Nanographitic coating enables hydrophobicity in lightweight and strong microarchitected carbon

Abstract

Metamaterials that are lightweight, stiff, strong, scalable and hydrophobic have been achieved separately through different materials and approaches, but achieving them in one material is an outstanding challenge. Here, stereolithography and pyrolysis are employed to create carbon microlattices with cubic topology and a strut width of 60–70 µm, with specific strength and stiffness of up to 468.62 MPa cm3 g−1 and 14.39 GPa cm3 g−1 at a density of 0.55 g cm−3, higher than existing microarchitected materials and approaching those of the strongest truss nanolattices. Subsequent fast Joule-heating then introduces a hierarchical nanographitic skin that enables hydrophobicity, with a water contact angle of 135 ± 2°, improving the hydrophilic response of pyrolytic carbon. As the Joule heating induced sp2-hybridization and nano-texturing predominantly affect the strut sheath, the effect on mechanical response is limited to a reduction in the distribution of compressive strength of as-pyrolyzed architectures by ~80% and the increase of the mean effective stiffness by ~15%. These findings demonstrate a technique to fabricate high strength, low density, and hydrophobic nanographite-coated carbon microlattices.

Macro‐ and Nano‐Porous 3D‐Hierarchical Carbon Lattices for Extraordinarily High Capacitance Supercapacitors

“…[32,34] Although stereolithography mainly works with photocurable resin and has a poor selection of printable materials, printed resin samples can be converted to microarchitected solid carbons by pyrolysis, opening up a pathway of alternative 3D printing of carbon. This emerging class of 3D-printed carbon materials so-called carbon microlattices can lead to innovations in structural, [35,36] energy, [37] biomedical, [38] and other fields of engineering.…”

Macroscale Fabrication of Lightweight and Strong Porous Carbon Foams through Template‐Coating Pair Design

“…[22][23][24][25][26] For high-strength applications specifically, pyrolytic carbon is an attractive material as it can be made porous to minimize density and precisely architected at the micron scale to adopt lattice topologies (microlattices) to maximize strength. [27][28][29][30][31][32] Researchers have primarily looked at the two-step fabrication of pyrolytic carbon microlattices.…”

Fabrication and Application of Nano-copper Superwetting Fabric Coating: A Chemical Science Popularization Experiment

“…性质，它在很大程度上取决于表面的物理结构和化学成分。自然界中常见的"出淤泥而不染"的荷 叶、可在沙漠中集水的纳米布沙漠甲虫，正是由于其具有超浸润特性的表面 [3,4] 。基于这类自然结 构，科学工作者开发了一系列具有特殊浸润特性的智能界面，例如超疏水玻璃、超浸润油水分离膜 等 [5][6][7][8][9] 。通过调控界面成分，还可以构建其他亲疏水性的表面，例如油下超疏水、水下超疏油表面 等 [10][11][12] 。 图1 亲/疏水表面接触角示意图与疏水性示意图 (a) 亲水性表面；(b) 疏水性表面；(c) 微纳结构表面的凸起和水滴附着在表面形成气室产生疏水性示意图 在电镜下观察，发现这类表面大多具有密集的纳米级凸起形成的微纳结构，暴露在空气中时会 在这些结构中形成小气室 [13] (如图1c所示)。当表面滴加水时，水在表面张力的作用下倾向于形成球 形，而水滴的直径(毫米级)远大于这些小气室的直径(微米甚至纳米级)，因此水滴并不能进入气室， 于是无法润湿表面，表面显示疏水性 [14] [9] 。 3.5 油水分离实验 本实验所制备的超疏水和超亲水材料其独特的性能使其在防污、油水分离等各个领域具有广阔 的应用前景 [15,16]…”