Decoding the Morphological Diversity in Two Dimensional Crystalline Porous Polymers by Core Planarity Modulation

Abstract

The Crystalline Porous Polymeric materials (CPPs) also well known as Covalent Organic Frameworks (COFs) have concerned substantial research interest because of their extensive applications in molecular storage and separation, catalysis, sensing, opto-electronics etc. [1]. The overall properties and real time employments of such materials not only rely on the compositions but also their nano-scale morphology which plays an incredible role [2]. Therefore, an explicit understanding of the morphology-modulation with respect to their constituents is really demanding. This study accounted a detailed molecular level investigation on morphological evaluation in COFs emanates entirely from its primary building units. Here two new highly crystalline, permanently porous imine linked based COFs named 2,3-DhaTta (Surface area 1700 m2/g) and 2,3-DhaTab (Surface area 413 m2/g) was solvothermally synthesised by faintly varying linker core while retaining all other external factors unchanged. These COFs are found to self template into diverge morphologies including ribbons (2,3-DhaTta) and hollow spheres (2,3-DhaTab). Their mechanisms of formation have been thoroughly and systematically investigated where hollow sphere formation in this case was guided by inside out Ostwald Ripening phenomenon. Moreover, based on DFT (Density Functional Theory) study a significant correlation between stacking energy of two adjacent COF layers with their backbone planarity was established which was believed to be the predominant guiding factor for governing their crystallinity, porosity and morphological diversity evaluation [3].

Precision Construction of 2D Heteropore Covalent Organic Frameworks by a Multiple‐Linking‐Site Strategy

“…The SEM images show that the two COFs exist as spherical particles of different sizes, some of which are interconnected. [51][52][53] To the best of our knowledge, this is the first example of hollow spherical COFs having hierarchically porous shells. Interestingly, the SEM image of SIOC-COF-4 shows that the surfaces of the spheres are covered with flakes,w hich have never been observedi nt he morphologies of other COFs before.…”

Manipulation of Amorphous‐to‐Crystalline Transformation: Towards the Construction of Covalent Organic Framework Hybrid Microspheres with NIR Photothermal Conversion Ability

“…Specifically,F e 3 O 4 nanoclusters are encapsulated by ad isordering polyimine network via the Schiff-base reaction. [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. 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.…”

“…This emerging family presents high and regular porosity,tunable pore size and pore wall chemistry,a nd structural predictability and stability. [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. [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.…”

Equilibration of Imine‐Linked Polymers to Hexagonal Macrocycles Driven by Self‐Assembly

“…The product of this reaction, performed under identical reactionc onditions, exhibited as imilar GPC chromatogram ( Figure S4) and selectivity for the hexagonal structural by MALDI-MS ( Figure S5). [37][38][39] The long-range order of the aggregated macrocycles was characterized by in situ wide-angle X-ray scattering.A1-PDA macrocycle suspension in 1,4-dioxane providedd iffraction peaks consistent with ah exagonal packed arrangemento f macrocycles with P6 symmetry ( Figure 4A). These conditions delay the onset of macrocycle precipitation to approximately 35 min, providing more time to monitor the solution composition.…”