以CTAB微乳为模板制备碳酸钙-环糊精复合材料

采用复分解反应法在阳离子表面活性剂十六烷基三甲基溴化铵微乳模板中合成了碳酸钙-环糊精纳米复合材料(无机相为以方解石为主的方解石、球霰石、文石混合晶型的碳酸钙,有机相为环糊精)。结果表明,生成球霰石、文石的最佳工艺条件为:反应温度80℃,反应时间12 h,氯化钙浓度3.50 g/dm,环糊精浓度0.135 g/dm。复合材料粒子形状为菱形片状,有些系统中可以观察到类似贝壳珍珠层的"砖-泥"式层状结构,这种结构是环糊精与方解石(110)晶面作用的结果。     

以CTAB微乳为模板制备碳酸钙-环糊精复合材料

采用复分解反应法在阳离子表面活性剂十六烷基三甲基溴化铵微乳模板中合成了碳酸钙-环糊精纳米复合材料(无机相为以方解石为主的方解石、球霰石、文石混合晶型的碳酸钙,有机相为环糊精)。结果表明,生成球霰石、文石的最佳工艺条件为:反应温度80℃,反应时间12 h,氯化钙浓度3.50 g/dm,环糊精浓度0.135 g/dm。复合材料粒子形状为菱形片状,有些系统中可以观察到类似贝壳珍珠层的"砖-泥"式层状结构,这种结构是环糊精与方解石(110)晶面作用的结果。     

以16-12-16胶束模板合成碳酸钙-环糊精复合材料

用动态光散射实验考察了不同浓度的双子型表面活性剂16-12-16系统,以及16-12-16/正十二醇系统的胶束粒径,并以这两种系统为模板,利用碳酸化法合成了碳酸钙-环糊精复合材料.材料无机相为方解石型碳酸钙,有机相为环糊精.与无模板时合成的材料相比,模板的加入使纳米材料尺寸变小、边缘平滑.无醇的胶束模板的合成产物中,发现层状结构的纳米颗粒,加醇后层状结构消失.研究了模板尺寸、电性与复合材料形貌的关系,讨论了层状结构生成的机制.     

乙氧羰基化-β-环糊精的合成工艺优化

选用环境友好的碳酸二乙酯为原料,研究了乙氧羰基化-β-环糊精的绿色合成新工艺。β-环糊精和碳酸二乙酯在无水碳酸钾的作用下经酯交换反应生成了乙氧羰基化-β-环糊精。研究了反应物的摩尔比、反应温度、反应时间和催化剂用量四个参数对反应的影响。利用响应曲面试验设计法进行试验设计,建立乙氧羰基化-β-环糊精的合成工艺模型。通过回归方程和响应曲面,得到乙氧羰基化-β-环糊精最佳合成工艺:10 gβ-环糊精溶于80 mLDMF中,反应温度126℃,催化剂用量(相对于β-环糊精的质量百分数)为12%,n(DEC):n(β-CD)=20.2:1,反应时间8.5 h。验证试验结果显示,在此条件下,乙氧羰基化β-环糊精的收率达到98%。通过高效液相色谱分析反应结果并利用半制备色谱分离获得纯产物,对其进行了FT-IR,MS,1H-NMR表征。     

环糊精-氧化石墨烯复合材料的制备及其对■的吸附性能研究

采用改进的hummer法制备出氧化石墨烯,再与适量的环糊精溶液以及水合肼和氨水进行还原反应得到环糊精-氧化石墨烯复合材料,测定了复合材料在不同pH、时间、温度等条件下对水体中的Cu~(2+)的吸附量。结果表明,环糊精-石墨烯复合材料对水溶液中的Cu~(2+)具有优异的吸附性能,在中性条件下,经24 h后吸附量达212.44 mg/g,吸附率为83.46%;这主要是因为氧化石墨烯的巨大表面积和表面含氧基团对Cu~(2+)的静电吸引力,以及环糊精的空腔结构所致。     

一种β-环糊精共聚物山梨酸钾配合物的制备方法及其抑菌应用

<正>本发明属于功能材料领域,特别涉及一种β?环糊精共聚物山梨酸钾配合物的制备方法及其抑菌应用。通过酰化反应合成β-环糊精衍生物,再将其与苯乙烯通过自由基聚合反应合成β-环糊精共聚物。利用环糊精共聚物空腔结构包合山梨酸钾,制备β-环糊精共聚物山梨酸钾配合物。将配合物作为抑菌     

紫外光引发双单体法合成超支化聚(β-环糊精)

通过对β-环糊精单体的功能化改性合成出BBx'型环糊精大单体,再通过双单体法在紫外光引发的条件下,用BBx'型单体与A2型单体反应,合成出超支化聚(β-环糊精).对BBx'型环糊精人单体及聚合物的结构进行了表征,结果表明所合成的单体及聚合物与设计的结构相一致.     

Mitsunobu反应合成单取代β-环糊精胺基衍生物

在超分子化学领域,胺基修饰环糊精是一类合成化学修饰环糊精的重要中间体。传统方法需要多步反应才能实现环糊精胺基衍生物的合成。以β-环糊精为起始原料,经两步Mitsunobu反应合成了标题化合物。和传统方法相比,该方法步骤短且收率较高,为环糊精衍生物的合成提供了一种新的选择。     

β-环糊精-Cu(Ⅱ)配合物催化氧化邻苯二酚及其反应动力学

以β-环糊精(β-CD)作为骨架,经磺酰化反应、卤代反应和与L-组氨酸的亲核取代反应,得到了两种β-环糊精-组氨酸衍生物配体,再将配体与Cu(Ⅱ)配位,合成了具有多酚氧化酶催化活性的β-环糊精-Cu(Ⅱ)配合物。采用元素分析、傅里叶变换红外光谱、核磁共振波谱和原子吸收光谱等方法对配体和配合物的结构进行了表征。以O₂为氧化剂,用分光光度法测定了它们催化邻苯二酚氧化反应的性能,并考察了反应温度、pH值等因素对催化反应速率的影响。结果表明：β-环糊精-Cu(Ⅱ)配合物具有良好的催化性能;C-2位修饰得到的环糊精类金属衍生物因为活性基团与反应中心之间相对位置适宜,表现出较大的加速效果;反应动力学表明组胺基配位Cu(Ⅱ) 、β- CD疏水空腔和碱催化作用是反应加速的3个因素。     

Oxidation of catechol catalyzed by β-cyclodextrin-Cu(Ⅱ) complexes and its reaction kinetics

以β-环糊精(β-CD)作为骨架,经磺酰化反应、卤代反应和与L-组氨酸的亲核取代反应,得到了两种β-环糊精-组氨酸衍生物配体,再将配体与Cu(Ⅱ)配位,合成了具有多酚氧化酶催化活性的β-环糊精-Cu(Ⅱ)配合物。采用元素分析、傅里叶变换红外光谱、核磁共振波谱和原子吸收光谱等方法对配体和配合物的结构进行了表征。以O₂为氧化剂,用分光光度法测定了它们催化邻苯二酚氧化反应的性能,并考察了反应温度、pH值等因素对催化反应速率的影响。结果表明：β-环糊精-Cu(Ⅱ)配合物具有良好的催化性能;C-2位修饰得到的环糊精类金属衍生物因为活性基团与反应中心之间相对位置适宜,表现出较大的加速效果;反应动力学表明组胺基配位Cu(Ⅱ) 、β- CD疏水空腔和碱催化作用是反应加速的3个因素。     

Hydrate Formation during Pressure Release of Wet CO2,View‐Cell Observations

The objective of this work is the evaluation of the blocking risk of pipelines by hydrate crystals in processing steps. Two topics were investigated: (I) hydrate formation during pressure release and isochore cooling and (II) the influence of a contact surface on hydrate formation. The investigated materials were steel, glass, and polytetrafluoroethylene (PTFE). Experiments were carried out in a 87 mL view‐cell to observe hydrate formation in the bulk CO₂ phase, since crystals of that size can cause the problems mentioned. The starting conditions of all experiments were within the temperature range of T = 278–285 K and the pressure range of p = 6–20 MPa. The results of the experiments suggest that the major criterion for hydrate formation during pressure release is the degree of supersaturation. Visible hydrate formation can be observed at a minimum subcooling of ΔT = 7 K. With a starting temperature of T = 285 K and a starting pressure of p = 6 MPa no hydrate formation is observed. The surface properties of the material have no direct influence on the hydrate formation process. However, during pressure release hydrate crystals detach from hydrophobic materials like PTFE, whereas they stick to hydrophilic materials like glass and steel. Thus, the adhesion between hydrate crystals and hydrophilic surfaces is stronger than between hydrate crystals and hydrophobic surfaces.     

Bioadhesion on Textured Interfaces in the Human Oral Cavity—An In Situ Study

Extensive biofilm formation on materials used in restorative dentistry is a common reason for their failure and the development of oral diseases like peri-implantitis or secondary caries. Therefore, novel materials and strategies that result in reduced biofouling capacities are urgently sought. Previous research suggests that surface structures in the range of bacterial cell sizes seem to be a promising approach to modulate bacterial adhesion and biofilm formation. Here we investigated bioadhesion within the oral cavity on a low surface energy material (perfluorpolyether) with different texture types (line-, hole-, pillar-like), feature sizes in a range from 0.7–4.5 µm and graded distances (0.7–130.5 µm). As a model system, the materials were fixed on splints and exposed to the oral cavity. We analyzed the enzymatic activity of amylase and lysozyme, pellicle formation, and bacterial colonization after 8 h intraoral exposure. In opposite to in vitro experiments, these in situ experiments revealed no clear signs of altered bacterial surface colonization regarding structure dimensions and texture types compared to unstructured substrates or natural enamel. In part, there seemed to be a decreasing trend of adherent cells with increasing periodicities and structure sizes, but this pattern was weak and irregular. Pellicle formation took place on all substrates in an unaltered manner. However, pellicle formation was most pronounced within recessed areas thereby partially masking the three-dimensional character of the surfaces. As the natural pellicle layer is obviously the most dominant prerequisite for bacterial adhesion, colonization in the oral environment cannot be easily controlled by structural means.     

Anodic chlorate formation on platinized titanium

The mechanism of anodic chlorate formation on platinized titanium was studied under well-controlled forced-convection conditions identical to those of previous experiments with graphite. Experimental results obtained in 4m NaCl and in 0·05m NaCl were compared to those predicted by mass transfer models describing anodic chlorate formation on graphite. In concentrated NaCl solution anodic chlorate formation rates for both electrode materials are smaller than expected for a diffusion controlled process. In dilute NaCl the ratio between measured rates and those predicted for diffusion control is shifted to higher values in qualitative agreement with predictions. Quantitative differences observed between the two electrode materials were attributed to the fact that hypochlorite oxidation on platinized titanium did not proceed at limiting current because of the slowness of the heterogeneous oxidation reaction.     

Cl2 Adsorption and Desorption over Ordered Mesoporous Carbon Materials as an Indicator for Catalytic Phosgene Formation

The presented work evaluates the implementation of adsorption and desorption experiments with Cl₂ over carbon materials towards the development of more active and stable catalysts for industrial phosgene synthesis. By using a soft templating method as a tool, ordered mesoporous carbon materials with tunable porosity, surface area, and degree of graphitization were synthesized and utilized as model system. The Cl₂ adsorption/desorption properties of these materials were studied and compared to commercial activated carbon. To draw correlations between Cl₂ adsorption/desorption behavior and catalytic performance, the materials were further tested in the phosgene formation in a plug flow reactor. However, the chemical reaction of Cl₂ with carbon during the adsorption/desorption experiment hinders a direct correlation.     

有机相变乳液中HCFC–141b水合物生成及稳定性

为了促进水合物形成，在HCFC–141b、有机相变材料（正癸酸和十二醇）和水体系中添加表面活性剂Tween 80和Span 80作为乳化剂，采用高速搅拌的方法制备了有机相变材料-表面活性剂-制冷剂-水乳液体系，增大水分子与制冷剂的接触面积。实验研究了静态条件下有机相变材料和表面活性剂添加量对水合物形成的影响。研究结果表明添加乳化剂可以有效提高水合物的蓄冷量，减少水合物形成诱导时间，降低水合物生成的随机性；温度越低，水合物促进效果越好。水合物生成/分解循环实验表明，添加Tween 80的乳液体系的稳定性好，有机相变乳液提高了水合物生成/分解循环过程的稳定性。     

以双子表面活性剂模板合成 碳酸钙-环糊精复合材料*

以阳离子双子表面活性剂溴化N,N,N’,N’-四甲基-N,N’-双十二烷基-1,6-己二铵（12-6-12）与阴离子表面活性剂十二烷基硫酸钠（SDS）混合系统,以及12-6-12/正丁醇/正辛烷/水微乳系统为模板,利用碳酸化法合成了具有贝壳珍珠层“砖-泥”结构碳酸钙-环糊精仿生复合材料。以X射线衍射（XRD）、红外光谱（IR）、透射电 镜（TEM）表征产品的组成与形貌。讨论了模板尺寸、电性与复合材料形貌的关系。提出了“砖-泥”式层状结构生成机制。     

Compatibilization of polysulfone/polyamide-blends by reactive polysulfones – evidence for copolymer formation

In order to compatibilize polysulfone/polyamide-blends by reactive blending melt blending studies using polysulfones with different functional groups (carboxyl-, anhydride) and polyamide were performed in a batch-type mixer. The obtained materials were investigated by solvent extraction and transmission electron microscopy. Model experiments reveal the possibility to compatibilize polysulfone/polyamide-blends by reactive blending techniques using functionalized polysulfones. Extraction studies as well as the morphologies of the prepared samples give evidence for a copolymer formation during the melt blending experiments. Received: 13 November 1997/Revised version: 26 November 1997/Accepted: 27 November 1997     

表面印迹耦合溶胶-凝胶法制备4-硝基酚印迹材料及性能表征

采用表面印迹和溶胶?凝胶相结合的方法,以4-硝基酚(4-NP)为模板分子、α-甲基丙烯酸(α-MAA)为功能单体、三羟甲基丙烷三甲基丙烯酸酯(TRIM)为交联剂、偶氮二异丁腈(AIBN)为引发剂,制备可选择性识别吸附去除水中4-NP污染物的印迹吸附材料,考察了4-NP与α-MAA和4-NP与TRIM摩尔比、致孔剂种类、提取液种类对所制材料吸附性能的影响,并通过正交实验优化材料制备条件,用扫描电子显微镜、傅立叶红外光谱仪、比表面积分析仪、热重?差热分析仪和纳米粒度仪等设备对最优条件下合成的材料进行了表征。结果表明,4-NP:α-MAA摩尔比为1:8,4-NP:TRIM摩尔比为1:10,致孔剂为乙醇,提取液为甲醇/乙酸(7:3,体积比)时所制印迹材料对4-NP的去除效果最佳,达6.23 μmol/g;4-NP成功印记在硅胶表面,印迹材料能特异性吸附4-NP。     

PVA/PAA-Based Antibacterial Wound Dressing Material with Aloe Vera

The incorporation of drugs into the dressings make these dressings antimicrobial and help in control of infection around the wound. The wound dressing materials based on PVA/PAA, ciprofloxacin HCl, and aloe vera have been designed and developed so that the wound undergoes proper healing and scar formation is minimal. These wound dressing materials are produced using the electrospinning method. The wound dressing materials are characterized using the FT-IR, DSC, DTA, TGA, and SEM techniques. The wound dressing materials are tested for microbial activity tests and drug release experiments. Controlled ciprofloxacin HCl release is observed.     

多孔材料中甲烷水合物生成的传热数值模拟研究

水合物储运(NGH)是近几年发展起来的天然气储运技术,已具备实现工业化的潜力。但水合物的生长是传质传热控制的反应,因此在放大实验中存在诸多不确定因素。针对该问题,对水合物反应器中多孔材料内甲烷水合物生成传热过程建立了基于化学反应动力学和多孔材料内传质传热的甲烷水合物生成传热数学模型,可用于计算反应器内水合物生成分布和热量分布,指导水合反应器的设计和优化。通过模拟与实验数据对比验证了该模型的可靠性,并对使用了不同热导率填料的水合反应过程进行数值模拟。结果显示,模拟值与实验值的绝对平均相对误差小于6%,生成传热模型准确性高;在水合反应过程中,热量传递是影响水合物生成速率的关键因素之一。导热不良时,易在水合物生成中心部分形成局部过热,对水合物生长造成热抑制。在进行水合物生成放大实验时,应特别注意反应器内部的热量控制。