyanuric acid accumulates with repeated additions and must be removed to maintain free hypochlorite for disinfection. This study describes the development of methods for using a cyanuric acid-degrading enzyme contained within nonliving cells that were encapsulated within a porous silica matrix. Initially, three different bacterial cyanuric acid hydrolases were compared: TrzD fromAcidovorax citrullistrain 12227, AtzD fromPseudomonassp. strain ADP, and CAH fromMoorella thermoaceticaATCC 39073. Each enzyme was expressed recombinantly inEscherichia coliand tested for cyanuric acid hydrolase activity using freely suspended or encapsulated cell formats. Cyanuric acid hydrolase activities differed by only a 2-fold range when comparing across the different enzymes with a given format. A practical water filtration system is most likely to be used with nonviable cells, and all cells were rendered nonviable by heat treatment at 70°C for 1 h. Only the CAH enzyme from the thermophileM. thermoaceticaretained significant activity under those conditions, and so it was tested in a flowthrough system simulating a bioreactive pool filter. Starting with a cyanuric acid concentration of 10,000 μM, more than 70% of the cyanuric acid was degraded in 24 h, it was completely removed in 72 h, and a respike of 10,000 μM cyanuric acid a week later showed identical biodegradation kinetics. An experiment conducted with water obtained from municipal swimming pools showed the efficacy of the process, although cyanuric acid degradation rates decreased by 50% in the presence of 4.5 ppm hypochlorite. In total, these experiments demonstrated significant robustness of cyanuric acid hydrolase and the silica bead materials in remediation.

scholarly journals Large magnetocaloric effect in fine Gd2O3 nanoparticles embedded in porous silica matrix

2016 ◽  
Vol 109 (12) ◽  
pp. 122412 ◽  
Author(s):  
A. Zeleňáková ◽  
P. Hrubovčák ◽  
O. Kapusta ◽  
V. Zeleňák ◽  
V. Franco
Keyword(s):  
Magnetocaloric Effect ◽  
Porous Silica ◽  
Silica Matrix ◽  
Gd2o3 Nanoparticles

Porous Silica Matrix Obtained from Pyrex Glass by Hydrothermal Treatment: Characterization and Nature of the Porosity

2003 ◽  
Vol 86 (7) ◽  
pp. 1196-1201 ◽  
Author(s):  
Fernando Aparecido Sigoli ◽  
Sérgio Feliciano ◽  
Marcus Vinicius Giotto ◽  
Marian Rosaly Davolos ◽  
Miguel Jafelicci Júnior
Keyword(s):  
Hydrothermal Treatment ◽  
Porous Silica ◽  
Silica Matrix ◽  
Pyrex Glass

VOC decomposition over a wide range of temperatures using thermally stable Cr6+ sites in a porous silica matrix

2015 ◽  
Vol 72 ◽  
pp. 161-164 ◽  
Author(s):  
Shoichi Somekawa ◽  
Hiroto Watanabe ◽  
Yuya Oaki ◽  
Hiroaki Imai
Keyword(s):  
Porous Silica ◽  
Silica Matrix ◽  
Thermally Stable ◽  
Wide Range

scholarly journals Magnetic Study of CuFe2O4-SiO2 Aerogel and Xerogel Nanocomposites

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2680
Author(s):  
Alizé V. Gaumet ◽  
Francesco Caddeo ◽  
Danilo Loche ◽  
Anna Corrias ◽  
Maria F. Casula ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Porous Silica ◽  
Chemical Properties ◽  
Silica Matrix ◽  
Superparamagnetic Nanoparticles ◽  
Blocking Temperature ◽  
Copper Ferrite ◽  
Transmission Electron ◽  
Magnetic Features

CuFe2O4 is an example of ferrites whose physico-chemical properties can vary greatly at the nanoscale. Here, sol-gel techniques are used to produce CuFe2O4-SiO2 nanocomposites where copper ferrite nanocrystals are grown within a porous dielectric silica matrix. Nanocomposites in the form of both xerogels and aerogels with variable loadings of copper ferrite (5 wt%, 10 wt% and 15 wt%) were synthesized. Transmission electron microscopy and X-ray diffraction investigations showed the occurrence of CuFe2O4 nanoparticles with average crystal size ranging from a few nanometers up to around 9 nm, homogeneously distributed within the porous silica matrix, after thermal treatment of the samples at 900 °C. Evidence of some impurities of CuO and -Fe2O3 was found in the aerogel samples with 10 wt% and 15 wt% loading. DC magnetometry was used to investigate the magnetic properties of these nanocomposites, as a function of the loading of copper ferrite and of the porosity characteristics. All the nanocomposites show a blocking temperature lower than RT and soft magnetic features at low temperature. The observed magnetic parameters are interpreted taking into account the occurrence of size and interaction effects in an ensemble of superparamagnetic nanoparticles distributed in a matrix. These results highlight how aerogel and xerogel matrices give rise to nanocomposites with different magnetic features and how the spatial distribution of the nanophase in the matrices modifies the final magnetic properties with respect to the case of conventional unsupported nanoparticles.

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