乳液聚合法制备亚微米级分子印迹聚合物微球

以西咪替丁为印迹分子，2-丙烯酰胺-2-甲基丙磺酸(AMPS)为功能单体，三羟甲基丙烷三甲基丙烯酸甲酯(TRIM)为交联剂，采用乳液聚合法制备了亚微米级分子印迹聚合物微球．利用扫描电镜对此聚合物微球的形貌进行了观察，探讨了影响乳液稳定性、粒径大小与分布的主要因素，重点对聚合工艺和配方进行了优化，并将所得的聚合物用作吸附剂研究了其分子识别与选择性能．研究表明，乳液聚合法能够制得单分散性较好的、平均粒径在0．169μm～0．407μm的分子印迹聚合物微球，且该微球对其印迹分子呈现出较好的特异识别与选择性能，当以苯丙氨酸为竞争分子时，分离因子可达1．70．     

单分散PS/PAA聚合物微球的研制

以苯乙烯为单体,采用分散聚合法制备了单分散性的聚苯乙烯(PS)微球,然后以PS微球作为种子、丙烯酸(AA)进行无皂种子乳液聚合制备了PS／PAA微球。考察了单体、引发剂、分散剂用量,反应介质极性和交链剂等因素对微球粒径大小及其分布的影响,探讨了分散聚合的反应机理。结果表明,通过改变反应工艺条件,能够制备粒径为1．0～3．0μm、单分散性很好的PS微球;通过无皂种子乳液聚合得到的核壳结构的PS／PAA微球粒径为2．50μm,多分散系数(PI)为0．0325,酸值为10．27mgNaOH／g,其表面带有羧基的特性能进一步扩大应用范围。     

改进的微悬浮聚合法制备聚合物微球

微悬浮聚合法是制备聚合物微球的方法之一,它是先将单体相分散为一定粒度的微液滴,再在低速搅拌(75～100r/min)下进行聚合反应~[1,2],对聚合设备无特殊要求,且避免了悬浮聚合法制备微球时连续数小时的高速搅拌~[3],只要有合适的均化器即可大批量制备1～50μm的聚合物微球,且可适当控制粒度.但由于一般单体在分散介质中均有一定的溶解性,且液滴粒径越小单体溶解度越大,致使聚合过程中单体可通过介质扩散而产生单体在不同粒     

含C60聚苯乙烯微球的制备及光电导性能研究

目前,多功能、高性能聚合物微球的合成及应用已成为研究热点.制备聚合物微球的方法有乳液聚合法、分散聚合法、无皂乳液聚合法、超微乳液聚合法和悬浮聚合法等.制备微米级微球通常采用乳液聚合法和分散聚合法.     

分散聚合法制备窄分布聚苯乙烯微球

窄分布聚合物微球有相当广泛的用途，如用于色谱柱填料，过滤器效能和孔径的测定标准，生化反应的载体等［１］．制备聚合物微球的方法有多种：如悬浮聚合物法可以制得微米级球体，但粒径分布较宽［２］；超微乳液聚合法，却仅能制得小于１μｍ的超微球［３］；唯有分散聚...     

改进的种子聚合——单分散交联聚苯乙烯微球的合成

本文结合了种子聚合法和二步溶胀法的特点,提出用改进的种子聚合法以合成粒径大于3微米、粒度呈单分散的交联聚苯乙烯微球。文中采用的粒径为1—2微米的聚苯乙烯胶乳种子是由无皂乳液聚合法制备的。文章研究了溶胀温度、溶胀剂比例、溶胀时间、交联剂、小分子化合物及表面活性剂等因素对生成微球的粒径和分散性的影响。     

改进的种子聚合——单分散交联聚苯乙烯微球的合成

 本文结合了种子聚合法和二步溶胀法的特点,提出用改进的种子聚合法以合成粒径大于3微米、粒度呈单分散的交联聚苯乙烯微球。文中采用的粒径为1—2微米的聚苯乙烯胶乳种子是由无皂乳液聚合法制备的。文章研究了溶胀温度、溶胀剂比例、溶胀时间、交联剂、小分子化合物及表面活性剂等因素对生成微球的粒径和分散性的影响。     

种子溶胀悬浮聚合法制备分子印迹聚合物微球

 以酪氨酸为印迹分子 ,甲基丙烯酸为功能单体 ,三羟甲基丙烷三甲基丙烯酸酯 (TRIM )为交联剂 ,采用种子溶胀悬浮聚合法在水溶液中制备了一系列分子印迹聚合物微球 (MIPMs)。利用扫描电镜 (SEM)对此微球的粒径大小、粒径分布、表面孔与孔径分布等进行了分析研究 ,探讨了影响其形貌的主要因素 ,并将所得微球用作固定相研究了其分子选择吸附性能。研究表明 ,种子溶胀悬浮聚合法能够制得单分散性较好的、表面带有微孔的分子印迹聚合物微球 ,且该微球呈现出较好的特异吸附性能。     

单分散聚苯乙烯微球的制备及影响因素研究

以聚乙烯吡咯烷酮为分散剂，无水乙醇为反应介质，偶氮二异丁腈为引发剂，采用分散聚合工艺，通过优化反应条件，制备出了粒径为5μm单分散（分散系数≤5％）聚苯乙烯微球。所制备的聚苯乙烯微球标准偏差δ＝0．16μm，分散系数ε＝0．02，且具有良好的球形度，表面非常光滑，无破损，无缺损。对影响单分散聚苯乙烯微球的因素进行了研究，结果表明：随着分散稳定剂用量的增加，聚苯乙烯微球的粒径减小；随着单体和引发剂用量的增加，聚苯乙烯微球的粒径增大。分散稳定剂和单体用量是影响聚苯乙烯微球粒径分布的两个主要因素。     

单分散亚微米级磁性微球的合成

以磁性氧化铁胶体粒子为种子粒子，采用吸附－溶胀法，进行苯乙烯－丙烯酸－二乙烯基苯的乳液聚合，制备亚微米级磁性高分了微球。研究了分散介质、丙烯酸、种子粒子、苯乙烯和ＰＨ调节剂等因素对聚合行为和磁性微球的影响，成功地合成了平均粒径为０．１３和０．２７μｍ、单分散性很好的磁性微球。     

生物热化学和热动力学研究进展

生命相关过程伴随着极其复杂的化学和物理过程,包含着物质变化和能量转换,其中部分能量不可避免地会以热的形式表现出来。用微量热技术和热动力学方法,研究复杂生命体系和相关反应的热动力学过程,可宏观地、本质地反映生命相关过程的内在规律。本文综述了生物量热学方法和技术在生命科学中的应用,介绍了生物量热技术在生态系统、生物组织和器官、细胞水平、亚细胞水平和分子层面等不同生物层次和结构水平上的研究现状和进展。     

纳米碳点的制备与应用研究进展

纳米碳点是碳纳米材料家族的新成员,近年来在国内外受到广泛关注。与传统的荧光染料和半导体量子点发光材料相比,碳点不仅具有优异的光学性能及尺寸效应,且具有制备成本低廉、生物相容性好、易于官能化、能带结构可调等优势。本文在理清有关碳点概念的基础之上,介绍了碳点结构特征和制备策略,着重综述了纳米碳点在生物成像与诊疗、传感器件、催化、光电器件和能量存储领域的最新研究进展,探讨了碳点研究目前存在的问题及未来的发展方向。     

The Different Facets of Triclocarban: A Review

In the late 1930s and early 1940s, it was discovered that the substitution on aromatic rings of hydrogen atoms with chlorine yielded a novel chemistry of antimicrobials. However, within a few years, many of these compounds and formulations showed adverse effects, including human toxicity, ecotoxicity, and unwanted environmental persistence and bioaccumulation, quickly leading to regulatory bans and phase-outs. Among these, the triclocarban, a polychlorinated aromatic antimicrobial agent, was employed as a major ingredient of toys, clothing, food packaging materials, food industry floors, medical supplies, and especially of personal care products, such as soaps, toothpaste, and shampoo. Triclocarban has been widely used for over 50 years, but only recently some concerns were raised about its endocrine disruptive properties. In September 2016, the U.S. Food and Drug Administration banned its use in over-the-counter hand and body washes because of its toxicity. The withdrawal of triclocarban has prompted the efforts to search for new antimicrobial compounds and several analogues of triclocarban have also been studied. In this review, an examination of different facets of triclocarban and its analogues will be analyzed.     

Novel Fluorescent Methods for Biotechnological and Biomedical Sensoring: Assessing Antioxidants,Reactive Radicals,NO Dynamics,Immunoassay, and Biomembranes Fluidity

We proposed and developed a series of fluorescent methods for analysis and investigation of biological systems with a view of future biotechnological and biomedical applications. The methods we describe have been built upon several photochemical and photophysical phenomena including fluorescent quenching, photochrome photoisomerization, and energy transfer. Three new types of molecular probes have been developed and employed for such studies: (1) dual fluorophore–nitroxide compounds, (2) fluorescence–photochrome molecules, and (3) super molecules containing both fluorescence and fluorescent quenching segments. The fluorescent properties of the new probes were intensively exploited for several practical applications including a real-time analysis of antioxidants, nitric oxide, superoxide, reactive radicals, trinitrotoluene, and metal ions, investigation of molecular dynamics of biomembranes in a wide range characteristic times, detection of protein conformational transition, and characterization of surface system. Owning high sensitivity, simplicity, and availability of fluorescent techniques, these methods can be widely employed and are adaptable to fibrooptic sensoring. A general survey of the physical principles and application of the new fluorescent methods has been provided.     

纳米材料-蛋白质界面相互作用的分子机制

纳米材料由于其优异的性能在化工、电子、机械、环境、能源、航天等各个领域已经得到了广泛的应用,并且在生物医学方面的应用越来越受到重视。纳米材料-蛋白质界面相互作用是纳米生物医学领域重要的科学问题,对于纳米材料的生物医学应用以及生物安全性评价至关重要。蛋白质分子与纳米材料在界面的相互作用,一方面可以诱导蛋白质的构象、组装结构甚至功能的改变,另一方面可以引起纳米材料的表面亲疏水性、电荷性质等表面物理化学性质的改变。基于蛋白质与纳米材料相互作用检测技术及结果,本文从分子水平阐述了纳米材料与蛋白质分子在界面之间的相互作用机理及相应的结构与性质的变化,从而可以深化对两者之间复杂的相互作用机制的理解,对于推进纳米材料在生物医学的应用及健康、安全、持续发展具有重要意义。     

Photochemical Synthesis of Gold and Silver Nanoparticles—A Review

Nanomaterials have supported important technological advances due to their unique properties and their applicability in various fields, such as biomedicine, catalysis, environment, energy, and electronics. This has triggered a tremendous increase in their demand. In turn, materials scientists have sought facile methods to produce nanomaterials of desired features, i.e., morphology, composition, colloidal stability, and surface chemistry, as these determine the targeted application. The advent of photoprocesses has enabled the easy, fast, scalable, and cost- and energy-effective production of metallic nanoparticles of controlled properties without the use of harmful reagents or sophisticated equipment. Herein, we overview the synthesis of gold and silver nanoparticles via photochemical routes. We extensively discuss the effect of varying the experimental parameters, such as the pH, exposure time, and source of irradiation, the use or not of reductants and surfactants, reagents’ nature and concentration, on the outcomes of these noble nanoparticles, namely, their size, shape, and colloidal stability. The hypothetical mechanisms that govern these green processes are discussed whenever available. Finally, we mention their applications and insights for future developments.     

二维材料“遇见”生物大分子:机遇与挑战

二维材料的超薄原子层结构使其具有独特的力学性能、导热导电性以及巨大的比表面积,在能源存储、催化、传感和生物医学等领域引起了国内外学者的广泛关注。将二维材料与具有生物活性的生物大分子相结合可以为开发具有优异电学、力学和生物学功能的特种功能材料提供新的方法和途径。近年来,科研工作者针对这一方向展开了广泛的研究,取得了一系列重要的成果,使二维材料与生物大分子的结合与应用成为了新的研究热点。本文综述了近年来二维材料和生物大分子之间的相互作用及应用的研究进展,重点介绍了二维材料与生物大分子在分子水平上的相互作用机理,还总结了基于二维材料与生物大分子之间的相互作用在工程、疾病治疗和抗菌中的应用,并对其未来的研究趋势提出了展望。     

Applicability of ICP-OES,UV-VIS,and FT-IR Methods for the Analysis of Coffee Products

Spectroscopic methods were applied to study and compare the nutrient composition of ground, instant, and chicory coffee products. The total concentrations of 17 elements, including major (Ca, Mg, P) and trace (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, Ti, Zn) elements were determined in solid samples and infusions from ground coffee by means of inductively coupled plasma atomic optical spectrometry (ICP-OES). For measurement of As and Se levels, hydride generation technique (HG-ICP-OES) was used. The accuracy of the element measurements was verified by the analysis of certified reference materials (tea leaves (INCT-TL-1), apple leaves (1515), and TORT-2). Caffeine was determined by UV spectrometry. Infrared spectroscopy was applied to investigate organic matter of the coffees. Soluble oxalate was determined by a redox titration. Additionally, measurements of some physico-chemical parameters such as moisture, ash, pH, and starch (coffee adulteration) were performed. Differences in the composition of analyzed ground and instant coffees based on the contents of caffeine, oxalate, and minerals such as Cu, Mg, P, and Zn were found. FT-IR spectroscopy was a suitable tool to characterize the presence of caffeine and oxalate.     

食品及环境样品中双酚类物质的前处理及检测方法研究进展

双酚类物质作为一种环境内分泌干扰物,广泛存在于食品包装材料及环境介质中,对生态环境造成污染,也对人体健康产生一定危害。双酚残留是目前重要的食品安全问题,检测食品和环境样品中的双酚类物质的含量对人体健康具有重要的意义。由于残留目标物浓度通常较低,且实际样品存在基质干扰,因此需经一定的样品前处理,并结合仪器分析方法,提高检测效率,增强分析灵敏度与可靠性。常用的前处理分析方法主要有液液萃取、微波辅助萃取、固相萃取、固相微萃取、基质分散固相萃取、QuEChERS等,常用仪器分析方法包括液相色谱法、气相色谱法、毛细管电泳法、酶联免疫吸附测定法、生物传感器法等。该文综述了食品及环境样品中双酚类物质的样品前处理及仪器分析方法,为双酚类化合物的残留监测提供了参考依据。     

Wettability alteration of carbonate rocks from strongly liquid-wetting to strongly gas-wetting by fluorine-doped silica coated by fluorosilane

Wettability alteration is an important mechanism to increase recovery from oil and gas reservoirs. In this study, effect of fluorine-doped silica coated by fluorosilane nanofluid on wettability alteration of carbonate rock was investigated. The nanoparticle synthesized by sol-gel method was characterized using XRD, FTIR, SEM, and DLS. Adsorption of nanoparticle on rock was characterized by FESEM, and composition of rock after treatment was determined by EDXA. Effect of nanofluid on wettability was investigated by measuring static, advancing, and receding contact angle and surface free energy, imbibition of water, crude oil, and condensate of untreated and treated carbonate rock. Also, stability of contact angle and thermal stability of nanofluid were studied. ?Results show that contact angles for water, condensate, and crude oil were altered from 37.95°, 0°, ?and 0° to 146.47°, 145.59°, and 138.24°. In addition, water, condensate, and oil imbibition ?decreased more than 87, 88, and 80%, indicating that wettability was altered from strongly oil wet, ?condensate wet, and water wet to strongly gas wet. The ultraoleophobic and ultrahydrophobic stability were >48 hours and 120 minutes. Surface free energy of treated rock for water, crude oil, and condensate was ?2.24, 1.17, and 1.47mN/m. Thermal stability of nanofluids and adsorbed nanoparticle was up to 150°C.