粘胶纤维醚化反应的研究

为制备纤维状离子交换体,研究了粘胶纤维与二氯乙酸(DCA)在碱性介质中的非均相醚化反应。交联型羧乙基粘胶纤维(CCEV纤维)中羧基的形成速率R=k[DCA]～(1.03)[NaOH]～(1.05)(mmol/kgs)。醚化反应的表现活化能在低于66℃时为47.88kJ/mol.高于66℃时为42.73kJ/mol。CCEV纤维具弱酸性阳离子交换特性,含羧基450mmol/kg的CCEV纤维依旧保持纤维形态。     

Simultaneous determination of creatinine, creatine, and UV-absorbing amino acids using dual-mode gradient low-capacity cation-exchange chromatography

A simple and versatile cation-exchange chromatography technique for the simultaneous determination of urinary creatinine (Cre), creatine (Crn), methionine (Met), tyrosine (Tyr), phenylalanine (Phe), histidine (His), and tryptophan (Trp) was developed. A novel low-capacity cation-exchange column packed with a newly developed sulfoacylated hypercross-linked macroreticular polystyrene-divinylbenzene resin, referred to as TMR-A/75 (capacity: 75 microequiv/column), was successfully used with a binary dual-mode gradient eluting system. Two solvents, (A) 25 mM phosphoric acid-methanol (30:70, v/v) and (B) 25 mM disodium hydrogenphosphate-methanol (30:70, v/v) were pumped through the column by programming solvent delivery ratios as 0 to 5 min: A-B (55:45, pH 3.6); 5-21 min: A-B (49:51, pH 5.3); and 21-35 min: A-B (55:45, pH 3.6). The flow rate was simultaneously time-programmed to be 0.6 mL/min from 0 to 19 min and to be 1.0 mL/min from 19 to 35 min. This eluting system could permit the use of the UV detection at 210 nm. The analytes, Crn, Met, Tyr, His, Cre, Phe, and Trp, were well separated in this order in 27 min with minimum resolution of approximately 2, and the cycle time was about 35 min. Retention time of each analyte was very reproducible with relative standard deviations (RSDs) between 0.05 and 0.38% (n = 5). The peak area responses were also reproducible with RSDs between 0.74 and 2.24% (n = 5). Calibration lines based on area data were linear from 1 to 1000 microM with r2 values of 0.9998 (Crn), 0.9998 (Met), 0.9999 (Tyr), 0.9999 (His), 1.0000 (Cre), 1.0000 (Phe), and 0.9999 (Trp). The method was applicable to the screening and/or chemical diagnosis of inherited metabolic disorders such as phenylketonuria (PKU), tyrosinemia, and Lowe syndrome. The creatinine ratios of diagnostic markers (microM/microM Cre) were easily determined. The Phe/Cre ratios for five urines from patients with PKU ranged from 0.162 to 0.521, and the Tyr/Cre ratio for tyrosinemia was 0.147. The ratios of Tyr/Cre, Phe/Cre, and Trp/Cre for Lowe syndrome were 0.497, 0.321, and 0.495, respectively. In contrast, the creatinine ratios for healthy newborns showed one digit lower than those for patients did. The developed method is very practical and can provide useful information and results for the clinical or biomedical researches with low analytical run costs.     

Ionic rectification properties of a bipolar interface consisting of a cationic surfactant and cation-exchange membrane

A novel bipolar interface that consists of cationic surfactant and cation-exchange membrane was successfully prepared in an aqueous electrolyte system. This bipolar interface shows a ionic rectification behavior similar to that observed in bipolar membranes. However, different from bipolar membranes, this system has a total rectification behavior, where we cannot observe the occurrence of a water-splitting phenomenon, which always occurs in the bipolar membrane process under reverse bias conditions.     

烷基胺插层蒙脱土的阳离子交换容量研究

针对烷基胺作为插层抑制剂抑制黏土矿物水化膨胀缺少定量评价方法的问题，开展了烷基胺（己二胺和支化聚乙烯亚胺）插层蒙脱土的阳离子交换容量研究，研究中采用了红外光谱法表征了烷基胺-蒙脱土复合物，采用了不同阳离子交换容量法测量了烷基胺插层蒙脱土复合物的CEC值，并且通过光电子能谱法进行了定性验证。研究发现，氯化铵-乙酸铵法不仅能准确测量蒙脱土的CEC值，也能准确测量烷基胺-蒙脱土复合物的CEC值。支化聚乙烯亚胺比己二胺能置换更多的交换阳离子，暗示了伯胺基团数量越多，抑制性能越好。因此氯化铵-乙酸铵法可以定量测定烷基胺插层蒙脱土复合物的CEC值，为评价页岩插层剂的抑制性能提供一个准确的定量评价方法。     

超声波辅助固体酸催化塔尔油脂肪酸制备生物柴油

将强酸性阳离子交换树脂加入塔尔油脂肪酸和甲醇混合液中,并在超声波辐射辅助下得到生物柴油,对生物柴油的制备工艺和性能进行研究,同时建立动力学模型。结果表明,超声波辐射的辅助强化,能有效提高生物柴油的得率;在反应温度65℃、反应时间1h、甲醇与TOFA摩尔比为10∶1、脱水剂用量为TOFA6%、树脂NKC-9用量为TOFA40%的最佳工艺条件下,反应平衡常数可达11.18,生物柴油得率为90.0%。建立的动力学模型补充了超声波辐射辅助酯化反应动力学参数,并用此模型解释了各工艺参数呈现的规律。以廉价的制浆黑液回收物塔尔油脂肪酸为原料制备生物柴油,能有效地降低生物柴油价格,提高其市场竞争力,实现塔尔油高附加值利用,具有良好的发展前景。     

强阳离子交换整体柱的研制及其在电色谱多肽分离中的应用

以丙烯酸、2-丙烯酰胺-2-甲基丙磺酸为功能单体,N,N′-亚甲基双丙烯酰胺为交联剂,正十二醇、1,4-丁二醇及二甲基亚砜为致孔剂,偶氮二异丁腈为引发剂,原位聚合制备了丙烯酰胺类强阳离子交换整体柱。考察了驱动电压、有机调节剂、盐浓度、pH值等对电渗流的影响。结果表明,电渗流与驱动电压的线性关系良好,相关系数为0.9981;有机调节剂乙腈对电渗流的影响除与流动相的黏度有关外,还与固定相的溶胀有关,当浓度低时,电渗流随乙腈浓度的增加有反常的下降趋势;随着磷酸盐浓度逐渐增加,电渗流降低,与理论相符;在pH值为3～9范围内,电渗流基本上保持恒定,体现了整体柱使用酸碱范围宽的优越性。在优化的实验条件下,采用毛细管电色谱法在此整体柱上成功分离了5种多肽,体现了该类整体柱在多肽分离研究中的优势,为进一步将其应用于蛋白质分离研究打下了基础。     

不同价态阳离子盐改性沸石吸附氨氮能力差异

采用5种不同价态阳离子盐对天然斜发沸石进行改性,通过SEM,EDS,ICP以及氮吸附分析仪等测试手段对改性前后的沸石颗粒进行表征,发现不同价态阳离子和相同价态不同阳离子的盐改性沸石后对其物化性质和应用性能均会产生影响.EDS及ICP测试发现由于离子交换作用改性后沸石中5种盐对应的金属阳离子含量均会升高,其中KCl改性沸石中钾元素含量增加量最多.比表面积与孔径分布测试结果发现随着阳离子价态升高,沸石比表面积下降幅度逐渐增大,其中一价钾盐的改性沸石比表面积下降幅度最小为33.9m~2/g,三价铝盐下降幅度最大为29.27m~2/g;而改性沸石孔体积变化规律有所不同,其中一价盐改性沸石介孔体积增加量最大、大孔体积减少量最多.对不同价态阳离子盐改性沸石进行了阳离子交换容量和污水脱氮能力测试,结果表明,其阳离子交换容量和脱氮能力大小排序为:NaClAlCl_3CaCl_2MgCl_2KCl.说明改性沸石的污水脱氮能力与其阳离子交换容量呈正相关关系,但是阳离子价态的高低与改性沸石的阳离子交换容量、比表面积、孔体积和脱氮能力并不是正相关关系.     

新型阳离子交换纤维的制备、表征及对Fe~(3+),Pb~(2+),Ag~+的交换性能

以聚丙烯腈纤维(PAN)进行NH2OH化学改性制得的含有偕胺肟基的螯合纤维为原料,然后与BrCH2CH2SO3Na反应合成阳离子交换纤维.对阳离子交换纤维进行了IR表征,并测试了其对Fe3+、Pb2+、Ag+ 的交换性能.实验结果表明,该交换纤维对Ag+离子的交换率最大.     

Uptake of hydrophobic amino acids and sodium chloride by a strong cation exchanger: Application to desalting and separation by preparative liquid chromatography

Summary The uptake of sodium chloride, leucine and phenylalanine by a strong cation-exchange resin in the sodium form have been compared. Sodium chloride was excluded from the resin, as indicated by its parabolic upwards curved isotherm, and the corresponding desorption edge was sharpened (constant pattern). Isotherms for both amino acids constructed from a single elution experiment displayed slightly downwards curvature; the corresponding desorption edges spread in contrast to the breakthrough ones. The affinities of both amino acids for the resin were higher (from 15 to 40 %) in the presence of 1 M sodium chloride, indicating that hydrophobic interactions played a significant role in the mechanism of sorption. As expected from the isotherms, a mixture of 1 M sodium chloride, leucine and phenylalanine was separated with satisfactory recovery of both amino acids for a column loading of 10 % of the bed volume. Real mother liquors have also been separated under the same conditions.     

高效液相色谱分离牛胸腺多肽的研究

本文以不同色谱方法对牛胸腺多肽进行了分离,寻求出能对牛胸腺多肽得到满意分离的色谱条件。