细菌纤维素-聚丙烯酰胺水凝胶介观结构各向异性的自旋回波小角中子散射研究
Mesostructure anisotropy of bacterial cellulose-polyacrylamide hydrogels as studied by spin-echo small-angle neutron scattering
摘要：
用自旋回波小角中子散射（SESANS）研究了细菌纤维素（BC）和聚丙烯酰胺复合水凝胶的亚微米和微米尺度结构。这些水凝胶是通过丙烯酰胺的自由基聚合在BC膜中溶胀的反应溶液中进行的。在重水中溶胀到平衡态的样品没有观察到中子散射，但是当TbCl $_{3}$盐加入到溶剂中时出现SESANS信号。这些样品的SESANS依赖性揭示了所研究的水凝胶的介观结构的各向异性。在样品的一个特定方向上检测到11.5 $\pm$ 0.5 $μ$ m的特征尺度上的密度不均匀性，即BC的生长平面平行于由中子束和自旋回波长度形成的平面。所揭示的单轴各向异性与所提出的模型一致，该模型将这种行为归因于BC内部隧道状取向结构的存在。
英文摘要：
The submicron- and micron-scale structures of composite hydrogels based on bacterial cellulose (BC) and polyacrylamide were studied by spin-echo small-angle neutron scattering (SESANS). These hydrogels were synthesized via free-radical polymerization of acrylamide carried out in pellicle of BC swollen in the reaction solution. No neutron scattering was observed for the samples swollen in heavy water to the equilibrium state, but a SESANS signal appeared when TbCl$_{3}$ salt was added to the solvent. The SESANS dependences obtained for these samples revealed the anisotropy of mesostructure for the hydrogels under investigation. Density inhomogeneities on the characteristic scale of 11.5 $\pm$ 0.5 $μ$m were detected in one specific orientation of the sample, i.e. with growth plane of BC parallel to plane formed by neutron beam and spin-echo length. The uniaxial anisotropy revealed agrees with the proposed model, which attributes this behavior to the existence of the tunnel-like oriented structures inside BC.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
