丙烯酸-丙烯酸酯共聚物对钛酸铋水悬浮液性质的影响

研究了丙烯酸－丙烯酸酯共聚物对钛酸铋（Bi4Ti3O12)悬浮液表面化学性质及流变性的影响。结果表明，共聚物的加入使Bi4Ti3O12的等电点向低pH值方向偏移。共聚物在粉体表面的吸附属于物理吸附，其含量的变化可以引起共聚物在粉体表面吸附构型的变化，当共聚物含量＞1．5wt%时，部分高分子脱附。共聚物的加入可以显著改善悬浮液的稳定性，在低共聚物含量和高共聚物含量均可制备稳定的悬浮液，共聚物含量≤1．5wt%时，浆料的稳定通过静电位阻稳定机理来实现，共聚物含量≥2.0wt%时，可能通过空位稳定机理来实现。     

微米炭纤维吸附水溶液中镉离子的性能

采用煤基炭棒阳极,在氦气/乙炔气氛下直流电弧放电制备了直径0.4μm～0.6μm、长度数十微米的炭纤维。以该微米炭纤维(MCFs)为吸附剂,研究水中镉离子在其上的吸附性能。考察了MCFs的表面性质、时间、溶液pH值及镉离子初始浓度对吸附的影响。实验表明,浓硝酸氧化处理可明显增加MCFs表面含氧官能团数量,吸附能力显著增加;吸附动力学数据符合准二级速率方程。pH值对吸附影响较大。酸性条件下,吸附等温线可用Langmuir方程和Freundlich方程拟合;沉淀发生条件下,可用表面沉淀模型拟合。MCFs的单位质量和单位比表面积的吸附量都很大,当pH=5.50和平衡浓度为2 mg.L-1时其吸附量分别为5.7 mg.g-1和0.058 mg.m-2。结果表明,MCFs在环境保护中显示出潜在应用前景。     

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。     

大豆蛋白在聚砜膜上的吸附行为

结合扫描电镜（SEM）观察，系统研究了溶液化学特性（包括pH、离子强度和给液浓度）对大豆蛋白在疏水聚砜膜上吸附行为的影响．大豆蛋白一膜间的相互作用符合静电作用机理，吸附量在其等电点附近取得最大值．低pH时随pH升高吸附量增加；高pH时随pH升高吸附量降低，离子强度降低，同性电荷物质之间的静电排斥增加吸附，也降低异性电荷物质之间的静电吸引，降低吸附．溶液化学条件同样影响大豆蛋白在聚砜膜上的吸附速率（膜污染速率）．大豆蛋白吸附等温线遵循兰格缪尔方程，通过实验给出了有关的方程参数，由此可预计不同溶液化学条件的膜污染程度和速率．为了确定对流力和静电作用对大豆蛋白吸附行为的影响，进行了静态和动态吸附实验的比较，结果表明，静电作用在大豆蛋白吸附到膜表面的过程中起着关键作用，控制静电作用可以有效减轻大豆蛋白在膜表面的吸附，进而降低膜的长期通量降低．     

钠基累托石对水溶液中镍(Ⅱ)离子的吸附性能

将天然钙基累托石(Ca-REC)经适当处理得到钠基累托石(Na-REC).在静态条件下,研究了Na-REC对水溶液中Ni(Ⅱ)离子的吸附性能和吸附热力学,考察了pH值、离子强度、吸附时间等因素对吸附效果的影响.结果表明,pH值和离子强度是影响吸附的主要因素,离子交换反应和表面配位反应是Na-REC吸附Ni(Ⅱ)离子的主要机理;在25℃、pH=7.0～8.0、吸附时间为3 h、Na-REC用量为6 g/L、Ni(Ⅱ)浓度50 mg/L、离子强度为0.01 mol/L NaNO3的条件下,用Na-REC吸附水溶液中的Ni(Ⅱ)离子,Ni(Ⅱ)离子去除率可达98%以上;Na-REC对Ni(Ⅱ)的吸附是个自发的、反应度很大的过程,吸附符合Freun-dlich模型.     

丙烯酸高吸水树脂吸附阳离子染料废水研究

本研究对丙烯酸高吸水树脂的3种阳离子染料:孔雀石绿、亚甲基蓝和中性红的吸附效果进行了研究,考察树脂成分、吸附时间、pH值、树脂量、染料浓度5种因素对吸附效果的影响。结果表明,含羧基和磺酸基较多的吸水树脂对三种染料吸附较好,吸附率均超过90%。相应的平衡时间分别是20min、10min、180min;最佳树脂投放量分别为0.20g/L、0.20g/L、0.50g/L;最佳吸附pH值分别为5.0、6.0、6.3;染料的吸附容量会随染料初始浓度的增加而变大。     

树脂/聚醚砜复合膜的制备及其对碘离子的吸附性能

以聚醚砜(PES)为膜的基质材料,以粉末状阴离子交换树脂(201×7)为功能颗粒,采用相转化的方法制备了阴离子交换树脂/聚醚砜复合膜。用扫描电子显微镜(SEM)对膜形貌进行表征,采用电子拉伸试验机测定了复合膜的力学性能,采用傅里叶红外光谱(FTIR)对膜吸附机理进行了研究。SEM结果表明,树脂颗粒在聚合物膜中均匀镶嵌分布,树脂的添加提高了膜的孔隙率,且树脂含量越大孔径越大,复合膜的机械拉伸强度随树脂含量的增加而略有降低。选用树脂含量为60%(w/w)的复合膜进行吸附性能研究,结果表明,吸附可在120min内达到平衡,该吸附膜在pH值为3~9范围内对碘离子有很好的吸附去除效果;吸附量随初始浓度增加而增加,吸附符合Freundlich模型,无饱和吸附量,说明多层吸附在吸附过程中发挥重要作用。共存阴离子如硫酸根、氯离子、硝酸根离子的存在会降低碘离子吸附量。FTIR结果表明,复合膜对碘离子的吸附主要是物理吸附。吸附碘离子的复合膜可以脱附再生,且多次再生后,吸附量未见降低。     

聚丙烯酸-高岭土高吸水性树脂的制备及 对重金属离子的吸附性研究

将丙烯酸和高岭土等通过聚合反应制备出一种能吸附重金属离子的高性能树脂,为了研究该树脂对不同重金属离子的吸附状况,研究了该树脂对Cu2+、Ni2+和pb2+三种重金属离子分别在不同pH值溶液中,以及在同一溶液中 的吸附状况.结果表明,该树脂对金属离子的吸附随pH值的改变而改变,并且差别很大;在同一溶液中,和其他二种金属...     

二苯甲酮吸附量对HDPE表面光接枝丙烯酸的影响

研究了以二苯甲酮(BP)为光敏剂时,BP吸附量对HDPE光接枝丙烯酸(AA)的影响。BP在252nm处存在紫外(UV)特征吸收峰,根据吸收峰强度测定了HDPE表面BP的吸附量。研究发现,BP吸附量随预覆液中BP质量分数的增加而增加,当质量分数为3%时,吸附量达到最大值,此后吸附量不随BP的增加而变化。随BP吸附量增加,HDPE的接枝率增加,当BP吸附量为2.82×10-8mol/cm2时,接枝率由未预覆BP时的5%增加到22.5%,接枝效率也由44%提高到90%。接枝可改善HDPE膜的亲水性,接枝率为10%时,膜表面对水的接触角由未接枝时的83°降为36°     

五乙烯六胺改性活性炭对Cd离子的吸附效能

以稻壳活性炭（AC）为基体,采用五乙烯六胺（PEHA）为改性剂,制备了改性AC-PEHA。研究了AC-PEHA对溶液中Cd离子的吸附动力学、等温吸附曲线、pH的影响等吸附行为,考察了不同HCl浓度对解吸率的影响,并通过SEM、FTIR、BET比表面积等手段,对AC和AC-PEHA吸附剂进行了表征。结果表明:AC-PEHA对Cd离子的吸附在反应时间为60 min处达到平衡,符合准二级吸附动力学模型。在初始Cd离子浓度为10~350 mgL-1,pH值为5.0的条件下,AC-PEHA对Cd离子的吸附量达53.58 mgg-1,显著高于AC的吸附量26.15 mgg-1。初始pH值为6~8的条件下,碱性环境更有利于AC-PEHA对Cd离子的吸附。采用30 gL-1的HCl时AC-PEHA对Cd离子的解吸率为83.8%。改性后,由于PEHA进入AC孔道,虽然使其孔容和孔径分别降低了21.6%和7.4%,但同时使AC表面负载了伯胺N—H吸附基团,提高了AC-PEHA对Cd离子的吸附能力。      

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。     

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).     

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.     

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。