超声化学在纳米材料制备中的应用

纳米材料的稳定性、物理化学性能及粒子的大小与制备方法密切相关.近年来,超声技术已被用于纳米材料的制备,并初步显示了其优越性.本文介绍了超声沉淀法、超声热解法、超声还原法、超声电化学法、超声体相扩散法等制备纳米材料方法的进展,对这些方法有关的作用机理、影响纳米产物的因素、各种方法具备的优势进行了讨论.     

超声波在纳米材料制备中的应用

简要介绍了超声波的作用机理,综述了超声波在零维、一维以及具有特殊结构的纳米材料制备中的应用,并对超声波在纳米材料制备中的应用前景进行了展望.     

纳米材料研究进展Ⅱ：纳米材料的制备,表征与应用

本文综合介绍近十年来纳米材料的制备，表征与应用，探讨了各种方法的特点与适用性。     

纳米材料制备技术在化学综合实验课程中的应用

在应用化学等专业的化学综合实验课程中,开设24学时的综合实验项目＂金属氧化物无机纳米材料的合成、表征和性能研究＂,使学生了解纳米材料的化学制备方法及化学性能检测技术。介绍了该实验的开设背景,教学目的,教学内容及教学效果。     

超声化学在生物医学中应用的研究进展

超声是一类频率超过人类听力上限的机械波,具有高能和高穿透性的特点,能穿透生物体软组织的阻碍,在其内部诱导发生化学反应.近年来,超声化学手段越来越多地被应用于生物医学的研究当中,并为生物医学的发展提供了新的着力点.本文从三个方面,即超声的机械化学作用、声敏剂辅助的超声化学和超声的空化效应,总结并综述了超声化学在生物医学领域应用的研究进展.     

聚合物在纳米微粒制备中的应用

概述了近年来聚合物在纳米微粒制备中的应用，分析了应用极性高分子作为纳米微粒分散介质的可行性，讨论了用络合转换方法制备纳米微粒的普适性。     

电化学技术制备纳米材料研究的新进展

利用电化学方法制备与组装纳米材料是近年来发展起来的一项新技术.本文对电化学方法在纳米材料制备中的应用及其研究进展做了较为全面的概述,着重介绍了模板电化学法合成纳米材料、稳定剂保护下电化学还原法制备金属溶胶、电化学台阶边缘修饰法制备一维纳米材料以及脉冲超声电化学法制备纳米粒子,并对其应用前景做了展望.     

卟啉微纳米材料的制备及应用研究进展

综述了卟啉微纳米材料合成的制备方法,以及将其作为传感、光电器件等应用的研究进展。卟啉类化合物是广泛存在于自然界重要的生物分子,其独特的平面骨架和共轭大π结构,使之成为分子组装体系中优良的构筑基元。制备的卟啉微纳米材料因其良好的光、热稳定性,已被广泛用于分析化学、仿生、催化及材料科学等领域。     

纳米材料在电化学生物传感器中的应用

纳米材料因其具有独特的性质,被广泛应用于研制和发展具有超高灵敏度、超高选择性的电化学生物传感器.本文总结了纳米材料在电化学生物传感系统中的主要功能,介绍了近年来国内外基于纳米材料构建的电化学生物传感器的研究进展,并对该领域的发展前景做出了展望.     

纳米材料制备的电化学传感器在水合肼检测中的应用研究进展

综述了近年来纳米材料(贵金属、金属氧化物、金属硫化物、碳基复合材料及其他材料等)应用于电化学传感器的制备,并将其用于水合肼的检测的研究进展,对其发展前景进行了展望(引用文献51篇).     

纳米材料催化化学发光法测定车间废气中的丁酮

基于纳米材料催化丁酮的氧化反应产生化学发光的现象,建立了一种丁酮的快速测定方法。实验发现,丁酮在纳米级MgO和Al2O3表面都有较强的发光现象,但在MgO与Al2O3摩尔比为4：1的混合物上有较好的选择性。选择了最佳实验条件：分析波长为440nm;测定温度为335℃左右;载气流速为145mL／min;方法的检出限为6．2mg/／m^3;线性范围为20～1000mg/m^3;相关系数为0．9992。应用本法可快速测定车间空气中的丁酮。     

锂离子电池纳米材料研究

报道了作者最近在锂离子电池纳米材料方面的研究工作 .包括纳米负极材料 (如Sb ,SnSb ,CuSn及Si) ,纳米正极材料 (如CuS)合成 ,电化学性质 ,以及纳米材料的晶体结构与形貌在充放电过程中的变化等研究 .此外还报道了具有纳米尺度阴离子的锂盐在聚合物电解质中的增塑作用以及纳米硅Raman光谱和光致发光谱受电化学锂掺杂的影响 .最后对纳米材料的本征性质与其电化学性质的关系进行了讨论 ,并对其在锂离子电池中的应用及在基础研究方面的意义给予了评述 .     

Chemically Organizable Nanosized Materials Preparation and Applications

We are interested in fabricating well-organized assemblies of nanosized materials with wet chemical approaches for the purpose of investigating various interfacial and mesoscopic phenomena. The paper describes how to use self-assembling techniques to prepare assemblies of colloidal nanoparticles and single walled carbon nanotubes on solid surfaces. Gold nanocolloids are taken as the model system, including preparation of functionalized nanoparticles, assembling on tailored substrates, surface reorganization, and 1D, 0D controlled assembling with the aid of scanning probe lithography. The typical work we have been doing using these elaborated nanoparticle assemblies includes, the quantitative investigations of die electromagnetic coupling of particle-particle and particle-substrate in surface enhanced Raman scattering (SERS), the single electron tunneling in nanoparticle assemblies measured with scanning probe microscopy (SPM) technique, the atomic force microscopy (AFM) lithography using the surface-confined gold nanoparticles as mask.     

纳米材料的概述、制备及其结构表征

纳米材料在电子、光学、化工、陶瓷、生物和医药等诸多方面的重要应用而引起人们的高度重视。本文从以下3个方面加以论述。 一、纳米材料的概述:从分子识别、分子自组装、吸附分子与基底的相互关系、分子操作与分子器件的构筑,并通过具体的例证加以阐述,包括在STM操作下单分子反应;有机小分子在半导体表面的自指导生长;多肽-半导体表面特异性选择结合;生物分子/无机纳米组装体;光驱动多组分三维结构组装体;DNA分子机器。 二、纳米材料的若干制备方法和结构表征方法:制备方法包括:物理的蒸发冷凝法,分子束外延法(MBE),机械球磨法,扫描探针显微镜法(SPM)。化学的气相沉淀法(VCD),液相沉淀法,溶胶-凝胶法(Sol-gel),L-B膜法,自组装单分子层和表面图案化法,水热/溶剂热法,喷雾热解法,样板合成法或化学环境限制法及自组装法。 三、若干结构表征方法包括:X-射线法(XRD),扩展X射线精细结构吸收谱(EXAFS),X-射线光电子能谱(XPS),光谱法,扫描隧道显微镜/原子力显微镜(STM/AFM)和有机质谱法(OMS)。     

纳米合金的制备进展*

对纳米合金材料的制备方法和研究进展作了比较全面的综述.对机械合金化法(BM)、还原法、超声波法、脉冲电沉积法、静高压法、激光汽化器控制浓度法(LVCC)、氢等离子体-金属反应法、非晶晶化法等进行了介绍,并对这些方法有关的机理、特点、影响因素以及结果等进行了讨论.     

The effect of high intensity ultrasound on the synthesis of some polyurethanes

High intensity ultrasound has been applied to the preparation of polyurethanes from a number of diisocyanates and diols. In all cases, the sonochemical reactions proceeded faster in the early stages and led to higher molecular weight polymers. The effect of changing the ultrasound intensity is discussed and some speculation as to the mechanism of the reaction enhancement is given.     

The effect of high-intensity ultrasound on the ring-opening polymerisation of cyclic lactones

High-intensity ultrasound has been applied to the ring-opening polymerisation of δ-valerolactone and ε-caprolactone catalysed by dibutyl tin dilaurate. Sonication was found to accelerate the polymerisation. In the case of δ-valerolactone, sonication also promoted a depolymerisation reaction so that the molecular weight fell during later stages of the reaction. Co-polymers of the two monomers were synthesised and the use of ultrasound led to preferential incorporation of ε-caprolactone into the material, probably due to degradation of the valerolactone sequences.     

Discrete Fourier Transform Analysis of Chronoamperometric Currents Obtained Under Ultrasound

A discrete Fourier transform (DFT) technique was used to analyze chronoamperometric currents at a Pt microdisk electrode (Ø=15 μm) in an electrolyte containing [Fe(CN)₆]^3?/[Fe(CN)₆]^4? under ultrasound at a frequency of 26.3 kHz and the powers of 0–50 W. The currents were measured by a high‐speed data acquisition card. Considering the effects of acoustic vibrations and cavitations on the limiting currents, a microdisk electrode and a high frequency sampling (10 MHz) were used to collect the current signals to restrain the deviation of average from sampling period in other methods. The results show that the amplitudes at 0 Hz and 26.3 kHz are related to the decay of ultrasound at constant power output when the separation between sono‐horn and electrode increases, and also related to the reactant concentration at the same ultrasonic conditions. The frequency signals are always shown in frequency spectrum despite different ultrasonic conditions. The amplitudes reflect the intensity of ultrasound and the concentration of reactant in solution, so they can be called specific frequencies. This method can be used to analyze quantitatively the effects of ultrasound on electrochemical reaction, determine the reactant concentration and measure the distribution of ultrasonic intensity in a solution.     

An Efficient and Highly Chemoselective Method to Desilylate Silyl Ethers

An efficient and highly chemoselective desilylating method is described. Trimethylsilyl ethers (0.25 M) in a CH₃OH/CCl₄ (1:1) solvent mixture are deprotected to their corresponding alcohols with ultrasound in a commercial ultrasonic cleaning bath. Selective deprotection of tert-butyldimethylsilyl ethers of benzyl alcohols and phenols is achieved under ultrasonic conditions. We deprotected also tert-butyldimethylsilyl ethers of primary alcohols, whereas tert-butyldimethylsilyl ethers of secondary and tertiary alcohols are stable under these conditions.