Preparation And Properties Of Acrylic Ester Cryogel

Cryogel is a kind of polymer prepared under low temperature freezing condition which has interconnected supermacropores with the size of several micrometers to several hundred micrometers.It is often used to directly process complex biological liquid containing solid particles because of its unique macroporous structure,which makes it have a good application prospect in the separation and purification of biological macromolecules.The poly?hydroxypropyl methacrylate??p?HPMA??cryogel with supermacropores was prepared via a cryogelation method in the frozen state of-16°C using hydroxypropyl methacrylate?HPMA?as monomer,N,N'-methylenebisacrylamide?MBAAm?as cross-linker in the presence of redox initiator pair of N,N,N?,N?-tetramethylene diamine?TEMED?and ammonium persulfate?APS?.The influences of monomer concentration,cross-linker content,addition of dioxane in water as co-solvent and cooling rate on its properties were studied.The result of SEM showed that the pore walls of the cryogels is rough with small holes.The result of compress test showed that the cryogels have the ability to be compressed at least 80%without any breakdown.The result of swelling kinetics showed that the cryogels?monomer concentration between 7%-11%?can adsorb water quickly getting to swelling equilibrium in 10 s.The poly?hydroxypropyl methacrylate-glycidyl methacrylate??p?HPMA-GMA??cryogel was prepared via a cryogelation method in the frozen state of-16°C using hydroxypropyl methacrylate?HPMA?and glycidyl methacrylate?GMA?as monomers,N,N'-methylenebisacrylamide?MBAAm?as cross-linker in the presence of redox initiator pair of N,N,N?,N?-tetramethylene diamine?TEMED?and ammonium persulfate?APS?.Furthermore,the p?HPMA?-IDA cryogel was prepared by attaching iminodiacetic acid?IDA?on p?HPMA-GMA?,and the p?HPMA?-Cu²⁺cryogel was prepared by loading Cu²⁺on poly?hydroxypropyl methacrylate-iminodiacetic acid??p?HPMA?-IDA?and it is used for the adsorption of bovine serum albumin?BSA?from aqueous solutions.The results showed that the Langmuir model is more suitable for describing the adsorption process than the Freundlich model.At the same time,the adsorption capacity of p?HPMA?-Cu²⁺cryogel for BSA is significantly higher than that of p?HPMA?cryogel.The maximum adsorption capacity of BSA on p?HPMA?-Cu²⁺cryogel obtained by treating with 1M Cu²⁺can reach to 196.87 mg/g cryogel?equivalent to 20.48 mg/ml cryogel?at 25°C and pH of 7.8,which is 4.35 times higher than p?HPMA?cryogel.The adsorption capacity increases with the increase of Cu²⁺concentration when the concentration is between 0 and 0.6 M.The influence of temperature on the adsorption capacity of p?HPMA?-Cu²⁺is obvious,the adsorption capacity at 25°C is over 2 times than that at 15°C.The calculated Gibbs free energy??G?of adsorption indicated that the adsorption process was spontaneous and performed better at higher temperature.Thep?poly?ethyleneglycoldiacrylate???p?PEGDA??cryogelwith supermacropores was prepared via a cryogelation method in the frozen state of-16°C usingpoly?ethyleneglycoldiacrylate??PEGDA?asmonomer,N,N'-methylenebisacrylamide?MBAAm?as cross-linker in the presence of redox initiator pair of N,N,N?,N?-tetramethylene diamine?TEMED?and ammonium persulfate?APS?.The preparation and properties were investigated simply and characterized by scanning electron microscopy?SEM?,compression test,and swelling kinetics.The results of SEM showed that the pore walls are smooth with the pore size of 100-210?m.The result of compress test showed that the cryogels have the ability to be compressed at least 90%without any breakdown.The result of swelling kinetics showed that the cryogels get to swelling equilibrium quickly,and the maximum swelling degree and porosity is 18.8 g water/g cryogel and 83.1%,respectively.The adsorption of BSA on cryogels chelated with different metal ions was also studied.The results showed that the p?PEGDA?-Cu²⁺cryogel has the highest adsorption capacity for BSA than others.The maximum adsorption capacity is 226.4 mg/g cryogel which is 3.9 times than that of p?PEGDA-GMA?.The influence of temperature on the adsorption capacity of p?PEGDA?-Ca²⁺cryogel is greatest,the amount of adsorption increases first and then decreases with the increase of temperature,and a maximum adsorption capacity of129.68 mg/g reached at 25°C,a minimum adsorption capacity of 20.05 mg/g reached at5°C.The maximum adsorption capacity is 6.2 times of the minimum adsorption capacity.The adsorption capacity of p?PEGDA?-Cu²⁺and p?PEGDA?-Ca²⁺,p?PEGDA?-Co²⁺cryogels decrease gradually with the increase of NaCl concentration.The results showed that the binding ability of BSA on p?PEGDA?-Ni²⁺is not affected by the ionic strength.