中文摘要：

利用3D成型技术,通过先成型后冷冻交联2步法制备不同孔隙率的SiO_2/聚乙烯醇（PVA）水凝胶支架,研究了SiO_2/PVA水凝胶支架的重复摩擦行为,分析了SiO_2/PVA水凝胶支架的摩擦原理。结果表明：SiO_2/PVA水凝胶支架能够保持三维贯通的立体结构,最大孔隙率可达42.3%。低摩擦速率（10-6~10-3 m/s）下,SiO_2/PVA水凝胶支架摩擦力稍高于块体SiO_2/PVA水凝胶,且随孔隙率的提高而稍有降低;而高摩擦速率（10-2~1m/s）下,SiO_2/PVA水凝胶支架和块体SiO_2/PVA水凝胶的摩擦力相近,孔隙率对支架摩擦力影响不明显。低正压力载荷（0.3kPa）下,SiO_2/PVA水凝胶支架重复摩擦性优于块体SiO_2/PVA水凝胶,这与支架结构能保持稳定的水润滑层相关。

英文摘要：

SiO_2/polyvinyl alcohol（PVA）hydrogel scaffold with different porosities was prepared by two-step method of pre forming and post freezing cross-linking using 3Dprinting technology.The reproducible friction behaviors of SiO_2/PVA hydrogel scaffold was researched and the friction principle of SiO_2/PVA hydrogel scaffold was analyzed.The results show that SiO_2/PVA hydrogel scaffold can keep a three dimensional through structure with maximum porosity of 42.3%.At low friction velocity（10-6-10-3 m/s）,the frictional force of SiO_2/PVA hydrogel scaffold is slightly higher than that of bulk SiO_2/PVA hydrogel and decreases slightly with the increase of porosity.At high friction velocity（10-2-1m/s）,the frictional force of SiO_2/PVA hydrogel scaffold is equal to that of bulk SiO_2/PVA hydrogel and the effect of porosity on the frictional force for scaffold is not obvious.At small normal pressure load（0.3kPa）,SiO_2/PVA hydrogel scaffold shows better reproducible friction property than bulk SiO_2/PVA hydrogel.It is related to the structure of the scaffold which can keep a stable hydrated lubrication layer.