Mesostructure in Cat-anionic Surfactant-Polymer Films

这项提议是为了旅行，在悉尼ANSTO的Opal反应堆上的新仪器Platypus上进行使用中子反射率的实验。对于开放的液体表面样品，很难获得中子反射率波束时间，这是因为世界上配置为以这种几何形式采集样品的仪器数量很少，而且这项技术很受欢迎，这意味着现有仪器普遍超额认购。我们已经成功地在一个竞争性的同行评议的提案方案中获得了2天的波束时间，关于这个全新的仪器，现在申请旅行资金去悉尼进行这个实验。这项工作继续着我们对聚电解质-表面活性剂溶液的研究，这些溶液通过在EPSRC资助的EP/E029914/1资助下在空气-溶液界面上吸附形成固体膜。我们最初的研究集中在聚乙烯亚胺-阳离子表面活性剂体系，但我们现在发现，在存在水溶性聚合物的情况下，成膜是含有阳离子和阴离子表面活性剂混合聚集体的溶液的一般特征。这使得生物相容聚合物的使用成为可能，这意味着这些薄膜可以用于治疗药物的封闭化，用于受控给药应用，例如在伤口敷料中。在这个中子反射率实验中，我们将利用对比度变化来确定每种表面活性剂在含有CTAB和十二烷基硫酸钠的聚氧化乙烯或聚丙烯酰胺薄膜的细观结构中的比例。我们将考察几种不同的表面活性剂和聚合物总浓度对五种CTAB：十二烷基硫酸钠比例的影响，以研究其对体系结构形成的影响。在悉尼期间，我们还应邀访问了悉尼大学化学学院的Greg Warr教授，举办了一个研讨会，并观察了一种改装的小角X射线散射仪，类似于Edler博士在巴斯实验室的仪器，以期对Bath仪器实施这一改进。

This proposal is for travel to undertake experiments using neutron reflectivity on the new instrument Platypus on the OPAL reactor at ANSTO in Sydney. It is difficult to obtain neutron reflectivity beamtime for open liquid surface samples due to the small number of instruments world-wide which are configured to take samples in this geometry and the popularity of this technique which means existing instruments are generally oversubscribed. We have succeeded in obtaining 2 days of beamtime in a competitive peer reviewed proposal scheme, on this brand new instrument, and now request travel funding to go to Sydney to carry out this experiment. The work continues our investigations into polyelectrolyte-surfactant solutions which form solid films by adsorption at the air-solution interface funded under EPSRC grant EP/E029914/1. Our initial investigations focused on the polyethylenimine-cationic surfactant system but we have now found that film formation is a general feature of solutions containing mixed aggregates of a cationic and an anionic surfactant in the presence of water soluble polymers. This enables use of biocompatible polymers which mean these films may be able to be used in enacapsulation of therapeutics for controlled delivery applications for instance in wound dressings. In this neutron reflectivity experiment we will make use of contrast variation in order to determine the proportion of each surfactant in the mesostructures of films containing CTAB and SDS with polyethylene oxide or polyacrylamide. We will investigate several different total surfactant and polymer concentrations for five CTAB:SDS ratios to study the effects on structures formed in this system. While in Sydney we have also been invited to visit Prof Greg Warr at the School of Chemistry, Sydney University to give a seminar and to observe a modified small angle X-ray scattering instrument similar to an instrument in Dr Edler's lab in Bath, with a view to implementing this modification on the Bath instrument.