Highly Branched Pillar[5]arene-Derived Porous Aromatic Frameworks (PAFs) for Removal of Organic Pollutants from Water

Abstract

The adsorption process is widely used for the treatment of wastewater containing organic pollutants. We fabricated highly branched pillar [5]arene-based porous aromatic frameworks (PAFs), PAF-P5, for the adsorption and removal of organic pollutants (short-chain alkyl derivatives 1−3 and pesticide molecules 4−6) from water with high removal efficiency (RE). However, PAF-P5 was incapable of adsorbing aromatic organic dyes 7−9. Adsorption kinetic studies indicated that the adsorption is mainly driven by strong host−guest interactions between 1−3 and the pillar[5]arene units in PAF-P5, while 4−6 only weakly interacted with the pillar[5]arene units in PAF-P5. Moreover, chemically breaking down the pillar[5]arene rings in PAF-P5 caused changes in the pore size, the microenvironment inside of the pores, and the frame morphology, and the resultant frameworks, PAF-DeP5, exhibited poor adsorption toward 1−6 but adsorbed 7−9 possibly through physical adsorption as implied by fitting the experimental data into the adsorption kinetic models.

Organic pollutants in water-soluble cavitands and capsules: contortions of molecules in nanospace

“…2,3 In this context, novel strategies based on supramolecular host-guest recognition have attracted increased attention in recent years. [4][5][6][7] Some supramolecular hosts that function in watercyclodextrins, [8][9][10][11][12] calixarenes, 13,14 calix [4]pyrroles 15 and pillararenes [16][17][18][19] have been used for scavenging organic micropollutants by attaching them to insoluble covalent polymer networks. These show promising results in terms of efficiency and binding selectivity.…”

Porous organic polymers for drug delivery: hierarchical pore structures, variable morphologies, and biological properties

“…POPs have low mass as they are mainly composed of light elements (C, H, O, and N). 24 Based on the differences in their synthetic methods and structures, POPs can be divided into covalent organic frameworks (COFs), 25,26 hypercrosslinked polymers (HCPs), 27,28 polymers of intrinsic microporosity (PIMs), 29,30 porous aromatic frameworks (PAFs), 31,32 and conjugated microporous polymers (CMPs). 33,34 HCPs, PIMs, PAFs, and CMPs are amorphous, whereas COFs are highly crystalline.…”

Pillar[5]arene-Integrated Three-Dimensional Framework Polymers for Macrocycle-Induced Size-Selective Catalysis

“…Porous organic polymers (POPs) have emerged as an important candidate for heterogeneous catalysis by virtue of their mild preparation method, high surface-to-mass ratio, excellent chemical/thermal stability, and facile structural modification . However, due to the irreversibility of the polymerization, resulting in irregular internal pore structures, POPs are rarely used for size-selective catalysis. , In recent years, the introduction of pillar­[n]­arenes into POPs has become a new platform for gas adsorption and separation, − water treatment, − fluorescence sensing, and heterogeneous catalysis. − We envision that integrating pillar[5]­arene with defined cavity into POPs may help achieve size-selective catalysis, for the reason that only substrates with appropriate sizes are able to approach the catalytic center. To achieve this goal, we introduce a series of three-dimensional (3D) linkers to cross-link pillar[5]­arene building blocks.…”