Empa, Swiss Federal Laboratories for Materials Science and Technology, Cellulose and Wood Materials Laboratory, 8600, Dübendorf, Switzerland.
Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-ray Analytics, 8600, Dübendorf, Switzerland.
Carbohydr Polym. 2021 May 1;259:117716. doi: 10.1016/j.carbpol.2021.117716. Epub 2021 Feb 1.
We report on a procedure for the preparation, printing and curing of antibacterial poly(N-isopropylacrylamide) nanocellulose-reinforced hydrogels. These composites present a highly anisotropic microstructure which allows to control and modulate the resulting mechanical properties. The incorporation of such nanoparticles enables us to modify both the strength and the humidity-dependent swelling direction of printed parts, offering a fourth-dimensional property to the resulting composite. Antibacterial properties of the hydrogels were obtained by incorporating the functionalized peptide ε-polylysine, modified with the addition of a methacrylate group to ensure UV-immobilization. We highlight the relevance of well-adapted viscoelastic properties of our material for 3D printing by direct ink writing of self-supporting complex structures reaching inclination angles of 45°. The addition of cellulose nanoparticles, the overall ink composition and the printing parameters strongly determine the resulting degree of orientation. The achieved control over the anisotropic swelling properties paves the way to complex three-dimensional structures with programmable actuation.
我们报告了一种制备、打印和固化抗菌聚（N-异丙基丙烯酰胺）纳米纤维素增强水凝胶的方法。这些复合材料具有各向异性的微观结构，可用于控制和调节所得的机械性能。纳米粒子的加入使我们能够改变打印部件的强度和湿度依赖性的溶胀方向，为所得的复合材料提供了第四维的特性。通过加入功能化的ε-聚赖氨酸，修饰时添加一个甲基丙烯酰基以确保光固化，从而获得水凝胶的抗菌性能。我们强调了我们的材料具有良好的粘弹性，可通过直接喷墨打印自支撑的复杂结构达到 45°的倾斜角度，从而实现 3D 打印的相关性。纤维素纳米粒子的添加、整体油墨成分和打印参数强烈决定了所得的各向异性溶胀程度。对各向异性溶胀性能的控制为具有可编程致动的复杂三维结构铺平了道路。
