Preparation And Applications Of Multiple Carboxylic Acid And Cellulose Matrix Composite Aerogel

With the progress of modern industrial level and the rapid development of society,the toxic and harmful substances produced in industrial waste water and production accidents?Such as oil,heavy metal ion and color dyes,etc.?had brought serious harm to human beings,environment and natural biological.Using of natural renewable and biodegradable polymer materials for adsorption wastewater treatment has aroused more and more attention.But the disadvantageous properties of mechanical strength,adsorption quantity,and bad resistance to chemical faults had prevent its application from wastewater treatment.In this paper,for the use of removal dirty oil,heavy metal ions and dyes in wastewater by natural polymer cellulose.Inspired by?MOFs?new metal organicframework materials with mesh and large specific surface area.two kinds of porous aerogel materials through nanometer microcrystalline cellulose and secondary building units?SUBs?had been prepared;For the aim of removing organic matter such as toluene,cyclohexane and dodecane from the water,one porous aerogel composite material formed by 1,4 terephthalic acid and nano microcrystalline cellulose had been prepared;For the aim of removing heavy metal ions from water,porous aerogel was prepared by 1,2,4,5 benzene tetracarboxylic acid and nano microcrystalline cellulose,and the adsorption performance of Cu²⁺ had been invstigated;1,3,5-benzenetricarboxylate acid was used as crosslinking ligand for nano porous aerogel,and microcrystalline cellulose and its adsorption of methylene blue solution had been investigated.A metal organic-framework materials with new type structure characteristics had been prepared by solvothermal reaction and its adsorption performance of gas had been studied.?1?The porous aerogel composite materials by 1,4-terephthalic acid and nano microcrystalline cellulose had been prepared by sol-gel method.The difference of aerogels made by three ways different methods?vortex mixing,binocular injection mixing and ultrasonic mixing?had been compared.The aerogels have high density of 22.4-23.3 mg/cm3,porosity of 96.2-97.3% and pecific surface area of 195-303-10 m2/g.CNC aerogel has two kinds of pores?micro and nanoscale?which were confirmed by SEM test.The compression recovery percentage were investigated in water and air,it can restore to 94% in air and can be up to 96% in water.Because it has faster adsorption speed for water than that for toluene,cyclohexane and dodecane,so it can be used for the separation of oil/water mixture significantly.?2?The porous aerogel composite materials formed by 1,2,4,5-benzene tetracarboxylic acid and nano microcrystalline cellulose had been prepared by sol-gel method.The adsorption ability of Cu²⁺ ion had been studied.The adsorption time of Cu²⁺ ion had been investigated.The adsorption amount can reach to 95.17 mg·g-1 at optimal adsorption time of 3.5 h.The adsorption performance is best when p H is 6.5 and temperature is 30 ?.And the effect of common coexisting ions such as K+,Na+,Ca²⁺,and Mg²⁺ cations on the the aerogel had been studied.The correlation coefficient?R2=0.99677?of pseudo-first order quasi kinetics of Lagergren and correlation coefficient?R2=0.9917?of pseudo-second order fitting results had been used for comparing with the experimental results,it shows that the adsorption data are more according with the pseudo-first order kinetics model.Langmuir and Freundlich isothermal adsorption fitting model had been carried out on the experimental data,proved that the adsorption of Cu²⁺ ion on porous CNCs aerogel materials conformed to the Langmiur adsorption model.The conclusion can be confirmed that there are existing not only chemical adsorption,but also physical adsorption.?3?The porous aerogel composite materials formed by 1,3,5-benzenetricarboxylate acid?H3BTC?and nano microcrystalline cellulose had been prepared by sol-gel method.The adsorption of methylene blue had been investigated.The adsorption quantity of raw CNCs materials and CNCs aerogels had been compared.The removal rate of methylene blue dye by BTC ligands connected CNCs aerogel can reach to 93%,far more than CNCs raw materials.The adsorption effect of methylene blue at different concentrations had been investigated.For the solution of initial concentration of 100 and 200 mg·L-1,removal rate are 72.41% and 43.23% respectively.For the solution of initial concentration of 30 mg·L-1,removal rate can reach to 97.21%.The removal rate are 93.26% after desorption by 0.05 mol·L-1 HCl solution.After five consecutive adsorption-desorption,removal rate is still more than 85%.?4?With solvothermal method,one noval metal-organic framework materials of [Zn₂₂?btc?₁₂?H₂O?₂₂?NO₃?₈]·xguest?1?had been synthesized by 1,3,5-benzenetricarboxylate acid?H3BTC?and Zn?NO3?2·6H₂O,there are two types of second building units in it.One is typical 4-connected way of coordination with 4-paddle wheel structure,the other is 3-the connected way of coordination with 3-paddle wheel structure.For crystal compounds 1,there are two types of cage structure,big cage is a rhombic dodecahedron,while the small cage is coplanar cube.It could be consider as a super secondary building unit which the dodecahedron and adjacent cube sharing a common vertex,and connected to other units to form a 3d skeletal structure.The volume of each cell is up to 68.1%.The three different ways of activation treatment,such as benzenefreeze drying,vacuum drying,dry and super carbon dioxide?SCD?,had been used for the study of effect on its porosity of crystal compounds 1 and gas adsorption performance.In addition,the samples activated by SCD had been used to investigated adsorptive selectivity on carbon dioxide and methane gas.It has high selectivity of about 65.8 for CO₂.