功能化微纳米硅胶表面亚铁配位化学及其催化降解邻苯二酚的性质(英文)

含吡啶硫醚有机分子功能化的微/纳米硅胶粒子利用表面有机分子分别与氯化亚铁和硫酸亚铁发生配位作用,制得两种功能化材料,即FeC@L-NSiG和FeS@L-NSiG。采用红外光谱(FTIR)、紫外可见吸收光谱(UV-Vis)、热重(TGA)和扫描电镜(SEM)对这两种材料进行了表征;同时对材料表面Fe(Ⅱ)可能的配位化学性质以及其催化双氧水氧化降解邻苯二酚的性能进行了研究。为了探究两种材料表面上亚铁中心的配位化学性质,合成了类似于功能化微/纳米硅胶表面上的有机官能团(吡啶硫醚)的含"NS"杂原子的配体L,即2-((乙基硫代)甲基)吡啶。配体L与FeCl2反应后得到配合物[Fe(L)2Cl2],通过X-射线单晶衍射方法测定了它的晶体结构,并将该配合物作为对照物进行研究。结果表明:FeS@L-NSiG表现出更高的催化效果,几乎是FeC@L-NSiG的两倍。与材料FeC@L-NSiG相比,FeS@L-NSiG的催化效率上升是由于其表面上Fe(Ⅱ)中心含有更多的易离去配体(溶剂分子或水分子),从而使底物更容易接近金属中心。

功能化偶氮微孔有机聚合物的制备

利用微孔有机聚合物材料吸附分离CO_2,是被认为解决CO_2捕集分理最有潜力的一种方法。较高的比表面积及极性强的骨架,有利于获得高CO_2吸附容量和选择性。利用吡啶、嘧啶及三嗪功能化的芳胺单体进行氧化偶联反应,制备了一系列偶氮微孔聚合物。用FTIR表征反应前后单体与聚合物的红外谱图的变化,表明成功制备了偶氮微孔聚合物。

膜乳化-溶剂挥发法制备表面羧基功能化苯乙烯-马来酸酐共聚物微球

以苯乙烯-马来酸酐共聚物(PSMA)为原料,利用膜乳化-溶剂挥发法,成功制备了表面光滑、尺寸均一的表面羧基功能化聚合物微球。研究表明:将膜乳化法和溶剂挥发法相结合,可以有效提高微球粒径的均一性,乳化剂种类及浓度、连续相流速、分散相中聚合物浓度等参数对微球粒径及粒径分布有显著影响。此外,利用盐酸使微球酸酐基团水解,可以得到表面羧基官能化的共聚物微球,随着水解时间的延长,微球表面羧基含量增加,并于24 h后基本趋于饱和,且水解对微球的形貌影响不大。

磁性微纳米材料的功能化及其在食物样品前处理中的应用进展

磁性固相萃取是当前对复杂样品中痕量目标物进行有效分离富集的热门技术,功能化磁性微纳米粒子是该技术应用中的关键材料。本文综述了各种已报道的功能化磁性微纳米材料,总结了包括表面嫁接有机小分子、表面包覆碳或无机氧化物、表面嫁接或包覆聚合物、载体表面或孔道内负载磁性纳米粒子、载体骨架内掺入磁性纳米粒子、物理共混法制备磁性功能材料在内的6种功能化方法,并对功能化磁性微纳米材料在食物样品前处理中的应用进行了简要评述。

氨基功能化磁性微球对水中Pb^(2+)的吸附效果

目的利用氨基表面功能化磁性微球,考察不同条件下微球对水中Pb^(2+)的吸附去除效果,探索水中Pb^(2+)的去除净化方法。方法利用原子吸收光谱仪,探讨p H、磁珠吸附时间、最大吸附容量,以及K+、Ca2+、Na+、Cl-、SO42-等水中常见共存离子对Pb^(2+)吸附效果的影响,在优化好的条件下考察氨基功能化磁性微球的吸附容量。结果在p H 3~5范围内,氨基功能化磁性微球对水中Pb^(2+)具有较好的吸附效果,每10 mg氨基功能化磁性微球可吸附101.4 ng的Pb^(2+),一次吸附效率在60%左右,二次吸附效率接近80%左右,且该微球对水中常见离子显示了较好的抗干扰性能。结论氨基功能化磁性微球对水中Pb^(2+)显示了良好的吸附和去除效果,有较好的应用前景。

功能化氮化硼微球的制备与应用

采用球磨及高速剪切法对六方氮化硼进行剥离及改性,得到六方氮化硼纳米片(BNNSs),将BNNSs采用喷雾干燥技术组装成具有多孔结构的功能化六方氮化硼微球;利用SEM、TEM、BET、FTIR等技术对六方氮化硼微球进行形貌、比表面积、物相成分分析;将六方氮化硼微球用于吸附罗丹明B(RhB),研究吸附热力学和吸附动力学模型;对比六方氮化硼微球煅烧前、后吸附性能的差异,探究吸附条件对吸附性能的影响。结果表明:功能化六方氮化硼微球由氮化硼纳米片组成,呈多孔结构,平均直径约为6μm;BNNSs表面成功接枝氨基和羟基官能团,使得BNNSs组装成的六方氮化硼微球亲水性好,有利于对水相中RhB的吸附;当RhB质量浓度为20 mg/L时,功能化六方氮化硼微球比BNNSs的吸附性能更好,吸附容量大,且吸附速率快,吸附容量可达29.29 mg/g;吸附过程符合Langmuir等温吸附模型和拟二级动力学模型,为单分子层化学吸附,不受温度和pH的影响。

基于氨基功能化碳微球修饰丝网印刷电极制备辣椒素电化学传感器

本研究以葡萄糖为原料,用水热法制备碳微球(CMS),并将CMS氨基功能化,制备了分散性良好的复合材料。将氨基化碳微球(NH2-CMS)修饰到丝网印刷电极(SPE)上,构建了一种新型、高灵敏度的辣椒素电化学传感器。采用扫描电镜(SEM)、循环伏安(CV)对材料进行表征,在最佳条件下研究了辣椒素在修饰电极上的电化学行为,结果表明,辣椒素在修饰电极上响应灵敏。在pH=1.5的Britton-Robinson(BR)缓冲液中,氧化峰电流与其浓度在0.2~80μmol·L-1范围内呈线性关系,检出限达0.067μmol·L-1。将制备的电化学传感器应用于实际辣椒样品中辣椒素的检测,加标回收率在98.2%~102.0%之间。

聚苯乙烯复合微球的制备及应用进展

聚苯乙烯微球是一种性能优异的功能材料,具有比表面积大、不易生物降解、微球粒径均一、易回收等特点。本文综述了乳液聚合、分散聚合、悬浮聚合、沉淀聚合、种子溶胀聚合等聚苯乙烯微球的制备方法,探讨了单体、引发剂、溶剂等因素对微球性能的影响,并介绍了功能化聚苯乙烯微球的制备方法,及其在生物医学、催化、复合材料、废水处理、石油化工等领域的应用,最后对其应用前景进行了展望。

一种疏水型可聚合光引发剂的合成、表征及其应用

以2-羟基-4'-(2-羟乙氧基)-2-甲基苯丙酮与甲基丙烯酰氯为原料,通过Schotten-Baumann反应合成了一种疏水型可聚合紫外光引发剂2-(对2-羟基-2甲基苯丙酮)-甲基丙烯酸羟乙酯(HMEM)。对合成产物使用红外光谱、核磁共振谱和紫外-可见吸收光谱进行了分析和表征,证明甲基丙烯酰氯上的酰氯基团与2-羟基-4'-(2-羟乙氧基)-2-甲基苯丙酮上的伯羟基发生Schotten-Baumann反应生成酯基结构,从而制备了具有疏水性及光引发活性的新型光引发剂HMEM。随后将HMEM接枝到聚苯乙烯(PS)微球表面,并通过红外光谱和紫外-可见吸收光谱表征证明光引发剂以化学键合的方式存在于微球表面,从而使微球同时具有光引发活性和交联作用,完成了对微球表面的功能化构筑。

Micro-nanostructural designs of bifunctional electrocatalysts for metal-air batteries

Water-based rechargeable metal-air batteries play an important role in the storage and conversion of renewable electric energy.However,the sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)have limited the practical application of rechargeable metal-air batteries.Most of reviews were focused on single functional electrocatalysts while few on bifunctional electrocatalysts.It is indispensable but challenging to design a bifunctional electrocatalyst that is active and stable to the two reactions.Recently,attempts to develop high active bifunctional electrocatalysts for both ORR and OER increase rapidly.Much work is focused on the micro-nano design of advanced structures to improve the performance of bifunctional electrocatalyst.Transition-metal materials,carbon materials and composite materials,and the methods developed to prepare micro-nano structures,such as electrochemical methods,chemical vapor deposition,hydrothermal methods and template methods are reported in literatures.Additionally,many strategies,such as adjustments of electronic structures,oxygen defects,metal-oxygen bonds,interfacial strain,nano composites,heteroatom doping etc.,have been used extensively to design bifunctional electrocatalysts.To well understand the achievements in the recent literatures,this review focuses on the micro-nano structural design of materials,and the related methods and strategies are classed into two groups for the improvement of intrinsic and apparent activities.The fine adjustment of nano structures and an in-depth understanding of the reaction mechanism are also discussed briefly.

Microstructural characterization and mechanical properties of functionally graded Al2024/SiC composites prepared by powder metallurgy techniques

Al2024/SiC functionally graded materials (FGMs) with different numbers of graded layers and different amounts of SiC were fabricated successfully by powder metallurgy method and hot pressing process. The effects of increasing SiC content and number of layers of Al2024/SiC FGMs on the microstructure and mechanical properties of the composite were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) analyses indicated that Al and SiC were dominant components as well as others such as Al4C3, CuAl2, and CuMgAl2

Gut microbial diversity analysis using Illumina sequencing for functional dyspepsia with liver depression-spleen deficiency syndrome and the interventional Xiaoyaosan in a rat model

AIM To investigate gut microbial diversity and the interventional effect of Xiaoyaosan(XYS) in a rat model of functional dyspepsia(FD) with liver depression-spleen deficiency syndrome. METHODS The FD with liver depression-spleen deficiency syndrome rat model was established through classic chronic mild unpredictable stimulation every day. XYS group rats received XYS 1 h before the stimulation. The models were assessed by parameters including state ofthe rat, weight, sucrose test result and open-field test result. After 3 wk, the stools of rats were collected and genomic DNA was extracted. PCR products of the V4 region of 16 S rD NA were sequenced using a barcoded Illumina paired-end sequencing technique. The primary composition of the microbiome in the stool samples was determined and analyzed by cluster analysis.RESULTS Rat models were successfully established, per data from rat state, weight and open-field test. The microbiomes contained 20 phyla from all samples. Firmicutes, Bacteroidetes, Proteobacteria, Cyanobacteria and Tenericutes were the most abundant taxonomic groups. The relative abundance of Firmicutes, Proteobacteria and Cyanobacteria in the model group was higher than that in the normal group. On the contrary, the relative abundance of Bacteroidetes in the model group was lower than that in the normal group. Upon XYS treatment, the relative abundance of all dysregulated phyla was restored to levels similar to those observed in the normal group. Abundance clustering heat map of phyla corroborated the taxonomic distribution. CONCLUSION The microbiome relative abundance of FD rats with liver depression-spleen deficiency syndrome was significantly different from the normal cohort. XYS intervention may effectively adjust the gut dysbacteriosis in FD.

原子力显微术研究进展

原子力显微术是微纳米尺度实空间形貌成像与结构表征的关键技术之一。近些年,原子力显微术衍生发展出了一系列令人瞩目的功能化探测模式和新技术。文章从以下两个方面论述了原子力显微术的前沿进展:(1)原子力显微术的功能化探测模式及其在微纳米尺度物性研究与测量以及微纳加工等领域的应用;(2)原子力显微术自身在更高精度、更高分辨率、更快速度、更多功能等方面的进展及在基础和应用研究领域中的应用。文章还展望了原子力显微术的下一步发展方向和正在不断扩展的研究领域。

Microbial Remediation of Heavy Metal(loid)Contaminated Soil: A Review

Because of the rapid development of industrial processes, increased urban pollution and agricultural chemicals applied in recent years, heavy metal(loid) pollution in soil has been very serious, and there is an urgent need for fast and efficient removal of heavy metal(loid) pollution. Currently, environmental microorganisms are always used to perform biological alteration or improvement of soils and sewage. Using functional microorganisms that are resistant to toxic heavy metal(loid) ions for alteration and transformation of heavy metal(loid)s in ionic form is an effective measure for microbial remediation of heavy metal(loid)contaminated soil. This paper reviewed the microbial remediation mechanism of heavy metal(loid) contaminated soils, and the approaches for breeding bacteria those can be used for highly efficient removal of heavy metal(loid)s, as well as the application examples of microbial remediation and transformation of heavy metal(loid) contaminated soil, and finally described the future trends and further research work of heavy metal(loid) contaminated soils by microbial remediation.

Tribological Properties of Functionalized Ionic Liquids Containing Ester-group as Lubricants for Steel-Steel System

A series of functionalized ionic liquids （ILs） containing ester-group were synthesized and their tribological prop- erties as lubricants for steel-steel contact were studied and compared with a non-functionalized ionic liquid and perfluo- ropolyethers （PFPE）. The morphology and chemical composition of the worn scars were analyzed by scanning electron mi- croscopy and X-ray photoelectron spectroscopy, respectively, and the possible lubrication mechanism of ILs was discussed. As a result, all ILs demonstrated a better lubricity and a much higher load-carrying capacity than PFPE used as lubricants for the steel-steel tribomates system. The functionalized ILs with ester-group showed slightly worse friction reducing abil- ity than their nonfunctionalized counterparts at relatively lower loads owing to their higher viscosity, but then exhibited better antiwear ability because the ester group they contained had not only physical but also strong chemical reactions with the freshly exposed steel surface and formed chemical adsorption boundary films on the worn surface during friction pro- cess. Under high loads, some triboehemical reactions took place between the active elements, such as fluorine which were released from the ILs, and fresh metal surfaces of rubbing pairs to form the admixture reaction films, which were mainly composed of ferric fluoride mixed with ferric oxide, leading to lower friction coefficients and good wear resistance.

Microwave radiation one-pot synthesis of chloropropyl-functionalized mesoporous MCM-41

Chloropropyl-functionalized mesoporous MCM-41（MCM-41-（CH2）3Cl） was synthesized in alkaline medium by the microwave radiation one-pot method, using cetyltrimethy-lammoniumbromide （CTAB） as novel template, tetraethoxysilane （TEOS） as silica source, and chloropropyltriethoxysilane （C1PTES） as the coupling agent. The microstructure of MCM-41-（CH2）3Cl was characterized by the means of X-ray diffraction （XRD）, nitrogen absorption-desorption, Fourier transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results show that a successful synthesis of MCM-41-（CH2）3Cl with well structure is obtained. The optimal microwave power is 120 W and the best microwave time is 50 rain. The dosage of chloropropyltriethoxysilane on the structure of chloropropyl-functionalzed MCM-41 was also investigated. It is found that the chloropropyltriethoxysilane volume between 0.8 mL and 1.6 mL is favorable for the formation of highly ordered MCM-41-（CH2）3Cl mesostructure.

Surface Functionalization of Microporous Polypropylene Membrane with Polyols for Removal of Boron Acid from Aqueous Solution

Affinity membranes are fabricated for boric acid removal by the surface functionalization of microporous polypropylene membrane(MPPM)with lactose-based polyols.The affinity is based on specific complexation between boric acid and saccharide polyols.A photoinduced grafting-chemical reaction sequence was used to prepare these affinity membranes.Poly(2-aminoethyl methacrylate hydrochloride)[poly(AEMA)]was grafted on the surfaces of MPPM by UV-induced graft polymerization.Grafting in the membrane pores was visualized by dying the cross-section of poly(AEMA)-grafted MPPM with fluorescein disodium and imaging with confocal laser scanning microscopy.It is concluded that lactose ligands can be covalently immobilized on the external surface and in the pores by the subsequent coupling of poly(AEMA)with lactobionic acid(LA).Physical and chemical properties of the affinity membranes were characterized by field emission scanning electron microscopy and Fourier Transform Infrared/Attenuated Total Refraction spectroscopy(FT-IR/ATR).3-Aminophenyl boric acid(3-APBA)was removed from aqueous solution by a single piece of lactose-functionalized MPPM in a dynamic filtration system.The results show that the 3-APBA removal reaches an optimal efficiency(39.5%)under the alkaline condition(pH9.1),which can be improved by increasing the immobilization density of LA.Regeneration of these affinity membranes can be easily realized through acid-base washing because the complexation of boric acid and saccharide polyol is reversible.

阻抗蛋白质吸附载体微球的制备与性能研究

聚合条件对制备功能化微球起到至关重要的作用。在本文中,通过功能单体、烯丙基聚氧乙烯醚(APEG)和苯乙烯的分散共聚制备了一种阻抗蛋白质吸附的功能化微球;然后,通过红外光谱(FT-IR)、动态光散射(DLS)和扫描电镜(SEM)等手段分析这些功能微球的粒径、表面形态和性能;最后通过牛血清蛋白(BSA)吸附实验评价其阻抗吸附性能。实验结果表明:APEG兼具功能单体和稳定剂的功能,在合适的条件下,可以得到良好单分散性的微球。此外,每克聚(苯乙烯-烯丙基聚氧乙烯醚)(P(St-co-APEG))微球的BSA吸附量为0.66 mg,而每克聚(苯乙烯-甲基丙烯酸缩水甘油酯)(P(St-co-GMA))微球的BSA吸附量为4.8 mg。总之,通过分散共聚制备了一种阻抗蛋白质吸附的微球。

自驱动微纳米马达

自驱动微纳米马达能够自主运动,在药物运输、生物传感、细胞分离、微手术和环境治理等方面有着重要的变革性应用前景。在简要介绍自驱动微纳米马达的基本概念、驱动机理、构建策略和研究现状的基础上,重点介绍首次提出的生物相容性镁基微马达和在生物和环境介质中具有本征趋化运动行为的功能化精子微马达。然后,演示了包括双面神粒子、单层管状和各向同性粒子等各种结构的光控微纳米马达及其独特的运动控制性能,表明它们具备作为灵活的平台,以高度复杂的方式操纵和组装微型/纳米货物。最后,展望了应用于生物体中的微纳米马达应该具有强大的推力、特异性感知能力、外部跟踪能力和在血管等生理环境中的自我定位能力。

Warming and increased precipitation alter soil carbon cycling in a temperate desert steppe of Inner Mongolia

Warming and precipitation are key global change factors driving soil carbon(C)dynamics in terrestrial ecosystems.However,the effects of warming and altered precipitation on soil microbial diversity and functional genes involved in soil C cycling remain largely unknown.We investigated the effects of warming and increased precipitation on soil C cycling in a temperate desert steppe of Inner Mongolia using metagenomic sequencing.We found that warming reduced plant richness,Shannon-Wiener and Simpson index.In contrast,increased precipitation signifcantly infuenced Shannon-Wiener and Simpson index.Warming reduced soil microbial species by 5.4%while increased precipitation and warming combined with increased precipitation led to increases in soil microbial species by 23.3%and 2.7%,respectively.The relative abundance of Proteobacteria,which involve C cycling genes,was signifcantly increased by warming and increased precipitation.Warming signifcantly reduced the abundance of GAPDH(Calvin cycle)and celF(cellulose degradation)while it enhanced the abundance of glxR(lignin degradation).Increased precipitation signifcantly enhanced the abundance of pgk(Calvin cycle),coxL(carbon monoxide oxidation),malZ(starch degradation),and mttB(methane production).Moreover,a wide range of correlations among soil properties and C cycling functional genes was detected,suggesting the synergistic and/or antagonistic relationships under scenario of global change.These results may suggest that warming is benefcial to soil C storage while increased precipitation negatively affects soil C sequestration.These fndings provide a new perspective for understanding the response of microbial communities to warming and increased precipitation in the temperate desert steppe.