Synthesis Of A Series Of Mesoporous Hypercrosslinked Polymeric Adsorbents And Their Absorption Behavior

The hypercrosslinked polymeric adsorbent has the widespread application in the water treatment field. The post-crosslinked technology of the pendant vinyl groups was employed in this research to overcome the defects of traditional synthesis methods, namely complicated procedures, the use of carcinogenic substances and small pore diameter. The influence of different porogenic agents, different mixing ration and mixed poregens, was analyzed by investigating the adsorption behavior ofp-nitrophenol, RB-4 and other organic matters with varied molecular sizes.All the synthesized hypercrosslinked polymeric adsorbent exhibits high surface area (upwards 1000m2/g), fewer surface and volume of micropore and abundant distribution in mesopores. Surface area of synthesized resin could reach 1200m2/g, which is larger than that of commercial NDA150, when the ratio of monomer to porogenic agent was 1:2 and the ratio of toluene to other porogenic agents was 17:3.Adsorption dynamic showed that the significant difference in the adsorption rate of p-nitrophenol and RB-4 on synthesized hypercrosslinked polymeric adsorbent. The diffusion of p-nitrophenol was faster while the adsorption of RB-4 was slow due to its frequent collision with pore canal. The adsorption of p-nitrophenol well fitted pseudo-second-order dynamics while the first half adsorption of RB-4 followed pseudo-second-order dynamics and the latter half fitted pseudo-first-order dynamics. Thermodynamic experiments proved that the adsorption capacity of p-nitrophenol was relatively higher on resin with higher surface area and micropore area and the adsorbance of RB-4 was relatively higher on resin with abundant distribution in mesopores. All adsorption isotherm could be described by Freundlish model.The micropore area of synthesized H-1 is between XAD-4, a commercial macropore resin and NDA150, a hypercrosslinked polymeric adsorbent, and the micropore area determines the adsorption process of the p-nitrophenol, the adsorption capacity of p-nitrophenol on synthesized resins was higher than that on XAD-4 but relatively lower than that on NDA-150. Since H-1 possesses more suitable pore structure and mesoporosity, it showed better performance in the adsorption of RB-4.