Yu Rongtai, Huang Xiaodan, Liu Yang, Kong Yueqi, Gu Zhengying, Yang Yang, Wang Yue, Ban Wenhuang, Song Hao, Yu Chengzhong
School of Materials Science and Engineering Jingdezhen Ceramic Institute Jingdezhen Jiangxi 333403 P. R. China.
Australian Institute for Bioengineering and Nanotechnology The University of Queensland Brisbane Queensland 4072 Australia.
Adv Sci (Weinh). 2020 May 19;7(13):2000393. doi: 10.1002/advs.202000393. eCollection 2020 Jul.
Hollow spheres are charming objects in nature. In this work, an unexpected deflation-inflation asymmetric growth (DIAG) strategy is reported, generating hollow nanoparticles with tailored concave geometry for interface catalysis. Starting from aminophenol-formaldehyde (APF) nanospheres where the interior crosslinking degree is low, fully deflated nanobowls are obtained after etching by acetone. Due to APF etching and repolymerization reactions occuring asymmetrically within a single particle, an autonomous inflation process is observed similar to a deflated basketball that inflates back to a "normal" ball, which is rare at the nanoscale. A nucleophilic addition reaction between acetone and APF is elucidated to explain the chemistry origin of the DIAG process. Interestingly, the deflated APF hollow spheres enable preferential immobilization of lipase in the concave domain, which facilitates the stabilization of Pickering emulsion droplets for enhanced enzymatic catalysis at the oil-water interface. The study provides new understandings in the designable synthesis of hollow nanoparticles and paves the way toward a wide range of applications of asymmetric architectures.
空心球体是自然界中迷人的物体。在这项工作中，报道了一种意想不到的放气-充气不对称生长（DIAG）策略，该策略可生成具有定制凹面几何形状的空心纳米颗粒用于界面催化。从内部交联度较低的氨基酚-甲醛（APF）纳米球开始，用丙酮蚀刻后可得到完全瘪缩的纳米碗。由于APF蚀刻和再聚合反应在单个颗粒内不对称发生，观察到一个自主充气过程，类似于一个瘪了的篮球重新充气变回“正常”的球，这在纳米尺度上是罕见的。阐明了丙酮与APF之间的亲核加成反应以解释DIAG过程的化学起源。有趣的是，瘪缩的APF空心球体能够使脂肪酶优先固定在凹面区域，这有助于稳定皮克林乳液滴，以增强油水界面处的酶催化作用。该研究为空心纳米颗粒的可设计合成提供了新的认识，并为不对称结构的广泛应用铺平了道路。
