溶胶-凝胶结合超临界流体干燥法制备纳米掺锶羟基磷灰石的研究

以硝酸钙、氯化锶、磷酸氢二氨等无机盐为原料,采用溶胶-凝胶结合超临界流体干燥法,制备了羟基磷灰石(HAP)纳米微粒、钙被半取代的掺锶羟基磷灰石(SrCaHAP)纳米微粒以及钙被全取代的掺锶羟基磷灰石(SrHAP)纳米微粒.通过元素含量分析、TEM、XRD、FT-IR等手段,对这些纳米微粒的结构进行了分析;探讨了锶的掺入对羟基磷灰石(HAP)的结构、晶形以及结晶度的影响.结果表明:采用溶胶-凝胶结合超临界CO2干燥法,在给定的反应条件下按Sr/[Sr Ca]原子比为0、0.5、1,锶可以按化学计量比掺入到HAP的分子结构中,可分别制备纯度较高、晶型结构较好的HAP、SrCaHAP和SrHAP纳米微粒.HAP掺入锶元素后,不仅降低SrCaHAP和SrHAP 中OH(,PO3(主要官能团的红外光谱吸收峰的振动频率,还改变了纳米微粒的晶形,从短棒状的HAP改变为针状的SrCaHAP,再改变为短棒状的SrHAP.HAP中钙被锶半取代后形成SrCaHAP,微粒结晶度降低,生物学性能改善;当钙被锶完全取代后形成不含钙的SrHAP,微粒结晶度增加,生物学性能变差.     

微波合成掺锶羟基磷灰石

以SrCl2、Ca(NO3)2和(NH4)2HPO4为原料,采用微波法合成了掺锶羟基磷灰石。对制备的SrHAP进行元素含量分析,采用XRD对其结构进行了表征,并测定粉体产物的粒度。研究结果表明:采用微波法可以制备出元素组成接近原料计算化学计量比的掺锶羟基磷灰石;采用微波法可以快速得到结晶性好的SrHAP;掺锶量对微波合成的SrHAP的结构有显著影响;微波法比常规方法制备出的SrHAP粉体的粒度小。     

含锶纳米羟基磷灰石的制备及性能研究

采用化学沉淀法制备了纳米掺锶羟基磷灰石（Sr-CaHAP）,通过XRD、FT-IR、TEM等手段,对纳米掺锶羟基磷灰石进行了结构分析。以牛血清白蛋白（BSA）为吸附目标,研究了纳米掺锶羟基磷灰石的吸附性能。结果表明,实验制备的纳米掺锶羟基磷灰石分散性好,是具有一定粒径的纳米针状晶体。在吸附时间为1 h、反应温度为45 ℃、pH为7时,掺锶羟基磷灰石对牛血清白蛋白的吸附量最大;且随着牛血清白蛋白浓度的增加,对牛血清白蛋白的吸附量也随之增加。相比较,掺锶羟基磷灰石对牛血清白蛋白的吸附量较羟基磷灰石大。     

模拟含碱高放废液"碱-偏高岭土-矿渣"固化性能研究

研究了不同水热条件下粒化高炉矿渣(granulated blast-furnace slag,简写GBS,以下简称为矿渣)加入"碱-偏高岭土"体系后,其水化产物对Sr、Cs的吸附性能影响和力学性能变化;通过体系对Sr、Cs吸附性能和力学性能的变化情况,进一步研究了掺废液体系KS20经不同水热条件处理后,产物对废液离子浸出性能的影响.结果表明:"碱-偏高岭土"体系加入矿渣后,体系对Sr、Cs的吸附性能随矿渣加入量增加而降低;强度随矿渣加入量增加而提高;掺废液体系KS20合成温度升高,废液掺量增加,废液离子浸出百分数不断减少.     

影响磷灰石微球药物缓释效果的若干因素分析

利用十六烷基三甲基溴化铵(CTAB)模板剂的疏水基作用,经水热法制备了具备独特孔结构和表面特性的掺锶羟基磷灰石微球,通过X射线衍射、场发射扫描电子显微镜、比表面积、红外光谱、Zeta电位仪等手段对微球进行表征,并研究了制备条件,如:掺锶量、CTAB浓度、前驱体液pH值等,与微球孔结构、表面特性及载药/释药性能之间的关系。结果表明:当Sr与Sr+Ca的摩尔比为0.3时,微球具有最高的比表面积,同时调节CTAB用量和前驱体液pH值也能显著影响其结构和载药释药性能。     

掺铝α-FeOOH纳米微粒对铅离子吸附性能研究

采用金属离子化学共沉淀法制备掺铝α - FeOOH纳米微粒,通过透射电镜(rEM)和X射线衍射(XRD)对其进行表征,并研究了其对铅离子(Pb2+)的吸附性能.结果表明:制备的掺铝微粒为α- FeOOH,呈针状,是纳米级.pb2+初始质量浓度、吸附时间对吸附效果均有不同程度的影响.掺铝α - FeOOH纳米微粒对pb2+的吸附符合Langmuir模型,理论最大吸附量qm为5.043 mg/g.吸附过程可以用准二级动力学方程进行描述,准二级动力学速率常数k为0.088 g/(mg·min),平衡吸附量理论计算值qe为5.405 5 mg/g.     

固化条件对掺锶羟基磷灰石骨水泥凝结时间的影响

在类生理条件下制备了新型掺锶羟基磷灰石骨水泥,系统考察了固化条件,包括固化液浓度、固／液质量比、晶种含量、固化温度及掺锶量等对其凝结时间的影响规律。结果表明：合理选取稀磷酸固化液浓度、控制固／液质量比可以使该类水泥的凝结时间符合临床应用标准。固化液浓度较低时,加入适量的晶种可以有效缩短凝结时间。固化温度对掺锶羟基磷灰石骨水泥的固化过程有显著影响,提高温度促进水化进程,缩短了凝结时间。此外,相同固化条件下,掺锶量对该类水泥凝结时间有一定影响,表现出锶元素对羟基磷灰石结晶过程的阻滞效应。     

凹凸棒石对核素Sr2+的吸附性能与结构表征

本文采用间歇法研究了凹凸棒石在不同环境条件下(浓度、介质、pH值、温度)对Sr2+的吸附性能,并对吸附Sr2+后的凹凸棒石用XRD表征和分析,为评价中低放核废物处置效果提供一些参考依据.结果表明:凹凸棒石对Sr2+的平衡吸附量随Sr2+溶液的浓度升高而增大,而平衡吸附率和平衡吸附比随溶液的浓度增大而降低.凹凸棒石对Sr2+的吸附性能随pH增大而提高.在介质1中,凹凸棒石对Sr2+的吸附性能最好,在介质3、2、4中对Sr2+的吸附性能依次降低.在303 K以上时,凹凸棒石对Sr2+的吸附性能随温度升高而提高.吸附Sr2+后的凹凸棒石的晶胞参数a增大,晶胞参数b减小,其它晶胞参数变化在不同条件下各有规律.     

酵母菌固定化及对锶吸附的影响

酵母菌具有吸附富集重金属离子的能力.利用海藻酸钠对酿酒酵母菌进行固定,对固定化后的酿酒酵母菌吸附锶的能力做了对比研究.结果表明,海藻酸钠颗粒对锶有一定吸附作用,吸附速度较快,但是结合不稳定,未固定的酵母菌吸附较稳定,但是在低浓度时,吸附率不高;固定化酵母菌对锶的吸附分两个阶段,低质量浓度(10 mg/L)时,吸附率可达80%.在不同质量浓度梯度下(10～100 mg/L)吸附研究中发现,三者的吸附率均随浓度增大而减小,但吸附总量均有所增加.随培养时间延长,未固定与固定化酵母菌对锶的吸附率和吸附量趋于一致.结果表明海藻酸钠可以作为酵母菌活细胞生长固定化载体并表现出对低浓度Sr2+的较好吸附效果.     

BSA/SiO_2/Fe_3O_4磁性固相萃取-分光光度法测定水中铅

合成了牛血清蛋白修饰的二氧化硅包覆纳米四氧化三铁(BSA/SiO_2/Fe_3O_4)吸附剂,建立了基于BSA/SiO_2/Fe_3O_4吸附-分光光度法测定水中铅的分析方法。在40°C下,pH=5.0时,吸附50min可达到吸附平衡,最大吸附量qe=6.0mg/g。用于水样中铅的测定,检出限为6.2μg/L,RSD=17.1%,回收率在83%-104%。方法快速、简便,检出限也比国家标准方法提高了10-20倍。     

New metal chelate sorbent for albumin adsorption: Cibacron Blue F3GA-Zn(II) attached microporous poly(HEMA) membranes

Poly(2-hydroxyethyl methacrylate) [poly(HEMA)] membranes were prepared by UV-initiated photopolymerization of HEMA in the presence of an initiator (α-α′-azobis-isobutyronitrile, AIBN). The triazine dye Cibacron Blue F3GA was attached as an affinity ligand to poly(HEMA) membranes, covalently. These affinity membranes with a swelling ratio of 58% and containing 10.7 mmol Cibacron Blue F3GA/m² were used in the albumin adsorption studies. After dye-attachment, Zn(II) ions were chelated within the membranes via attached-dye molecules. Different amounts of Zn(II) ions [650–1440 mg Zn(II)/m²] were loaded on the membranes by changing the initial concentration of Zn(II) ions and pH. Bovine serum albumin (BSA) adsorption on these membranes from aqueous solutions containing different amounts of BSA at different pH was investigated in batch reactors. The nonspecific adsorption of BSA on the poly(HEMA) membranes was negligible. Cibacron Blue F3GA attachment significantly increased the BSA adsorption up to 92.1 mg BSA/m². Adsorption capacity was further increased when Zn(II) ions were attached (up to 144.8 mg BSA m²). More than 90% of the adsorbed BSA was desorbed in 1 h in the desorption medium containing 0.5M NaSCN at pH 8.0 and 0.025M EDTA at pH 4.9. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 657–664, 1998     

Dye‐ligand column chromatography: Albumin adsorption from aqueous media and human plasma with dye‐affinity microbeads

Cibacron Blue F3GA was covalently coupled with poly(ethylene glycol‐dimethacrylate‐2‐hydroxyethylmethacrylate) [poly(EGDMA‐HEMA)] microbeads via the nucleophilic substitution reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA molecules under alkaline conditions. The affinity sorbent carrying 16.5 μmol Cibacron Blue F3GA/g polymer was then used for bovine serum albumin (BSA) adsorption from aqueous protein solutions and from human plasma in a packed‐bed column. The BSA adsorption capacity of the microbeads decreased with an increase in the recirculation rate. High adsorption rates were observed at the beginning, then equilibrium was gradually achieved in about 60 min. The BSA concentration in the mobile phase was also effective on adsorption. BSA adsorption was first increased with BSA concentration, then reached a plateau that was about 57.3 mg BSA/g. Higher BSA adsorption was observed at lower ionic strength. The maximum adsorption was observed at pH 5.0, which is the isoelectric pH of BSA. Higher human serum albumin adsorption was achieved from human plasma (109.6 mg HSA/g). High desorption ratios (over 94% of the adsorbed albumin) were achieved by using 1.0M NaSCN (pH 8.0) in 30 min. It was observed that albumin could be repeatedly adsorbed and desorbed without a significant loss in adsorption capacity. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2803–2810, 1999     

用于蛋白质BSA识别的温度/pH双敏印迹聚合物

用N-异丙基丙烯酰胺(NIPAM)和壳聚糖为功能单体,牛血清白蛋白（BSA）为模板蛋白,在改性SiO₂表面制备温度/pH双敏蛋白质印迹聚合物。TEM、FTIR和TG等结果证明印迹层已成功接枝在载体表面。系统研究了聚合物的温度/pH双敏性、吸附容量、吸附动力学、特异性、竞争吸附性及重复性。结果表明,印迹聚合物（MIP）的溶胀率和吸附容量受温度和pH影响较大,高温碱性收缩,低温酸性溶胀。在pH 4.6和35℃下,对0.6mg/mL BSA吸附4h时获得较大的吸附容量（83.74mg/g）,印迹因子为2.02。同时MIP也有较好的特异性和竞争吸附性。重复5次后,吸附容量仍能维持在88%,说明重复性良好。这种新型的温度/pH双敏蛋白质分子印迹合成方法简单,在蛋白质的分离和识别方面有较好的应用前景。     

Equilibrium,Kinetics, and Thermodynamics of Bovine Serum Albumin Adsorption on Single-Walled Carbon Nanotubes

We investigated the equilibrium, kinetics, and thermodynamics of bovine serum albumin (BSA) adsorption on single-walled carbon nanotubes (SWNTs) from aqueous solutions with different pH and temperatures. We analyzed the experimental adsorption equilibrium and kinetic data to evaluate the adsorption characteristics of SWNTs for BSA. The results show that the effects of pH and temperature were important. Moreover, the adsorption isotherm data of BSA on SWNTs are consistent with the Langmuir and Freundlich models, while the kinetics can be expressed by the pseudo-first-order and the intraparticle diffusion rate models. The maximum protein adsorption capacity of SWNTs, which have a surface area of 191.2 m²/g, was found to be 609.8 mg g^?1 at pH 4 and 40°C, and this was the highest value obtained among our previous studies examined with various metal oxides. In addition, the zeta potential measurements were examined to understand the effects of charge density of the surface and the protein on the adsorption process. Thermodynamic analysis results indicate that the nature of adsorption changes with pH. SWNTs were found to be effective for BSA adsorption.     

Cibacron Blue F3G-A Attached Poly(Vinyl Alcohol) Particles for Specific Albumin Adsorption

Abstract

Poly(vinyl alcohol) (PVAL) particles (average size: 50 μm) were prepared in the present study by chemical crosslinking of PVAL with glutaraldehyde in an organic dispersion oil phase. Cibacron Blue F3G-A was attached to these hydrophilic PVAL particles. Bovine serum albumin (BSA) adsorption onto these dye-attached PVAL particles from aqueous solutions containing different amounts of BSA in three different salts (i.e., NaCl, CaCl₂, and NaSCN) at different pH and ionic strengths was investigated in batch reactors. The maximum adsorption capacity (about 35 mg BSA/g dye-attached PVAL) was observed around pH 6.0 in a medium containing NaCl with an ionic strength of 0.01. Nonspecific BSA adsorption on plain PVAL particles was almost zero. About 90% of the adsorbed BSA was desorbed by using a 0.5 M NaSCN desorption medium for 1 hour.     

Investigation of adsorption–desorption dynamism of bovine serum albumin on crosslinked N,N′‐diethylaminoethyl dextran microbeads: Solution phase

New hydrogel microspheres based on crosslinked dextran containing N,N′‐diethylaminoethyl (DEAE) groups with different chemical structures have been used in adsorption–desorption studies. Bovine serum albumin (BSA) is frequently used in biophysical and biochemical studies. BSA has a well‐known primary structure that has been associated with binding of many different categories of small molecules. Both adsorption kinetics and equilibrium isotherms for the adsorption of BSA on crosslinked DEAE dextran have been determined experimentally. These were only slightly dependent on the initial concentration of BSA but were considerably affected by the pH of the medium. The results fitted the Freundlich–Langmuir isotherm model for pH 6.9. The adsorption capacity factor and the adsorption equilibrium constant were obtained and mathematical modeling of adsorption, adsorption rate constants, and maximum adsorption were determined. Swelling kinetics of crosslinked DEAE dextran and optimum ionic strength, pH, and mass of hydrogel were also investigated. Desorption studies were finally determined under optimum medium conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Adsorption studies of Cr(III) ions from aqueous solutions by DEHPA impregnated onto Amberlite XAD7 – Factorial design analysis

The present paper investigates the adsorption of Cr(III) ions using the SIR, prepared by impregnation of Amberlite XAD7 with di-(2-ethylhexyl)-phosphoric acid (DEHPA), which has been chosen as an extractant for the purpose of this study. The Amberlite XAD7–DEHPA resin was impregnated with DEHPA and ethylic alcohol as solvent trough dynamic column impregnation method. The influence of different physicochemical parameters (pH, resin dosage, initial concentration of Cr(III) ions, contact time and temperature) upon the adsorption capacity of XAD7–DEHPA, in the Cr(III) ions removal process from aqueous solution, has been investigated. The pH for Cr(III) ions adsorption was found as 3.0 for this material. The results showed that the adsorption equilibrium was reached after 45 min. The adsorption process is best described by the pseudo-second order kinetic model. Langmuir adsorption isotherm gave a satisfactory fit of the equilibrium data. The maximum adsorption capacity is ∼3 mg Cr(III) ions/g SIR. The thermodynamic studies allowed us to determine the thermodynamic parameters ΔG°, ΔH° and ΔS°. In this paper the factorial design of experiments was used to study the performance of the adsorption process.     

表面带磺酸基团的聚苯乙烯微球的制备及其对蛋白质的吸附

研究了运用分散聚合法,在乙醇/水混合介质中,制备2-丙烯酰胺基-2-甲基丙磺酸(AMPS)与苯乙烯(St)的共聚微球。运用红外、核磁共振、激光光散射和扫描电子显微镜对功能微球进行表征。阐述了该微球对牛血清蛋白(BSA)的吸附量与吸附时间和pH值的关系。结果表明:功能微球对BSA的吸附先随时间的增长而增大,一段时间后达到平衡吸附。当pH值接近BSA等电点(pI=4.7)时,BSA的吸附量达到最大值。     

CoFe2O4-PPy@CS磁性纳米材料制备及吸附研究

用聚吡咯(PPy)和壳聚糖(CS)功能化CoFe2O4,制得CoFe2O4-PPy@CS磁性纳米复合材料。对所得材料的形貌和结构进行表征,并研究了不同环境参数对复合材料吸附Cu^2+、孔雀石绿(MG)和甲基蓝(MB)的影响。结果表明,复合材料吸附Cu^2+和MG(MB)的适宜pH分别为5~7、5~9;随着时间的延长,对Cu^2+、MG、MB的吸附量均逐渐增加,MB的吸附速率要明显快于Cu^2+和MG,并于120 min左右达到吸附平衡,而Cu^2+和MG则需要更长的平衡时间。对Cu^2+的吸附符合Langmuir等温线模型,对MG的吸附符合Freundlich等温线模型,且2种吸附等温线模型均能较好地拟合对MB的吸附过程,最大吸附量分别可达48.3、246.0、233.8 mg/g。三者的吸附动力学均遵循准2级动力学反应模型。