| Fruit acid is a type of organic carboxylic acid that naturally exists in fruits.It has the advantages of physiological and environmental safety(edible),natural renewable,and abundant resources.The use of fruit acids to prepare ionic liquids and the study of gel materials based on fruit acid ionic liquids have important scientific significance and potential practical value for resource development,enrichment and development of research and application fields of gel materials.In this paper,we selected gluconic acid(Gla)(monobasic fruit acid),L-malic acid(LMA)(binary fruit acid)and citric acid(CA)(tribasic fruit acid)as the source of anions and triethylamine(TEA)(tertiary amine without unsaturated bond),2-(Dimethylamino)ethyl methacrylate(DMAEMA)(polymerizable tertiary amine with unsaturated bonds)is a source of cations.Six kinds of ionic liquids were prepared through acid-base neutralization reaction,and their structures were identified by infrared and hydrogen spectroscopy nuclear magnetic resonance.The rheometer measures its glass transition temperature and viscosity.The results show that the glass transition temperatures of the six ionic liquids: Gla-TEA,LMA-TEA,CA-TEA,GlaDMAEMA,LMA-DMAEMA,and CA-DMAEMA are-0.5 ℃,-51.97 ℃,-63.11 ℃,-24.15 ℃,-44.54 ℃,-46.5 ℃,viscosities of 411785 m Pa·s,5876 m Pa·s,4393 m Pa·s,13838 m Pa·s,5600 m Pa·s,and 5800 m Pa·s,and densities of 1390 g/L,1050 g/L,1230 g/L,1220 g/L,1170 g/L,and 850 g/L,respectively.Using ammonium persulfate-sodium bisulfite as initiator and Methylene-BisAcrylamide as cross-linking agent,three polyionic liquids were prepared by radical polymerization of fruit acid-DMAEMA ionic liquid at room temperature Gel,the swelling properties of the gel and the release behavior of fruit acid ions were studied.When the crosslinking agent is 0.15%,the swelling performance of the gel is the best.Among them,the absorption capacity of Poly(DMAEMA-Gla),Poly(DMAEMALMA),Poly(DMAEMA-CA)deionized water is 143.64 g/ g,50.79 g/g,17.57 g/g,the absorption capacity in normal saline is 18.08 g/g,19.34 g/g,14.86 g/g,respectively.The three gels reached the swelling equilibrium within 400-480 min.The swelling in deionized water showed case II diffusion,non-fickian diffusion,and non-fickian diffusion,respectively;in normal saline,they showed case I diffusion,case I diffusion,and non-fickian diffusion,respectively.-fickian diffusion.In determining the response performance of the gel,Poly(CA-DMAEMA)showed the best p H resistance and salt resistance than the other two gels.Three or three kinds of gel can swell in some organic solvents,of which the absorption of methanol is 2.11 g/g,0.93 g/g,0.95 g/g,and the absorption of ethylene glycol is 4.54 g/g,0.69 g/g,1.06 g/g,absorption of lactic acid is 16.41 g/g,2.01 g/g,5.08 g/g,absorption of acetic acid is 3.83 g/g,3.09 g/g,4.65 g/g,The absorption of dimethyl sulfoxide was 5.54 g/g,2.99 g/g,4.09 g/g.The release behavior of the three kinds of gels when the anions swelled in the aqueous solution,the cumulative release rates were 23.65%,30.12%,20.49%;the cumulative release rates in physiological saline were 19.08%,92.10%,80.64%.Adopt cross-linked 2-(Dimethylamino)ethyl methacrylate poly(DMAEMA-Cl),cross-linked polyacrylamide poly(AM)and cross-linked sodium polyacrylate poly(AA-Na)to absorb fruit acid-triethylamine ionic liquid,A supported ionic liquid gel was prepared,and the swelling and ion release behavior of this type of gel was studied.The results show that only poly(DMAEMA-Cl)with a similar cationic structure can absorb fruit acid-triethylamine ionic liquid to form a supported ionic liquid gel;poly(DMAEMA-Cl)is used in a cross-linking agent at 0.05 wt% and The absorption capacity of fruit acid-triethylamine ionic liquid is the largest at 70 ℃,and the absorption capacity of Gla-TEA,LMA-TEA and CA-TEA are 3.01 g/g,8.08 g/g and 2.77 g/g,respectively.The time required for absorption saturation is 3 days,9 days,and 2 days,respectively.A blank gel was used to compare the swelling performance of the loaded gel,including poly(DMAEMA-Cl-co-Gla-TEA),poly(DMAEMA-Cl-co-LMA-TEA),poly(DMAEMA-Cl-co-CA-TEA)absorption in deionized water decreased by 0,43.5%,96.5%,and absorption in normal saline decreased by 58.9%,86.5%,81.9%.The anion release behavior of the loaded ionic liquid gel was studied,and the cumulative release rates of the anions of the three gels in deionized water were 39.03%,26.72%,and 34.62%,respectively,and the cumulative release rates in physiological saline were 35.79%,respectively,18.84%,75.32%. |
