Rapid Generation and Control of Microporosity, Bimodal Pore Size Distribution, and Surface Area in Davankov-Type Hyper-Cross-Linked Resins

Abstract

Synthesis of Davankov-type hyper-cross-linked resin beads has been carried out using gel-type and permanently porous poly(divinylbenzene-co-vinylbenzyl chloride) (DVB-VBC) precursor resins without any external electrophile. Of the Lewis acids examined (FeCl 3 , AlCl 3 , SnCl 4 ), FeCl 3 was by far the most effective catalyst. Rather remarkably in the case of a gel-type 2 mol % DVB-VBC precursor, extensive microporosity was generated within only 15 min of initiating the cross-linking reaction, yielding a surface area (N 2 sorption/ BET) of ∼1200 m 2 g -1 , which rose steadily to a maximum approaching 2000 m 2 g -1 after 18 h. In the case of porous DVB-VBC precursor resins, the presence of discrete pores in the precursor, accompanied by a micropore fraction on hyper-cross-linking, yields resins with a clearly bimodal distribution of pores. Manipulation of the Friedel-Crafts reaction variables and the structure of the precursor resin allows final resin products to be prepared with surface areas in the range ∼300-2000 m 2 g -1 .

Phosphate removal and recovery from water using nanocomposite of immobilized magnetite nanoparticles on cationic polymer

“…These results agree with the gel-type resins in the dry state that are characterized by very low porosity and a far lower surface area, which usually does not exceed 5 m 2 /g (N2 sorption, BET) [93].…”

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…The first stage can be any heterogeneous polymerization such as emulsion [97], suspension [98] or precipitation polymerization [99] while the second stage involves the FriedelCrafts hypercrosslinking where the seeds are simply swollen in dichloroethane and heated in the presence of FeCl 3 . These hypercrosslinked resins are commercially available from various manufacturers [94] because of their high surface area values reaching up to 2000 m 2 /g [100], resulting in very different sorption characteristics [101]. In the case of emulsion polymerized seeds [97], monodisperse beads as small as ∼500 nm with a surface area of 1200 m 2 /g are successfully prepared, which has never been achieved via another approach to the best of our knowledge.…”

Functional Porous Polymers by Emulsion Templating: Recent Advances

“…[ 84 ] Hypercrosslinking is a technique in which a polymer is swollen in a 'good' solvent, then the polymer is crosslinked, whereby on the removal of the solvent the swollen state of the polymer remains, forming a secondary pore structure [ 85 ] and resulting in high surface areas of up to 2000 m 2 g − 1 (measured by N 2 adsorption). [ 86 ] VBC-based polyHIPEs were hypercrosslinked via the Davankov method, [ 87 ] which involves the Friedel-Crafts crosslinking of benzyl chloride groups which results in the formation of methylene bridges between aromatic rings. These polyHIPEs have been investigated as support materials for catalysts [ 84 b] and could potentially be used for the purifi cation of water supplies, [ 88 ] as a sorbent for solid phase extraction, [ 89 ] or as a column for high performance liquid chromatography (HPLC), [ 90 ] utilizing both the macroporous structure of the polyHIPE, allowing for high permeability of liquids through the foam, and the microporous substructure which imparts the high surface contact that is desirable for the adsorption of molecules.…”

“…Other physisorption materials with high surface areas (up to ≈ 2000 m 2 g − 1 ) include hypercrosslinked polymers. [ 86 ] St and VBC hypercrosslinked polyHIPEs have been investigated as potential hydrogen storage materials. A surface area of ca.…”