scholarly journals Mid-IR sensing platform for trace analysis in aqueous solutions based on a germanium-on-silicon waveguide chip with a mesoporous silica coating for analyte enrichment

2020 ◽  
Vol 28 (18) ◽  
pp. 27013
Author(s):  
Nuria Teigell Benéitez ◽  
Bettina Baumgartner ◽  
Jeroen Missinne ◽  
Sanja Radosavljevic ◽  
Dominik Wacht ◽  
...  
2016 ◽  
Vol 4 (2) ◽  
pp. 105-112
Author(s):  
Lalchhing puii ◽  
◽  
Seung-Mok Lee ◽  
Diwakar Tiwari ◽  
◽  
...  

A mesoporous silica was synthesized by annealing (3-Aminopropyl) triethoxysilane grafted chitosan at 800˚C. The mesoporous silica was characterized by the XRD (X-ray diffraction) analysis. The BET specific surface area and pore size of silica was found to be 178.42 m2/g and 4.13 nm. The mesoporous silica was then employed for the efficient remediation of aqueous solutions contaminated with Cu(II) under batch and column reactor operations. The mesoporous silica showed extremely high per cent removal of Cu(II) at wide pH range i.e., pH ~2.0 to 7.0. Relatively a fast uptake of Cu(II) was occurred and high percentage removal was obtained at initial concentrations studied from 1.0 to 15.0 mg/L. The equilibrium state sorption data were utilized for the Langmuir and Freundlich adsorption isotherm studies. Moreover, the effect of an increase in background electrolyte concentrations from 0.0001 to 0.1 mol/L NaNO3 was assessed for the uptake of Cu(II) by mesoporous silica. The equilibrium sorption was achieved within 240 min of contact and the kinetic data is best fitted to the pseudo-second-order and fractal like pseudo-second-order kinetic models. In addition, the mesoporous silica was used for dynamic studies under column reactor operations. The breakthrough curve was then used for the non-linear fitting of the Thomas equation and the loading capacity of the column for Cu(II) was estimated.


2018 ◽  
Vol 1 (12) ◽  
pp. 7083-7091 ◽  
Author(s):  
Bettina Baumgartner ◽  
Jakob Hayden ◽  
Andreas Schwaighofer ◽  
Bernhard Lendl

2019 ◽  
Vol 31 (8) ◽  
pp. 1675-1682 ◽  
Author(s):  
D.O. Sulistiono ◽  
E. Santoso ◽  
R. Ediati

Impregnation of mesoporous silica MCM-41 on metal organic framework type HKUST-1 or often called CuBTC (BTC = 1,3,5-benzenetricarboxylate) has been successfully carried out by solvothermal methods in a solvent mixture of water, ethanol and N,N-dimethylformamide (DMF). The XRD patterns of the obtained solids showed that MCM-41/HKUST-1 composites had the same crystalline phase as pure as HKUST-1. SEM images revealed that the impregnation of the mesoporous silica to HKUST-1 did not alter the surface morphology of the original HKUST-1, which had octahedral shapes. In addition, the thermal stability of the MCM-41/HKUST-1 composites reached 302 °C, increased by 292 °C in comparison to the HKUST-1, even though the impregnation process resulted in a decreased in the specific surface area of the composites. Furthermore, MCM-41/HKUST-1 composites showed outstanding performance as adsorbent of methylene blue and Congo red in aqueous solutions. Results of adsorption studies showed that a pseudo-second order kinetics and Langmuir isotherm were observed for both types of dyes.


2018 ◽  
Vol 6 (41) ◽  
pp. 6585-6591 ◽  
Author(s):  
Qian Zhou ◽  
Dianping Tang

A newly portable detection sensing platform based on a graphene oxide (GO)-gated mesoporous silica nanocontainer (MSN) was designed for arsenite detection through the target-responsive release of glucose from the MSN with a glucometer readout.


2015 ◽  
Vol 1721 ◽  
Author(s):  
Jennifer L. Kahn ◽  
Necla Mine Eren ◽  
Osvaldo Campanella ◽  
Sherry L. Voytik-Harbin ◽  
Jenna L. Rickus

ABSTRACTPorous coatings at the surface of living cells have application in human cell transplantation by controlling the transport of biomolecules to and from the cells. Sol-gel-derived mesoporous silica materials are good candidates for such coatings, owing to their biocompatibility, facile solution-based synthesis conditions, and thin film formation. Diffusion and transport across the coating correlates to long-range microstructural properties, including pore size distribution, porosity, and pore morphology. Here, we investigated collagen-fibril matrices with known biocompatibility to serve as templating systems for directed silica deposition. Type 1 collagen oligomers derived from porcine skin are extensively characterized such that we can predict and customize the final collagen-fibril matrix with respect to fibril density, interfibril branching and viscoelasticity. We show that these matrices template and direct the deposition of mesoporous silica at the level of individual collagen fibrils. We varied the fibril density, silicic acid concentration, and time of exposure to silicifying solution and characterized the resulting hybrid materials by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and rheology. Microstructural properties of the collagen-fibril template are preserved in the silica surface of hybrid materials. Results for three different collagen fibril densities, corresponding to shear storage moduli of 200 Pa, 1000 Pa, and 1600 Pa, indicate that increased fibril density increases the absolute amount of templated silica when all other silica synthesis conditions are kept constant. Additionally, mechanical properties of the hybrid material are dominated by the presence of the silica coating rather than the starting collagen matrix stiffness.


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