Single‐step approach to β‐cyclodextrin‐bonded silica as monolithic stationary phases for CEC

Hsieh, Ming-Lung; Li, Guan-Yi; Chau, Lai-Kwan; Hon, Yung‐Son

doi:10.1002/jssc.200700631

Cited by 33 publications

(27 citation statements)

References 55 publications

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“…The high specific surface area, thermal and mechanical stability, highly uniform pore distribution, and tunable pores of ordered mesoporous silicas obtained with template sol–gel synthesis may provide greater accessibility of guest molecules to β-CD binding sites. Several attempts were made to introduce β-CD moieties into silica thought co-condensation of silica alkoxides with β-CD-containing organosilanes [28, 30, 32, 33, 37]. In most of these studies, the pore expander was used to obtain the pores of sufficient size.…”

Section: Resultsmentioning

confidence: 99%

Structural Variety and Adsorptive Properties of Mesoporous Silicas with Immobilized Oligosaccharide Groups

2017

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In this research, we report on the synthesis of mesoporous silicas with various quantities of immobilized oligosaccharide groups and different pore ordering degree. The hydrothermal co-condensation of tetraethyl orthosilicate and β-cyclodextrin-containing organosilane in the presence of cetyltrimethylammonium bromide template was employed. The purpose of this investigation was to show the opportunity of increasing β-cyclodextrin content in silica matrix by changing the molar ratio of initial reagents during organosilane synthesis and to determine whether the enhancing of immobilized groups on the surface influences on model aromatic compound adsorption from water. It was prepared several β-cyclodextrin-organosilanes by modification of (3-aminopropyl)triethoxysilane with oligosaccharide (the molar composition of reaction mixtures were 1:1, 3:1, and 5:1) with using N,N′-carbonyldiimidazole as linking agent. Three types of MCM-41 materials were obtained with 0.018, 0.072, and 0.095 mmol g−1 β-cyclodextrin-group loading according to chemical analysis of silicas. The IR spectroscopy and potentiometric titration were also performed to confirm the presence of functional groups in the silica matrix. Nitrogen sorptometry experiments exhibited the decrease of high surface area (from 812 to 457 m2 g−1) and the average pore diameter (from 1.06 to 0.60 cm3 g−1) of synthesized silicas with increasing of immobilized oligosaccharide groups. The influence of β-cyclodextrin-organosilane presence on the forming of hexagonally arranged porous structure of silicas was evaluated by X-ray diffraction and TEM analyses. As the loading of oligosaccharide groups increases in obtained silicas, the (100) reflex in diffraction patterns is even less intense and broader, denoting the decrease of long-range pore ordering. Adsorption experiments were carried out to study the effect of β-cyclodextrin groups’ attendance in silica matrix on benzene uptakes from aqueous solutions. Experimental kinetic curves of benzene adsorption on synthesized silicas were compared with theoretical models of Lagergren and Ho-McKay for pseudo-first and pseudo-second-order processes. Langmuir and Freundlich isotherm models were used to evaluate adsorption processes and parameters. Obtained β-cyclodextrin-containing MCM-41 silicas demonstrate adsorption level performance of known samples and could be very promising for benzene uptakes from aqueous solutions in water treatment processes.

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Section: Resultsmentioning

confidence: 99%

Structural Variety and Adsorptive Properties of Mesoporous Silicas with Immobilized Oligosaccharide Groups

2017

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“…9,35,36 Various volume ratios of HOAc and TEA added to methanol as mobile phase were selected for assessing effect on enantioseparation at 25°C and a flow rate of 0.3 mL/minute. The additives in mobile phase are critical for the enantioseparation, and the effect of acid and base additives has been previously reported by a number of studies.…”

Section: Effect Of Acid and Base Additivesmentioning

confidence: 99%

Enantioseparation of chiral pharmaceuticals by vancomycin‐bonded stationary phase and analysis of chiral recognition mechanism

Liu

Wang

et al. 2019

Chirality

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The drug chirality is attracting increasing attention because of different biological activities, metabolic pathways, and toxicities of chiral enantiomers.The chiral separation has been a great challenge. Optimized high-performance liquid chromatography (HPLC) methods based on vancomycin chiral stationary phase (CSP) were developed for the enantioseparation of propranolol, atenolol, metoprolol, venlafaxine, fluoxetine, and amlodipine. The retention and enantioseparation properties of these analytes were investigated in the variety of mobile phase additives, flow rate, and column temperature. As a result, the optimal chromatographic condition was achieved using methanol as a main mobile phase with triethylamine (TEA) and glacial acetic acid (HOAc) added as modifiers in a volume ratio of 0.01% at a flow rate of 0.3 mL/minute and at a column temperature of 5°C. The thermodynamic parameters (eg, ΔH, ΔΔH, and ΔΔS) from linear van 't Hoff plots revealed that the retention of investigated pharmaceuticals on vancomycin CSP was an exothermic process. The nonlinear behavior of lnk′ against 1/T for propranolol, atenolol, and metoprolol suggested the presence of multiple binding mechanisms for these analytes on CSP with variation of temperature. The simulated interaction processes between vancomycin and pharmaceutical enantiomers using molecular docking technique and binding energy calculations indicated that the calculated magnitudes of steady combination energy (ΔG) coincided with experimental elution order for most of these enantiomers.

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“…Interestingly, Ahmed et al. indicated that the single‐step or one‐pot approaches were beneficial to the reproducibility of CD‐functionalized monoliths and CD loadability as compared to the two‐step approach, whereas Svec et al. held the view that the single‐step approach was limited in that some functionalities may not be accessible in the copolymerization.…”

Section: Introductionmentioning

confidence: 99%

Effect of fabrication strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized polymethacrylate monoliths: A comparative evaluation

Yang

Guo

Lin

et al. 2017

J of Separation Science

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To evaluate the effect of the preparation strategy on the enantioseparation performance of β-cyclodextrin-functionalized monoliths, a series of β-cyclodextrin-functionalized organic polymeric monolithic columns were prepared through two-step, single-step, and one-pot approaches, using the same cyclodextrin, linker-spacer, and crosslinker. Physicochemical characterization of the columns was carried out by determining the morphology, β-cyclodextrin density, permeability, and chromatographic efficiency. For each type of monolithic column, the enantioresolution of 22 chiral compounds, including mandelic acid derivatives, nonsteroidal anti-inflammatory drugs, N-derivatized amino acids, and herbicides, was comparatively studied under optimum chromatographic conditions. The β-cyclodextrin-functionalized monolithic columns prepared through the one-pot approach exhibited higher enantioresolution for most chiral compounds, and they have the advantage of good controllability and simple preparation. On the other hand, the enantioresolution obtained on columns prepared through the single-step approach was quite unsatisfactory, and therefore the effect of using different linking spacers and crosslinkers was studied. A significant improvement of enantioresolution for 2-chloro-mandelic acid was obtained by using N,N-methylenebisacrylamide instead of ethylene dimethacrylate as the crosslinker in the single-step preparation.

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Single‐step approach to β‐cyclodextrin‐bonded silica as monolithic stationary phases for CEC

Cited by 33 publications

References 55 publications

Structural Variety and Adsorptive Properties of Mesoporous Silicas with Immobilized Oligosaccharide Groups

Structural Variety and Adsorptive Properties of Mesoporous Silicas with Immobilized Oligosaccharide Groups

Enantioseparation of chiral pharmaceuticals by vancomycin‐bonded stationary phase and analysis of chiral recognition mechanism

Effect of fabrication strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized polymethacrylate monoliths: A comparative evaluation

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