【摘要】 文章采用N,N-双(丙烯酰)胱胺(BACA)修饰银纳米线(AgNWs)作为多功能大分子交联剂和导电填料，以丙烯酸钠为离子型可聚合单体，重力场作用诱导多功能大分子交联剂组装形成质量浓度梯度，在催化剂和热引发条件下发生自由基聚合反应，制备基于质量浓度梯度的高度各向异性纳米复合水凝胶。通过扫描电子显微镜(scanning electron microscope, SEM)、透射电子显微镜(transmission electron microscope, TEM)、万能材料测试仪、电化学工作站、红外热像仪等对所制备的纳米复合水凝胶进行表征，结果表明，该纳米复合水凝胶网络密度自上而下逐级提高，表现出高度各向异性的机械、电学、光热等行为。通过对其相关性能的检测，结果表明，该纳米复合水凝胶可以快速地在水条件和近红外辐照下发生不对称形状变化，在柔性智能驱动领域有着广阔的应用前景。更多还原

【Abstract】 A gradient nanocomposite hydrogel was successfully fabricated via a free radical polymerization under catalyst and thermal initiation conditions by using N,N-bis(acryloyl)cystamine(BACA)-modified silver nanowires(AgNWs) as the multifunctional crosslinkers and conductive fillers. Under the effect of gravity, the concentration of BACA-modified AgNWs was assembled into gradient distribution and sodium acrylate was used as ionic polymerizable monomer in this system. Scanning electron microscope(SEM), transmission electron microscope(TEM), tensile machine, electrochemical workstation and infrared thermal imaging were used to investigate the performance of the gradient nanocomposite hydrogel. The results show that the density of network increases from top to bottom and the nanocomposite hydrogel exhibits highly anisotropic mechanical, electrical, and photothermal performances. As demonstrations of related mechanical performance, the nanocomposite hydrogel can quickly change its shape asymmetrically in water and under near infrared irradiation, which provides a new insight into flexible smart actuator for this kind of hydrogel.更多还原