Influência dos receptores opioides no efeito hipotensor arterial do propofol em humanos

O propofol é uma droga hipnótico-sedativa, amplamente utilizada em anestesiologia, devido à sua elevada eficácia hipnótica e ao seu despertar rápido e praticamente isento de efeitos residuais. A depressão cardiovascular, que é o efeito adverso mais importante e indesejável do propofol, parece estar intimamente relacionada à dose administrada, à velocidade de injeção do medicamento, à idade e ao estado físico dos pacientes, assim como, às condições de volemia e de reserva cardiovascular dos mesmos, podendo ser intensificada, ainda, pela associação de uma droga opioide ao propofol. A hipotensão arterial induzida pelo propofol parece possuir uma origem multifatorial, pois já foi evidenciada a participação de diversos sistemas nos efeitos produzidos pelo propofol, inclusive, a participação da via opioide no efeito antinociceptivo da droga. Portanto, o objetivo desse estudo foi investigar a participação dos receptores opioides no efeito hipotensor arterial do propofol. A pesquisa foi do tipo randomizada, transversal, aberta e comparativa. Foram estudados 40 pacientes estado físico ASA 1, submetidos a anestesia geral para cirurgias eletivas. Os desfechos avaliados neste estudo foram as pressões arteriais sistólica (PAS), diastólica (PAD) e média (PAM), a pressão venosa central (PVC) e a frequência cardíaca (FC). Portanto, após a monitorização contínua dos pacientes com cardioscopia com análise de ST, pressão arterial invasiva, pressão venosa central, oxicapnometria, análise eletroencefalográfica bispectral (BIS) e gasimetrias arteriais e venosas, estes foram divididos aleatoriamente através de programa de distribuição aleatória gerada por computador, de acordo com os 5 grupos existentes (n = 8 para todos os grupos). Foram 3 grupos de pacientes pré-medicados intravenosamente (iv) com naloxona 1 μg/Kg (PN1) ou 3 μg/Kg (PN3), ou com salina para controle (CP), 2 minutos antes da administração iv de propofol (2,5 mg/Kg). Outros 2 grupos controle da naloxona foram pré-medicados com naloxona 1 μg/Kg (CN1) ou 3 μg/Kg (CN3), mas não receberam propofol. Os resultados demonstraram que há mais de um mecanismo envolvido no efeito hipotensor arterial do propofol, que é composto por uma rápida redução inicial da PAM opioide-independente e uma lenta redução final da PAM, que foi dependente, ao menos parcialmente, de ação opioide. O propofol, na dose de 2,5 mg/Kg, reduziu a PAS, PAD e PAM de forma significativa e independente do efeito hipnótico do anestésico, dos valores iniciais de PVC e de modificações na FC dos pacientes, apesar de ter sido evidenciada a inibição do baroreflexo induzida pelo anestésico. A hipotensão induzida pelo propofol pôde ser parcialmente reduzida, de forma significativa e dose-dependente, pela prévia administração iv de naloxona de 3 μg/Kg, menor dose efetiva. Este efeito da naloxona ocorreu, principalmente, através de um aumento significativo da PAD, sem importar em modificações significativas da PAS, FC, PVC, BIS ou do ECG. Foi concluído que a hipotensão arterial induzida pelo propofol possui uma origem multifatorial, sendo produzida parcialmente por um mecanismo que é opioide-dependente e sensível ao pré-tratamento dos pacientes com a naloxona. Nosso estudo não recebeu nenhum financiamento externo.

Diet shifts of juvenile red snapper (Lutjanus campechanus) with changes in habitat and fish size

We examined the diets and habitat shift of juvenile red snapper (Lutjanus campechanus) in the northeast Gulf of Mexico. Fish were collected from open sand-mud habitat (little to no relief), and artificial reef habitat (1-m3 concrete or PVC blocks), from June 1993 through December 1994. In 1994, fish settled over open habitat from June to September, as shown by trawl collections, then began shifting to reef habitat — a shift that was almost completed by December as observed by SCUBA visual surveys. Stomachs were examined from 1639 red snapper that ranged in size from 18.0 to 280.0 mm SL. Of these, 850 fish had empty stomachs, and 346 fish from open habitat and 443 fish from reef habitat contained prey. Prey were identified to the lowest possible taxon and quantified by volumetric measurement. Specific volume of particular prey taxa were calculated by dividing prey volume by individual fish weight. Red snapper shifted diets with increasing size. Small red snapper (<60 mm SL) fed mostly on chaetognaths, copepods, shrimp, and squid. Large red snapper (60–280 mm SL) shifted feeding to fish prey, greater amounts of squid and crabs, and continued feeding on shrimp. We compared red snapper diets for overlapping size classes (70–160 mm SL) of fish that were collected from both habitats (Bray-Curtis dissimilarity index and multidimensional scaling analysis). Red snapper diets separated by habitat type rather than fish size for the size ranges that overlapped habitats. These diet shifts were attributed to feeding more on reef prey than on open-water prey. Thus, the shift in habitat shown by juvenile red snapper was reflected in their diet and suggested differential habitat values based not just on predation refuge but food resources as well.

Reproductive biology, artificial propagation and larval rearing of two freshwater eels, Monopterus cuchia and Mastacembelus armatus

Studies on reproductive biology and artificial propagation including larval rearing of freshwater mud eel, Monopterus cuchia and spiny eel, Mastacembelus armatus were attempted. The gonadosomatic index (GSI) of mud eel ranged from 0.41 (August) to 5.52 (June) in males and 0.53 (August) to 7.61 (June) in females. In both cases the GSI showed a peak in June. Fecundity ranged from 228 (TL - 396 mm; W - 78g) to 5510 (TL - 865 mm; W - 630 g). In case of spiny eel, the GSI varied from 0.65 (August) to 8.30 (July) in males and 0.70 (August) to 10.46 (July) in females. GSI showed single peak in July. Fecundity ranged from 570 (TL - 240 mm; W - 30 g) to 10870 (TL - 601; W - 350g). Histology of the testes and ovaries of the eels were carried out to investigate the gonadal development stages during the reproductive months (August to November 2003). In case of male M. cuchia, the secondary primordial germ cells, primary spermatogonium, some spermatogonia A and clone of spermatogonium B in testis were observed in September. In October-males different sized lobules having spermatogonia, spermatocytes and spermatids were observed. In the ovary of M. cuchia, polygonal shaped oocytes were seen during September. The oogonia were reduced with dense and irregular shaped during October. Numerous pycnotic cells were visible during November. In male M. armatus numerous broken lobule walls were found in testes during September. In October, abundant primary germ cells, pycnotic nests of degenerating cells, spermatogonia and spermatids were observed. In females, ovaries had distinct yolk vesicles stage and yolk granules stages in August. In September, the follicular cells of the oogonia were ruptured, shrunk forming irregular shaped in October. Oogonia were also shrunk with thin, irregular shaped structure but broken parts of the ruptured follicular cells were scattered in case of M. armatus. Experimental attempts on artificial propagation indicated that both freshwater eels were difficult to breed using inducing agents like pituitary glands (PG) of 10, 20, 50, 100 and 150 mg per kg of body weight. Same doses were used for both sexes with equal sex-ratio. In both cases, brood fish died at higher doses of injection given at 100 and 150 mg PG/kg bodyweight. However, M. cuchia breed naturally in cisterns when provided with water hyacinths and tunnel in muddy bottom. M. cuchia fed with chopped cooked fish attained a mean weight of 18.75 ± 2.3 g and cent percent survival. While in case of M. armatus best growth by weight (12.0 ± 2.48 g) and cent percent survival were achieved using chopped raw fish. Car tyre was observed as best shelter for attaining the mean weight gain 22.53 ± 2.24 g and cent percent survival of M. cuchia. While PVC pipe was found to be the best shelter for M. armatus, where it attained the mean weight of 12.73 ± 1.88 g and cent percent survival.

Compressive response of glass fiber composite sandwich structures

Sandwich panels with crushable foam cores have attracted significant interest for impulsive load mitigation. We describe a method for making a lightweight, energy absorbing, glass fiber composite sandwich structure and explore it is through thickness (out-of-plane) compressive response. The sandwich structure utilized corrugated composite cores constructed from delamination resistant 3D woven E-glass fiber textiles folded over triangular cross section prismatic closed cell, PVC foam inserts. The corrugated structure was stitched to 3D woven S2-glass fiber face sheets and infiltrated with a rubber toughened, impact resistant epoxy. The quasi-static compressive stress-strain response of the panels was experimentally investigated as a function of the strut width to length ratio and compared to micromechanical predictions. Slender struts failed by elastic (Euler) buckling which transitioned to plastic microbuckling as the strut aspect ratio increased. Good agreement was observed between experimental results and micromechanical predictions over the wide range of core densities investigated in the study.

Dipole assisted photogated switch in spiropyran grafted polyaniline nanowires

In this work we show dipole-assisted photogated switching by covalent grafting of photoactive molecules to conducting polymers. Photochromic spiropyran molecules were covalently attached to polyaniline (PANI) nanowires via N-alkylation reaction to the quinoic part of PANI. Upon irradiation with ultraviolet light spiropyran transformed to a large dipole containing molecule, merocyanine form. We show that this transformation leads to a substantial (ca. 2 orders of magnitude) increase in conductance of the photochromic PANI nanowires, which were evident by an increase in field-effect mobility and calculated band gap narrowing of the system. Finally, this transformation was found to be fully reversible with no significant photofatigue. © 2011 American Chemical Society.

STUDIES ON MIXED MASS CULTIVATION OF ANABAENA SPP (NITROGEN-FIXING BLUE-GREEN-ALGAE, CYANOBACTERIA) ON A LARGE-SCALE

Studies on mixed mass cultivation of Anabaena spp. on a large scale (5170 m2) were conducted continuously for 3 years. Under the continental monsoon climate in northern subtropics (30-degrees-N, 115-degrees-E), 7-11 g dry weight m-2 day-1 of microalgal biomass on average was harvested in simple plastic greenhouses in the effective growth days during the warmer seasons. The maximum productivity was 22 g m-2 day-1 in the middle of summer. Observations on the productive properties of strains of Anabaena spp. indicated that they were different from and could compensate for each other in their productivities and adaptations to the seasonal changes. With different lining materials (PVC sheets, concrete, sand and soil) in the culture ponds, no significant variation of productivity was found, but bubbling with biogas in the middle of the day and the application of some growth regulating substances (2,4-D, NaHSO3 and extracts of oyster mushroom spawn) was able to improve the production. The cost of microalgal biomass in this way was around 0.75-1.0 US dollar(s) per kilogram.

喷流-移动床垃圾衍生燃料热解燃烧特性研究

垃圾的处置已成为全球性环境问题。与填埋法相比，焚烧、热解和气化等热处理法具有减容、减量和能源化利用等优点。如何控制垃圾焚烧过程中HCI、二恶英和未燃尽碳氢化合物等污染物的排放也引起越来越多国家的关注。采用先热解（或气化）再气相燃烧的方法以及对垃圾预处理保持垃圾组成相对稳定的RDF技术是减少二次污染的有效手段。喷动技术能够用相对较小气量流化较粗大颗粒，是进行RDF热解的较佳选择。但RDF具有密度小、流动性差等特点，考虑减少空气量和改善RDF流动性，在喷动床中水平引入辅助气，称为"喷流一移动床"。本论文首先在室温下对喷流一移动床的流体力学特性进行了研究。结果表明，水平辅助气的引入可以降低中心最小喷动气速，调控喷泉高度，提高环流区颗粒的流动速度，增大颗粒的循环流量。在此基础上，根据先部分燃烧部分热解后气相燃烧以及自热型的原则，设计了下部为喷流一移动床热解室上部为气相燃烧室的两段式RDF热解燃烧反应器，并利用实验室内制备的RDF对该反应器的运行特性进行了评价。论文对喷动空气量和辅助空气量对热解室温度分布、气体分布，二次空气对燃烧室温度分布以及CO和NOx的释放特性的影响进行了研究，然后对有机氯（PVC）和无机氯（NaCI）产生Hcl特性、Ca（OH）2对HCI的脱除特性及机理进行了研究。实验结果表明，RDF可以成功地进行自热型的先热解后气相燃烧，通过改变空气／燃料比可以控制热解室温度，水平辅助气的引入可以使热解室轴向温度分布更加均匀，热解室中可以得到O2含量低于2v％热解气体，热解气体在燃烧室中能完全燃烧。二次空气能够控制燃烧室温度以及Co和NOx的排放。PVC中氯能产生较大数量的HCI外,NaCl同样也可生成HCl；温度对PVC生成HCI量的影响很小，而对NaCI却起主要影响作用。漓温不利于钙化物与HCI反应的进仃，同时CaC12在高温时与石英砂(SiO2)、水蒸汽反应产生HCl，因此Ca（OH）2的脱氯效率会降低。

核壳结构改性剂增韧聚氯乙烯的机理及性能优化

我国是世界上聚氯乙烯产量最大的国家。由于在氯乙烯分子中氯的含量大于50%，而氯又是制碱工业的必然副产物，因此聚氯乙烯工业成为氯碱平衡中的主要杠杆。随着近年来世界石油资源的日益短缺和价格的上涨及国内聚氯乙烯产能过剩，开发聚氯乙烯的新用途，发展聚氯乙烯树脂的改性具有深远的意义。本工作的目的是以开发PVC核壳结构改性剂MBS和注塑级PVC/ABS合金为背景，对核壳粒子改性的聚氯乙烯的屈服机理和改性剂性能优化进行了研究。 对于增韧剂的研究，人们总是希望用最少的增韧剂用量来达到最好的增韧效果，即提高增韧剂的增韧效率，而且MBS改性的PVC在应用时还需要保持较高的透光率和具有一定的抗应力发白的能力。为此我们成功开发了具有高增韧效率、高透明及抗应力发白的MBS增韧剂，并研究了MBS结构特性对PVC/MBS共混物力学性能及屈服机理的影响。结果表明：粒径范围在80nm~280nm的橡胶粒子均能有效地对PVC进行增韧。大粒径的MBS通过空洞化释放三维静张应力引发基体的屈服来吸收能量，而小粒径的MBS不能产生空洞，但同样能引起基体的屈服起到增韧的作用。为了兼顾PVC/MBS共混物的韧性和透明性，我们在制备MBS时将一部分苯乙烯单体与丁二烯共聚结合来提高丁苯胶乳的折光指数与PVC基体相匹配，而另一部分苯乙烯单体以接枝的方式结合，这样可以保持MBS的弹性，并且制备的PVC/MBS共混物具有高韧性和高透明；同时我们发现MBS的内包容物及多层结构都会削弱PVC/MBS共混物的透光率。研究表明橡胶粒子的空洞化是引发共混物应力发白的主要原因。为此通过制备小粒径及具有一定交联程度的MBS来抑制空洞的产生，制备了兼有抗应力发白和韧性的MBS。成功开发了多个牌号的MBS产品，并在吉化集团公司建成了年产5000吨的生产车间，实现了MBS的工业化生产。 由于PVC的熔体流动性较差，通过与熔体流动性好的ABS树脂共混，成功开发了注塑级PVC/ABS合金。ABS树脂是SAN树脂和PB-g-SAN的共混物，在PVC中加入ABS使增韧对象由PVC基体转化为PVC/SAN共混基体，并研究了基体性质的改变对增韧效果的影响。结果表明随着PVC/ABS共混体系基体中PVC含量的增加共混物的冲击强度显著增加，形变机理发生了由银纹向剪切屈服的转变。

电化学SPR研究及形貌可控的纳米结构合成

围绕论文题目“电化学SPR研究及形貌可控的纳米结构合成”，我们将SPR传感膜同时用作电化学研究的界面，开展了相关的EC-SPR研究工作。同时，在一些可控纳米结构的合成与表征方面进行了创新研究。 本论文研究工作的主要内容和创新点表现在以下几个方面：1．生物分子模板生长法为构建具有特定功能的新颖材料提供了新的途径。报道了一种基于固定的DNA为模板通过电化学途径合成DNA-聚苯胺复合物的方法。在这种条件下，目标生物分子能保持其天然结构和生物活性，能用于构建功能多样性的导电聚合物结构。2．首次用溶液中溶解氧现场原位还原产生的活性氧中间体作氧化剂，在蒸镀的金膜电极上阴极极化合成聚苯胺（PANI）。聚苯胺膜的厚度可很容易地在分子水平的尺度上控制，其表面形貌对金膜表面层原子的结晶取向非常敏感。在多晶金电极上可得到岛型的纳米结构，而在单晶Au（111）电极上则聚合得到超薄膜。3．在金电极表面电化学聚合形成的导电聚合物聚吡咯（PPy）膜被用作双层磷脂 膜（BLMs）的新的支撑体。PPy膜支撑的双层脂膜的形成依赖于所用脂分子的化学结构，在一定程度上PPy膜支撑的双层脂膜类似于传统的双层脂膜结构，在脂膜结构的内外两侧保持着水介质环境。PPy膜支撑的双层磷脂膜可很方便地用于仿生膜研究。4．采用光刻法构建SPR阵列传感器的金膜点阵列，拟将来用于SPR成像分析。把正型光刻胶旋涂于SPR金片表面，紫外光通过自制掩模曝光后，用碱液显 影。然后采用选择性化学刻蚀暴露出的金膜，最后用剥离液去掉未曝光的光 胶层，从而构建所需的金膜点阵列，点的大小和间距可方便地由掩模来控制。用壳聚糖为例进行了金膜点阵列的表面修饰与组装。点阵列间的玻璃表面能 抑制亲水性和疏水性分子的吸附，这在SPR成像分析及高通量筛选方面将非常有用。5．在生物学上，生物大分子或有机体通常能调节及控制生物／无机杂化材料和晶 体的形貌及组装，这个过程被称为生物矿化。我们报导了基于生物小分子，L一氨基酸的金纳米结构的生物合成。在没有表面活性剂及硬模板存在下，天冬氨酸能直接还原氯金酸生成大量的厚度小于30nm的金纳米盘，该纳米盘为单晶结构，主要晶面为｛111｝，特征形貌为平均边长为590nm的对称六角形以及平均边长为840nm的去顶角三角形纳米晶体。6．苯胺及其衍生物作为模型化合物被用于有意图地构建金属纳米材料。苯胺还原氯金酸生成金核直径38nm壳gnm的核／壳结构的球形纳米粒子，3-氨基苯甲酸（3-ABA）调制生成厚度为20nm边长为105nm的形状规则的金纳米片，4一氨基苯甲酸（4-ABA）指导生成直径为18nm长度为微米级的纳米线结构，2一氨基苯磺酸（2-ABS）能调节生成直径为13．7nln长度可达几十微米的“之”字形的金纳米线，而1-（4-氨基苯基）乙二胺-N，N，N'，N'-四乙酸（4-ABEDTA）能还原氯金酸并相应控制生成结构完好由平均直径为19nm的金球形纳米粒子连接的线结构并进一步组织成纳米分形网络结构，表明苯胺环上取代基的种类和位置对金属纳米结构形貌的调节有直接影响。

功能高分子膜离子选择电极研究

功能高分子是新近开发的离子选择电极活性材料。本文叙述了功能高分子膜离子选择电极的发展和现状，叙述了交流阻抗等方法在离子选择电极研究中的应用，从下面几个方面研究了功能高分子膜离子选择电极：1．用热压方法研制了功能高分子为活性物的PVC膜氯离子选择电极，探索了膜制备方法，测试了电极性能。2．用相敏检波法测试了压片PVC膜氯离子选择电极的交流阻抗行为（改变膜活性物用量、电极面积和厚度、溶液离子浓度、温度等条件）。频率范围10~4-1Hz。在所有情况下，复平面阻抗图上为一个近似完整的半园，等效于RC并联线路，呈现膜主体离子传输过程的势垒阻抗。计算了相应条件下的膜直流电阻R_∞、膜主体电容C_g，时间常数τ以及离子传输活化能E_α等膜电化学参数，讨论了膜电荷传输机理。3．用恒电位逐点测试和慢扫描法测定了电极的稳态极化曲线，计算了不同条件下的电极交换电流i°，反应电阻Rr，根据电化学极化方程式讨论了电极的稳态极化特性，探讨了电极在外加电压下的电流响应行为，讨论了电极零电位电流的分析特性。4．用快速三角波电位扫描法和快速方波电位法测试了电极的暂态响应行为，根据电流－时间曲线及电位－时间曲线计算了电极的有关电化学参数，讨论了膜电极的电流分析特性。5．探讨了电极活化过程的动力学行为，测试了膜电极电阻－时间曲线（R－t曲线），归纳了R-t曲线的经验公式，用离子在膜中的扩散解释R-t曲线，理论与实验结果吻合。

稀土高子选择电极的研制

（一）本文首次提出一类新型离子选择电极－水膜电极。推导了水膜电极遵循的能斯特方程式。具体研制了氯化钕水膜电极，用于测定环已酮中Nd(PMBP)_3螯合物。结果与理论相符合。研究了参比电极电位在非水介质中保持稳定的条件。发现了两不相溶溶液界面上的电位响应可以是双向的，而且响应曲线斜率的绝对值基本相同。水膜离子选择电极可以做到完全不受有机溶剂的腐蚀。这是水膜电极的一个优点。水膜离子选择电极的研制成功，为非水介质中的研究和分析开创了一条新路。（二）随着稀土化学的进展，对稀土离子选择电极的需要日益增加。本文研制了如下两种稀土离子选择电极。1.以镱－P507螯合物为电活性物质的PVC膜镱离子选择电极。其电极电位与镱（III）离子浓度的负对数有线性关系。线性范围1*10~(-4)～1.9*10~(-5)M。室温下，响应曲线的斜率为75.4 mv/PC_((Yb)~(3+))。检测下限为1.4*10~(-5)M。2.以钕－PMBP螯合物为电活性物质的PVC膜钕（III）离子选择电极。室温下，其电极电位与钕（III）离子活度的负对数呈能斯特关系。线性范围为4.8*10~(-2)～1.0*10~(-5)M。

傅立叶变换红外光谱法对高聚物共混体系的研究

本论文主要包括以下三方面的工作：1. 傅立叶变换红外光谱法对含有特殊相互作用的高聚物共混体系的相容性及其他性质进行了研究。实验表明，在EVA／CPE（PVC）体系中，当两组分分子间处于互容的情况时，属于EVA的羰基伸缩振动频率向低频移动且谱峰加宽。利用这一光谱上的特征，可以表征出共混体系的相容性。得出，该体系的相容性与EVA中VA含量以及CPE中氯含量成正比。由升温实验还得出了EVA(VA：40%)/CPE(Cl:64%)共混体系的相图。运用同样的手段，考察了PcL/SAN体系的相容性。通过计算机分峰，得出PcL的羰基伸缩振动的结晶谱带和非晶变带。发现，随着SAN加入量的增多，上述PcL的非晶谱带ν_(c=o)向低频移动。说明该体系中PcL的非晶部分与SAN在室温下是相容的。FT－IR还用来研究了该体系中PcL的等温结晶过程。利用红外中的差谱技术，考察了PVF_2/PMMA共混体系的相容性。实验得出，当PMMA含量较高时，体系处于相容状态；而当PMMA含量较低时，由于体系中PVF_2 的结晶度较大，妨碍了PVF_2与PMMA分子的相互“混溶“，则为不相容状态。初步考察了涂膜法制备不同晶型PVF_2/PMMA样品的条件。2. 首次运用FT－IR法，对不含有特殊相互作用的高聚物共混体系（LLDPE／NR，LLDPE／SBR）的相容性进行了研究。发现，在这两个体系中皆发生相类似的光谱现象，即LLDPE的加入，使得分别属于NR和SBR的＝CH－面外摇摆振动峰，强度增大，峰宽变窄。通过一系列实验证明，上述变化与PE中的非晶含量有关，得出LLDPE的非晶部分与NR或SBR分子间存在着一定程度的相互渗透。其他实验手段测得的结果支持了上述解释。3. 详细研究了LLDPE在LLDPE／SBR共混体系中的结晶动力学和熔融热力学过程。发现SBR的加入，对LLDPE的平衡熔点Tm°影响不大，晶体表面能略有增大。根据这实验现象，提出了该体系中LLDPE的晶体结构模型。实验表明，SBR的加入，还对共混体系中LLDPE的结晶度，微晶尺寸，球晶结构，片层结构等产生较大的影响。

非水溶剂电位法研究

离子选择电极在水溶液中的研究和应用，已取得很大进展。但是，在实际工作中人们常遇到一些困难，许多化合物不溶解于水，或不以人们所要求的状态存在，因而不能在水溶液中时行研究和测定。因此，将离子电极技术应用于非水介质，扩展电位法的研究和应用领域，具有重要的意义。由于有机溶剂对离子电极有腐蚀、破坏作用，使目前能用于非水介质电极只有玻璃电极、固体膜电极等少数几种。发展新型的用于非水介质测定的离子电极,已成为非水溶剂电位法研究的首要课题。1986年陈方平受液膜电极工作原理启发，提出了水膜电极，并在低介电常数有机溶剂中响应成功，我们的工作，是对水膜电极作进一步和系统的研究。1. 参比电极 用于非水溶剂电位测定的参比电极已有多种。本文制备的Pt/(I_3~-+I~-)参比电极，在多种有机溶剂中有稳定电位，与Ag/Agu、甘汞电极比较有其独特的优点。实验证明，选择Pt/(I_3~-+I~-)电极作为水膜电极测定的参比电极，能取得满意的结果。2. 测定体系的选择 鉴于介电常数较大的有机溶剂，已有许多作者研究，我们采用低介电常数有机溶剂－磷酸三丁酯作为水膜电极测定的有机溶剂，并以加入支持电解质的方法解决被测体系内阻的问题。我们不选择甲醇、乙醇、丙醇、丁醇、戊醇等介电常数有规律变化的溶剂作为被测溶剂系列，以探讨溶剂性质对水膜电极响应的影响。考虑到一价离子是非水溶剂电位法中研究最多的离子，二价、三价离子研究较少，我们选择二价钴、镍离子和三价钐离子作为非水溶剂测定的研究对象。3. 水膜电极的制备 将水膜支撑材料封接于玻璃管的一端，充入内参比液，待内参比液透过水膜支撑材料，便在电极末端形成水膜。制备水膜电极的关键，在于水膜支撑材料的选择及水膜溶液的确定。水膜支撑材料可直接影响水膜电极响应的斜率。由实验发现，具有均匀微小颗粒结构的陶瓷，较适宜于作为水膜电极的水膜支撑材料。水膜溶液的组成决定了水膜电极的性质和种类。在我们研制的水膜钴、镍、钐电极中，水膜钴电极的水膜组成液是pH=2, 10~(-2)M氯化钴溶液，水膜镍电极的水膜组成液是pH=2, 10~(-2)M氯化镍溶液，水膜钐电极的水膜组成液是1MHCl, 10~(-2)M氯化钐溶液。水膜电极水膜组成液中离子浓度及pH值的改变，可影响水膜电极响应的线性范围和斜率。对不同离子的水膜电极其影响情况不同。我们以水膜钴、镍、钐电极为对象，进行了探讨。4. 影响水膜电极响应的其它因素 水膜电极在有机相中测定，有机溶剂中离子强度大小和水、有机溶剂两相间的液接电势均构成影响电极响应的因素，在一些低价电常数剂中这种影响尤为明显。因此需要加入适当的支持电解质固定被测体系的总离子强度。支持电解质的种类、浓度不同，对电极响应的影响情况也不同。实验表明，高氯酸四丁铵是水膜镍电极在磷酸三丁酯中响应的较为理想的支持电解质。待测有机体系的内阻，是非水电位测定的一个重要问题。由于非水溶剂的介电常数远小于溶液的介电常数，电解质在其中的离解度也小于在水溶液中的离解度，因而有机溶剂体系的内阻比水溶液体系的内阻大得多。我们一方面采用输入阻抗较高的仪器来测定，另一方面对内阻过大的低介电常数溶剂，加入适当的支持电解质，以改善溶液的导电性。5. 有机溶剂性质对水膜电极响应的影响以水膜电极在介电常数及水溶性有规律变化的甲醇、乙醇、丙醇、丁醇、戊醇中的响应，以及水膜电极在磷酸三丁酯－醇混合溶剂中的响应，来初步探讨有机溶剂性质对水膜电极响应的影响。实验结果表明：水膜电极直接在低介电常数有机溶剂中的响应，往往是非能斯特响应，但加入支持电解质后，可改善体系的导电性，使电极响应状况好转。在介电常数较大的有机溶剂中，水膜电极在不加支持电解质的情况下响应仍能得到满意的结果。但是，若介电常数大的有机溶剂具有水溶性，水溶性越高，水膜电极的灵敏度就越低，水溶性越小，水膜电极的灵敏度就越高。与水完全互溶的有机溶剂，不能用水膜电极进行测定。6. 水膜电极的应用 将水膜电极直接用于实际样品的分析测定，尚有一定的困难。但是根据离子在两互不相溶液－液界面上迁移是双向可逆的原则，利用水膜电极的一些研究结果，可以探索和制备新型的液膜和PVC膜离子电极。我们分别制备了液膜和PVC膜稀土电极，其中PVC膜钐离子电极在高浓度硝酸中具有能斯特响应这一结果，打破了稀土电极不能在酸性条件下测定的界限。为稀土电极的研究，闯出了一条新路。

聚乙烯与极性聚合物共混物的增容及相互作用的研究

本论文主要包括增容剂LLDPE－g－PMMA的合成及其在LLDPE与极性聚合物共混体系中增容作用的研究。增容剂LLDPE－g－PMMA系采用自由基引发的悬浮聚合方法合成的。产物经丙酮抽提后，经IR分析证明，接枝物中有PMMA的特征吸收峰，证明了用这种方法可以合成出LLDPE－g－PMMA。接枝物的接枝率一般为10wt%左右。合成实验中发现悬浮聚合体系越稳定，产物的接枝率越高。对接枝物LLDPE－g－PMMA分别用电镜（SEM.TEM），DSC，SAXS及动态力学等进行了结构方面的研究。PMMA主要接枝在LLDPE的非晶区，产物中大部分的LLDPE未参与接枝反应。TEM照片的结果表明，PMMA在接枝物中聚集，聚集的PMMA以分散相存在于LLDPE连续相中，PMMA接枝到LLDPE上后，使LLDPE的结晶变得完整， LLDPE－g－PMMA的Tm.Tc略有升高。SAXS测出的接枝物中LLDPE的长周期较均聚物LLDPE的大，说明接枝LLDPE－g－PMMA增加了LLDPE的非晶部分。动态力学结果表明，接枝物中LLDPE的β松驰向温度高的区域移动，反映了接枝段PMMA对LLDPE中非晶区链段运动有阻碍作用。接枝物LLDPE－g－PMMA对LLDPE与不同极性聚合物共混的增容效果和作用的研究表明：LLDPE－g－PMMA对LLDPE／PMMA。LLDPE／PVC共混体系均有增容作用。使分散相的颗粒变小，两相界面的粘着得以改善。力学性能提高。分别用DSC，SEM，FTIR及动态力学等方法深入研究了LLDPE－g－PMMA对LLDPE／PVF_2共混体系的增容效果。SEM结果表明：增容剂LLDPE－g－PMMA可以明显地改善LLDPE／PVF_2共混物中两相间界面的粘着情况，使分散相应变小，力学性能提高。动态力学结果表明，增容剂LLDPE－g－PMMA可使LLDPE／PVF_2共混物中PVF_2的Tg升高，表明接枝段PMMA仍可与PVF_2互溶，但较均取PMMA稍差。DSC结果表明：共混增容体系中PVF_2的Tm.Tc降低，反映了接枝段PMMA使PVF_2的结晶变得困难，结晶速率降低，球晶生长速率变慢。由于接枝段PMMA与PVF_2之间存在相互作用，所以导致共混物中PVF_2的IR特征吸收峰产生位移。综上所述，接枝物LLDPE－g－PMMA对LLDPE／PMMA、LLDPE／PVC和LLDPE／PVF_2共混体系均有增容作用，但增容效果以LLDPE／PVF_2共混体系为最好。

非水溶剂电位法的研究——水溶性高分子膜电极的研制及性能

非水溶剂在各方面的应用越来越广泛, 由于它不同于水的性质。在其中发生的化学过程较为复杂，因而，利用各种手段对非水溶剂进行深入的研究，也就十分必要和有意义。非水溶剂中的电位法研究有其独特的优点。但是，目前除玻璃电极一些磋玻璃基质的固体膜电极外，大部分离子电极的电极膜及电极体易受非水溶剂的腐蚀甚至溶解，使研究受到一定的限制。所以，发展新型的可用于非水溶剂中的离子电极成为非水溶剂的电位法研究的首要课题之一。论文围绕着此课题进行了一系列的研究。1 水溶性高分子膜电极的研制；2 PVC膜钡离子电极的研制；3 Ag/Ag~+参比电极的研制。