| The research and development of polymer biological materials has played an important role in the modern medicine progress. One key part of the study is the blood compatible polymer materials contacting with the human blood environment. Previous studies showed that, in accordance with the "bionic design" idea, the introduction of small molecular liquid crystal to polymer substrate produced polymer / LC composite materials, which demonstrated anti-clotting properties.At first liquid crystal CTGC was coupled to PMHS to prepare PMHS-CTGC, and the structure and performance of the product PMHS-CTGC were observed by Infrared Spectrum, Optical Polarization Microscopy. The results show that under certain condition, the active Si-H bond in PMHS fractured when coupling reaction occurred; the substitution degree of the reaction is 0.636. PMHS-CTGC can be observed the special colorful stripe texture of Cholesteric Liquid Crystal, behave as the thermotropic liquid crystal, and the existence of liquid crystal in 37℃.Then, the CTGC, PMHS-CTGC were blent with PU and PVC to prepare series composite membranes in SIPS method respectivly. The surface characteristics of various composite membrane, include the phase separation degree, LC domain shape, LC domain distribution, were observed through the Optical Polarization Microscopy, Scanning Electron Microscope and Atomic Force Microscope, when the relationships between all the results and the LC nature, LC content was discussed. The results tell us, liquid crystals exhibit circular shape and distribute uniformly, especially in PMHS-CTGC membranes; PMHS-CTGC molecules exist in the compound membranes as a band-like state, and such band-like structures form a network formation when the content of LC were enhanced; in PU/LC compound membranes, a better phase separation structure can be observed.Contact angle test result indicates that the addition of liquid crystal increase the hydrophilicity of materials, PMHS-CTGC has a bigger improvement. The polymer / LC composite membranes' BSA absorption properties were determined by Coomassie brilliant blue method. The study shows that: the structure modified composite membranes have enhanced absorption capacity of BSA, and the PU / PMHS-CTGC composite membranes have an outstanding BSA adsorption property. With the temperature increasing, the BSA absorption on composite membrane surface added due to the enhancement of the blending LC mobility. Finally, the measurement of haemolysis ratio, the erythrocyte morphology characterization, the dynamic blood clotting test and platelet adhesion test were employed to evaluate the blood compatibility of the composite membranes. The results revealed that the haemolysis ratio of composite membranes with different LC natures and contents are all less than 5%, in line with the requirements of biological material. And polymer / LC composite membrane can maintain a better morphology of erythrocyte adhered on the membrane surface. The antithrombogenicity of the polymer / PMHS-CTGC composite membranes have a more marked improvement. Compare to the one on pure polymer membrane, the platelets attached on composite membrane surface play more natural condition, and PU / PMHS-CTGC composite membranes own small platelet adhesion as well as slight platelet deformation.In short, different with the traditional CTGC, the new type liquid crystal compound PMHS-CTGC improve the anti-clotting properties of the polymer membranes in a greater degree, and make up some shortages of the blending LC for the composite membrane. |
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