Application Of Glow Discharge Electrolysis Plasma In Macromolecular Material

Glow discharge electrolysis is a novel electrochemical process, and non-Faraday electrolysis process. The plasma is sustained by a direct current (DC) glow discharge between an electrode and the surface of electrolyte. The conventional electrolysis turns into glow discharge electrolysis when the applied voltage is sufficiently high in aqueous media. There are a lot of energetic species produced by glow discharge electrolysis, such as H₂O₂,·OH,·H, e-aq, HO2·and so on, and these energetic species can diffuse into the solution around the anode. Therefore, glow discharge plasma can provide rich active intermediates for many kinds of chemistry reaction in aqueous solution under ordinary conditions. We explore the application of glow discharge plasma technology in macromolecular material synthesis.This paper includes four parts:Part 1 Characteristics of plasma were described. Methods to produce cold plasma and the mainly application fields were also discussed in brief. There was a review concerning synthesis macromolecular material using cold plasma technology. The basic concept of glow discharge electrolysis plasma (GDEP) was also introduced. The applications in wastewater treatment, chemical synthesis and macromolecular material were summarized.Part 2 The graft polymerization of acrylic acid on starch was carried out by using the glow discharge electrolysis plasma (GDEP). The effects of five important parameters on the graft polymerization, such as the ratio of acrylic acid to starch, the amount of crosslinking agent, post polymerization temperature, post polymerization time and neutralization of acrylic acid were investigated based on the orthogonal test. For the glow discharge electrolysis plasma, the discharge time and the discharge power were also observed. Results showed that a satisfactory starch-graft-acrylic acid superabsorbent resin with 47% graft percentage and high absorbency (765 g.g^-1 in distilled water, 81 g.g^-1 in 0.9% NaCl solution) was achieved. The product has been characterized by means of the Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).Part 3 A novel polyacrylamide grafted hydrous ferric oxide adsorbent composite has been synthesized by using glow discharge electrolysis plasma. To optimize the synthesis conditions, the following parameters were examined in detail: applied power, discharge time, post polymerization temperature, post polymerization time, amount of crosslinking agent and hydrous ferric oxide gel added and so on. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The thermodynamic and kinetic of Pb(II)-capture were also studied, results indicated that the adsorption reaction was a spontaneous and an endothermic process, and it seems to be obeyed a pseudo-second-order rate model. Moreover, the adsorption isotherm of Pb(II)-capture is following the Langmuir and Freundlich isotherm models.Part 4 A novel imprinted polymer (MIP) for salicylic acid (SA) has been synthesized firstly by glow discharge electrolysis plasma (GDEP). The MIP–SA composite was characterized by FT-IR, SEM. Adsorptive isotherm studies show that imprinted polymer has specific binding affinity for salicylic acid. Results indicated that the MIP–SA prepared by GDEP exhibited better selectivity for salicylic acid than that composite prepared by chemical initiator.