Preparation And Application Of Maltodextrin Polymer Nanosponge

Organic dye pollutants in wastewater are one of the most serious environmental problems.The chromogenic groups in organic dyes,especially for cationic molecules,are mostly nitrogen containing groups,which are easy to be reduced to form toxic amines,which leads to serious environmental pollution.Therefore,it is of great significance to realize the special removal of these pollutants in wastewater.At present,adsorption removal method is one of the lowest cost and most effective removal methods.However,there are still many disadvantages of commercial adsorbents,such as low adsorption efficiency,difficult recovery,easy to cause secondary pollution and other problems.Based on this,this paper takes linear maltodextrin as raw material,selects two kinds of cross-linking agents to synthesize new nano-sponge adsorption materials with different cross-linking ratios,and realizes the efficient adsorption of a variety of cationic dyes.The specific research contents are as follows:Firstly,nine kinds of maltodextrin crosslinked polymers MDP(MDP 1:4,MDP 1:6,MDP1:8),MDB(MDB 1:4,MDB 1:6,MDB 1:8)and MDB/P(MDB/P 1:2:2,MDB/P 1:3:3,MDB/P1:4:4)were synthesized by condensation crosslinking method from maltodextrin(MD),pyromellitic anhydride(PDA)and biphenyltetracarboxylic dianhydride(BPDA).Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),zeta potential and other methods were used to characterize the structure of the polymers,which proved that the cross-linked polymers were successfully synthesized.Secondly,we systematically discussed the above nine different proportions of maltodextrin cross-linked polymers MDP(MDP 1:4,MDP 1:6,MDP 1:8),MDB(MDB 1:4,MDB 1:6,MDB1:8)and MDB/P(MDB/P 1:2:2,MDB/P 1:3:3,MDB/P 1:4:4)on the removal performance of malachite green(MAG),methyl violet(MV)and methylene green(MG)cationic organic dye pollutants.It was found that different proportions of maltodextrin crosslinked polymers MDP,MDB and MDB/P had good removal effects on MAG,MV and MG cationic pollutants.The removal rate of cation is very fast,and it can reach 90% equilibrium in 5 minutes.The special removal of cationic organic dye pollutants by MDP,MDB and MDB/P was confirmed.The results of isothermal adsorption showed that the adsorption effects of MDP 1:6,MDB 1:6 and MDB/P 1:3:3 were more prominent.A new method for selective removal of cationic organic pollutants from wastewater was established.Finally,the organic dyes such as basic Red 46(CRX),brilliant green(BG),Victoria blue B(VB),malachite green(MAG),methyl violet(MV)and methylene green(MG)in water were removed by using the above optimal ratios of MDP 1:6,MDB 1:6 and MDB/P 1:3:3.The experimental results show that different crosslinked polymers have different adsorption properties for different molecular structures and sizes of cationic dyes.The adsorption of cationic and cationic mixed dyes showed that MDP,MDB and MDB/P could selectively remove cationic organic pollutants from wastewater.The above results show that MDP 1:6,MDB 1:6and MDB/P 1:3:3 have good application potential in the field of dye removal,which provides a new idea for the development of new adsorbent materials.