Preparation And Properties Of Acyclic Halogenated Antibacterial Resins And Modified Activated Carbon Materials

In recent years,with the continuous improvement of people's living standards,people begin to pay more attention to the external factors that harm their own health,and have more and more high demands for their own health.In the daily life,because of the widespread and extensive distribution of various bacteria and viruses in nature,they threaten the health of people,even endanger the harmonious stability of society and the sustainable development of the economy.Therefore,it is very important to study the new environmentally friendly and healthy antibacterial materials to safeguard people's daily lives.At present,N-halamine antibacterial materials have attracted wide interest of researchers due to their powerful antibacterial efficacy,broad-spectrum antimicrobial activity,and reproducibility of antibacterial functional groups.However,not too much study on acyclic N-halamine materials has been done at home and abroad.Therefore,this thesis focuses on the research of acyclic N-halamine materials.In this thesis,a macroporous antibacterial resin containing acyclic N-halamine functional groups was synthesized successfully,and a polymer-modified antibacterial activated carbon containing acyclic N-halamine functional groups was prepared.(1)Preparation and performance study of macroporous antibacterial resin containingacyclic N-halamine functional groupsAccording to the published literature,a kind of macroporous resin P(TAIC-AC)was synthesized via a suspension co-polymerization of triallyl isocyanurate(TAIC)and vinyl acetate(VA)and hydrolysis of polymerized products under certain conditions.Then,in aqueous solution,a macroporous resin containing acyclic N-halamine precursor functional groups P(TAIC-VA-MBAA)was synthesized through the grafting reaction between active hydroxyl groups on P(TAIC-VA)resin and methylene-bis-acrylamide(MBAA)under the catalysis of sodium carbonate.Finally,after a chlorination reaction in sodium hypochlorite solution,a macroporous resin containing acyclic N-halamine functional groups P(TAIC-VA-MBAA-Cl)was obtained.The as-synthesized P(TAIC-VA-MBAA-Cl)was characterized by the Brunauer-Emmet-Teller(BET),field emission scanning electron microscopy(FE-SEM),infrared spectroscopy(FTIR),X-ray energy spectrum(XPS).The test of oxidative chlorine content showed that the effective oxidative chlorine content reached 0.48%,which is suitable for the sterilization of water.Antibacterial test showed that the as-synthesized P(TAIC-VA-MBAA-Cl)resin was able to completely kill 1.12x10~8 CFU/m L of staphylococcus aureus and 3.24x10~7 CFU/m L of E.coli within 5 min.Storage stability showed that the oxidation chlorine content of the as-synthesized P(TAIC-VA-MBAA-Cl)only decreased from 0.48%to 0.41%after storage for 20 weeks,indicating that the antimicrobial N-halamine functional groups in P(TAIC-VA-MBAA-Cl)has excellent storage stability at room temperature.Also,the regenerability of the antimicrobial N-halamine functional groups in P(TAIC-VA-MBAA-Cl)was evaluated.m(2)Preparation and performance study of polymer-modified antibacterialactivated carbon containing acyclic N-halamine functional groupsWith polyvinyl alcohol(PVA)as the polymer framework,a polymer containing acyclic N-halamine precursor functional groups(PVA-MBAA)was obtained via grafting reaction between the active hydroxyl groups on PVA and?,?-unsaturated functional groups of methylene-bis-acrylamide(MBAA)under the catalysis of sodium carbonate in aqueous solution.After a certain amount of activated carbon was added into above reaction solution,the polymer-modified activated carbon containing acyclic N-halamine precursor functional groups(PVA-MBAA@AC)was obtained.Then,the polymer-modified antibacterial activated carbon containing acyclic N-halamine functional groups(PVA-MBAA-Cl@AC)was obtained via the chlorination of amide functional groups on PVA-MBAA@AC.A 0.72%oxidation chlorine content in PVA-MBAA-Cl)@AC was achieved by optimizing the preparation conditions of PVA-MBAA-Cl@AC(molar ratio of grafted reactants,concentration of grafted reactants,grafting reaction temperature,grafting reaction time,and chlorination time).The as-prepared materials were characterized by X-ray energy spectrum(XPS)and field emission scanning electron microscopy(FE-SEM).The antibacterial efficacy test showed that the as-prepared PVA-MBAA-Cl@AC has very strong bactericidal ability and could completely kill 2.51×10~7 CFU/m L of staphylococcus aureus and 1.36×10~8 CFU/mL of E.coli within 1 min.The regenerative performance test showed that the N-halamine antimicrobial functional groups in PVA-MBAA-Cl@AC have very good regeneration ability and after 8regeneration cycles,the content of the oxidized chlorine in PVA-MBAA-Cl@AC was still 0.68%.The storage stability test showed that the N-halamine antibacterial functional groups on PVA-MBAA-Cl@AC have good storage stability.In the first 3weeks,the content of the oxidized chlorine in the prepared material decreased to a certain extent,and then tended to be stable.After 5 weeks,the content of the oxidized chlorine could still reach 85%of the initial value.