Tropine-type chiral ionic liquid with proline anion was immobilized on silica gel by chemical modification method for the first time, which was proved by elemental, infrared spectrum and thermogravimetric analysis. Secondly, the performance of this kind of ionic liquid-modified silica gel was investigated in the adsorption of some metal ions, which included Cu(2+), Fe(3+), Mn(2+) and Ni(2+). Then the effects of time, initial concentration and temperature on adsorption for Cu(2+) ions were studied in detail, which was followed by the further research of adsorption kinetics and thermodynamics. The adsorption could be better described by pseudo-second-order kinetics model and that the process was spontaneous, exothermic and entropy decreasing. In the mode of 'reuse after adsorption', the ionic liquid-modified silica gel with saturated adsorption of Cu(2+) was finally used in resolution of racemic amino acids for the first time. The static experiment showed that adsorption rate of two enantiomers was obviously different. Inspired by this, the complex was packed in chromatographic column for the separation of racemic amino acids and d-enantiomers were firstly eluted by water or ethanol. Steric hindrance was found as one of key influencing factors for its effect on the stability of the complex.
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http://dx.doi.org/10.1016/j.chroma.2015.11.083 | DOI Listing |
Materials (Basel)
February 2025
School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
In order to improve the dispersion state of silica fume (SF) in cement concrete, accelerate the hydration rate of high-strength steam-cured cement concrete, and reduce production costs. In this paper, SF was made into a wet-ground silica fume (WSF) suspension solution through a wet grinding process and was applied to high-strength steam-cured concrete to replace the SF so as to improve the difficult dispersion of the inner SF and enhance the compressive strength of concrete. The physical and chemical properties of WSF were studied by XRD, SEM, and ZETA potential, and its effects on the mechanical properties, hydration development, and microstructure of cement concrete were studied using XRD, SEM, TG, BET, and NMR.
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February 2025
Building Materials and Structures Research Centre, Faculty of Civil Engineering and Architecture, Kaunas University of Technology, Studentu st. 48, Kaunas LT-51367, Lithuania.
This paper focuses on the alkaline activation of municipal waste incineration (MSWI) bottom ash to create a dense, non-porous composite structure. Normally, high pH solutions are used to activate MSWI bottom ash, but this has the side effect of creating residual effects in the bottom ash. Due to the uniqueness of the incineration process, the bottom ash retains metallic aluminum, which reacts with the alkali to produce hydrogen gas, which forms a porous structure in the sample during the hardening of the composite.
View Article and Find Full Text PDFInt J Mol Sci
February 2025
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
Maternal melatonin (MT) readily crosses the placental barrier to enter the fetal circulation, and it holds the potential to enhance hair follicle (HF) development, possibly augmented through nutritional interventions during pregnancy. However, the specific impact of maternal MT treatment on fetal HF development remains largely unexplored. In this study, we implanted pregnant rabbits with 10 mg of MT-containing and non-MT-containing silica gel microcapsules.
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February 2025
Hebei Key Laboratory of Inorganic Nano-Materials, College of Chemistry and Material Sciences, Hebei Normal University, Shijiazhuang 050024, China.
A group of silica-based supports with varying Al/Si ratios (S-x) was synthesized using the sol-gel method, followed by a chlorosulfonic acid modification to produce supported sulfonic acids (SA-x). The S-x and SA-x materials, along with their adsorption products, were characterized via techniques such as FTIR, BET, and HPLC-MS. The analysis revealed that the sulfonic acid groups in the SA-x materials existed in two anchoring states: the covalently bonded (CB) state [SiOx-O]-SOH and the ion-paired (IP) state AlO:OSOH.
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February 2025
Eduardo Torroja Institute for Construction Science (IETcc-CSIC), Serrano Galvache, 4, 28033 Madrid, Spain.
Magnesium silicate hydrate (M-S-H) binders, synthesized from magnesia and silica, exhibit promising mechanical and thermal properties but face challenges in early strength development due to delayed kinetics and limited MgO solubility. This study investigates the impact of early exposure to CO-saturated atmospheres on MgO-SiO cementitious systems, emphasizing the role of carbonation in phase evolution and mechanical performance. Early carbonation promotes the formation of hydrated magnesium hydroxycarbonates (HMHC), altering hydration pathways and reducing M-S-H gel content.
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