State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, P. R. China.
J Mater Chem B. 2022 May 11;10(18):3434-3443. doi: 10.1039/d2tb00329e.
A conductive hydrogel P(AAm--AA)/CS-Fe with double cross-linked networks was fabricated using a one-step polymerization by UV irradiation and a soaking process in Fe(NO) solution. In this hydrogel, the rigid chain of chitosan (CS) and the soft chain of copolymer P(AAm--AA) with acrylic acid (AA) and acrylamide (AAm) act as the backbone, among which large amounts of hydrogen bonds are formed by the amino, hydroxyl, and carboxyl groups on the two polymers. Ferric irons (Fe) are introduced and form coordination interactions with carboxyl and amino groups of the polymers. The double cross-linked interactions in the system can enhance the tensile strength and toughness of the hydrogel. Thus, the prepared P(AAm--AA)/CS-Fe hybrid network hydrogel shows excellent mechanical properties in many aspects: a strength of up to 550 kPa, a broad strain-range up to 800%, fast self-recovery ability (30 min), and low hysteresis strain (<100%). The conductive hydrogel demonstrates high strain sensitivity (gauge factor (GF) = 6.6 at a strain of 700%) as a flexible sensor. Human movements (for example, finger bending, vocal cord vibration, and other human activities) can be sensitively detected using the P(AAm--AA)/CS-Fe hydrogel sensor.
采用一步紫外光辐照聚合法和 Fe(NO₃)₃溶液浸泡法制备了具有双交联网络的导电水凝胶 P(AAm--AA)/CS-Fe。在该水凝胶中，刚性链壳聚糖（CS）和具有丙烯酸（AA）和丙烯酰胺（AAm）的共聚物 P(AAm--AA)的软链作为主链，其中两种聚合物上的氨基、羟基和羧基形成大量氢键。铁离子（Fe）被引入并与聚合物的羧基和氨基形成配位相互作用。该体系中的双交联相互作用可以提高水凝胶的拉伸强度和韧性。因此，所制备的 P(AAm--AA)/CS-Fe 杂化网络水凝胶在多个方面表现出优异的机械性能：强度高达 550 kPa，应变范围宽达 800%，快速自恢复能力（30 分钟），滞后应变低（<100%）。该导电水凝胶作为一种柔性传感器具有较高的应变敏感性（应变 700%时的应变系数（GF）=6.6）。P(AAm--AA)/CS-Fe 水凝胶传感器可以灵敏地检测到人体运动（例如，手指弯曲、声带振动和其他人体活动）。
