He Sanfeng, Wang Hongliang, Zhang Cuizheng, Zhang Songwei, Yu Yi, Lee Yongjin, Li Tao
School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China . Email:
Chem Sci. 2018 Dec 12;10(6):1816-1822. doi: 10.1039/c8sc03520b. eCollection 2019 Feb 14.
We report a generalizable approach to construct MOF@polymer functional composites through surface-initiated atom transfer radical polymerization (SI-ATRP). Unlike conventional SI-ATRP that requires covalent pre-anchoring of the initiating group on substrate surfaces, in our approach, a rationally designed random copolymer (RCP) macroinitiator first self-assembles on MOF surfaces through inter-chain hydrogen bond crosslinking. Subsequent polymerization in the presence of a crosslinking monomer covalently threads these polymer chains into a robust network, physically confining the MOF particle inside the polymer shell. We demonstrated the universality of this approach by growing various polymers on five MOFs of different metals (Zr, Zn, Co, Al, and Cr) with complete control over shell thickness, functionality and layer sequence while still retaining the inherent porosity of the MOFs. Moreover, the wettability of UiO-66 can be continuously tuned from superhydrophilic to superhydrophobic simply through judicious monomer(s) selection. We also demonstrated that a 7 nm polystyrene shell can effectively shield UiO-66 particles against 1 M HSO and 1 M NaOH at elevated temperature, enabling their potential application in demanding chemical environments.
我们报道了一种通过表面引发原子转移自由基聚合(SI-ATRP)构建MOF@聚合物功能复合材料的通用方法。与传统的需要在底物表面共价预锚定引发基团的SI-ATRP不同,在我们的方法中,一种经过合理设计的无规共聚物(RCP)大分子引发剂首先通过链间氢键交联在MOF表面自组装。随后在交联单体存在下进行聚合,将这些聚合物链共价连接成一个坚固的网络,将MOF颗粒物理限制在聚合物壳内。我们通过在五种不同金属(Zr、Zn、Co、Al和Cr)的MOF上生长各种聚合物,证明了这种方法的通用性,同时完全控制壳厚度、功能和层序,同时仍保留MOF的固有孔隙率。此外,只需明智地选择单体,UiO-66的润湿性就可以从超亲水连续调节到超疏水。我们还证明,一个7纳米的聚苯乙烯壳可以在高温下有效地保护UiO-66颗粒免受1 M HSO和1 M NaOH的侵蚀,使其在苛刻的化学环境中具有潜在的应用价值。