氯化镁介质中氧化铝表面的相互作用力

利用原子力显微镜研究了氯化镁介质中氧化铝表面的相互作用力随盐浓度、ｐＨ的变化规律．在中性条件下;当ＭｇＣｌ_２盐浓度由１０^－５ｍｏｌ／Ｌ增加到１０^－2ｍｏｌ／Ｌ时,长程排斥作用由于双电层压缩,作用范围从一百多纳米减弱到十几纳米,实验测得的双电层厚度的实际值与理论值较好的吻合．保持ＭｇＣｌ_２介质浓度不变;ｐＨ由３．６４变化到９．０９;氧化铝表面的相互作用始终表现为排斥力,与测得的Ｚｅｔａ电位值始终为正值相一致．当ｐＨ＝９．５时,由于镁离子的水合氢氧化物在氧化铝表面的特性吸附,产生了短程非静电徘斥力,首次用原子力显微镜证实了Ｍｇ^２＋特性吸附层的存在,厚度约为５ｎｍ。     

载锰活性炭纤维（SACF—Mn）的制备及对乙基硫醇吸附性能的研究：——I SA …

制备了载锰剑麻基活性炭纤维（ＳＡＣＦ－Ｍｎ），并研究了制备条件对ＳＡＣＦ－Ｍｎ的结构及表面形态的影响。研究表明：增大锰溶液的浓度，提高ｐＨ值，高价态的锰离子都有利于ＳＡＣＦ对锰的吸附；锰化合物的阴离子类型，不仅影响ＳＡＣＦ对锰的吸附，而且对载锰后ＳＡＣＦ的表面形态的影响更显著。     

载锰活性炭纤维(SACF-Mn)的制备及对乙基硫醇吸附性能的研究ⅠSACF-Mn的制备及结构研究

制备了载锰剑麻基活性炭纤维（ＳＡＣＦ－Ｍｎ），并研究了制备条件对ＳＡＣＦ－Ｍｎ的结构及表面形态的影响。研究表明：增大锰溶液的浓度，提高ｐＨ值，高价态的锰离子都有利于ＳＡＣＦ对锰的吸附；锰化合物的阴离子类型，不仅影响ＳＡＣＦ对锰的吸附，而且对载锰后ＳＡＣＦ的表面形态的影响更显著     

聚乙烯亚胺在SiC粉体上的定量吸附研究

利用紫外一可见光谱研究了分散剂聚乙烯亚胺在粉体ＳｉＣ上的定量吸附情况．加入酸性ＰＥＩ后粉体ＳｉＣ表面的电性发生改变,等电点由ｐＨ＝２．０移至ｐＨ＝１０．５．分散剂在粉体上的吸附满足Ｌａｎｇｍｕｉｒ单层吸附方程．对分散剂ＰＥＩ－Ｈ^＋（ｐＨ＝３．５７）来说,单层吸附值为０．０１７２ｍｇ／ｍＬ．对分散剂ＰＥＩ－Ｈ^＋（ｐＨ＝６６１）来说,单层吸附值为０．０２０８ｍｇ／ｍＬ．利用富利叶红外光谱证实了这种吸附作用．     

PBTCA稳定Al_2O_3悬浮液及沉积物分形特性的研究

测定了２－膦酸丁烷－１;２,４－三羧酸（ＰＢＴＣＡ）的电离特性,并通过Ｚｅｔａ电位、粒径分布、沉降、比表面积等手段研究其在Ａｌ２Ｏ３表面的吸附及其对电动特性和稳定性的影响．结果表明;ＰＢＴＣＡ在Ａｌ２Ｏ３表面发生化学吸附,并能显著提高颗粒表面的带电量,从而改善浆料的稳定性．ＦＴＩＲ研究表明;羧基及磷酸基均参与了ＰＢＴＣＡ在Ａｌ２Ｏ３表面的化学吸附,从而提高了吸附强度．通过对沉积物表面ＳＥＭ照片的灰度分析发现,其表面形貌具有分形特征,且悬浮液的稳定性越好,沉积物表面的分维值Ｄｆ越大．     

四(4-磺酸苯基)-卟啉在聚4-乙烯基吡啶接枝的乙烯-乙烯醇膜表面的吸附和自组装行为

四(4-磺酸苯基)-卟啉(TPPS)是一种水溶性卟啉,在一定条件下可以自组装形成超分子聚集体,将这种超分子聚集体与膜材料相结合,可以形成超分子负载膜。文中以乙烯-乙烯醇共聚物(EVAL)为膜材料,4-乙烯基吡啶(4VP)为单体,采用紫外辐照表面接枝法制备了表面带有P4VP接枝链的EVAL-P4VP接枝膜,利用非共价键作用将TPPS负载于EVAL原膜及EVAL-P4VP接枝膜上,研究了p H值、离子强度、接枝率等因素对TPPS吸附过程以及TPPS在膜表面存在形态和自组装行为的影响。结果表明,TPPS溶液中自身聚集及离子强度的增加对其在膜上的吸附产生不利影响;吸附过程可用Langmuir等温吸附模型进行描述;接枝率的增加、p H值的减小和吸附量的增加有利于TPPS在接枝膜表面形成J-聚集体。     

聚丙烯酸铵在纳米Y-TZP上的定量吸附研究

利用紫外－可见分光光度计研究了聚丙烯酸铵在纳米Ｙ－ＹＺＰ上的定量吸附情况。测定波长为２６０ｎｍ。分散剂的吸附量受球磨时间、溶液的酸碱性以及分散剂加入量的影响。当ｐＨ＝１．０２时,吸附属于高度亲和型吸附,最高吸附百分数达９８％,加入分散剂后,除强酸条件下,整个体系为ｐＨ趋近８．３,Ｚｅｔａ电势在－３５～４０ｍＶ之间,在较宽的ｐＨ范围里,体系初始的ｐＨ值对吸附情况影响较小。分析产生这种现象的原因是由于     

氯化物浓度及pH值对ICr13不锈钢微动腐蚀的影响

利用自制的微动腐蚀系统,研究了不同浓度的 ＮａＣｌ溶液和 ３．５％ＮａＣｌ溶液中不同的 ｐＨ值对 ＩＣｒ１３不锈钢微动腐蚀的影响。结果表明,微动腐蚀失重量随ＮａＣｌ浓度的增加而增加,随ｐＨ值的升高而下降;ＮａＣｌ的浓度（０～１２）％及ｐＨ值（４～１４）对微动腐蚀失重量的影响遵循不同的指数规律,影响大小的绝对值都在同一数量级,但影响方向相反;ＮａＯＨ对ＮａＣｌ溶液中的微动腐蚀有一定的抑制作用。     

利用声波粒度仪研究Mg~(2 )在Al_2O_3表面的特性吸附

利用声波粒度仪、Ｚｅｔａ电位仪详细研究了金属镁离子在氧化铝粉体表面的特性吸附行为．发现Ｍｇ２＋浓度、体系ｐＨ以及浆料的固体含量都对氧化铝颗粒表面的Ｚｅｔａ电位有显著影响,在不同的实验条件下引起粉体颗粒表面电荷的反转或等电点的位移．不同ｐＨ条件下的粒度测量结果所反映的体系稳定性与Ｚｅｔａ电位较好的吻合．首次用ＡＦＭ证实了特性吸附条件下,氧化物表面水化层的存在．     

中性水介质中碳钢CO_2腐蚀与其表面膜结构关系

采用电化学方法研究了碳钢在中性水介质中的ＣＯ２腐蚀速率及溶液ｐＨ值变化对腐蚀过程的影响。通过对碳钢表面形成的ＦｅＣＯ３膜在腐蚀前后的ＳＥＭ和Ｘ衍射分析与观察发现,膜的致密性和稳定性,在ｐＨ值为７．６～８．４时较好,ｐＨ值过高或过低都会使膜的结构发生明显变化,因而会增加腐蚀。在中性水溶液中,由于ＨＣＯ３浓度增加,ｐＨ值虽上升,但阴极还原反应仍在增加,因而ＦｅＣＯ３膜结构的变化影响不大。     

微波辅助溶剂热法制备磷酸钙微球和多面体

磷酸钙材料具有良好的生物相容性, 被广泛应用于生物材料领域。本研究以Ca(CH₃COO)2、NaH₂PO₄?2H₂O和双亲嵌段共聚物PLA-mPEG为原料, 通过微波辅助120℃水热反应30 min, 合成了自组装结构磷酸钙微球。以相同的反应原料, 在水和乙二醇混合溶剂中, 通过微波辅助120℃溶剂热反应30 min, 制备了具有多面体结构的磷酸钙。通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和热重分析(TG)对所制备样品的物相和形貌进行了表征。研究发现乙二醇的加入对磷酸钙的结构和形貌具有显著的影响。以牛血红蛋白为模型, 研究了所制备的两种不同磷酸钙材料的蛋白吸附效果。磷酸钙材料的牛血红蛋白吸附量随装载溶液中牛血红蛋白浓度的增加而增大, 随样品制备过程中的乙二醇加入量的增加而减小。     

Adsorption of zinc from aqueous solutions to bentonite

The adsorptive properties of natural and Na-enriched bentonite in zinc rich aqueous environment have been studied. The results show that adsorption behavior of both bentonites was strongly depending on the pH. At low pH values, the mechanisms that govern the adsorption behavior of bentonites are dissolution of crystal structure and competition of the metal ions with the H+. Between pH 4 and 7, the basic mechanism is an ion exchange process. The alkaline and alkaline earth metals located in the exchangeable sites of bentonites are replaced with Zn2+ cations present in the aqueous solution. At higher pH values (i.e. pH 8), formation of zinc hydroxyl species may result either participation to the adsorption or precipitation onto the bentonites. Therefore, a rapid increase in the equilibrium removal of zinc was obtained above pH 7. Increase in the initial metal ion concentration led to the increase in equilibrium adsorption to a certain degree; then, a plateau was obtained at higher concentrations. The rate of zinc removal depends also on the solid concentration of the suspension. Reducing the slurry concentration allows particles to get in the more dispersed form, resulting higher available sorption sites for zinc. As a result, the adsorption performance of Na-enriched bentonite is better than the natural bentonite in all physical and chemical changes. The data were fitted both Langmuir and Freundlich isotherms.     

The effects of hydroxyl groups on Ca adsorption on rutile surfaces: a first-principles study

Hydroxyl groups on titanium surfaces have been believed to play an important role in absorbing Ca in solution, which is crucial in the formation of bioactive calcium phosphates both in vitro and in vivo. CASTEP, a first-principles density functional theory (DFT) code, was employed to investigate Ca adsorption on various rutile (110) surfaces in order to clarify how hydroxyl groups effect Ca adsorption. The surfaces modeled in the present study include a bare rutile (110) surface, a hydroxylated rutile (110) surface, an oxidized rutile (110) surface, and a rutile (110) surface bonded with mixed OH groups and water. The results reveal that not all OH groups favors to attract Ca adsorption and loosely bonded OH and water on a rutile surface actually combine with Ca during adsorption. An oxidized rutile surface has the highest ability to attract Ca atoms, which partially explains that alkali-treated Ti surfaces could induce hydroxyapatite formation in alkaline environments.     

非晶态Ni-W-WC复合镀层的制备及镀层性能研究

在非晶态Ni—W合金镀液中加入WC微粒，采用复合电沉积工艺制各非晶态Ni—W—WC复合镀层，井考察了复合镀层在碱性介质中的电催化析氢性能。结果表明，复合镀层中WC微粒的含量随镀液中WC微粒的浓度和电流密度的增加而增加；加入WC微粒后所获得的复合镀层仍然是非晶态结构；复合电板的电催化析氢性能明显优于Ni—W合金电板，性能的提高与其较高的比表面积和较低的析氢反应标准活化自由能有关。     

Concentration effect on tuning of block copolymer-mediated synthesis of gold nanoparticles

Synthesis of gold nanoparticles has been examined using triblock copolymer Pluronic P85 (EO26PO39EO26) at different concentrations as a function of hydrogen tetrachloroaureate (III) hydrate (HAuCl4 x 3H2O) in aqueous solution. The concentration of P85 block copolymer was varied from 0.5 to 2 wt% at fixed temperature (30 degrees C) in presence of HAuCl4 x 3H2O in the range of 0.002 to 0.2 wt% for each P85 concentration. The surface plasmon resonance in the time-dependent UV-visible spectra reveals that increase in the block copolymer concentration increases the yield of the gold nanoparticles but decreases their stability. Both small-angle neutron scattering (SANS) and dynamic light scattering (DLS) show that the number density of block copolymer micelles increase almost linearly with the concentration, which is related to result in higher numbers of nucleation centers and therefore increase in the yield of gold nanoparticles. The fact that increase in the number density of nanoparticles also increases the chances of aggregation and this tends to decrease the stability at higher block copolymer concentration. Transmission electron microscopy (TEM) images confirm the larger sizes of the nanoparticles formed in these systems at higher concentrations.     

Phosphate removal using sludge from fuller's earth production

This study assesses the phosphate removal capacity and mechanism of precipitation or adsorption from aqueous solutions in batch experiments by an industrial sludge containing gypsum (CaSO(4).2H(2)O) obtained as a by-product from a fuller's earth process. The potential capacity for phosphate removal was tested using various solution concentrations, pH values, reaction times, and amount of sludge. The maximum phosphate adsorption capacity calculated using the Langmuir equation was 2.0 g kg(-1). The pH for the maximum adsorption by the sludge was neutral to alkaline (pH 7-12). Over 99% of phosphate was removed from a phosphate solution of 30 mg L(-1) using 0.15 g of sludge in a 9-h reaction. Sulfate (SO(4)(2-)) concentration increased with increasing initial phosphate concentration, possibly because of dissolution of gypsum and adsorption of both sulfate and phosphate. At high phosphate concentration (>1000 mg L(-1)), relative constant concentration of Ca(2+) was not consistent with adsorption of the most important phosphate removal mechanism. Results suggest that precipitation of calcium phosphate is principally responsible for phosphate removal under its high concentration. Agglomerated precipitate in the reaction sludge was observed by SEM and identified as brushite (CaHPO(4).2H(2)O) by XRD, FT-IR, and DTA. Based on thermodynamic considerations, it is suggested that the brushite will readily transform to more stable phases, such as hydroxyapatite (Ca(5)(PO(4))(3).OH).     

聚合物P(NIPAM-AM-NPA)的合成及溶液性能

以丙烯酸壬基酚聚氧乙烯酯(NPA)、丙烯酰胺、N-异丙基丙烯酰胺为单体,采用自由基水溶液聚合方法制备了水溶性共聚物P(NIPAM-AM-NPA)。采用FT-IR、1H-NMR对该共聚物以表征;研究了共聚物浓度、温度以及不同电解质对共聚物溶液性能的影响。结果表明,随着盐浓度的增加,聚合物溶液表观黏度有较大幅度上升。在相同情况下,NaCl的增粘效果最为显著,而MgCl2和CaCl2则影响不大。该共聚物的盐水溶液在升温条件下可保持良好的增粘作用,适当条件下还会出现黏度随温度升高而上升的独特现象。     

纳米Y-TZP悬浮液的团聚抑制研究

研究了几种阴离子型分散剂对纳米Y-TZP水悬浮液的胶体特性、流变特性的影响,并通过等温吸附研究了分散剂与粉体的相互作用.结果发现,几种分散剂均可在粉体表面发生化学吸附,分散剂的加入使Y-TZP在碱性条件下的zeta电位由-20mV变为-40～-50mV左右.流变性测试表明,分散剂的加入使浆料流动性明显改善,粘度大大降低.最后对分散剂抑制团聚的机理进行了讨论.     

纳米SiO2载银抗菌剂的研究

以化学沉淀法制备得到多孔纳米SiO2,采用吸附法在其表面负载银,用载银的粉体抑菌囤直径表征抗菌性能。研究了吸附时间、硝酸银浓度及吸附温度与负载量的关系,并考查了焙烧温度与抗菌性能的关系。