通过聚合物水溶液流经滤膜的流出曲线计算不溶凝胶含量的方法

本文对聚合物水溶液在通过多孔滤膜时的流动行为进行了数学分析,进而建立了一套在恒压模式下聚合物溶液通过多孔滤膜时的流动曲线分析方法,得到了聚合物水溶液中≥滤膜微孔可封堵尺度的不溶凝胶含量,可以有效评价聚合物溶液的溶解性和均匀性。与传统的过滤因子测试方法相比,该方法获得的参数与溶液的均匀性和滤膜孔径相关,排除了其他测量条件的影响,同时有更高效的测试效率。对于三次采油中大量使用的驱油剂聚丙烯酰胺,本文设计的方法能有效评价其中不溶凝胶含量。通过该方法计算也可以得到过滤因子与对应的不溶凝胶含量的关系曲线,计算发现,驱油剂用聚丙烯酰胺的通用行业标准中的过滤因子1.5对应溶液中的不溶凝胶含量应在0.4%左右。

应用溶凝胶工艺制备离子传感器的敏感材料NASICON

本文介绍应用溶凝胶工艺制备离子传感器的敏感材料NASICON,并与传统的陶瓷工艺作了比较。首次介绍采用溶凝胶浸泡涂布法制备NASICON薄膜,简要介绍实验结果和存在的问题。

用光学方法探测溶凝胶玻璃特性

Ｅｕ３＋（铕）掺杂硅溶凝胶玻璃的光学荧光和衰变时间可以通过以下过程函数来测得。这些过程函数有：稠化温度、ｐＨ值和水／预聚体比率。

掺入若丹明B的SiO_2溶凝胶涂层的研究

掺入若丹明Ｂ的ＳｉＯ_２溶凝胶涂层的研究本文报道了溶凝胶过程实验条件对ＳｉＯ２涂层内掺入染料若丹明Ｂ及所导致的光学性、浸出性和耐光性的影响。若每个若丹明Ｂ分子至少有２０个烷氧基硅且这些硅烷经充分水解，染料将被三维Ｓｉ－Ｏ键＂笼＂包封。若未包封，染料不?..

乳糖胆盐体系大肠菌群测试片的研制及性能验证

该文以结晶紫中性红胆盐培养基(violet red bile agar,VRBA)组分为体系基础,通过筛选凝胶,正交试验优化凝胶、乳糖与胆盐添加量,以及添加乳糖发酵诱导剂,进行了大肠菌群测试片的研制。研究表明,使用卡拉胶代替琼脂作为载体,将卡拉胶、乳糖与胆盐的添加量分别优化为15、10、1.2 g/L,同时添加250 mg/L乳酰基-N脂酰基鞘氨醇作为乳糖发酵诱导剂,大肠菌群测试片的理化与微生物性能达到最优。测试片性能符合国标方法对VRBA培养基的控制要求;与国标大肠菌群平板计数方法相比,测试片方法在实际样本的检测结果无明显差异的同时,将检测周期缩短了24 h,结果观察更为直观,提升了对弱产气型目标菌的检测能力。该文所研制的大肠菌群测试片便捷快速准确,可适用于食品检测,并可为商业化测试片的研制提供借鉴意义。

ABS塑料注塑产品环境测试后异常现象的原因分析

通过对某品牌预上市的漱口水容器配件进行UV辐照暴露测试与抗漱口水测试,出现了外观发黄、磨砂外壳局部变透明、熔流结合线变粗,以及出现白色附着物等异常现象。使用金相显微镜与扫描电镜探索微观结构的演变情况,最终发现异常现象的原因。研究表明:经过UV辐照暴露测试和抗漱口水测试后,光氧化降解导致外观发黄;抗漱口水中的乙醇溶解腐蚀ABS的丁二烯组分,以及ABS中含苯化合物向乙醇迁移导致磨砂外壳局部变透明、熔流结合线变粗;白色附着物为“泊洛沙姆407”因溶剂蒸发所形成的无法溶解的白色凝胶。

用溶胶-凝胶法制CaO-SiO_2凝胶及其玻璃

利用溶胶-凝胶法制备块玻璃、玻璃纤维、粉末和陶瓷材料等方面的研究成果早已有所介绍。从能量观点看,这种方法是可行的。用溶胶-凝胶法制得的玻璃,同用常规法获得的组成相同的玻璃相比,具有相同的物理性质与化学性质。它还具有高纯度、高均匀度等的特点。由于溶胶-凝胶法的合成温度较低,同常规玻璃生产方法相比,大大降低了能耗。溶胶-凝胶法特别适合于制备难熔玻璃和高温下不稳定的玻璃,几种处于微分相区域的含碱或碱土金属的硅酸玻璃已用该法制备出来。这在一定程度上扩大了玻璃形成范围。 本文介绍利用溶胶-凝胶法制备玻璃,其组成均处在常规法中CaO-SiO_2系统微分相区域。

氧化钨/氧化钛溶胶凝胶薄膜的气体感测性质研究

在氧化钨溶凝胶中,添加10%的二氧化钛溶凝胶,煅烧后可得形成氧化钨/氧化钛复合粉体.所得粉体,以XRD、SEM、FT-IR、光学特性分析等仪器进行粉体的基本性质与结构检测.随后将氧化钨/氧化钛复合粉末包覆于气体感测电极上,进行气体感测的各种相关检测与分析.结果显示,添加10.0%氧化钛的氧化钨/氧化钛,由100℃的ε-WO3单斜晶结构,随着热处理温度达到300℃,缓慢转变成三斜晶的δ-WO3.比较不同参数的粉体,添加10.0%氧化钛的氧化钨/氧化钛具有较优异感测性质;在200℃,3×10-6的NO2下,灵敏度为29.9.而在150℃,相同浓度下,有最佳灵敏度为86.1.

基于溶-凝胶制备工艺的SiO2基复合相变材料研究综述

相变材料可吸收或释放潜热,从而拥有储能调温潜力。溶-凝胶工艺制备的SiO2基体可为相变材料提供优良的骨架结构,改善相变材料的泄露问题。总结国内外相关文献,介绍了溶-凝胶制备工艺及SiO2基复合相变材料的形貌。阐述了SiO2基体与相变材料间的化学相容性、SiO2基体对相变材料结晶性能的影响以及SiO2基复合相变材料的热物性、热循环稳定性和储/放热性能。最后对引入碳纤维/碳纳米管和金属/金属氧化物粒子等功能型材料,以增强其导热性能及光热转化能力的两类增强型SiO2基复合相变材料进行了概述。

凝胶型菌落总数测试片的研制

本文以脑心浸液(BHI)肉汤为营养组分,以黄原胶与卡拉胶两种冷水可溶凝胶作为复合凝胶,研制出可应用于食品微生物菌落总数检测的凝胶型测试片。通过正交试验确定测试片培养基附加组分最优添加组合,并试验了两种凝胶不同复配比例对理化及微生物结果的影响,最终确定测试片培养基组分为BHI 38.5 g/L,TTC 0.008 g/L,SAP 0.05 g/L,丙酮酸钠2.0 g/L,且黄原胶与卡拉胶比例为8:2时,测试片达到最优性能。本文研制的菌落总数测试片,与国标平板计数方法相比,两种方法线性相关性达到0.99以上,测试片检出限可达2 CFU/mL,灵敏度达到100%;与行业主流产品3M Petrifilm菌落总数测试片相比,定量结果无明显差异,R2达到0.99。本文所研制的凝胶型菌落总数测试片可应用于食品中菌落总数的检测。

Pb^2＋改性TiO2薄膜性能的研究

以玻璃为载体，采用溶凝胶胶法制备Pb^2+-TiO2薄膜。采用AFM、XRD等技术，考察Pb^2+掺杂后对TiO2晶型结构和光催化活性的影响，结果表明，在相同制备条件下掺杂后使TiO2晶型由锐钛型向金红石型转变温度降低，经AFM分析，掺杂后使TiO2粒径增大，苯酚水溶液的光催化氧化分解反应结果表明，掺杂后TiO2的光催化活性有所提高。

直接用超细粉末棒生长单晶光纤的研究

采用激光加热基座生长（ＬＨＰＧ）法，本文研究了直接用超细粉末棒进行单晶光纤的生长，超细粉末用溶胶凝胶法制得，并在室温下将粉末冷压成薄片，然后再切成本研究所需要的源棒．

Hydrophilic and photocatalytic activities of Nd-doped titanium dioxide thin films

The Nd-doped TiO2 thin films with higher hydrophilic and photocatalytic activities were prepared on glass slides by an acid-catalyzed sol？gel method. The effects of Nd doping on crystalline phase, surface composition and optical property were investigated by means of techniques such as X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-IR）, optical contact angle tester and UV-Vis spectroscopy. The results show that Nd doping obviously influences the hydrophilic and photocatalytic activities of TiO2thin films. Nd doping could cause the TiO2 lattice distortion, inhibit phase transition from anatase to rutile, cause red shift of the absorption spectrum edge, produce hydroxyl radicals （·OH）, and accelerate surface hydroxylation, which result in a significant improvement in the hydrophilicity and photoreactivity of Nd-doped TiO2 thin films. When the content of Nd is 0.1% （mass fraction）, TiO2 thin films achieve the smallest grain size （about 15 nm）, and the hydrophilic and photocatalytic activities of TiO2 thin film reach the maximum, the contact angle is only 8.1°, and 92% of methylene blue is finally degraded. Moreover, the modification mechanism of Nd doping was also discussed.

Surface modification of NiTi alloy by sol-gel derived porous TiO_(2)film

Titania films with nano-sized pores were prepared on the NaOH？HCl pretreated NiTi alloy substrate by sol？gel method.A crack-free film is obtained for the sample with a dense inner layer and a porous outside layer（sample TC1＋1）.The X-ray diffraction shows that the titania films are composed of anatase,and a little Ni4Ti3 phase in the heat treated substrate is also detected.The X-ray photoelectron spectroscopy results indicate that the titania film completely covered the NiTi substrate for sample TC1＋1.The sample TC1＋1 is hydrophilic with a contact angle about 20°,and UV illumination treatment for 15 min further decreases the contact angle to（9.2±3.2）°.The potentiodynamic polarization test in 0.9% NaCl solution reveals a better corrosion resistance of sample TC1＋1 than the polished NiTi sample.

Preparation of long alumina fibers by sol-gel method using malic acid

The precursor sol of alumina was prepared by sol-gel method with aluminum nitrate and malic acid as raw materials.The effects of content of malic acid and polyvinylpyrrolidone （PVP） on sol spinnability were explored.The gel fibers with above 80 cm in length were obtained by mixing aluminum nitrate,malic acid and PVP on mass ratio of 10 3 1.5.Thermogravimetry-differential scanning calorimetry （TG-DSC）,Fourier transform infrared （FTIR） spectrum,X-ray diffractometry （XRD）,and scanning electron microscopy （SEM） were used to characterize the properties of the gel and ceramic fibers.The alumina fibers with a smooth surface and about 20μm in diameter were obtained by sintering at 1 200℃,and their main phase was indentified to be α-Al2O3.

Influence of pH value and chelating reagent on performance of Li_3V_2(PO_4)3/C cathode material

The Li3V2（PO4）3/C composite cathode material was synthesized via sol-gel method using three different chelating agents （citric acid, salicylic acid and polyacrylic acid） at pH value of 3 or 7. The crystal structure, morphology, specific surface area and electrochemical performance of the prepared samples were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and galvanostatic charge/discharge test. The results show that the effects of pH value on the performance of the prepared materials are greatly related to the chelating agents. With salicylic acid or polyacrylic acid as the chelating reagent, the structure, morphology and electrochemical performance of the samples are greatly influenced by the pH values. However, the structure of the materials with citric acid as the chelating agent does not change as pH value changes, and the materials own uniform particle size distribution and good electrochemical performance. It delivers an initial discharge capacity of 113.58 mA·h/g at 10C, remaining as high as 108.48 mA·h/g after 900 cycles, with a capacity retention of 95.51%.

Synthesis and electrochemical properties of highly dispersed Li_(4)Ti_(5)O_(12)nanocrystalline for lithium secondary batteries

A sol-gel method using lauric acid as surfactant was used to synthesize Li4Ti5O12 nanocrystals with an ultra-fine particle size distribution between 120 and 250 nm.In order to obtain the electrode materials with the best electrochemical performance,the content of lauric acid during Li4Ti5O12 synthesis was systematically studied.The physical and electrochemical properties of the synthesized samples were characterized by X-ray diffraction（XRD）,field emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM）,laser particle size analysis,alternating current impedance（AC） and galvanostatic charge-discharge experiments.The highly dispersed Li4Ti5O12 nanocrystals obtained at 800 ℃ for 10 h can deliver a specific capacity of 163.3 mA-h/g at 1C rate without obvious capacity fade up to 50 cycles.The results suggest that well dispersed Li4Ti5O12 nanocrystals shorten the Li-ion diffusion length and enhance the electrochemical kinetics of the samples,which are very crucial to high rate capability.

Effect of Mn-doping on performance of Li_3V_2(PO_4)_3/C cathode material for lithium ion batteries

Li3V2-2/3xMnx（PO4）3（0≤x≤0.12） powders were synthesized by sol-gel method. The effect of Mn2＋-doping on the structure and electrochemical performances of Li3V2（PO4）3/C was characterized by XRD, SEM, XPS, galvanostatic charge /discharge and electrochemical impedance spectroscopy（EIS）. The XRD study shows that a small amount of Mn2＋-doped does not alter the structure of Li3V2（PO4）3/C materials, and all Mn2＋-doped samples are of pure single phase with a monoclinic structure （space group P21/n）. The XPS analysis indicates that valences state of V and Mn are ＋3 and ＋2 in Li3V1.94Mn0.09（PO4）3/C, respectively, and the citric acid in raw materials was decomposed into carbon during calcination, and residual carbon exists in Li3V1.94Mn0.09（PO4）/C. The results of electrochemical measurements show that Mn2＋-doping can improve the cyclic stability and rate performance of these cathode materials. The Li3V1.94Mn0.09（PO4）3/C cathode material shows the best cyclic stability and rate performance. For example, at the discharge current density of 40 mA/g, after 100 cycles, the discharge capacity of Li3V1.94Mn0.09（PO4）3/C declines from initial 158.8 mA·h/g to 120.5 mA·h/g with a capacity retention of 75.9%; however, that of the Mn-undoed sample declines from 164.2 mA·h/g to 72.6 mA·h/g with a capacity retention of 44.2%. When the discharge current is increased up to 1C, the intial discharge capacity of Li3V1.94Mn0.09（PO4）3/C still reaches 146.4 mA·h/g, and the discharge capacity maintains at 107.5 mA·h/g after 100 cycles. The EIS measurement indicates that Mn2＋-doping with a appropriate amount of Mn2＋ decreases the charge transfer resistance, which is favorable for the insertion/extraction of Li＋.

Grinding sol gel synthesis and electrochemical performance of mesoporous Li_3V_2(PO_4)_3 cathode materials

Li3V2（PO4）3 precursor was obtained with V2Os.nH2O , LiOH＇H2O, NH4H2PO4 and sucrose as starting materials by grinding-sol-gel method, and then the monoclinic-typed Li3Vz（PO4）3 cathode material was prepared by sintering the amorphous Li3V2（PO4）3. The as-sintered samples were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, N2 adsorption-desorption and electrochemical measurement. It is found that Li3Vz（PO4）3 sintered at 700 ℃ possesses good wormhole-like mesoporous structure with the largest specific surface area of 188 cmZ/g, and the smallest pore size of 9.3 nm. Electrochemical test reveals that the initial discharge capacity of the 700 ℃ sintered sample is 155.9 mA.h/g at the rate of 0.2C, and the capacity retains 154 mA.h/g after 50 cycles, exhibiting a stable discharge capacity at room temperature.

A Novel Approach to Synthesizing Porous ZnO Films: Inorganic Chelating Sol-Gel Method

Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.