Macroscale Conjugated Microporous Polymers: Controlling Versatile Functionalities Over Several Dimensions

Abstract

covalently bonded organic moieties. Because of their unique properties derived from their tunable porous structures and the multiple functional groups, which can be included in their backbones, POPs have been actively investigated for multiple applications including gas storage/separation, [2,3] catalysis, [4][5][6] optoelectronics, [7,8] sensing, [9][10][11] energy storage, and conversion. [12,13] Aside from their high specific surface areas, they furthermore show excellent chemical stability, light-weight and a versatile chemistry for modification and functionalization. POPs can be further classified into two categories based on their crystallinity. Crystalline POPs are usually summarized under the name covalent organic frameworks [14][15][16] (COFs). Amorphous POPs are further divided, based on their structure or construction principles into hyper-crosslinked polymers [17,18] (HCPs), polymers of intrinsic microporosity [19,20] (PIMs), porous aromatic frameworks [21,22] (PAFs), and others. Recent research has seen increasing interest on amorphous POPs, especially when their skeleton is π-conjugated. In these highly porous networks, π-conjugation is superimposed with meso-/microporosities, i.e., electron transport in the polymer backbone is accompanied by mass transport in the porous system, which enable many intriguing properties and applications, e.g., in energy storage and conversion, [23,24] or optoelectronics. [25,26] As such, the importance of π-conjugation in porous polymer networks has defined another emerging functional POP class-the conjugated microporous polymers (CMPs). As mentioned, such CMPs [27] are a unique class of POPs exhibiting extended π-conjugated structures and permanent nanopores (Table S1). Earlier, McKeown et al. [28] discussed an important concept of preparing robust nanoporous materials by the covalent binding of planar molecules via a rigid spirocyclic linker. In 2007, Cooper et al. [29] reported a highly cross-linked, microporous poly(arylene ethynylene)s network, thus the first microporous polymer network with distinct π-conjugation and introduced the term "conjugated microporous polymer (CMP)" for this class of materials. Since their discovery, CMPs chemistry has intrigued scientists across the globe and been promoted rapidly, resulting in a strong growth in publications over the last decade. For instance, Thomas et al. [30] reported a spirobifluorene-type CMP with stable interface and application potential in organic light emitting diodes Since discovered in 2007, conjugated microporous polymers (CMPs) have been developed for numerous applications including gas adsorption, sensing, organic and photoredox catalysis, energy storage, etc. While featuring abundant micropores, the structural rigidity derived from CMPs' stable π-conjugated skeleton leads to insolubility and thus poor processability, which severely limits their applicability, e.g., in CMP-based devices. Hence, the development of CMPs whose structure can not only be controlled on the micro-but also on the macroscale have...

Facile metal-free synthesis of pyrrolo[3,2-b]pyrrolyl-based conjugated microporous polymers for high-performance photocatalytic degradation of organic pollutants

“…62 In recent years, pyrrolo [3,2-b]pyrrole derivatives have attracted much interest because of their large two-photon absorption (2PA) cross-sections and high fluorescence quantum yields. [53][54][55][56][57][58][59][60][61][62][63][64][65] Because of their photophysical properties, pyrrolo [3,2-b]pyrroles have been used in various electronic devices, including transistors, solar cells, and electrochromic devices. [66][67][68] Moreover, the pyrrolo[3,2-b] pyrrole structure is believed to be the most effective electron donor among the known 10π-electron systems, including thieno[3,2-b]pyrrole and thieno [3,2-b]thiophene.…”

“…[54][55][56][57][58] Few metal-free reactions were employed to produce CMPS. [59][60][61] For example, pyridyl-based CMPs were prepared through a metal-free reaction between the aromatic ketones and aldehydes in the presence of nitrogen source ammonium acetate. 59 Therefore, the challenge remains to develop simple, inexpensive, and environmentally friendly syntheses of CMPs with acceptable functionalities and optoelectronic structures for the effective adsorption and photodegradation of organic dyes.…”

Recent Advancements in Microneedle Technology for Multifaceted Biomedical Applications

“…Several types of MNs are majorly categorized based on the fabrication method and applications of MNs [ 10 , 11 ]. Each type of MNs has its merit and pitfalls over others for drug delivery applications.…”

Application of Metal–Organic Framework in Diagnosis and Treatment of Diabetes

“…Based on the characteristics of the internal environment in diabetic wounds, in recent years, many porous materials and biodegradable polymers have received extensive attention and demonstrated important applications in wound repair. Compared with traditional inorganic polymers (mesoporous silica) [ 112 , 113 ], hollow polymeric nanosphere (HPN) [ 114 ], porous organic polymers [ 115 ] (covalent organic frameworks (COF) [ 116 , 117 ], hypercrosslinked polymers (HCP) [ 118 ], inherently microporous polymers (PIM) [ 119 ], porous aromatic frameworks (PAF) [ 120 ], conjugated microporous polymers (CMP) [ 121 ], and other biodegradable polymers (polypeptides) [ 122 , 123 ], MOF-based composites offer great opportunities for multifunctionalization by virtue of their unique organic–inorganic hybrid composite structures, ordered porous structures, and high biocompatibility [ 124 ]. When dealing with complex wounds, MOFs can achieve wound healing effects by releasing metal ions and loading drugs, including regulating the oxidative stress response, antibacterial effects, and promoting angiogenesis, collagen deposition, and re-epithelialization [ 125 , 126 , 127 ], by improving wound site infection and blood flow reperfusion to accelerate the wound healing process and restore normal skin function ( Table 2 ).…”