Amato Dahlia N, Amato Douglas V, Sandoz Michael, Weigand Jeremy, Patton Derek L, Visser Claas Willem
School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States.
Engineering Fluid Dynamics Group, Thermal and Fluid Engineering Department, Faculty of Engineering Technology, University of Twente, Drienerlolaan 5, 7500AE Enschede, The Netherlands.
ACS Appl Mater Interfaces. 2020 Sep 16;12(37):42048-42055. doi: 10.1021/acsami.0c07945. Epub 2020 Sep 6.
Fabrication of macroporous polymers with functionally graded architecture or chemistry bears transformative potential in acoustic damping, energy storage materials, flexible electronics, and filtration but is hardly reachable with current processes. Here, we introduce thiol-ene chemistries in direct bubble writing, a recent technique for additive manufacturing of foams with locally controlled cell size, density, and macroscopic shape. Surfactant-free and solvent-free graded three-dimensional (3D) foams without drying-induced shrinkage were fabricated by direct bubble writing at an unparalleled ink viscosity of 410 cP (40 times higher than previous formulations). Functionalities including shape memory, high glass transition temperatures (>25 °C), and chemical gradients were demonstrated. These results extend direct bubble writing from aqueous inks to nonaqueous formulations at high liquid flow rates (3 mL min). Altogether, direct bubble writing with thiol-ene inks promises rapid one-step fabrication of functional materials with locally controlled gradients in the chemical, mechanical, and architectural domains.
制造具有功能梯度结构或化学性质的大孔聚合物在声阻尼、储能材料、柔性电子学和过滤领域具有变革潜力，但目前的工艺很难实现。在此，我们在直接气泡写入中引入硫醇-烯化学，这是一种用于增材制造泡沫的最新技术，可实现局部控制泡孔尺寸、密度和宏观形状。通过直接气泡写入，在无与伦比的410 cP墨水粘度（比以前的配方高40倍）下制备了无表面活性剂和无溶剂的梯度三维（3D）泡沫，且无干燥引起的收缩。展示了包括形状记忆、高玻璃化转变温度（>25°C）和化学梯度在内的功能。这些结果将直接气泡写入从水性墨水扩展到了高液体流速（3 mL min）下的非水性配方。总之，使用硫醇-烯墨水进行直接气泡写入有望快速一步制造出在化学、机械和结构领域具有局部可控梯度的功能材料。
