modified silica
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2022 ◽  
Author(s):  
Wera M Schmerer

Abstract Protocols utilized for the extraction of DNA vary significantly with regards to steps involved and duration of the overall procedure due to material-specific requirements for ensuring the highest possible yield in recovery of DNA. This variation mostly affects aspects of sample preparation and digestion steps required to release the DNA from the sample material.In contexts such as the development of new PCR-based assays - which always includes a test of species-specificity - reference samples from a number of species are utilized, requiring extraction of DNA from a variety of source materials, each with their specific conditions for effective isolation of DNA.The method presented here follows the strategy of synchronizing sample material-specific aspects such as sample preparation and digestion in such a way that one common protocol can be utilized for the actual extraction and purification of the DNA, allowing for an overall more efficient extraction process, while maintaining optimized conditions for DNA recovery.


Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 39
Author(s):  
Stefan Bucur ◽  
Aurel Diacon ◽  
Ionel Mangalagiu ◽  
Alexandra Mocanu ◽  
Florica Rizea ◽  
...  

This study presents the synthesis of silica particles bearing two beta-cyclodextrin (BCD) (beta-cyclodextrin-BCD-OH and diamino butane monosubstituted beta-cyclodextrin-BCD-NH2). The successful synthesis of the BCD-modified silica was confirmed by FT-IR and TGA. Using contact angle measurements, BET analysis and SEM characterization, a possible formation mechanism for the generation of silica particles bearing BCD derivatives on their surface was highlighted. The obtained modified silica displayed the capacity to remove bisphenol A (BPA) from wastewater due to the presence of the BCD moieties on the surface of the silica. The kinetic analysis showed that the adsorption reached equilibrium after 180 min for both materials with qe values of 107 mg BPA/g for SiO2-BCD-OH and 112 mg BPA/g for SiO2-BCD-NH2. The process followed Ho’s pseudo-second-order adsorption model sustaining the presence of adsorption sites with different activities. The fitting of the Freundlich isotherm model on the experimental results was also evaluated, confirming the BCD influence on the materials’ adsorption properties.


2021 ◽  
Author(s):  
Ling Lin ◽  
Chunxia Wang ◽  
Haiyan Mao ◽  
Huanling Wu ◽  
Ziyin Li

Abstract Research on multi-functional fabrics is an inevitable trend in the future development of textile field. Nevertheless, the key to the development of multifunctional fabric is how to solve the problem of contradictory function combination and how to achieve the multifunctions. In this work, a novel multifunctional fabric based on cellulose/silica microcapsules was developed by using green, facile and economical methods. Owing to the loaded essence and hydrophobic coupling reagent and UV absorber modified silica of microcapsules, the coated fabric not only exhibited slow-release property of fragrance, but also had excellent superhydrophobicity and ultraviolet (UV) protection. Furthermore, multifunctional fabric also displayed the durable superhydrophobicity and UV protection even after chemically or mechanically damaged. The development of mulfunctional fabrics largely depends on the development of textile functional finishing agent and finishing technology. Therefore, it is very important to develop new functional micrcapsules or finishing agent.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1511
Author(s):  
Karna Wijaya ◽  
Melynatri Laura Lammaduma Malau ◽  
Maisari Utami ◽  
Sri Mulijani ◽  
Aep Patah ◽  
...  

Sulfated silica (SO4/SiO2) and nickel impregnated sulfated silica (Ni-SO4/SiO2) catalysts have been successfully carried out for the conversion of ethanol into diethyl ether (DEE) as a biofuel. The aims of this research were to study the effects of acidity on the SO4/SiO2 and Ni-SO4/SiO2 catalysts in the conversion of ethanol into diethyl ether. This study focuses on the increases in activity and selectivity of SiO2 with the impregnation of sulfate and Ni metal, which had good activity and acidity and were less expensive. The SO4/SiO2 catalysts were prepared using TEOS (Tetraethyl Orthosilicate) as a precursor and sulfuric acid with various concentrations (1, 2, 3, 4 M). The results showed that SO4/SiO2 acid catalyst treated with 2 M H2SO4 and calcined at 400 °C (SS-2-400) was the catalyst with highest total acidity (2.87 g/mmol), while the impregnation of Ni metal showed the highest acidity value at 3%/Ni-SS-2 catalyst (4.89 g/mmol). The SS-2-400 and 3%/Ni-SS-2 catalysts were selected and applied in the ethanol dehydration process into diethyl ether at temperatures 175, 200, and 225 °C. The activity and selectivity of SS-2-400 and 3%/Ni-SS-2 catalysts shown the conversion of ethanol reached up to 9.54% with good selectivity towards diethyl ether liquid product formation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kenichi Nagase ◽  
Teruno Nishiyama ◽  
Masakazu Inoue ◽  
Hideko Kanazawa

AbstractTherapeutic drug monitoring is a key technology for effective pharmacological treatment. In the present study, a temperature-responsive chromatography column was developed for safe and simple therapeutic drug monitoring without the use of organic solvents. Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel-modified silica beads were prepared via a condensation reaction and radical polymerization. The temperature-dependent elution behavior of the drugs was observed using a PNIPAAm-modified silica-bead packed column and an all-aqueous mobile phase. Sharp peaks with reproducible retention times were observed at temperatures of 30 °C or 40 °C because the PNIPAAm hydrogel on the silica beads shrinks at these temperatures, limiting drug diffusion into the PNIPAAm hydrogel layer. The elution behavior of the sample from the prepared column was examined using a mixture of serum and model drugs. The serum and drugs were separated on the column at 30 °C or 40 °C, and the concentration of the eluted drug was obtained using the calibration curve. The results show that the prepared chromatography column would be useful for therapeutic drug monitoring because the drug concentration in serum can be measured without using organic solvents in the mobile phase and without any need for sample preparation.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1463
Author(s):  
Honghai Wang ◽  
Wenda Yue ◽  
Shuling Zhang ◽  
Yu Zhang ◽  
Chunli Li ◽  
...  

Silica xerogels have been proposed as a potential support to immobilize enzymes. Improving xerogels’ interactions with such enzymes and their mechanical strengths is critical to their practical applications. Herein, based on the mussel-inspired chemistry, we demonstrated a simple and highly effective strategy for stabilizing enzymes embedded inside silica xerogels by a polydopamine (PDA) coating through in-situ polymerization. The modified silica xerogels were characterized by scanning and transmission electron microscopy, Fourier tranform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and pore structure analyses. When the PDA-modified silica xerogels were used to immobilize enzymes of Candida antarctica lipase B (CALB), they exhibited a high loading ability of 45.6 mg/gsupport, which was higher than that of immobilized CALB in silica xerogels (28.5 mg/gsupport). The immobilized CALB of the PDA-modified silica xerogels retained 71.4% of their initial activities after 90 days of storage, whereas the free CALB retained only 30.2%. Moreover, compared with the immobilization of enzymes in silica xerogels, the mechanical properties, thermal stability and reusability of enzymes immobilized in PDA-modified silica xerogels were also improved significantly. These advantages indicate that the new hybrid material can be used as a low-cost and effective immobilized-enzyme support.


2021 ◽  
Author(s):  
Mohammed Sayed ◽  
Rajesh Saini ◽  
Hooisweng Ow

Abstract Gas reservoirs contain substantial amounts of natural gas and, in some cases, associated high API liquid hydrocarbons. Condensation of heavy hydrocarbons, especially in the area closer to the wellbore, occurs as a direct result of the decline in reservoir pressure. This hydrocarbon condensate, and in some cases water, tends to accumulate in the pore space and form a liquid bank. This liquid bank will result in a reduction in gas relative permeability and overall reduction in the well's productivity. This paper illustrates the synthesis and utilization of surface modified silica nanoparticles to mitigate the liquid banking phenomenon in gas reservoirs. Silica nanoparticles (S-NPs), of different sizes, were synthesized using the Stöber process. The impact of the nanoparticle size and degree of functionalization with different hydrophobic and omniphobic groups on altering the rock wettability properties to mitigate liquid banking in gas reservoirs were studied. The S-NPs (of sizes between 50-400 nm) were functionalized with various linear and branched fluoroalkyl groups, terminal amine, and epoxy groups. The particle size of surface modified silica nanoparticles was determined using dynamic light scattering (DLS). The performance of the surface modified silica nanoparticles was evaluated through measuring surface charge, change in contact angle, and by performing core flow experiments at reservoir conditions. A glass slide dip coated with 135 nm surface modified silica nanoparticles solution derivatized with terminal amine and perfluoroalkyl group provided a contact angle of 120° and 83° with water and decane, respectively. The contact angle can be tailored by changing the amount of amine and perfluoroalkyl concentrations on the particle surfaces. A contact angle of around 90° indicates a nonwetting neutral surface that results in minimizing capillary pressure and enhancing mobility of both hydrocarbon and water liquid phases. Using core flow studies and by estimating the improvement in gas and liquid relative permeabilities, surface modified silica nanoparticles treatment demonstrated a comparable performance to commercially available solutions at 1/5 the treatment volume. The surface modified silica nanoparticles sustained its performance indicating a stable and permanent coating on the rock surface. The silica nanoparticles functionalized with fluoroalkyl group, terminal amine and epoxy can be directly pumped without the need for a pretreatment of the rock surface. This results in less complexity when it comes to the field operation. The dual- functionalized silica nanoparticles were found to be effective in changing the rock surface wettability to neutral or nonwetting, thereby providing a potential solution to liquid banking problem in gas reservoirs.


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