ε-聚赖氨酸吸附条件的优化

以吸附率为指标,通过单因素试验比较了5种不同的树脂类型、p H值、溶质浓度和树脂量对ε-聚赖氨酸(ε-PL)的吸附效果,进一步采用响应面设计优化了HZD-3B和D155树脂的吸附条件,分析了两种树脂吸附ε-PL的吸附等温线以及吸附动力学曲线。结果表明,试验的5种树脂中,HZD-3B和D155树脂的吸附效果较好。HZD-3B最佳静态吸附条件为:溶液起始p H 8.5、起始浓度40g/L、树脂用量150g/L、温度25℃、吸附13h,ε-PL的最大吸附率是97.69%;D155最佳静态吸附条件为:溶液起始p H 8、起始浓度40g/L、树脂用量150g/L、温度25℃、吸附14h,ε-PL的最大吸附率是96.84%;等温线数据拟合均较符合Freundlich方程,动力学数据拟合均较符合二级动力学方程。发酵液验证试验结果显示,ε-PL最大吸附量与纯品吸附量基本一致。     

717型阴离子交换树脂吸附L-赖氨酸的特性

通过静态吸附实验,考察了溶液中温度、pH值、氯离子浓度对717型阴离子交换树脂吸附L-赖氨酸的影响,并测定了25℃时的吸附等温线。结果表明:717离子交换吸附L-赖氨酸的吸附率随温度的升高呈略下降的趋势,是个放热过程;随着溶液中氯离子浓度的增大L-赖氨酸的吸附率降低,当氯离子浓度达到1.0mol/L时,吸附率仅20%;从含有L-赖氨酸的L-精氨酸溶液中除去L-赖氨酸,最佳pH值为10.5±0.2;717离子交换树脂吸附L-赖氨酸的最大吸附量为30g/kg。     

单宁酸修饰的超高交联吸附树脂对酚类化合物的吸附研究

通过氯甲基化的苯乙烯-二乙烯苯共聚物的后交联及单宁酸的化学修饰反应制备了单宁酸修饰的超高交联吸附树脂(TAMR),通过红外光谱、元素分析、扫描电镜和比表面孔径分析对TAMR树脂的结构特征和表面参数及形貌进行表征.通过等温吸附实验和吸附动力学实验研究了苯酚、对硝基苯酚和对氯苯酚在TAMR树脂上的吸附性能和吸附机理.结果表明,TAMR树脂具有较高的比表面积(780.1 m2/g)和较丰富的微孔(482.3 m2/g),树脂表面修饰了较丰富的羟基.TAMR树脂对苯酚、对硝基苯酚和对氯苯酚均具有较好的吸附性能,288 K时吸附量分别可达1.43、2.07和2.48 mmol/g(c0为500 mg/L).3种酚类化合物在TAMR树脂上的吸附为典型的物理吸附,其吸附焓变和熵变均为负值.当酚类化合物以分子形态存在时,有利于其被TAMR树脂吸附.Langmuir和Freundlich方程均能较好地拟合酚类化合物在TAMR树脂上的吸附等温线.吸附动力学过程符合准一级动力学方程,颗粒内扩散过程是TAMR树脂吸附这3种酚的吸附速率的主要控制步骤.     

8-羟基喹啉接枝PGMA的合成及对Cd~(2+)的吸附性能

合成了一种带8-羟基喹啉功能基的交联聚甲基丙烯酸缩水甘油酯树脂(HQPGMA),采用红外光谱和热重分析对合成树脂进行了表征。探讨了该合成树脂对Cd2+的静态吸附性能。考察了在不同的温度、Cd2+离子浓度、吸附时间及p H值等条件下,HQPGMA树脂对Cd2+的吸附情况。结果表明,HQPGMA树脂对Cd2+具有良好的吸附作用。当p H值约为4.5时,吸附效果最佳,当Cd2+初始浓度为0.01888mol/L时,其最大吸附量为0.861mmol/g;树脂对Cd2+的吸附过程符合Langmuir和Freundlich等温吸附方程;其吸附动力学与准二级动力学方程拟合的更好;吸附为自发的吸热过程;0.2mol/L HNO3对树脂上吸附的Cd2+的脱附率可达85.7%。     

6-氨基青霉烷酸在弱碱性阴离子树脂IRA67上的吸附研究

用静态法研究了6-氨基青霉烷酸在弱碱性阴离子交换树脂IRA67上的吸附行为．在溶液pH为8．0，6-APA起始浓度介子3.00mg／m1-20．00mg／ml条件下，测定了25℃时IRA67树脂的静态交换动力学曲线、吸附等温线，并求得了IRA67树脂的平衡速率常数及吸附等温线方程．分别用Langmuir型和Frendlich型方程对IRA67树脂吸附等温线进行线性回归拟合，结果表明，6-APA在IRA67树脂上的吸附更符合Langmuir型吸附．     

间氨基酚在超高交联树脂上的吸附特征

研究了两种超高交联吸附树脂DA-01和DZH-04对间氨基酚的静态吸附热力学及动力学特征。结果表明,在295K~315K及研究的浓度范围内,Freundlich和Langmuir方程能够对静态吸附等温线进行很好的拟合,DA-01和DZH-04树脂对间氨基酚的吸附符合准一级动力学方程。两种树脂吸附间氨基酚的能力都比较强,用乙醇和2mol/LNaOH混合溶液(体积比1:1)洗脱,温度338K,DZH-04树脂的脱附率为99.50%,DA-01树脂的脱附率为75.36%。     

弱酸性氨基二硫代甲酸酯功能化聚氯乙烯树脂对Hg2+的吸附与脱附性能

以聚氯乙烯为原料依次与四乙烯五胺、CS2和ClCH2COONa反应合成了一种含氮、氧、硫的弱酸性氨基二硫代甲酸酯功能化的聚氯乙烯螯合树脂,树脂的结构经红外分析和元素分析表征。探讨了在不同pH值、Hg2+初始浓度、吸附温度和时间等条件下合成树脂对Hg2+的吸附性能。结果表明,螯合树脂对Hg2+有较快的吸附速率,pH=2.0左右时树脂对Hg2+的吸附效果最好,随着温度的升高吸附量逐渐增大,35 ℃时Hg2+起始浓度为0.01766 mol/L时,树脂对Hg2+的吸附量可达3.330 mmol/g。树脂对Hg2+的吸附符合Langmuir和Freundlich等温式。用0.2 mol/L硝酸-10%硫脲对吸附后的树脂进行洗脱,脱附率达99.2%。     

氨基修饰聚苯乙烯树脂对酚酸物质的吸附性能

通过对XAD 4聚苯乙烯树脂的氨基修饰制备了一种亲水性的NDA 10 0树脂 .研究了NDA 10 0树脂对苯酚和对羟基苯甲酸等酚酸类物质的吸附动力学和热力学行为 .结果表明 ,NDA 10 0树脂对苯酚和对羟基苯甲酸具有良好的吸附性能 ,在研究的浓度范围内 ,吸附平衡数据符合Langmuir和Freundlich等温吸附方程 ,吸附为放热的物理吸附过程 .吸附动力学符合Lagergren准二级速率方程 ,颗粒内扩散为吸附速率的主要控制步骤 .     

亲和吸附剂对细菌内毒素吸附性能的研究

制备了以球形纤维素为载体、8种氨基酸和1种聚赖氨酸为配基的吸附剂,对质量浓度为100.0pg/mL的内毒素水溶液进行了吸附研究,绘制了吸附等温线,并初步探讨了吸附机理.结果表明,精氨酸和赖氨酸配基具有良好的吸附能力,在1.5mL100.0pg/mL内毒素溶液中吸附量分别达到182.0和160.0pg/mL;吸附等温线显示,以赖氨酸为配基的吸附剂其吸附量随溶液内毒素浓度增加而线性增加,符合Langmuir吸附方程,吸附能力强,具有一定的临床应用前景.     

羟基磷灰石对牛血清白蛋白的吸附特性研究

研究了羟基磷灰石表面电位随溶液PO₄^3-浓度、Ca²⁺浓度、离子强度和pH的变化规律;测定了不同操作条件下牛血清白蛋白在羟基磷灰石上的吸附容量;吸附等温线的测定结果表明该吸附属于Langmuir型;通过对该吸附过程的动力学研究,计算得到的表观活化能和吸附热数值较低,表明该吸附是物理吸附.     

碱性树脂吸附有机羧酸的溶胀现象

选用强碱性树脂（201×4）,弱碱性树脂（D301G）为吸附剂,以乳酸和乙酸稀溶液为吸附分离对象,实验测定了碱性树脂对有机酸和水的组分吸附量,讨论了树脂的溶胀现象．结果表明,随吸附温度的上升,碱性树脂的溶胀程度增大;随着树脂上酸的吸附量的增大,水的组分吸附量也增大．通过对水的组分吸附量的分析,提出溶胀中存在吸水量和表面增益量两个方面的影响．以水的表面增益量为基础,讨论了强碱性树脂201×4和弱碱性树脂D301G对酸－水体系的选择分离性能．     

Adsorption Equilibrium Equation of Carboxylic Acids on Anion-Exchange Resins in Water

The adsorption of propionic acid and benzoic acid on anion-exchange resins was analyzed, and an adsorption equilibrium equation of carboxylic acids was proposed. The adsorption of carboxylic acids on the anion-exchange resins was considered to be the sum of the physical adsorption of the molecule and the ion-exchange adsorption of the ion, which were independent of each other. For the physical adsorption of carboxylic acids, it was conformed to the Freundlich equation. For the ion-exchange adsorption of carboxylate ions, the equilibrium equation corresponded well with the experimental results for wide ranges of concentration and pH. The equation contains a selectivity coefficient S(A)(Cl) for the chloride ion versus the carboxylate ion, which was considered essentially a constant. The influent of the bicarbonate ion from carbon dioxide in air could also be expressed by the additional equilibrium equation with the selectivity coefficient S(HCO(3))(Cl) for the chloride ion versus the bicarbonate ion. Consequently, an adsorption equilibrium equation can estimate the equilibrium adsorption amounts. Even the effect of a coexisting bicarbonate ion is inconsequential when the parameters of the Freundlich isotherm equation and the selectivity coefficients of the carboxylate ion and the bicarbonate ion in each resin are determined in advance. Copyright 2001 Academic Press.     

羧基化氧化石墨烯的血液相容性

氧化石墨烯的官能团修饰可促进氧化石墨烯与生物体液、聚合物基体等不同环境的融合. 通过超声法制备了氧化石墨烯, 并利用化学改性的方法, 将氧化石墨烯表面的羟基和环氧基转变为羧基. 红外图谱上羧基化氧化石墨烯(GeneO-COOH)的羧基振动明显, 峰强增大. GeneO-COOH的主要失重表现为羧基官能团缩合以一个水分子的形态释放失去结构水[OH2]. 复钙动力学曲线随着GeneO-COOH的浓度增加, 曲线上升趋势由陡峭趋于平缓, 当浓度为1.25 μg/mL时复钙时间延长了11 min, 平台期OD值降低了8.14 %; 在0.5~100 μg/mL浓度范围内溶血率均<5 %. GeneO-COOH比GeneO在同等低浓度下的抗凝血性能有一定程度的改善, 主要是因为带负电的羧基可直接络合凝血因子. 因此, 羧基修饰氧化石墨烯是提高血液相容性的有效手段, 羧基化氧化石墨烯可作为潜在的生物医用材料的填料.     

Coagulation of Carboxylic Acid-Functionalized Latexes

In the present work, the stability of particles produced by emulsion polymerization and stabilized by carboxylic acid groups was studied from turbidity measurements. To achieve this, a number of copolymerization runs was carried out under different reaction conditions, including the use of different carboxylic monomers. Partitioning analyses using conductimetric and potentiometric titrations were performed in order to assess the distribution of carboxylic monomers among the main phases of the produced latexes. Additionally, the stability and coalescence of particles were measured by turbidimetry in a diluted latex considering either the presence or not of the anionic surfactant sodium lauryl sulfate. Coalescence of particles was provoked in the latex samples at different temperatures by addition of an aliquot of a concentrated solution of electrolyte. The influence of surfactant, temperature and type of carboxylic acid group on the particle stability was investigated.     

高吸水性树脂

综述了国内高吸水性树脂的研究进展,其中包括高吸水性树脂的制备方法、类型、影响其吸水性能的因素以及功能与应用。     

Synthesis of Diethylaminoethyl Carboxylic Esters

Dialkylaminoethyl carboxylic esters (1-5) with two biologically active moieties, carboxylic acid and dialkylaminoethanol were previously reported to show some biological activity in the presence of the coordinated effect of the two parts.     

离子交换树脂

简要介绍了离子交换树脂的概念、发展简史、组成、分类、作用原理、合成路线及性能。用表格简列出应用的各个方面,并说明了应用的优、缺点,最后扼要地指出了发展的方向。     

降解型环氧树脂*

设计与合成带有可降解官能团的环氧树脂是热固性树脂回收领域的一个重要课题。本文首先简要概括了传统回收环氧树脂的方法并指出其缺点,然后分别对国内外热降解型、光降解型、生物降解型环氧树脂的降解特性、环氧固化物的降解条件和降解机理予以重点解释和举例介绍。最后,指出了降解型环氧树脂存在的问题并对将来的发展前景进行了展望。     

Reactions of Titanocene Derivatives with Molecular Carboxylic Acids and Copolymers Bearing Carboxylic Acid Groups

Linear, soluble copolymers containing titanium are of interest for use in targets for inertial-confinement fusion (ICF) experiments because the titanium is a useful spectroscopic probe for studying the nuclear fusion process. We have studied the reactions of dichloro- titanocene and diphenyltitanocene with carboxylic acids to determine if these can be used to prepare such polymers. Model reactions of dichlorotitanocene with p -toluic acid show that both mono- and di-carboxylates are formed. We have prepared a soluble titanium-containing copolymer via the reaction of poly(styrene- co -methacrylic acid) with an excess of dichlorotitanocene but attempts to remove the excess molecular titanocene from the copolymer result in crosslinking of the copolymer. Model reactions of benzoic and pivalic acids with diphenyltitanocene demonstrate that monosubstituted carboxylato(phenyl)titanocenes are formed but that these products are stable only at low temperatures and decompose readily at ambient temperature. Proton NMR studies of the reaction of diphenyltitanocene and benzoic acid at −20 °C indicate that this reaction is second order, suggesting that the reaction does not proceed through a benzyne intermediate. © 1997 by John Wiley & Sons, Ltd.