Preparation And Properties Of Naphthalene Methylene Derived Carbon Materials

Naphthalene is a widely used fused ring aromatics in industry.Due to the high biological toxicity,carcinogenicity and accumulation of naphthalene,the removal of contaminated naphthalene in fresh water has attracted a widespread attention.This thesis summarizes the research progress about the types of adsorbents used to remove naphthalene and polycyclic aromatic hydrocarbon such as naphthalene in recent years.Based on this understanding,two kinds of adsorption materials used to remove naphthalene were prepared,the structures of the obtained materials were characterized.And the adsorption performance of the obtained materials for naphthalene from aqueous phase was evaluated.Naphthyl based polyaromatic oligomer were synthesized by Friedel-Crafts alkylation of one-step condensation polymerization using chloromethyl naphthalene as raw material.A carbon material with good thermal stability was obtained by carbonization dehydrogenation and cross-linking,and then a porous carbon material with high specific surface area（CMNAC）was prepared by KOH activation at high temperature.The effects of the activation temperature and the proportion of the activator on the material structure were investigated.The structures and morphologies of intermediates and porous carbon materials were characterized by the FT-IR,XPS,SEM and N₂ adsorption–desorption.The results show that the specific surface area and pore volume of the material increase with increasing of activation temperature,S_BETreaches to 1020.06 m²/g.XPS analysis shows that the C atoms of carbon materials are mainly composed of sp² hybrids,indicating that during the activation process,the unsaturated naphthalene ring structural units are still preserved.The porous carbon material absorbed naphthalene from aqueous quickly and the adsorption equilibrium was reached in 10 min.The adsorption experimental data fitted well with the Langmuir isothermal model and pseudo-second-order model,the maximum theoretical adsorption capacity estimated by the Langmuir model could reach 186 mg/g.Adsorption thermodynamics studies show that the adsorption of naphthalene on CMNAC-800（2:1）is a spontaneous and exothermic process.The removal efficiency of naphthalene could reach 99.7%using CMNAC-800（2:1）as an adsorbent for 1 h at 25 ^oC.And the removal efficiency was still 91%after four cycles.It shows that CMNAC-800（2:1）has high adsorption performance and recyclability.Naphthalene methyleneated hyper-crosslinked polymers（HCPs）were prepared by the Friedel-Crafts alkylation of 1,4-dichloromethylnaphthalene and chloromethyl naphthalene with naphthalene.The effects of chloromethyl naphthalene and 1,4-dichloromethylnaphthalene in the preparation of hyper crosslinked polymers were discussed,and the effect of the ratio of 1,4-dichloromethylnaphthalene to naphthalene on the formation of HCPs was investigated.The SEM analysis showed that there were uniform nano-spherical particles on the surface of HCP-8.The adsorption experimental data show that HCPs have a fast adsorption rate for naphthalene,and the adsorption can reach equilibrium in 20 min.The adsorption kinetic data conforms to the pseudo-second-order model.The adsorption isotherm data can be fitted with Freundlich isotherm model,the adsorption capacity of HCP-8 can reach 176.60 mg/g.The internal diffusion model does not fit the experimental data well,indicating that internal diffusion is not the only speed-controlling step,and there may beπ-πelectron interaction between the adsorbent and the adsorbate.The adsorption thermodynamics studies show that adsorption is a spontaneous process.