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.

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.

scholarly journals Carbon Dioxide Capture in Homogeneous and Heterogeneous Surfaces of Porous Silica Glass

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1260
Author(s):  
Chontira Boonfung ◽  
Chaiyot Tangsathitkulchai ◽  
Atichat Wongkoblap
Keyword(s):  
Carbon Dioxide ◽  
Functional Groups ◽  
Adsorption Isotherms ◽  
Silica Glass ◽  
Surface Defects ◽  
Porous Silica ◽  
Surface Heterogeneity ◽  
Slit Pore ◽  
Porous Silica Glass ◽  
Carbon Dioxide Co2

Experimental and simulation studies for carbon dioxide (CO2) adsorption on porous silica glass were performed to reveal how surface heterogeneity can affect the adsorption mechanism of CO2. In performing the simulation, the structure of porous silica glass was modeled as a slit pore consisting of parallel walls of connected SiO4 units. The adsorption isotherms of CO2 at 283 K were generated for a series of pore widths using a Monte Carlo ensemble. The defective surfaces created by random removal of surface atoms and the surfaces containing hydroxyl functional groups were chosen to represent the surface heterogeneity for the simulation tasks. The isotherms derived for the defective surfaces showed a rapid adsorption at low pressures because of the stronger interaction between the rough nonuniform surfaces and CO2 molecules. For the role of surface functional groups, the adsorption isotherms dramatically increased with an increasing number of functional groups. The amount of CO2 adsorbed for randomly placed functional groups was greater than that for the presence of functional groups at the pore edges. The proper control of surface heterogeneity by manipulating both the amounts of hydroxyl surface groups and surface defects should help enhance the efficient capture of CO2 in porous silica glass.

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

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

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
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