Preparation And Adsorption Performance Of The Poly (Catechol-amine)

Inspired by the combination of phenol-amine self-polymerization of mussel adhesion protein and phenol-hydroxyl-hydroxyl hydrogen bond,polyphenol-amine cellulose modified materials?PCA@AC?,polyphenol-amine iron oxide composite materials?PTHA@FeO?OH?n?andtannicacidpolyvinylalcohol phenol-hydroxy-hydroxy hydrogen bond binding materials?TA-PVA/SA?were designed and prepared in this paper.The micro-morphology,structure,composition,elements and specific surface of the material were analyzed by environmental scanning electron microscopy?SEM?,Fourier transform infrared spectroscopy?FT-IR?,thermogravimetric analysis?TGA?,X-ray photoelectron spectroscopy?XPS?,X-ray diffraction?XRD?,specific surface area aperture analyzer?BET?,energy dispersive spectrometer?EDS?,particle size analyzer,etc.The adsorption performance of the adsorbent was evaluated by using heavy metal ions(Cr???and dye ions?MB,CR?as adsorbents in simulated sewage.The effects of different proportion of adsorbent,contact time,solution pH value,initial solubility,dosage of adsorbent and environmental temperature on the adsorption performance of the adsorbent were investigated.The reproducibility of the adhesives was compared and recycled,and the experimental data were processed by the model.This paper is mainly divided into three parts:?1?A new type of composite adsorption PCA@AC was successfully prepared by using cellulose as base material and catecholamine copolymer as coating layer.The material exhibits excellent removal performance of Cr???.The results of many factors affecting the adsorptive performance of PCA@AC were systematically studied.The results showed that 25mg adsorbent prepared at the ratio of 0.11:1.1 was the best choice.Because of the existing form of Cr???in aqueous solution,the optimum condition for obtaining high removal rate of Cr???is pH=2.According to the quasi-second-order kinetic model,the qe value increased rapidly to 207.88 mg/g in the first 10 minutes.The R%value of low concentration solution is about 100%.According to Langmuir model,the single layer adsorption qm value of PCA@AC for Cr???was calculated to be 507.61mg/g.Additional ions of SO₄^2-and PO₄^3-lead to a decreasing trend in the removal of Cr???.The mechanism study shows that electrostatic interaction and reduction reaction are the main reasons for the removal of Cr???in the adsorption process.?2?The complex PTHA@FeO?OH?n of polyphenolamine and iron oxide was formed by iron oxide with tannic acid and hexamethylenediamine in weak alkaline condition.The removal performance of Congo red from aqueous solution by this adsorbent is better than that of other adsorbents.The PTHA@FeO?OH?n adsorbent was characterized by various characterization methods.The results of particle size analysis and specific surface area showed that the particle size of PTHA@FeO?OH?n adsorbent added with iron oxide was several orders of magnitude smaller than that of PTHA adsorbent,which undoubtedly increased the specific surface area of PTHA@FeO?OH?n.We believe that this is one of the factors to improve the adsorbent adsorption capacity.In addition,the results of many factors affecting the adsorption performance of PTHA@FeO?OH?n were systematically studied.The results showed that the 25 mg PTHA@FeO?OH?n adsorbent prepared at the ratio of 1:0.4 had the best removal efficiency of CR in aqueous solution.In the initial stage of the adsorption process,the adsorption rate of CR dye ion was very fast.At 45 min,the adsorption capacity was 310.4 mg/g.According to Langmuir model,the single layer adsorption qm value of PTHA@FeO?OH?n for CR was calculated to be 588.24mg/g and the temperature was 30^oC.?3?In this chapter,a three-dimensional reticulated TA-PVA/SA hydrogel microsphere was prepared using PVA as the framework and instantaneous shelling method,and characterized.The ability of TA-PVA/SA hydrogel microsphere as adsorbent to remove MB dye from simulated wastewater was also explored.The results show that the content of TA has an important influence on the removal of MB dyes by TA-PVA/SA hydrogel microspheres.The q_m value of TA-PVA/SA hydrogel microspheres is 147.06 mg/g,which is obviously better than that of TA-free hydrogels.The removal ability of TA-PVA/SA hydrogel microspheres for MB dyes is influenced by TA content,contact time,pH value of solution,initial concentration of solution,amount of adsorbent,ambient temperature and competitive ions.The experimental data are in good agreement with the Langmuri isotherm model.The corresponding R² value is 0.996 and the calculated q_m value is 147.06 mg/g,which is obviously higher than the adsorption capacity of MB dye by other adsorbents reported in the literature.Thermodynamics of TA-PVA/SA hydrogel microspheres adsorbing MB dyes was also investigated.The experimental data showed that the removal of methylene blue dye ions was a spontaneous reaction and exothermic process.After five cycles of adsorption-desorption analysis,the adsorption capacity of TA-PVA/SA hydrogel microspheres for MB dyes can still be maintained at a stable value of about 100 mg/g.The above results show that TA-PVA/SA hydrogel microspheres are a good adsorption material which can effectively remove MB dye ions from wastewater and can be reused.They have high adsorption capacity,good reusability and low reusability.The advantages of low preparation cost and no secondary pollution make TA-PVA/SA hydrogel microspheres more competitive in treating dye wastewater containing MB.The phenolamine resin material and the tannic acid polyvinyl alcohol phenolic hydrogen bond material are prepared in a mild condition,simple in operation,easy to handle,and rich in monomer source and low in price.More importantly,the phenolic amine resin adsorbent has a large adsorption capacity and an obvious adsorption effect.