An approach to transforming amorphous organic networks into crystalline covalent organic frameworks (COFs) with retention of the colloidal nanosize and uniform morphology is presented. Specifically, Fe O nanoclusters are encapsulated by a disordering polyimine network via the Schiff-base reaction. The formed imine bonds could be reconstructed under thermodynamic control to reform the polyimine networks into imine-linked COFs in situ. Such a core-shell microsphere exhibits the uniform size and spherical shape, controllable COF shell thickness, accessible surface modification, and improved solution dispersibility as well as maintenance of high surface area, periodic micropores, and superior magnetic responsiveness. Additionally, the photothermal conversion effect is demonstrated for the first time on the nanoCOF layers upon exposure to near infrared light, providing convincing evidence for potential use in phototherapy.

Guest-dependent dynamics having both crystal contraction and expansion upon inclusion of various guests is uncovered in a 3D covalent organic framework (COF) prepared with a facile and scalable method. A molecular-level understanding of how the framework adjusts the node geometry and molecular configuration to perform significant contraction and large amplitude expansion are resolved through synchrotron in-house powder X-ray diffraction (PXRD) and Rietveld refinements. We found that the COF adopts a contracted phase at ambient conditions upon capturing moisture and is also adaptive upon inclusion of organic solvents, which is highlighted by a large crystal expansion (as large as 50% crystallographic volume increment and a 3-fold channel size enlargement). With this new knowledge of the structural adaptability, the diverse responses and coherent switchability are thereby presented to pave the way to rational design and deliberate control of dynamic COFs.

Mesoporous ZnO(-COO)-based metal-organic frameworks (MOFs), including UMCM-1, MOF-205, MUF-7a, and the newly synthesized MOFs, termed ST-1, ST-2, ST-3, and ST-4 (ST = ShanghaiTech University), have been systematically investigated for ultrahigh capacity methane storage. Exceptionally, ST-2 was found to have the highest deliverable capacity of 289 cm/cm (567 mg/g) at 298 K and 5-200 bar, which surpasses all previously reported records held by porous materials. We illustrate that the fine-tuned mesoporosity is critical in further improving the deliverable capacities at ultrahigh pressure.

An approach to transforming amorphous organic networks into crystalline covalent organic frameworks (COFs) with retention of the colloidal nanosize and uniform morphology is presented. Specifically,F e 3 O 4 nanoclusters are encapsulated by ad isordering polyimine network via the Schiff-base reaction. The formed imine bonds could be reconstructed under thermodynamic control to reform the polyimine networks into imine-linked COFs in situ. Suchacore-shell microsphere exhibits the uniform sizea nd spherical shape, controllable COF shell thickness,a ccessible surface modification, and improved solution dispersibility as well as maintenance of high surface area, periodic micropores,and superior magnetic responsiveness.A dditionally,t he photothermal conversion effect is demonstrated for the first time on the nanoCOF layers upon exposure to near infrared light, providing convincing evidence for potential use in phototherapy.Covalent organic frameworks (COFs) are two-or threedimensional crystalline porous polymers that originate from the topological polymerization of building blocks with predesigned geometry and symmetry by virtue of dynamic covalent bonds (e.g.i mine, [1] enamine, [2] hydrazine, [3] azine, [4] b-ketoenamine, [5] and boronate ester [6] ). This emerging family presents high and regular porosity,tunable pore size and pore wall chemistry,a nd structural predictability and stability. [7] These characteristics endow COFs with outstanding performances for aw ide-range of applications,s uch as gas storage, [8] heterogeneous catalysis, [9] luminescence, [10] optical sensing, [11] proton conduction, [12] and photoconduction. [13] Against this backdrop,t here has been significant interest very recently in the miniaturization of COFs to the nanometer scale, [14] for the sake of extending the applicability and enhancing the proper-ties of COFs.I ndeed, the nanoCOFs can overcome,t os ome extent, the poor solution properties of the corresponding bulk materials,and they have been developed into nanocarriers for biomedical applications,such as drug delivery [15] and enzyme immobilization. [14b] However,most of the materials described were not very compatible with biomedical and pharmaceutical applications,a nd, with few exceptions,t hey were not engineered as dispersible nanoparticles to enable in vivo circulation by intravenous administration. As far as is known, the COF assemblies are prepared with no way of controlling size and morphology under solvothermal conditions.

Utilizing fluorescence reporters and SERS probes as the security labels, a series of dual-mode encoded magnetic composite microspheres with micrometer size was designed and prepared for anticounterfeiting applications. At first, the micro-meter-sized melamine formaldehyde microspheres with different fluorescence molecules (FMF) were prepared by precipitation polymerization, and then the magnetite composite microspheres (FMF/MNPs) were fabricated by direct immobilization of magnetic nanoparticles (MNPs) onto the surface of FMF microspheres. After deposition of Ag nanoparticles (Ag-NPs) onto FMF/MNPs microspheres, the SERS probes were absorbed onto the surface of Ag-NPs, and then a protection layer of silica was coated on the composite microspheres by Stöber method. The combination of different fluorescence reporters and SERS probes greatly increased the encoding complexity and volume for high-level anticounterfeiting. The structure of the dual-encoded FMF/MNPs/Ag-NPs/SiO2 composite microspheres was characterized by FESEM, TEM, FLS(fluorescence spectrometer), XRD, VSM, UV-vis and EDS. The embedded magnetic nanoparticles enable the composite microspheres to be quickly isolated from the marked latex paint by magnet at the concentration of as low as 1 ppm, and the covert tag information can be read out even from one composite microsphere. In addition, the covert security information in the marked coating film can be also read out in situ and the existence of the composite microspheres does not influence the visible appearance of the coating film. All the above outstanding properties will make these dual-mode encoded composite microspheres as advanced security tags for next-generation anticounterfeiting applications.