Nanoscale
·
2015
·Vol. 7
·期 27
·11720-11726
·
IF 7.394
Juan Zheng,Yeru Liang,Shuqin Liu,Yajuan Ding,Yong Shen,Tiangang Luan,Fang Zhu,Ruifen Jiang,Dingcai Wu,Gangfeng Ouyang
Development of facile and effective methods for fabrication of high-performance solid phase microextraction (SPME) fibres remains a great challenge. Herein, a new class of ordered mesoporous polymers (OMPs) in situ coated on a stainless steel wire were successfully developed and utilized as a highly sensitive and stable SPME fibre for the first time. Because of the highly ordered mesoporous structure of its OMP coating, the π–π interactions and the dispersion forces, the OMP-coated SPME fibre exhibited much better extraction properties as compared to the commercial PDMS fibre. The findings could provide a new benchmark for preparing well-defined porous materials for the SPME application.
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高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Dan Wang,Yuanmin Gong,Meiting Yan,Jiaqi Chen,Xueping Tao,Yang Zhou,Yan Ma,Li Rao,Panpan Chen,Qifeng Fu
Carbon dots (CDs) hold great potential for chromatographic separations. However, their application in chromatographic stationary phases has been limited by two major synthetic challenges: (1) insufficient control over surface chemoselectivity caused by impurity co-adsorption, and (2) structural heterogeneity arising from uncontrolled solvothermal byproducts. To address these limitations, we developed a self-polymerization-driven strategy to synthesize high-purity hydrophobic CDs from 8-amino-2-naphthol (8N2OH) and 2,3-dihydroxynaphthalene (DHN). These CDs were incorporated into organic polymer monoliths via in situ copolymerization, yielding novel 8N2OH-CDs and DHN-CDs hybrid monolithic stationary phases for reversed-phase capillary liquid chromatography. The synthesized CDs were thoroughly characterized, with high purity confirmed by proton nuclear magnetic resonance. The resulting monolithic columns exhibited high permeability and uniformity, as demonstrated by field emission scanning electron microscopy, attributed to the excellent dispersion of the CDs. The chromatographic performance was evaluated using nine types of neutral, alkaline, and acidic compounds, as well as Tanaka standard test mixtures. Compared to unmodified columns, the CD-modified monoliths showed significantly enhanced retention strength and selectivity, supported by Tanaka tests revealing multifactorial retention mechanisms. This work demonstrates the potential of high-purity hydrophobic CDs as versatile modifiers for high-performance chromatographic stationary phases.
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ELECTROPHORESIS
·
2015
·Vol. 36
·期 17
·2120-2127
·
IF 3.028
Lu Yangfang,Wang Hui,Xue Yun,Gu Xue,Wang Yan,Yan Chao
Submicron, non-porous, chiral silica stationary phase has been prepared by the immobilization of functionalized β-CD derivatives to isocyanate-modified silica via chemical reaction and applied to the pressurized capillary electrochromatography (pCEC) enantio-separation of various chiral compounds. The submicron, non-porous, cyclodextrin-based chiral stationary phases (sub_μm-CSP2) exhibited excellent chiral recognition of a wide range of analytes including clenbuterol hydrochloride, mexiletine hydrochloride, chlorpheniramine maleate, esmolol hydrochloride, and metoprolol tartrate. The synthesized submicron particles were regularly spherical and uniformly non-porous with an average diameter of around 800 nm and a mean pore size of less than 2 nm. The synthesized chiral stationary phase was packed into 10 cm × 100 μm id capillary columns. The sub_μm-CSP2 column used in the pCEC system showed better separation of the racemates and at a higher rate compared to those used in the capillary liquid chromatography mode (cLC) system. The sub_μm-CSP2 possessed high mechanical strength, high stereoselectivity, and long lifespan, demonstrating rapid enantio-separation and good resolution of samples. The column provided an efficiency of up to 170 000 plates/m for n -propylbenzene.
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JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Jing Li,Li Xu,Zhi-guo Shi
In this study, the ethyl-bridged hybrid silica microsphere with hierarchically meso-macroporous structure was initially synthesized through a method combining dispersion polymerization with sol-gel transition and phase separation. The flow-through macropores rendered the microsphere a rough surface like a waxberry, and thus the material was named as waxberry-like ethyl-bridged hybrid silica sphere (WEHS). WEHS was characteristic of appropriate alkali-stability, which was highly difficult for the pure silica. Additionally, WEHS possessed hierarchical meso- and macropores, which added additional value for faster mass transfer than the conventional fully porous silica materials. Taking the advantages of WEHS, it was successfully applied as the substrate to immobilize lipase; the prepared immobilized lipase exhibited high catalytic activity and favorable reusability under alkaline conditions, which was significant in pitch control of neutral-alkaline papermaking industry. Moreover, as the high-performance liquid chromatographic stationary phase matrix, WEHS made the separation under alkaline mobile phase into a reality for the silica-based materials. Besides, an ultra-fast and efficient separation in minutes was achieved with lower consumption of solvents and saving analytical time, which is highly desired in modern analysis. In general, WEHS was a novel and promising candidate in the myriads of silica-based materials.
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2015
·
IF 4.169
Xing Gao,Rongzhen Mo,Yibing Ji
In this research, a novel organic polymer coated stationary phase modified with inorganic nanomaterial was prepared for open-tubular capillary electrochromatography (OT-CEC). The capillary was developed by covalent attaching graphene oxide (GO) onto the tentacle-type polymer chains grafted capillary which was derivatized with ammonium hydroxide. Scanning electron microscopy (SEM) and Raman spectroscopy provided evidences that the tentacle-type polymer and GO were coated to the capillary inner wall. This novel GO-polymer modified capillary column generated a strong and stable electroosmotic flow (EOF) from anode to cathode with the running electrolytes of pH ranging from 4.0 to 9.0, and showed excellent separation ability toward neutral small molecules, amino acids and ephedrine–pseudoephedrine isomers with resolution higher than 2.30 and column efficiency up to over 170,000 plates/m. The repeatabilities of the GO-GMA@capillary were satisfying with relative standard deviations for intra-day and inter-day runs less than 3.27%, and column-to-column runs less than 7.49%. Additionally, the separation performance of GO-polymer modified capillary was compared with that of the polymer coated capillary and GO coated capillary.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
·
IF 3.4
Hongyu Wang,Fumin Wang,Kaiwei Wang,Xubin Zhang,Changhao Bing,Xiaolu Fan,Tongxue Zhang,Syed Mujtaba ul Hassan
Developing an approach for the efficient synthesis of TS-1 zeolites with desirable morphologies and tunable coordination environments for Ti active sites is a pivotal challenge in the design of high-performance catalysts and zeolite crystal engineering. Herein, we report a cost-effective and efficient additive, guanidinoacetic acid (GAA), and conduct a systematic study on the synthesis of plate-like TS-1 zeolites using GAA as an additive. Introducing GAA during hydrothermal synthesis not only modulates the morphology of TS-1 crystals but also permits GAA to adequately chemically interact with titanium precursors to form hexa-coordinated Ti species. TS-1 zeolites with a controllable b-axis thickness in the range of 80–110 nm, and abundant framework Ti and hexa-coordinated Ti species are successfully achieved by optimizing the synthetic parameters. Through SEM, FT-IR, XPS, TEM, and XRD analysis, the mechanism of GAA altering crystal growth is mainly to inhibit the growth of the (010) plane. A b-axis-oriented TS-1 zeolite enriched with hexa-coordinated Ti species displays better catalytic performance in the 1-hexene epoxidation reaction than the conventional TS-1 zeolite containing only framework Ti species (35 vs 24%). This can be ascribed to the more active hexa-coordinated Ti species and shorter diffusion distance. This synthetic strategy provides a way to change the zeolite morphology and tune the number and distribution of Ti species in TS-1 zeolites.
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