Modification Of Activated Carbon And Its Adsorption And Release Of Resveratrol

Activated carbon(AC)is widely used in the fields of food,medicine,and environmental treatment because of its good adsorption performance and biocompatibility.Resveratrol(RES)is a natural polyphenol compound with various physiological activities such as anti-tumor,anti-inflammatory,and antioxidant.However,due to its poor water solubility and instability,its application in food and medicine is limited.RES carrier materials are expected to solve the problems of resveratrol in the above-mentioned application.Based on this,this thesis modified the activated carbon,and studied the adsorption performance and in vitro release behavior of RES before and after modification.The main research results obtained are as follows:(1)The adsorption and in vitro release behavior of RES by AC have been studied and obtained.The saturated adsorption capacity of AC on Res is 106.38 mg/g,and the kinetics followed pseudo-second order.Activated carbon carrier(AC-RES)loaded with resveratrol was prepared under the condition of saturated adsorption,the cumulative release rates of AC-RES in simulated gastric fluid(pH=1.0)and simulated intestinal juice(pH=6.8 and 7.4)within 10 h were 2.32%,8.70%,and 12.50%.The material analysis shows that the surface of AC is rough,the pore structure distribution is irregular,and the oxygen-containing functional groups such as-C=O and-C-O-are favorable to adsorb RES.The specific surface area of AC decreased from 1383.032 m2/g to 580.692 m2/g,and pore volume decreased from 0.585 mL/g to 0.409 mL/g,indicating that RES was successfully loaded in AC.However,the total specific surface area of activated carbon failed to recover but decreased,which proved that the pores of the activated carbon were blocked,and the RES could not be effectively released.(2)NAC was prepared by modifying AC with oxidized amination,RES loaded NAC sustained release(NAC-RES)was studied and the adsorption of NAC on RES was obtained in vitro release behavior.The saturated adsorption capacity of NAC to RES is 183.15 mg/g,and the kinetics followed W-M adsorption model Within 48 h,the cumulative release rates of NAC-RES in simulated gastric fluid(pH=1.0)and simulated intestinal juice(pH=6.8,pH=7.4)to RES were 7.79%,42.22%,and 33.82%,The release process conforms to the Higuchi release kinetics.FT-IR and XPS analyses showed that the AC successfully introduced polar groups-C(O)NH and-NH2 end groups effectively improved the adsorption and in vitro release of RES.The total specific surface area decreased from 263.488 m2/g to 122.930 m2/g,and pore volume decreased from 0.585 mL/g to 0.409 mL/g,indicating that RES was successfully loaded in NAC.After the simulated intestinal fluid-released RES,the total specific surfce area of NAC increased to 140.826 m2/g,and the pore volume increased to 0.265 mL/g,it shows it shows that part of the RES was released in the simulated physiological fluid.(3)XAC was prepared by modifying AC with Milk protein,RES loaded XAC sustained release(XAC-RES)was studied and the adsorption of XAC on RES was obtained In vitro release behavior.The saturated adsorption capacity of XAC to RES is 151.52 mg/g,and the kinetics followed pseudo-second order.Within 48 h,the cumulative release rates of XAC-RES in simulated gastric fluid(pH=1.0)and simulated intestinal juice(pH=6.8,pH-7.4)to RES were 8.44%,32.89%,and 24.23%,and the release process conforms to Higuchi release kinetics.FT-IR and XPS analyses showed that after the milk protein coating was modified,a large amount of-COOH and-NH2 was obtained on the surface of AC,which was conducive to the adsorption and in vitro release of RES.The total specific surface area decreased from 777.542 m2/g to 43.153 m2/g,and pore volume decreased from 0.393 mL/g to 0.120 mL/g,indicating that RES was successfully loaded in XAC.The total specific surface area and pore volume of XAC after the release of RES were restored to the original state,indicating that part of the RES in XAC-RES was released in the simulated physiological fluid.Based on obtaining the adsorption and in vitro release behavior of Res by AC,aiming at the existing defects,oxidation amination and milk-protein coating techniques were used to directionally modify the surface chemical properties of activated carbon to achieve the modification of activated carbon.Two kinds of activated carbon sustained-release form materials loaded with resveratrol were constructed.While enhancing the adsorption capacity of activated carbon for resveratrol,it effectively improves its release effect under simulated intestinal fluid conditions.The results of this thesis provide a basis for the development and application of activated carbon to resveratrol and polyphenolic natural active ingredients with similar structure and properties in drug carrier materials.