The Synthesis And Efficiency Evaluation Of Novel Decontamination Agent Against Nerve Agent Based On Nanomaterials

Objective:Nerve agent was a high lethal compound which could kill human in seconds.So the ideal decontamination material against the agent should meet three basic requirements-quickly,effectively and low causticly.It was still a great challenge to systhesis a material to meet all the requirements until now.In our work,we focoued on the strategy and method to integrate the three basic and key proporities for decontamination into a nano-unit by design the nanostructure and screening the component material.Based on the research,the regularity between decontaminating efficiency and structure/material were explored,which would support the further work for the new composited decontamination materials.Methods:1.Synthesis of composite decontamination nanomaterials.4 kinds of mild materials were used as the core?such as BSA,DFPase,ZnO and SiO₂?,and 2 kinds of polymers was modified to the outside of core,to build composite decontamination nanomaterials.?1?Synthesis of BSA-DMAEMA or BSA-F127 composite decontamination nanomaterials.BSA was polymerized with DMAEMA or F127respectively through multi-step reactions to obtain BSA-DMAEMA or BSA-F127composite decontamination nanomaterials.?2?Synthesis of DFPase-DMAEMA and DFPase-F127 composite decontamination nanomaterials.The DFPase was extracted and purified from porcine liver and then polymerized with DMAEMA or F127 through multiple steps to obtain DFPase-DMAEMA or DFPase-F127.?3?Synthesis of ZnO NP-DMAEMA composite decontamination nanomaterials.The ZnO NP was synthetized and modificated with 4-pentenoic acid,and then polymerized with DMAEMA through multi-step reactions to obtain ZnO NP-DMAEMA.?4?.Synthesis of 360nm and 100nm SiO₂ NP-DMAEMA composite decontamination nanomaterials.SiO₂ NP of different sizes were introduced reactive groups with silane coupling agents to the surface,and then reacted with DMAEMA to obtain SiO₂ NP-DMAEMA.2.Physical characterization of composite decontamination nanomaterials.Transmission electron microscopy?TEM?,scanning electron microscope?SEM?and particle size instrument were used to observe the internal structure,micromorphology,particle size and zeta potential of these materials;infrared spectroscopy?IR?was used to analyze its chemical bond structure;X-ray diffraction?XRD?was used to analyze its diffraction pattern.3.Evaluation of decontamination capability of composite decontamination nanomaterials.The decontamination capability to soman of these materials was determined by benzidine chromogenic reaction.Rat skin was exposed to soman,decontaminated with BSA-DMAEMA and then determined decontamination capacity.The materials was smeared on rat skin and the epidermis was taken for pathological examination.Results:1.Synthesis of composite decontamination nanomaterials.After reacted with N-acryloyloxysuccinimide?NAS?to add the acryloyl group,the BSA and DFPase were combined with the comonomer Methacrylic acid 2-?dimethylamino?ethyl ester,and then a synthesized to BSA-DMAEMA composite decontamination nanomaterials by freedom polymerization reaction..The F-127 was activated by 4-dimethylaminopyridine and N-hydroxysuccinimide and then cosslink to the surface of BSA and DFPase.2.Physical characterization of composite decontamination nanomaterials.It's proved that the core outer layers of BSA,DFPase,ZnO,and SiO₂ are successfully coated with DMAEMA or F127 and the nanomaterials were within the nanometer size by the characterization of transmission electron microscopy?TEM?,scanning electron microscope?SEM?and particle size instrument.the results of infrared spectroscopy?IR?analysis have futher proved that the polymer linked on the core after the synthesis.Analyzing by the diffraction pattern of X-ray diffraction?XRD?,the nanomaterials had new crystal faces compared with the original polymer and the core material.3.Evaluation of decontamination capability of composite decontamination nanomaterials.Soman was selected as the tested nerve agent for test,and its content was measured by benzidine chromogenic reaction.After testing,BSA-DMAEMA,BSA-F127,DFPase-DMAEMA and DFPase-F127 had obvious decontamination effects,while the core and polymer monomer were invalid.The decontamination rate results showed that the composite decontamination nanomaterials reached the maximum decontamination rate instantaneously?within 2 seconds?.Common decontaminants?such as NaHCO₃,activated carbon and H₂O₂?needed a long time to decontaminate soman,and only NaOH had high decontamination.Both of the decontamination efficiency and rate of ZnO NP-DMAEMA were obviously better than these of ZnO NP,achieving the dual function of fast adsorption and catalytic decontamination.The decontamination results show that the decontamination efficiency of the 100nm SiO₂ NP-DMAEMA group was better than 360nm SiO₂ NP-DMAEMA group during the whole process.BSA-DMAEMA was effective in decontamination of rat skin exposed to soman?n=8,p<0.05?,and was superior to the same concentration of NaHCO₃?n=8,p<0.05?.It's confirmed that this materials had no obvious skin irritation by pathological results.Conclusion:Composite decontamination nanomaterials based on BSA,DFPase,ZnO NP,and SiO₂ NP were successfully synthesized,and these materials could effectively decontaminate nerve agent.These materials with BSA and DFPase as the core could achieve extremely rapid decontamination of nerve agent.They have potential wide application because of no toxicity and high safety,such as animal skin decontamination.It was demonstrated by lots of these nanomaterials'decontamination capbility that the radial structure materials with nano-material as the core which modified by polymer on the outer layer,could achieve effective and ultra-speed decontamination of nerve agents.In totally,we put forward to a hypothesis that the nerve agent could be adsorbed by the core-shell nanostructure which composed by a nanocore and polymer layer modificated on the surface of core.The kind of materials which composed to the nanostructure have no obvious influence on the decontamination property.In the nanostructure,the polymers were linked on the surface of nanoparticles and regular arranged to form a dynamic space with 1.6 nm size,which could effectively adsorb the nerve agent molecular.In another side,the well openness of the dynamic space and the sufficient disoersion extremely increased the collision probability between nerve agent and decontenimation material,leading to the ultra-speed adsorbent ability.