Spontaneous Microalgae Dewatering Directed by Retrievable, Recyclable, and Reusable Nanoparticle-Pinched Polymer Brushes
Spontaneous Microalgae Dewatering Directed by Retrievable, Recyclable, and Reusable Nanoparticle-Pinched Polymer Brushes
复制标题
DOI：
10.1021/acs.chemmater.9b00336
复制
发表时间：
2019-07-09
影响因子：
8.6
通讯作者：
Liang, Hongjun
中科院分区：
文献类型：
--
作者：
Kuang, Liangju;Goins, Jason;Liang, Hongjun
选择性捕获和分离溶液携带的浮游细胞是从生物膜减轻、癌症诊断和水处理到微藻生物燃料的各种领域中普遍存在的挑战。微藻是碳中性生物燃料的有前途的原料，这将减轻我们对化石燃料的依赖，但目前的微藻脱水技术增加了最终产品的高昂成本。我们在这里报告了一个纳米颗粒捏聚合物刷（NPPB）的设计，将普通的聚合物絮凝剂转化为超凝结剂，通过模仿细菌外膜囊泡，促进细菌共聚集。重要的是，NPPB可通过具有成本效益的磁泳分离回收，在藻油提取和残余生物质去除后可回收，并可重复使用于重复操作循环，从而显著降低絮凝剂的无休止材料成本及其对下游工艺和环境的潜在污染。利用DLVO和自洽场理论分别模拟微藻的胶体稳定性和聚合物刷的动态响应，我们揭示了从传统的链状聚合物絮凝剂NPPBs在调节藻间对电位的根本转变。与仅诱导具有剂量敏感的絮凝解离平衡的缓慢微藻脱水的链状聚合物絮凝剂不同，NPPBs直接快速且不可逆的微藻絮凝。虽然NPPBs上的最小刷尺寸被预测为启动凝结，但是增加刷尺寸的益处迅速减弱，并且存在最佳刷尺寸，超过该最佳刷尺寸，凝结效率达到平台，这与我们的实验观察一致。我们预计，可回收、可回收和可重复使用的NPPB概念适用于在溶液中捕获广泛的活细胞。
Selective capture and separation of solution borne planktonic cells is a ubiquitous challenge in diverse fields ranging from biofilm mitigation, cancer diagnostics, and water treatment to microalgae biofuels. Microalgae are promising feedstocks for carbon-neutral biofuels that will alleviate our repentant dependency on fossil fuels, but current technologies for dewatering microalgae add a prohibitive cost to the final products. We report here a nanoparticle-pinched polymer brush (NPPB) design that transforms ordinary polymer flocculants into supercoagulants by mimicking bacterial outer membrane vesicles in promoting bacteria coaggregation. Importantly, the NPPBs are retrievable via cost-effective magnetophoretic separation, recyclable after algae oil extraction and residual biomass removal, and reusable for repeated cycles of operations that significantly reduces the endless material cost of flocculants and their potential contamination of downstream processes and the environment. Using DLVO and self-consistent field theory to model the colloidal stability of microalgae and the dynamic response of polymer brushes, respectively, we reveal a fundamental transition from conventional chain-like polymer flocculants to NPPBs in modulating the interalgae pair potentials. Unlike the chain-like polymer flocculants that only induce slow microalgae dewatering with dose-sensitive flocculation dissociation equilibria, NPPBs direct rapid and irreversible microalgae coagulation. Although a minimum brush size on the NPPBs is predicted to initiate the coagulation, the benefit of increasing brush size quickly wanes and there is an optimal brush size beyond which the coagulation efficiency plateaus, which is consistent with our experimental observations. We anticipate that the concept of retrievable, recyclable, and reusable NPPBs is adaptable for capturing a broad range of live cells in solution.