Study On The Hemostasis Of Chitin And The Adsorption And Reduction Of Noble Metal Ions By Chitin

The 21st century is a new era for the exploitation of marine resources.It has become a global research hotspot to develop and utilize the abundant biomass resources in the ocean and promote the high value utilization of marine resources.In addition,as the most abundant natural polysaccharide in the ocean,chitin has the advantages of cexcellent biocompatibility,biodegradability and non-toxicity,which makes it show great potential in the fields of chemical industry,food,textile and biomedicine.Therefore,it is of great strategic significance to carry out basic research and application development based on chitin.In this thesis,chitin was used as a raw material to construct new chitin functional materials,then their applications in the fields of hemostasis,oil/water separation and noble metal ion recovery were explored.The main contents are as follows:（1）The chitin microspheres（CTMS）were prepared by the electrospraying method.Then they were modifided with 3,4-dihydroxyphenylpropionic acid（HCA）to obtain hemostatic microspheres.Scanning electron microscopy showed that the surface of CTMS-HCA microspheres had nanofibrous structure with a specific surface area of 270.3 m²/g,and their water absorption ratio was as high as 2499%.In our study,we found that CTMS-HCA showed significant hemostatic performance,and its in vitro procoagulant time was102 s,while the hemostasis time on liver and femoral artery modles was 61 s and 55 s,respectively.At the same time,CTMS-HCA was highly adsorptive to red blood cells and platelets.These properties of CTMS-HCA suggested their potential applications in hemostasis.（2）Partially deacetylated chitin nanofibers were prepared by the surface modification cationization method,followed by the vacuum filtration to obtain chitin ultrafiltration membrane（CNFM）.We found that the inner structure of CNFM exhibited a nanofiber-woven porous structure through the scanning electron microscopy.Meanwhile,the surface of CNFM has super-hydrophilic/underwater super-oleophobic infiltration properties.Therefore,CNFM showed high separation performance for micro-nano oil emulsion droplets,and its oil interception rate could reach 99%.In addition,CNFM can directly and efficiently adsorb noble metal ions in the oil emulsion separation process through the cooperation of chitin’s amino group to metal ions,and its adsorption capacity for Au³⁺,Ag⁺,Pt⁴⁺and Pd²⁺ions is 243.2,136.5,217.8 and 197.8 mg?g^-1,respectivly.It is worth noting that the noble metal ions adsorbed on the CNFM can be directly reduced into metal nanoparticles by the amino group of the chitin in situ.And these metal nanoparticles have high catalytic activity,which would make them widely used in biosensing,green catalysis and other related fields.These basic research results in this paper provide important scientific basis and theory for the research,development and utilization of renewable resources chitin,and can promote the process of sustainable development.Therefore,this paper has important academic value and application prospects.