Application Of Ionic Liquids For Preparation Of Biomaterial And Storage Of DNA

Cellulose, the most abundant renewable natural biopolymer available on earth, is consideredas an ideal replacement for traditional crude oil. Compared with raw fossil fuel, cellulose widelyexists in nature and avails more conveniently. Cellulose also has good biocompatibility andbiodegradability and can be used widely in biomaterials. The hydroxyl groups of cellulose can befunctionalized with different moieties for preparation of biomaterials with excellent performanceto meet the specific requirement.Ionic liquid, composed completely of cation and anion, is a salt in liquid state below100°C.Ionic liquids have been widely applied in the dissolution, regeneration, separation, andfunctionalization of biopolymers (such as cellulose, chitosan, protein, and DNA), as well asbiological catalysis due to their good compatibility and unique propertiesThis thesis described the preparation of amino acid functionalized TEMPO-oxidizedcellulose (TOC-AA)/silver nanoparticles biocomposite films, cellulose sponge, andcellulose/chitosan sponge, as well as the DNA storage in hydroxyl-functionalized ionic liquids.Details are as follows:Firstly, novel2biocomposite films (TOC-Phe-AgNPs and TOC-Try-AgNPs) were preparedby employing amino acid functionalized TEMPO-oxidized cellulose (TOC-AA), which preparedby means of oxidation of microcrystalline cellulose with TEMPO-NaBr-NaClO system, withsilver nanoparticles (AgNPs) produced in situ by reduction by silver nitrate and sodiumborohydride via homogeneous and heterogeneous approaches. The films prepared byhomogeneous process have better dispersion of silver nanoparticles and exhibited betterantibacterial activities than films prepared by heterogeneous process.Secondly, using ionic liquid1-butyl-3-methylimidazolum chloride ([BMIM]Cl) asnon-derivative solvent to dissolve cellulose and chitosan to prepare cellulose sponge andcellulose/chitosan composite sponge. The as-prepared sponges show good water-absorbingcapability. This protocol provides an additional methodology for preparation of cellulose sponge,or cellulose/chitosan composite sponge. Lastly, the interaction between the Salmon sperm DNA with6kinds of ionic liquidsincluding [2,3-dhpmim]BF4,[2,3-dhppy]PF6,[2,3-dhpmim]Cl,[cmmim]BF4,[chpmim]BF4, and[2,3-dhppy]Cl have been explored. The results show that5kinds of ionic liquid as-mentionedcan be used for DNA storage. This may provide a novel way for DNA storage and forensicanalysis.