P(St-AM)核壳聚合物微球的制备及其光子晶体膜

采用一步乳液聚合法,调节引发剂用量,制备了不同粒径的具有核壳结构的功能性聚(苯乙烯-丙烯酰胺)乳胶微球.用透射电子显微镜表征了乳胶微球的核壳结构和粒径,所制微球的粒径分别为195,217,234和255 nm.用红外光谱对微球的化学成分进行了表征,证实聚丙烯酰胺已包覆在聚苯乙烯外层.通过竖直沉积自组装法制备了聚合物微球的光子晶体薄膜.扫描电子显微镜表征了所制光子晶体膜的表面形貌,反射和透射光谱表征了光子禁带.结果表明,聚合物微球以面心立方紧密堆积,其(111)面与基底平行;微球粒径不同,光子晶体的光子禁带不同.制备了不同光子禁带的光子晶体,禁带分别位于473,515,574和630 nm,相应的薄膜分别呈蓝色、绿色、黄色和红色,对于光子晶体的拓展和应用具有重要的意义.     

胶态磁组装分子印迹光子晶体及其对L-苯丙氨酸的响应性

将胶态磁组装光子晶体与分子印迹技术结合, 通过磁场诱导快速、 可逆地组装得到一种灵敏度高、 选择性强且响应速度快的胶态磁组装分子印迹光子晶体(CMA-MIPCs), 并将其用于L-苯丙氨酸(L-Phe)分子的响应性研究. 结果表明, 细乳液聚合法制得的L-Phe磁性分子印迹纳米粒子(MMIPs)具有规则的球形形貌和明显的核-壳结构, 平均粒径为104.3 nm. CMA-MIPCs对L-Phe分子的识别可直接通过光学信号进行表达, 当L-Phe的浓度从6.0×10^-7 mol/L增加至6.0×10^-4 mol/L时, CMA-MIPCs的衍射色发生从紫色到深黄色的明显变化, 最大衍射峰位置红移181 nm, 响应过程仅需1 min. CMA-MIPCs对L-Phe的结构类似物L-酪氨酸(L-Tyr)和L-色氨酸(L-Trp)均无响应性, 表明CMA-MIPCs具有良好的选择性.     

PNDC-b-PNTPE自组装制备兼具结构色和荧光色的薄膜

设计合成了含有聚集诱导发光四苯乙烯基的大位阻单体四苯乙烯基降冰片烯(NTPE),通过NTPE与含有双癸烷基的树状单体对苯二甲酸癸烷苯酯基降冰片烯(NDC)的顺序开环易位聚合(ROMP)制备具有聚集诱导发光性质的大位阻树状嵌段聚合物(PNDC-b-PNTPE).利用薄膜自组装制备了兼具结构色和荧光色的一维光子晶体薄膜.结果表明,PNDC-b-PNTPE在四氢呋喃(THF)中随着溶剂的挥发而快速自组装成为蓝色的一维光子晶体薄膜,其最大反射波长(λ_max)为443 nm.一维光子晶体薄膜的横截面扫描电子显微镜照片表明,PNDC-bPNTPE组装为周期为133 nm的层状结构.荧光发射光谱分析结果表明,一维光子晶体薄膜在368 nm波长紫外光的激发下能够发射最大波长为425 nm的荧光.该兼具结构色和荧光色的薄膜在防伪和显示方面有潜在的应用前景.     

部分水解聚丙烯酰胺-羟乙基纤维素的水相pH响应性自组装

为考察无规共聚物在全水相环境中的自组装行为, 合成了结构类似于无规共聚物的低相对分子质量的部分水解聚丙烯酰胺(HPAM). 尝试改变水溶液pH值来诱导HPAM与羟乙基纤维素(HEC)发生自组装, 采用透射电子显微镜(TEM)观察到不同pH值时分别获得了100 nm的似正方体胶束, 200 nm×100 nm的类椭球胶束, 100 nm的串珠状胶束以及500 nm×300 nm×50 nm的半月形胶束等pH响应性核壳型聚合物胶束. 建立了金在胶束表面原位还原耦合TEM表征方法, 用于检测低衬度聚合物胶束的纳米细节; 配合电子探针X射线微区分析(EPMA)和扫描电子显微镜(SEM), 证实了半月形聚合物胶束的精致分级构造为亲水性内囊@疏水性连续囊壁@亲水性外壳的多泡囊泡, 并证实pH=0.9时多泡囊泡崩解为疏水性内核@亲水性外壳的10 nm类球体小胶束. 通过分析链节质子化状态的pH响应性, 结合zeta电位和吸光度测定结果, 阐释了不同pH值时组成聚合物胶束的核和壳的链段归属, 获得了全水相中HPAM自组装驱动力和形貌方面的全新知识.     

二氧化钛反蛋白石薄膜的制备及其在化学传感器中的应用

用提拉成膜法将单分散295 nm聚甲基丙烯酸甲酯(PMMA)胶体微球自组装成蛋白石光子晶体膜. 在PMMA蛋白石光子晶体膜的空隙里填充15 nm二氧化钛纳米颗粒, 经500 ℃的处理除去PMMA膜板, 制备出大面积, 结构均一的二氧化钛反蛋白石光子晶体膜. 扫描电子显微镜(SEM)观察和X射线光电能谱(XPS)分析表明, 这种二氧化钛反蛋白石光子晶体薄膜是六方紧密堆积. 用这种二氧化钛反蛋白石光子晶体膜对溶液折射率的检测实验表明该传感膜分辨率可达0.01.     

三聚氰胺分子印迹光子晶体水凝胶膜传感器的制备及应用

该文将光子晶体与分子印迹技术结合，制备了分子印迹光子晶体水凝胶膜（MIPHs）作为光学传感器，用于样品中三聚氰胺的快速识别检测。以三聚氰胺为模板分子，通过垂直沉降自组装、填充聚合、去除模板3个步骤，制备得到了反蛋白石结构的三聚氰胺MIPHs。扫描电子显微镜的形貌表征表明，MIPHs具有高度有序的三维大孔结构。该MIPHs作为光学传感器可以将三聚氰胺的分子特异识别过程转换成光学信号，在对目标分析物分析时具有选择性高、响应快、灵敏度高的优点。此外，可以根据MIPHs的颜色变化利用图像软件分析或裸眼识别的方式实现目标分析物快速识别。实验结果表明，在最优条件下，三聚氰胺浓度为10^-11~10^-6mol/L时，MIPHs的布拉格衍射峰位移从563 nm红移到608 nm，而对三聚氰胺的结构类似物没有明显响应。     

多重环境响应性蓝光共聚物的合成与表征

采用Suzuki偶联反应合成了一系列具有聚集诱导荧光增强特性的双亲性共聚物Pa,Pb和Pc,这些共聚物都有较高的分子量和可进一步支链化的羟基.聚合物Pa,Pb和Pc在四氢呋喃溶液中的紫外吸收峰在380 nm左右,荧光发射峰在470 nm左右,属于蓝光材料.对这些聚合物在四氢呋喃和水的混合溶剂中发光特性的研究发现,这类聚合物在一定比例混合溶剂中都有聚集诱导荧光增强现象,通过表征自组装得到胶束的粒径和形貌进一步验证了这一结果.3种共聚物在混合溶剂中的聚集诱导荧光增强特性与聚合物中聚集诱导荧光增强结构单元的含量有关,并且该特性只有在一定比例混合溶剂中才能体现.通过研究聚合物Pa在不同混合溶剂中荧光发射和自组装行为,发现聚合物Pa在四氢呋喃中处于高度分散状态,聚合物呈小的胶束;当减少混合溶剂中四氢呋喃的含量时,聚合物聚集形成了稳定的胶束并且粒径比较集中;当继续减小四氢呋喃的含量,聚合物部分析出.从动态光散射和透射电子显微镜结果中明显发现聚合物胶束的粒径有很大波动.聚合物Pb和Pc在不同溶剂中自组装得到的胶束的大小演变规律和聚合物Pa相似,说明共聚物中芴和聚集诱导荧光增强结构单元之间的比例只影响聚合物聚集时水的比例,并不对聚集形成胶束的演化过程产生明显影响.通过改变共聚物Pa,Pb和Pc自组装所用溶剂的比例和种类,可以得到尺寸在10到900 nm之间的胶束.聚合物Pa在不同溶剂中自组装形成胶束的尺寸分散性比较单一,而聚合物Pb和Pc在不同溶剂中自组装形成胶束的尺寸分布比较宽,形貌多样化.通过原子转移活性自由基聚合在聚合物Pb引入聚(N-异丙基丙烯酰胺)侧链,得到具有更高分子量、更窄分子量分布的水溶性和温度敏感性多重环境响应性蓝光聚合物P-N.在聚(N-异丙基丙烯酰胺)最低临界溶解温度附近,随着溶液温度的改变,该聚合物荧光发光峰的位置基本保持不变,但发射强度变化,聚合物P-N在混合溶剂中自组装形成胶束的大小和形貌也随之改变.     

新型两亲性含糖嵌段聚合物的合成与自组装

以β-环糊精(β-CD)和2-乙基-2-噁唑啉(EtOz)为原料, 通过活性端基化学偶联法制备了乙酰麦芽七糖/聚(2-乙基-2-噁唑啉)两嵌段聚合物(AcMH-b-PEtOz), 借助核磁共振氢谱、红外光谱和凝胶渗透色谱等手段证实了产物的化学结构. 采用核磁共振氢谱、荧光光谱、透射电子显微镜、动态光散射及紫外-可见分光光度等方法探讨了产物在水溶液中的自组装行为. 结果表明, 所得嵌段聚合物直接溶于水后可通过自组装形成纳米球形“核-壳”结构胶束, 同时具有温度响应性. 所得聚合物的临界胶束浓度(cmc)为4~7 mg/L, 平均粒径(d)为83~115 nm, 临界相转变温度(LCST)为49~64 ℃, 并且均可通过PEtOz的链长进行调控.     

连续测量水中挥发性有机物的膜进样-单光子电离-质谱仪的研制及其应用

研制了膜进样-单光子电离-飞行时间质谱仪,并应用于水中挥发性有机物(VOCs)的连续在线快速测量.以50 μm硅橡胶膜为富集膜,用蠕动泵和电动切换阀,实现了水中VOCs的自动进样、富集和测量,无记忆效应.采用真空紫外灯发出的10.6 eV的光子,对待测有机物实现单光子电离,无碎片离子,便于根据分子量进行定性分析.苯、甲苯、二甲苯和氯苯等样品的响应时间均低于100 s; 苯的检出限可达3×10-9(V/V),且在10×10-9～1×10-6(V/V)范围内具有良好的线性.将仪器应用于某化工厂排污水的在线检测中,在200 s时间内可检测到20多种10×10-9(V/V)量级的有机物.结果表明: 膜进样-单光子电离-飞行时间质谱在水中VOCs在线检测方面具有广泛应用前景.     

端羧基芳脂型超支化聚酯自组装性能的研究

利用聚电解质逐层浸渍 ( layer- by- layer dipping)法制备自组装膜是最近发展起来的进行表面改性的新方法[1～ 3] .一方面 ,从理论上来说 ,只要是带电荷的聚合物都可以利用该技术制备具有优异性能的自组装膜 ;另一方面 ,还可以通过调节溶液的 p H值和离子强度等控制阴阳离子的组装过程 ,从而控制自组装膜的内部结构和表面形态 ,为在纳米级范围内设计和控制聚合物聚集态内部结构提供了可能性 .近年来 ,具有高度支化结构的超支化分子由于具有独特的物理和化学性能而受到了广泛的关注 [4 ,5] ,但以聚电解质逐层浸渍法制备超支化分子自组装膜…     

Online stacking of carboxylated magnetite core–shell nanoparticles in capillary electrophoresis

The stacking effect on carboxylated magnetite core–shell nanoparticles using sodium borate buffer pH 9.5 as the background electrolyte is presented. The ionic strength of the background electrolyte ranged from 5 to 100 mM, and the ionic strength of a sample zone ranged from 5 to 100 mM. Moreover, water was used as the sample dispersant. Both stacking and de‐stacking effects were observed when conductivities of the sample zone and the background electrolyte differed. An explanation of carboxylated magnetic core‐shell nanoparticles behavior was suggested based on the Derjaguin–Landau–Verwey–Overbeek theory supposing that the aggregation point is defined by the energetic barrier as the sum of energies given by electrostatic interactions and Van der Waals interactions. Moreover, the stacking conditions were applied for the evaluation of the lowest detectable dilution of magnetic nanoparticles. The carboxylated magnetic nanoparticles were dispersed in 10 mM borate/NaOH pH 9.5 and injected for 60 s to the background electrolyte composed of 100 mM borate/NaOH pH 9.5 that allowed the detection of 100‐fold diluted nanoparticles.     

Ion-pair chromatographic monitoring of photographic effluents

Ion-pair chromatographic technique was developed for the rapid and simple determination of the main contaminants (bromide, iodide, sulphite, thiosulphate, thiocyanate, iron(III)-EDTA chelate, free EDTA, hydroquinone and phenidone) in spent photographic solutions. Free EDTA was converted into stable Ni(II)-EDTA chelate prior to analysis. The optimal mobile phase conditions were established by varying the concentrations of tetrabutylammonium (TBA) phosphate and acetonitrile, pH and ionic strength. Separation of five inorganic anions, two metal chelates and two neutral compounds was accomplished in about 30 min using a mobile phase containing 7.5 mmol/L TBA-phosphate, 10 mmol/L NaCl (pH 6.5) and 20% (v/v) acetonitrile. The detection limits (UV detection at 210 nm) ranged from 0.4 μmol/L for phenidone to 8 μmol/L for sulphite with a linearity of 2–2.5 orders of magnitude. The method was applied to the rapid monitoring of spent photographic solutions before and after decomposition. The recovery tests established for two samples were within the range 95–103%.      

Preparation of silica-polystyrene core-shell particles up to micron sizes

A method for producing silica-core composite particles with a polystyrene shell is proposed. Silica particles were prepared by the St?ber method through condensation and hydrolysis of tetraethyl orthosilicate in a water-ethanol-ammonia solution. The silica particles were the surface-modified with a coupling reagent, methacryloxypropyltrimethoxysilane (MPTMS), to introduce vinyl groups onto the particle surfaces. Polymerization of styrene was conducted with an initiator, potassium persulfate (KPS), and an anionic monomer, sodium p-styrenesulfonate (NaSS), in the presence of the silica particles. In these coating experiments, the average size of the silica particles was varied from 339 to 1210 nm with the concentration ranges of MPTMS (0-10 mmol/l), NaSS (0-10 mmol/l), KPS (4-12 mmol/l), and styrene (0.12-0.4 mol/l). Selection of reaction conditions enabled the preparation of composite particles that contained one core of silica. The coefficient of variance of size distribution of the composite particles was less than 7%, and shell thickness was in the range 125 to 410 nm.     

Ionic liquids as mobile phase additives for determination of thiocyanate and iodide by liquid chromatography

An analytical method was developed for the simultaneous determination of thiocyanate and iodide by reversed‐phase liquid chromatography with UV detection using imidazolium ionic liquids as mobile phase additives. The chromatographic behaviors of the two anions on a C₁₈ column were studied and compared with four types of reagents including imidazolium ionic liquids, pyridinium ionic liquids, 4‐aminophenol hydrochloride and tetrabutylammonium as mobile phase additives. The effects of the concentrations of imidazolium ionic liquids, organic solvents and detection wavelength on separation and detection of the anions were investigated. The role of ionic liquids, retention rules and mechanisms were discussed. The separation of the anions was performed on the C₁₈ reserved‐phase column using acetonitrile‐0.3 mmol/L 1‐amyl‐3‐methylimidazolium tetrafluoroborate (10:90, v/v) as mobile phase, with column temperature of 35°C, flow rate of 1 mL/min and detection wavelength of 210 nm. Under these conditions, the two anions can be completely separated within 6 min. The limits of detection were 0.05 mg/L. The method was applied for the determination of thiocyanate and iodide in ionic liquid samples and iodide drugs, and the spiked recoveries ranged from 97 to 101%. The method is simple, accurate and meets the requirements of quantitative analysis for thiocyanate and iodide.     

Indirect laser-induced fluorescence detection for capillary electrophoresis using a frequency-doubled diode laser

A blue (452 nm) frequency-doubled diode laser with a quasi-cw optical output power of 10 microW is used for indirect laser-induced fluorescence detection in combination with the capillary electrophoretic separation of inorganic anions. As fluorescing probe ion the anion of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) was selected having an absorption maximum of 454 nm in alkaline medium. Employing a capillary coated with linear acrylamide, baseline separation of eight inorganic anions was possible within 5 min. With a separation buffer containing 50 micromol.L(-1) HPTS and 10 mmol.L(-1) lysine the limits of detection for sulfate, nitrite, nitrate, azide, thiocyanate, and chlorate were between 0.9 and 4.7 micromol.L(-1). Separation of chloride and sulfate was achieved by adding 0.25 mmol.L(-1) calcium hydroxide to the separation buffer. Inorganic anions in several mineral and tap water samples have been determined with the technique developed and results are compared to data obtained by ion chromatography in combination with conductivity detection after conductivity suppression.     

基于单颗粒电感耦合等离子体质谱法测定环境基质水样中纳米银颗粒

采用单颗粒电感耦合等离子体质谱法(SP-ICP-MS)同时测定环境水样中纳米银颗粒(AgNPs)的颗粒浓度、质量浓度和粒径分布,并考察了溶液的pH值、溶解性有机质(DOM)浓度以及离子强度等对AgNPs测定的影响。结果表明:SP-ICP-MS方法对60 nm AgNPs标准溶液的测定结果与标准值一致,准确性较好;pH值(5.0～7.0)、离子强度(≤1 mmol/L)和DOM浓度(≤30 mg/L)对测定结果影响较小;当溶液的pH值≤5.0或离子强度1 mmol/L时,AgNPs的颗粒浓度和粒径随pH值的下降或离子强度的增强而减小。采用SP-ICP-MS方法测定河水、染料废水、养殖废水3种水样中AgNPs的加标回收率分别为98.1%、83.3%和93.3%,表明该方法在合适的基质条件下可用于快速准确测定环境水样中AgNPs的颗粒浓度、质量浓度和粒径分布。     

离子液体作高效液相色谱流动相添加剂分离测定芳香胺

建立了以离子液体作反相高效液相色谱流动相添加剂分离测定邻苯二胺、苯胺和对甲苯胺3种芳香胺的方法。实验以C18反相色谱柱为分离柱,采用紫外检测方法,考察了检测波长、甲醇含量、咪唑离子液体烷基链长度、离子液体溶液浓度等条件对分离和测定的影响,并与其它分离测定芳香胺的方法进行了比较。优化的色谱条件为:以甲醇/1-丁基-3-甲基咪唑四氟硼酸盐水溶液(3.0mmol/L,乙酸调节pH 3.5)=30/70(V/V)为流动相;检测波长254 nm;流速1.0mL/min;柱温30℃。在此条件下,3种芳香胺达到基线分离,在6.5 min之内分离完全;在1～40 mg/L范围内,线性回归方程的相关系数达到0.99以上;检出限为0.07～0.41 mg/L。将本方法应用于废水的测定,加标回收率在92.3%～96.7%之间,相对标准偏差小于3.5%。     

反相离子对色谱法测定硫代硫酸根和碘离子的研究

首次利用Ｓ２Ｏ２－３和Ｉ－与Ｈｇ－ＥＤＴＡ二元络合物通过柱前衍生形成ＥＤＴＡ－Ｈｇ－Ｓ２Ｏ３和ＥＤＴＡ－Ｈｇ－Ｉ两种三元络合物的方法,实现了对Ｓ２Ｏ２－３和Ｉ－的间接反相离子对色谱分离和紫外检测。在ＺｏｒｂａｘＯＤＳ柱上,用甲醇∶水＝２３∶７７作流动相,内含对离子ＴＢＡ＋３．０ｍｍｏｌ／Ｌ,ＥＤＴＡ１．０ｍｍｏｌ／Ｌ,ＮａＮＯ３２．０ｍｍｏｌ／Ｌ和缓冲剂ＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４（ｐＨ７．０）,紫外２５４ｎｍ检测。Ｓ２Ｏ２－３和Ｉ－的最小检出限分别为６１．１ｎｇ和３７．６ｎｇ。方法简便,选择性好。     

磁性纳米复合物的制备及对铜离子(Ⅱ)的传感检测

采用化学共沉淀法合成硅包覆的磁性纳米粒子Fe_3O_4@SiO_2,进一步通过六亚甲基二异氰酸酯将吡哆酰肼分子(Pyh)接枝到Fe_3O_4@SiO_2表面,制得功能化的磁性纳米复合物(Fe_3O_4@SiO_2-Pyh)。通过傅里叶变换红外光谱、透射电子显微镜、X射线衍射等技术手段对其结构、形貌和磁性能进行了表征。Fe_3O_4@SiO_2-Pyh粒子具有规则的核壳结构,粒径分布在50~55 nm,壳层厚度约为15 nm。Fe_3O_4@SiO_2-Pyh结构中含有酰腙类活性基团—CO—NH—N=CH—,能与Cu~(2+)形成稳定的配合物,在此基础上采用紫外可见吸收光谱特性建立了测定Cu~(2+)的分析方法,线性范围为3.4×10~(-7)~4.5×10~(-6)mol/L,检出限为1.03×10~(-7)mol/L。此外,利用Fe_3O_4@SiO_2-Pyh良好的磁响应,通过外部磁场能够有效地除去水中过量的铜离子,在环境领域具有潜在的应用价值。     

反相高效液相色谱法测定对氨基酚及其相关化合物

用反相高效液相色谱法测定对氨基酚及其杂质４,４′－二氨基二苯醚和苯胺的含量。选择了最佳色谱条件,提供了各组分的紫外光谱图。对氨基酚、苯胺和４,４′－二氨基二苯醚的线性范围分别为５～２５０,５～１５０和０．２～１２０ｍｇ／Ｌ,检测限分别为０．１,０．６和０．６ｎｇ。所建立的方法已应用于超声催化氢化法合成反应的跟踪监测和工业样品的分析鉴定,结果令人满意。