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1.
Xu-Chun WANG Jin-Ze LI Guang-Yong LI Jin WANG Xue-Tong ZHANG Qiang GUO 《物理化学学报》2017,33(11):2141-2152
气凝胶由于其优异的理化性能和广阔的应用前景,近年来的发展十分迅速。然而传统的气凝胶多为块体材料,一定程度上忽略了特殊应用场景下对尺寸和形状的特定需求。将气凝胶材料制备成微球,一方面能够拓宽气凝胶材料的应用领域,另一方面也丰富了多孔微球材料的内涵。本文从几类主要的气凝胶体系(氧化硅气凝胶、纤维素气凝胶、间苯二酚-甲醛(RF)/碳气凝胶和石墨烯气凝胶)出发,综述了这些气凝胶微球的制备方法及其应用实例,并对气凝胶微球的研究现状及发展趋势做了简要评述。 相似文献
2.
Microspheres and microcapsules have been widely used in biomedical field, such as delivery systems for drugs, vaccines. Uniform particle is required for precise drug delivery and disease treatment, since the particle diameter is a key factor which controls the pharmacokinetics and efficacy of loaded drug. However, there is no universal method to prepare uniform particles either from monomer or preformed polymer raw materials. We have developed two membrane emulsification techniques (MET) to prepare uniform particles with controllable size. In this review, we introduce two MET processes and their mechanisms, and how to develop MET to different emulsion systems to obtain various uniform microspheres and microcapsules with interesting morphologies. Then, the advantages of uniform particles on biomedical application results are focused. Finally, particle design and applications as “Chassis” to form synthetic vaccine are described. What is the most favorite and original chemistry developed in your research group? We clarified the mechanism for obtaining uniform microspheres and microcapsules in O/W, W/O and double emulsion systems, which enabled us to develop the technique to a universal technique, successfully preparing various uniform particles including hydrophobic, hydrophilic and composite functional particles, and leading to the original systematic studies on biomedical applications including “Synthetic Vaccine”. How do you get into this specific field? Could you please share some experiences with our readers? I started the research on preparation of nanospheres from my master course. At that time, I knew there were few universal methods to obtain uniform microspheres and microcapsules. So, after I became an assistant professor, I began to consider this scientific topic. How do you supervise your students? Our group motto is “Enjoy Science, Enjoy Work, Enjoy Life”. I tried to lead the students to like their research, and tried to find interesting results with students together based on their primary experimental results. What is the most important personality for scientific research? Pure, Passion, Perseverance. How do you keep balance between research and family? Work hard, and let my family know I am enjoyable and happy with my research, getting support and encouragement from family. Who influences you mostly in your life? My father. He always read books at the desk. He always gave me encouragement no matter happy or sad. 相似文献
3.
This paper describes an experiment directed toward the preparation of monodispersed porous polymer microspheres with a diameter of ca. 50 m, which is applicable to the chromatographic separation of biomolecules such as proteins and peptides by size exclusion. Fairly monodispersed polymer microspheres were successfully prepared by suspension copolymerization of polyethylene glycol monomethacrylate and ethylene glycol dimethacrylate as monomer and cross-linker, respectively. Monodispersed O/W emulsion was prepared by the SPG membrane emulsification technique, and was used in the subsequent droplet-swelling process in which monodispersed seed droplets were swollen by adsorbing the secondary emulsion droplets. The effects of the organic diluent in suspension polymerization and comonomer on the porous structure of the polymer microspheres were investigated by scanning electron microscopy and mercury-intrusion porosimetry, and the separation performances of polystyrene, polyethylene glycol, and various biomolecules by size-exclusion chromatography. As a result, it was evident that benzene, 1-butanol, and butyl acetate worked as nonsolvents for the polymer prepared in this study, and that polymer microspheres prepared with these solvents had larger pores. Size-exclusion chromatography revealed that the exclusive limiting molecular weight was 1.9×105 when polystyrene was used as a standard polymer, and 3.5×104 when polyethylene glycol was used as a standard polymer. Furthermore, we confirmed that the monodispersed polymer microspheres with defined pores clearly separated the six representative kinds of biomolecules with molecular weights ranging from 75 to 6.4×105. 相似文献
4.
Magnetic polymer microspheres have been considered as a kind of new biopolymer materials with great advantages in bioseparation
engineering and biomedicine engineering because they have not only polymer functional groups but also magnetic characteristics.
Styrene-acrylic acid copolymer (p(S-AA)) magnetic microspheres were synthesized by dispersion polymerization with Fe3O4 as core and p(S-AA) as shell. The microspheres were characterized by SEM, size analysis, molecular weight and solid content
measurement. All of them indicate that the microspheres are small in size, narrow in distribution, stable in chemistry and
rich in functional groups on their surface.
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Translated from Journal of Beijing Union University (Natural Science) 2008, 21(3): 82–84 相似文献
5.
Novel silver-poly(acrylamide-co-methacrylic acid) [Ag-P(AM-co-MAA)] composite microspheres, in tens of micrometer size range, with patterned surface and core/shell structures were prepared
by chemical reduction of Ag2CrO4-P(AM-co-MAA) composite microspheres in ethanol. Characterization with various techniques revealed that the chemical composition of
the “shell” is dominated by Ag, but the “core” is dominated by the template, P(AM-co-MAA). It was also demonstrated that the surface morphology of the Ag-polymer composite microspheres is similar to that of
their precursors and can be controlled to a certain extent by varying the composition of template copolymer, approaches, and
amount of Ag2CrO4 deposited. This morphology transfer technique is also applicable for other silver salts-polymer composite microspheres. The
same silver-polymer composite microspheres with very different morphology have also been prepared by utilizing this technique,
but the different precursor microspheres, Ag3PO4-P(AM-co-MAA), were used.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
The present review covers the summary of recent progress in designing and developing Biginelli reaction strategies particularly the greener strategies with higher yields, short times and simple work-up, in which the inorganic materials such as alumina, silica gel or zeolite directly or having doped with other reagents were used as catalysts for such a type of transformations. Moreover, several aspects and available references of heterogeneous catalysis using inorganic catalysts in promoting reactions are provided briefly in this review. There is also a concise account covering the better alternative syntheses and some of improved and robust protocols of biginelli reaction for the preparation of dihydropyrimidin-2(1H)-one/thiones analogs. 相似文献
7.
After first report on diketopyrrolopyrrole in 1974 by Farnum et al., a wide variety of its derivatives have been reported for material and biological applications. In this review we discuss various design strategies used for the synthesis of metal functionalized diketopyrrolopyrrole derivatives along with their photophysical and electrochemical studies with respect to material and biological applications. Some exciting applications of ferrocenyl functionalized diketopyrrolopyrrole derivatives such as non‐linear optics, organic solar cells and photothermal therapy were recently reported, which are also discussed in this review. 相似文献
8.
Agar microspheres were prepared by water–oil emulsification and cross‐linked under alkaline condition. The thermoresponsive hydrophobic copolymer, poly(N‐isopropylacrylamide‐co‐lauryl methacrylate‐co‐acrylamide), was grafted on the agar microspheres via atom transfer radical polymerization. The agar microspheres grafted with copolymers were characterized by light microphotography, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. The chain lengths and hydrophobic monomer ratio of the grafting linear polymer had significant effects on the hydrophobicity and adsorption capacity of agar microspheres at different temperatures. The thermoresponsive microspheres were used for separation of proteins and showed binding and release behavior by change of temperatures without change in mobile phase composition. Thus, we suggest thermoresponsive agar microspheres as an alternative separation media for all‐aqueous bioseparations. 相似文献
9.
In this paper, hollow poly(styrene-co-divinylbenzene-co-methacrylic acid) microparticles possessing various morphologies were synthesized by a combination of seeded polymerization and SPG membrane emulsification. Three families of polystyrene (PS) microspheres with various molecular weights but similar diameters were fabricated by SPG membrane emulsification. These PS microspheres were used as seeds to investigate the effect of their molecular weight on the phase separation between the PS seeds and microgel-like networks formed during seeded polymerization and on the morphologies of the resultant particles. Our study revealed that three resultant microparticles possessed diameters of ca. 10?μm and hollow cavities. The shell thickness of the particles became thinner as M w increased from 3.5?×?104 to 28.0?×?104. The morphological evolution of the microparticles during seeded polymerization was monitored, and these results verified the influence of the molecular weight of the PS seeds on the phase separation behavior and hence the morphologies of the resultant particles. 相似文献
10.
Constructing planar, rigid, and high electronically delocalized π-conjugated molecular system is the most basic requirements of obtaining high-performance polymeric semiconductors for organic field-effect transistors (OFETs). In this regard, diarylethylene (DAE)-based polymers show great potential because many substantive progresses related to polymer field-effect transistors had been achieved from the kind of polymer materials in recent years. In the brief review, series of DAE-based polymer are highlighted, based on which several design strategies have been summarized by the way of comparative research method. These strategies have important guiding significance not only for further developing new DAE-based and other polymeric semiconductors for OFETs but also for developing specific polymeric semiconductors for other organic electronics, such as organic photovoltaics and organic light-emitting diodes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 585–603 相似文献
11.
TiO2-based photocatalysis has become a viable technology in various application fields such as (waste)water purification, photovoltaics/artificial photosynthesis, environmentally friendly organic synthesis and remediation of air pollution. Because of the increasing impact of bad air quality worldwide, this review focuses on the use and optimization of TiO2-based photocatalysts for gas phase applications. Over the past years various specific aspects of TiO2 photocatalysis have been reviewed individually. The intent of this review is to offer a broad tutorial on (recent) trends in TiO2 photocatalyst modification for the intensification of photocatalytic air treatment. After briefly introducing the fundamentals of photocatalysis, TiO2 photocatalyst modification is discussed both on a morphological and an electronic level from the perspective of gas phase applications. The main focus is laid on recent developments, but also possible opportunities to the field. This review is intended as a solid introduction for researchers new to the field, as well as a summarizing update for established investigators. 相似文献
12.
Murtaza Hasan Ihsan Ullah Hina Zulfiqar Komal Naeem Arfa Iqbal Huma Gul Muhammad Ashfaq Nasir Mahmood 《Materials Today Chemistry》2018
Synthesis of nanomaterials is being gained extensive attention in the fields of chemistry, applied physics, catalysis, drug delivery and the most important in diagnosis and therapeutic applications. Recently, many reports have been published on physical and chemical synthesis of magnetic as well as metallic nanoparticles (NPs) with viable surface functionalization, but still there is a dire need of such strategies that can combine synthetic methodology with stable surface modification found in nature. Synthesis of NPs via biological methods is the possible way to solve these barriers. However, systematized summary and outlooks of NPs synthesis via biological entities with various influencing factors e.g. temperature, pH, concentration of reactants and reaction time has rarely been reported. This review will present the distinct advantages of biological synthesis of NPs over physical and chemical methods. It will also highlight the recent progress on synthesis of NPs via various biological systems i.e. plant, fungus, bacteria, and yeast. Furthermore, it will explain various factors that control the size, shape, and morphology of these NPs. Finally, it would present the future perspectives of green chemistry for the development of nano-science and -biotechnology. 相似文献
13.
Philippe dAbadie Michel Hesse Amandine Louppe Renaud Lhommel Stephan Walrand Francois Jamar 《Molecules (Basel, Switzerland)》2021,26(13)
Inert microspheres, labeled with several radionuclides, have been developed during the last two decades for the intra-arterial treatment of liver tumors, generally called Selective Intrahepatic radiotherapy (SIRT). The aim is to embolize microspheres into the hepatic capillaries, accessible through the hepatic artery, to deliver high levels of local radiation to primary (such as hepatocarcinoma, HCC) or secondary (metastases from several primary cancers, e.g., colorectal, melanoma, neuro-endocrine tumors) liver tumors. Several types of microspheres were designed as medical devices, using different vehicles (glass, resin, poly-lactic acid) and labeled with different radionuclides, 90Y and 166Ho. The relationship between the microspheres’ properties and the internal dosimetry parameters have been well studied over the last decade. This includes data derived from the clinics, but also computational data with various millimetric dosimetry and radiobiology models. The main purpose of this paper is to define the characteristics of these radiolabeled microspheres and explain their association with the microsphere distribution in the tissues and with the clinical efficacy and toxicity. This review focuses on avenues to follow in the future to optimize such particle therapy and benefit to patients. 相似文献
14.
15.
Ghulam Bary Muhmmad Imran Jamil Muhammad Arslan Lubna Ghani Waqar Ahmed Haseen Ahmad Gohar Zaman Khurshid Ayub Muhammad Sajid Riaz Ahmad Duohui Huang Futi Liu Yue Wang 《Journal of Saudi Chemical Society》2021,25(7):101260
Alkene is an attractive substrate for chemists due to its easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. It reacts under ionic and free radical mechanisms including single electron transfer (SET). In this review, strategies used for C–C and C-heteroatom functionalization of alkene has been discussed with emphasis on the regio, stereoselectivity, mechanistic detail and sustainability aspects. These strategies mainly follow the free radical mechanism, and the highly reactive carbon radicals show uncontrollable regio- and stereoselectivities. Thus these strategies still need to be focused; especially in the asymmetric versions. The regio- and stereoselectivities of functionalization of alkenes have been highlighted and debated. In addition, the hazardous reagents such as Cl2, Br2 I2, CO, peroxides, and benzene have also been discussed with the emphasis on their impact on the environment. Their plausible green alternatives have also been suggested, such as MX as halogen replacement; CO surrogates (formaldehyde etc.); sustainable aromatic solvents as benzene replacement. The non-green strategies relying on pre-formed silyl hydride and their green alternative strategies such as transfer hydrogenations have also been indicated. The applications of the functionalization of alkenes for the total synthesis of bioactive compounds have also been discussed in detail. In addition, future perspectives are also highlighted for further developments in the functionalization of alkenes. 相似文献
16.
Nanoscale gaps, which enable many research applications in fields such as chemical sensors, single‐electron transistors, and molecular switching devices, have been extensively investigated over the past decade and have witnessed the evolution of related technologies. Importantly, nanoscale gaps employed in hydrogen‐gas (H2) sensors have been used to reversibly detect H2 in an On–Off manner, and function as platforms for enhancing sensing performance. Herein, we review recent advances in nanogap design for H2 sensors and deal with various strategies to create these gaps, including fracture generation by H2 exposure, deposition onto prestructured patterns, island formation on a surface, artificial manipulation methods, methods using hybrid materials, and recent approaches using elastomeric substrates. Furthermore, this review discusses a new nanogap design that advances sensing capabilities in order to meet the diverse needs of academia and industry. 相似文献
17.
Xian-mo Deng Xiao-hong Li Ming-long Yuan Xiong-wei Li Cheng-dong Xiong Zhi-tang Huang Wen-xiang Jia Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu China Institute of Chemistry Chinese Academy of Sciences Beijing China West China University of Medical Sciences Chengdu China 《高分子科学》1999,(3):265-270
Poly-dl -lactide-poly(ethylene glycol ) (PELA) triblock copolymers were synthesized withlanthanum acetate as the initiator. PELA microspheres with entrapped Vibrio Cholera antigen and outermembrane protein (OMP) were prepared by a double emulsion W/O/W based on solvent extraction methods.The obtained microspheres showed smooth and spherical surface and their size varied between 0.5 and 5.0μm, which are suitable for oral targeting delivery system. The distribution tests in rabbits and mice throughscanning electronic micrography and fluorescence microscope indicated that microspheres have successfullyreached the immunization-related tissues, such as the liver, spleen and intestinal peyer's patches, followingoral administration. The PELA microspheres were also evaluated as an efficient antigen delivery system byenhancing a higher protective ratio against live Vibrios Cholera. 相似文献
18.
The preparation of polyvinylpyrrolidone (PVP) microspheres in ethyl acetate by dispersion polymerization with N-vinylpyrrolidone (NVP) as initial monomer, poly(N-vinylpyrrolidone-co-vinyl acetate) (P (NVP-co-VAc)) as dispersant, and 2, 2′-azobisisobutyronitrile(AIBN) as initiator is reported. The influences of monomer concentration,
dispersant concentration and initiator concentration on the size of PVP microspheres as well as the monomer conversion were
studied. The structure and properties of PVP microspheres were analyzed. The results show that the prepared PVP microspheres
have a mean diameter of 3-4 μm. With an increase in NVP concentration, the size and the molecular weight of the PVP microspheres
as well as the monomer conversion all increase. With increasing P(NVP-co-VAc) concentrations, the PVP molecular weight and monomer conversion both increase while the size of the microspheres becomes
smaller. As the concentration of AIBN increases, the microsphere size and monomer conversion increase whereas the PVP molecular
weight decreases. The PVP prepared by dispersion polymerization has a crystal structure, and its molecular weight is lower
compared to that prepared by solution polymerization.
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Translated from Acta Polymerica Sinica, 2007, 11 (in Chinese) 相似文献
19.
Rahmawati Rahmawati Yeni Wahyuni Hartati Jalifah binti Latip Tati Herlina 《Journal of separation science》2023,46(12):2200800
Plants in the genus Erythrina is a potential source of chemical constituents, one of which is flavonoids, which have diverse bioactivities. To date, literature on the flavonoids from the genus Erythrina has only highlighted the phytochemical aspects, so this review article will discuss isolation techniques and strategies for the first time. More than 420 flavonoids have been reported in the Erythrina genus, which are grouped into 17 categories. These flavonoid compounds were obtained through isolation techniques and strategies using polar, semi-polar, and non-polar solvents. Various chromatographic techniques have been developed to isolate flavonoids using column flash chromatography, quick column chromatography, centrifugally accelerated thin-layer chromatography, radial chromatography, medium-pressure column chromatography, semi-preparative high-performance liquid chromatography, and preparative high-performance liquid chromatography. Chromatographic processes for isolating flavonoids can be optimized using multivariate statistical applications such as response surface methodology with central composite design, Box–Behnken design, Doehlert design, and mixture design. 相似文献
20.
Ito F Fujimori H Honnami H Kawakami H Kanamura K Makino K 《Colloids and surfaces. B, Biointerfaces》2008,66(1):65-70
Monodisperse poly(lactide-co-glycolide) (PLGA) microspheres containing rifampicin (RFP), anti-tubercle drug, as hydrophobic model drug were prepared by solvent evaporation method with a membrane emulsification technique using Shirasu Porous Glass (SPG) membranes. Five kinds of rifampicin-loaded PLGA (RFP/PLGA) microspheres with different sizes were prepared by changing pore size of the membranes. Effect of polyethylene glycol (PEG) added to polyvinyl alcohol (PVA) solution (continuous phase) upon the monodispersity of microspheres was studied. PEG was used as a stabilizer for microspheres dispersing in PVA solution. The most suitable molecular weight of PEG as a stabilizer was 20,000. RFP/PLGA microspheres prepared with PEG20000 were apparently more uniform than those prepared without PEG. The yield of RFP/PLGA microspheres was 100%. The initial burst observed in the release of RFP from RFP/PLGA microspheres was suppressed by the addition of PEG. 相似文献