单分散高纯硅胶色谱柱填料的制备

在氨水和氨气催化下使单晶硅粉水解, 合成了单分散、高纯的纳米二氧化硅水溶胶; 再利用聚合诱导胶体凝聚法(PICA)制备单分散脲醛二氧化硅复合微球, 经过高温煅烧后得到球形硅胶色谱柱填料. 通过电感耦合等离子-质谱(ICP-MS)、电子显微镜和BET比表面积测试等手段对球形硅胶的纯度、粒径分布及比表面积进行了表征, 并通过色谱分离对硅胶填料的性能进行了评价. 实验结果表明, 该方法合成的色谱柱填料具有纯度高、粒径分布均匀、机械强度高及分离能力强等优点.     

溶胶-凝胶法原位复合PVA/HA水凝胶的结构表征与性能研究

采用溶胶-凝胶原位复合的方法制备了聚乙烯醇/羟基磷灰石生物活性复合水凝胶,探讨了HA含量对复合水凝胶结构性能的影响,用X射线衍射分析、红外光谱分析、DSC、扫描电镜等方法对HA在PVA水凝胶体系中的晶态结构及分散状态进行了表征,并与物理共混复合法进行了比较.研究发现,采用溶胶-凝胶法原位复合可在PVA水凝胶中形成具有生物活性的HA结晶结构,且分散良好,分布均匀.HA粉体作为异相成核剂,促进了PVA水凝胶基体的结晶,提高了复合水凝胶的力学性能.     

苯丙水溶胶的合成与性能研究(I) 聚合工艺和反应组分对聚合稳定性和胶体性能的影响

用一次投料法、半连续滴加法和单体预乳化法三种聚合工艺，合成了苯丙乳液聚合物，并加氨微细化，转化成水溶胶，考察了聚合工艺和反应组分（乳化剂，功能单体等）对苯丙乳液及其水溶胶反应稳定性和粒子大小及分布等胶体性能的影响。     

氢氧化铝镁正电溶胶制备及性能研究

氢氧化铝镁正电溶胶制备及性能研究侯万国，张春光，孙德军，梁晓丽，王果庭（山东大学胶体与界面化学研究所，济南，２５０１００）关键词混合金属氢氧化物，溶胶，超细颗粒混合金属氢氧化物的合成、组成及结构等已得到广泛研究［１，２］．我们也曾用插入法合成了混合金...     

溶胶凝胶法制备光催化薄膜材料及其性能表征

采用溶胶凝胶法制备TiO2胶体,再采用旋涂法在玻璃基体上负载得到TiO2薄膜,并对制备的TiO2结构进行表征,以2,4二-氯苯酚为探针,考察薄膜的光催化性能。通过实验,学生基本了解溶胶-凝胶法的原理、薄膜的制备方法、光催化剂的性能表征,可以作为开放性实验。     

纳米氧化铁的制备及其对砷的吸附作用

用均匀沉淀法、溶胶-凝胶相转移法和溶胶-凝胶蒸发干燥法制备了纳米氧化铁,研究了制备条件,并对产品进行了表征。扫描电镜和X射线衍射分析结果表明,以上3种方法制备的氧化铁,颗粒均在100~300 nm之间。用溶胶-凝胶蒸发干燥法制备的样品C和样品D具备典型α型Fe2O3的物相特征。吸附实验表明,合成的纳米氧化铁对砷(Ⅴ)均有较强的吸附性能,在初始砷质量浓度为2 mg/L,pH值在4.0~6.0的范围内,能使溶液中的砷含量降到0.01 mg/L以下,且吸附速度快,平衡时间短。溶胶-凝胶蒸发干燥法制备的纳米氧化铁在pH值为3.0、7.0和10.0时的最大砷吸附容量分别为30.96、30.58和17.06 mg/g,与其他纳米氧化物相比,用此方法制备的纳米氧化铁对As(V)有较大的吸附能力,较普通块体氧化铁的吸附除砷性能更优。其吸附等温线能用Langmuir方程进行拟合,确定系数R2>0.95。     

掺杂TiO2光催化膜材料的制备及其灭菌机理

采用sol-gel技术制备了掺杂TiO2膜,考察了制备条件对溶胶稳定性的影响,并从TiO2光催化反应的角度分析了膜功能材料的灭菌机理.结果表明,溶胶化过程中温度对掺杂胶体形成速度及胶体粒径分布影响很大,40℃时制备周期短,胶体稳定.TiO2膜材料的灭菌本质在于其光照激活后产生的自由基OH·和O-2·直接攻击细菌的细胞,致使细菌蛋白质变异或脂类分解,从而杀灭细菌并使之分解.TiO2膜功能材料的灭菌效果与TiO2晶相组成直接相关,其灭菌率随膜层中锐钛矿含量的增加而提高.     

修饰晶种法合成MFI型分子筛膜包覆的活性炭颗粒

由于分子筛膜的分离和催化作用, 分子筛膜包覆的传统催化剂颗粒可以实现高效的催化过程. 活性炭颗粒作为一种常用的催化剂载体, 由于其表面的憎水性和不平整, 在不规则活性炭颗粒表面直接水热合成包覆一层分子筛膜非常困难. 为了克服上述缺点, 本文采用一种勃姆石凝胶修饰的晶种法在活性炭颗粒表面合成连续的分子筛膜. 以勃姆石溶胶为前驱体, 在活性炭颗粒表面通过喷涂预先形成一层相对平整的勃姆石凝胶层以改善活性炭表面. 在随后的晶种涂覆过程中, 晶种分散液加入部分勃姆石溶胶为胶粘剂, 所得的晶种层覆盖载体完全, 与载体结合牢固, 无需焙烧处理. 将晶种涂覆后颗粒在旋转动态水热175℃处理6 h, 得到分子筛膜包覆的活性炭颗粒, 所得材料分别用X射线衍射和扫描电镜进行表征. 包覆的分子筛膜为MFI 结构, 厚度约为5μm. 对比实验表明, 没有勃姆石溶胶修饰的活性炭颗粒上不能成膜. 这种勃姆石凝胶修饰晶种法为在各种惰性载体上合成分子筛膜提供了便捷的方法.     

具有环状结构的二氧化硅微聚集体的制备、表征及应用

通过溶胶-凝胶法制备二氧化硅溶胶,并采用喷雾干燥法对其进行形态调控.扫描电镜(SEM)结果表明,喷雾干燥使二氧化硅颗粒发生了形态重组,形成均匀的具有环状结构的二氧化硅微聚集体(PC16MS).通过熔融共混制备了二氧化硅/聚丙烯(PP)纳米复合材料,研究了PC16MS的加入对其微观结构、晶体结构、结晶行为、球晶形态、结晶成核密度和球晶生长速率等方面的影响.采用差示扫描量热(DSC)、偏光相差显微镜(POM)和广角X射线衍射(WAXRD)分析表明,在PP结晶初始阶段,PC16MS的加入大幅度提高了基体材料的成核密度,且使晶粒细化,缩短了结晶时间;当添加2%(质量分数)的PC16MS时,复合材料的结晶温度相对于纯PP提高了10.4℃,成核效率达到39.1%,优于大部分无机成核剂的成核效率.在相同条件下,添加2%未经过喷雾干燥处理的纳米二氧化硅(NC16MS),复合材料的结晶温度相对于纯PP提高3.26℃,成核效率达到12.3%.结果表明,喷雾干燥使二氧化硅颗粒发生了形态重组,形成的均匀介稳态微聚集体在熔融挤出过程中重新分散成纳米粒子,从而有效提高了二氧化硅作为成核剂的成核效率.     

甲基丙烯酸对聚合物乳胶粉再分散性影响机理

采用半连续种子乳液聚合法,以甲基丙烯酸(MAA)为壳层亲水功能单体,合成了丙烯酸酯原乳液,并通过喷雾干燥法制得具有可再分散性的聚合物乳胶粉.讨论了原乳液粒子粒径随pH值和MAA量的变化关系;重点研究了MAA量对乳胶粉水分散液稳定性、再分散乳液zeta电位、乳胶粒粒径分布及乳胶粉内部微观形貌的影响,并分析其作用机理.研究结果表明:原乳液粒子粒径随pH值的增大逐渐增大,且MAA含量越高,粒径增幅越大;随MAA量增加,再分散液稳定性增强,zeta电位绝对值增大,平均粒径逐渐变小,乳胶粉再分散性显著改善.透射电子显微镜(TEM)结果显示:当MAA含量较高时,乳胶粉内部出现较大孔径的中空微孔结构.中空微孔结构提供水分向乳胶粉内部扩散通道,因而优化其水分散性,再分散乳液的"绒毛结构"与较高的zeta电位赋予其优异的分散稳定性.     

Analysis of Biological Samples Using Paper Spray Mass Spectrometry: An Investigation of Impacts by the Substrates, Solvents and Elution Methods

Paper spray has been developed as a fast sampling ionization method for direct analysis of raw biological and chemical samples using mass spectrometry (MS). Quantitation of therapeutic drugs in blood samples at high accuracy has also been achieved using paper spray MS without traditional sample preparation or chromatographic separation. The paper spray ionization is a process integrated with a fast extraction of the analyte from the raw sample by a solvent, the transport of the extracted analytes on the paper, and a spray ionization at the tip of the paper substrate with a high voltage applied. In this study, the influence on the analytical performance by the solvent–substrate systems and the selection of the elution methods was investigated. The protein hemoglobin could be observed from fresh blood samples on silanized paper or from dried blood spots on silica-coated paper. The on-paper separation of the chemicals during the paper spray was characterized through the analysis of a mixture of the methyl violet 2B and methylene blue. The mode of applying the spray solvent was found to have a significant impact on the separation. The results in this study led to a better understanding of the analyte elution, on-paper separation, as well as the ionization processes of the paper spray. This study also helps in establishing a guideline for optimizing the analytical performance of paper spray for direct analysis of target analytes using mass spectrometry.     

Influence of thermal annealing on the structural and optical properties of maghemite (γ‐Fe2O3) nanoparticle thin films

In this study, maghemite (γ‐Fe₂O₃) nanoparticles were initially synthesized via chemical co‐precipitation and then deposited by spray pyrolysis as thin films on white glass substrates. The thin films were annealed for 8 h at 400, 450, 500, 550, and 600 °C in an oven. The structural studies of maghemite nanoparticles were carried out using X‐ray diffractometer. Structural properties that we investigated by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, SEM, and Energy dispersive X‐ray analysis (EDS). Optical properties of the samples were also investigated by ultraviolet‐visible (UV–vis) spectroscopy. The results showed that maghemite nanoparticles have crystalline structure with domain that increases in size with increasing annealing temperature. The optical band gap values were found to reduce from 2.9 to 2.4 eV with increase in annealing temperature. Copyright © 2015 John Wiley & Sons, Ltd.     

Spray dried excipient base: a novel technique for the formulation of orally disintegrating tablets

Orally disintegrating tablets (ODT) are gaining popularity over conventional tablets due to their convenience in administration and suitability for patients having dysphagia. Moreover no water is required for swallowing the tablets and hence suitable for geriatric, pediatric and traveling patients. The purpose of this study is to assess the suitability of spray dried excipient base in the formulation of ODTs of Valdecoxib (low aqueous solubility) and Metoclopramide (high aqueous solubility). Spray dried excipient base was prepared using Scientech spray drier. Super disintegrants (such as Ac-Di-Sol, Kollidon CL, sodium starch glycolate), diluent (mannitol) alongwith sweetening agent (aspartame) were used in the formulation of tablets. The tablets were evaluated for hardness, friability, water absorption ratio, disintegration time (DT) and in vitro drug release. Using the same excipients, the tablets were prepared by direct compression and were evaluated in the similar way. Maximum drug release and minimum DT were observed with Kollidon CL excipient base as compared to tablets prepared by direct compression, showing the superiority of the spray dried excipient base technique over direct compression technique.     

结晶条件对聚丙烯晶胞参数影响的研究

研究了不同方式和条件下形成的等规聚丙烯结晶的晶胞参数，用步进扫描测定试样的宽角Ｘ 射线衍射，用广义逆矩阵法编的计算机分峰程序和晶胞参数拟合计算程序对测定结果进行计算和数据处理．结果表明结晶方式和条件对晶胞参数的影响是明显的，结晶密度依以下次序减小：１４５℃结晶５ｈ＞初生态＞熔融后冰水淬火＞溶液结晶．用差示扫描量热（ＤＳＣ）考察了这些试样的热行为，表明熔融吸热峰Ｉ与结晶密度相关．     

Quantitative Analysis of Therapeutic Drugs in Dried Blood Spot Samples by Paper Spray Mass Spectrometry: An Avenue to Therapeutic Drug Monitoring

A method is presented for the direct quantitative analysis of therapeutic drugs from dried blood spot samples by mass spectrometry. The method, paper spray mass spectrometry, generates gas phase ions directly from the blood card paper used to store dried blood samples without the need for complex sample preparation and separation; the entire time for preparation and analysis of blood samples is around 30 s. Limits of detection were investigated for a chemically diverse set of some 15 therapeutic drugs; hydrophobic and weakly basic drugs, such as sunitinib, citalopram, and verapamil, were found to be routinely detectable at approximately 1 ng/mL. Samples were prepared by addition of the drug to whole blood. Drug concentrations were measured quantitatively over several orders of magnitude, with accuracies within 10% of the expected value and relative standard deviation (RSD) of around 10% by prespotting an internal standard solution onto the paper prior to application of the blood sample. We have demonstrated that paper spray mass spectrometry can be used to quantitatively measure drug concentrations over the entire therapeutic range for a wide variety of drugs. The high quality analytical data obtained indicate that the technique may be a viable option for therapeutic drug monitoring.     

Improved polyvinylpyrrolidone (PVP)/graphite nanocomposites by solution compounding and spray drying

In order to evaluate the roles of graphite dispersion on the functional properties of the composites, PVP/graphite nanocomposites were prepared by blending the aqueous suspension of expanded graphite sheets and polyvinylpyrrolidone (PVP) aqueous solution by ultrasonic treatment, followed by spray drying and direct drying as a comparison individually. The effects of graphite loading and drying method on the dispersion of graphite and the resultant properties of the composites such as electrical and thermal conductivity, friction, and dynamic mechanical properties were studied. The results from transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X‐ray diffraction showed that the composites prepared by fast spray drying exhibited a higher degree of exfoliation and a better dispersion of graphite sheets in the PVP matrix than the corresponding composites prepared by direct drying, leading to a conclusion that fast spray drying can effectively prevent from re‐stacking of the exfoliated graphite sheets as illustrated. As a result, dynamic mechanical thermal analysis showed significant increases in the storage modulus and glass transition temperature for the composites prepared by spray drying. Besides, the spray drying as well greatly improved the electrical and thermal conductivity of the composites. It was also found that the electrical and thermal conductivity of the composites strongly depended on the graphite dispersion, while the friction coefficient unexpectedly does not. Increasing graphite loading level might enhance the probability of graphite sheets re‐stacking, resulting in poor graphite dispersion. Copyright © 2011 John Wiley & Sons, Ltd.     

聚对苯二甲酸乙二酯光学特性的椭圆偏振光谱研究

概要介绍椭圆偏振光谱 (SE)的原理与特点 ,并用椭偏光谱测定了一组结晶度不同的无取向PET薄膜的光学常数谱 ,研究半结晶性高聚物PET不同结晶形态对其光学性能的影响 ,发现随结晶度的增加 ,其光学常数显著增大 ,并趋于晶态的光学常数 .光学性质的改变可能与微晶的尺寸有关     

Au膜结构及其微观应变的测定

介绍用Ｘ－ 射线衍射方法测定Ａｕ 薄膜材料结构及其微观应变 。利用不对称布拉格反射ＳＴＤ（ｓａｍｐｌｅ ｔｉｌ＿ｔｉｎｇ ｄｉｆｆｒａｃｔｉｏｎ） 扫描模式与常规ＣＢＤ（ｃｏｎｖｅｎｔｉｏｎａｌ Ｂｒａｇｇ ｄｉｆｆｒａｃｔｉｏｎ） 扫描模式, 确定Ａｕ 膜的结构及取向, 同时采用直接测量法（ 非卷积法） 来测定Ａｕ 的微观应变。     

Study on the Preparation of Cr‐based Catalysts Doped by Zn using Sol–Gel Auto‐Combustion Method and Its Application for Synthesis of 1‐Chloro‐2,3,3,4,4,5,5‐heptafluorocyclopentene

High‐surface‐area chromium‐based catalysts in the presence of a small amount of zinc were prepared via a sol–gel auto‐combustion method using chromic nitrate, zinc nitrate, and citric acid. First, the auto‐combustion behavior of the dried gel was investigated by derivative thermogravimetry and (DTG)‐TG and infrared (IR) techniques. The results revealed that the dried gel exhibited self‐propagating combustion properties. Second, the as‐burnt powders were characterized by IR , X‐ray diffraction (XRD) , Brunauer–Emmett–Teller analysis (BET) , and scanning electron microscopy (SEM) . The findings showed that the gels were directly converted into CrZn ‐O nanoparticles with high surface area during the auto‐combustion process. Third, the pre‐fluorination Cr‐Zn catalysts were characterized by XRD , BET , SEM , X‐ray photoelectron spectroscopy (XPS) , and Fourier transform (FT)‐IR spectroscopy of pyridine adsorption techniques. It was found that the presence of zinc led to significant structural changes in the catalyst, the particle size was smaller, the surface area became larger, and more active sites appeared. Finally, the catalytic activities of the samples were tested for the fluorination of 1,2‐dichlorohexafluorocyclopentene (1,2‐F6 ) with anhydrous hydrogen fluoride. The obtained results indicated that the pre‐fluorination activated Cr‐Zn catalysts prepared by this sol–gel auto‐combustion method exhibited high efficiency in the synthesis of cyclic hydrofluorocarbons.     

Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry

Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached –90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent.

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