Nano-chitosan Quaternary Ammonium Salt On The Anti-bleeding Of Water-soluble Writing On Archive

As the most important file carrier,paper records very important historical information.Paper based archives have high evidential value and social historical value and are the one of the most important cultural heritage of human beings.There are a huge amount of paper based archives around the world.However,many of paper them are suffering acidification,decay,discoloration,breakage,microbial damage,writing diffusion,fading,stain,ect.,due to the influence of collection conditions and human factors,which seriously affect the utilization and value of paper based archives.Mounting is the most usually used traditional method for the conservation of paper based archives.But a large number of water-soluble handwriting difused during the process of mounting,which leads to the disappearance of valuable information and seriously endangers to the information security of paper based archives.It is of great significance to study an anti-diffusing method which can not only effectively prevent diffusing of water-soluble writing in paper archives,but also conserve paper.Focusing on this issue,this paper carries out the following four aspects of research:1.Preliminary study on the anti-diffusing effect of several cationic polyelectrolytesThe anti-diffusing effect of cationic starch,cationic polyacrylamide and chitosan quaternary ammonium salt for the writing of red ink and blue ink were compared.The results show that cationic polyacrylamide has poor anti-diffusing properties for the writing with red ink and blue ink,and is not suitable for the research of water-soluble writing in paper archives.The cationic starch has a certain anti-diffusing effect for the writing with red ink,but it cause the writing of blue ink slight fading.The chitosan quaternary ammonium salt has better anti-diffusing effect for the writing with red ink,and perfect anti-diffusing effect for the writing with blue ink.In order to improve the anti-diffusing properties,and obtain cationic polyelectrolytes with small particle size,cationic starch and chitosan quatermary ammonium salts were milled respectively by ball milling method.The results show that ball milling have poor effect on the reducing particle size of cationic starch,but the particle size of chitosan quaternary ammonium salt can be greatly reduced by ball milling,and the nano-chitosan quaternary ammonium salt is obtained.The physicochemical properties of chitosan quaternary ammonium salt after milling such as substitution degree,particle size and molecular structure were characterized by silver nitrate titration method,laser particle size analyzer,SEM,TEM,FTIR,XRD and 1H-NMR separately.The results show that nano-chitosan quaternary ammonium salt with particle size around 20 nm is successfully prepared by ball milling chitosan quate-nary ammonium salt for 120 h.After ball milling,the crystallinity of the chitosan quaternary ammonium salt decreases.The molecule structure has not change after milling,especially the branch chain of the the chitosan quaternary ammonium salt has not been destroyed and the nano-chitosan quaternary ammonium salt maintains its original high degree of substitution.2.Study on the anti-diffusing properties of nano-chitosan quaternary ammonium salt for water-soluble writing of archivesThe adsorption of nano-chitosan quaternary ammonium salt on several ink dyes,red ink and blue ink were studied by ultraviolet-visible absorption spectroscopy.The results show that nano-chitosan quatermary ammonium salt has good adsorption properties for dyes and inks,among which it has excellent adsorption effects for direct blue dye,methyl blue dye and blue ink.Simulating the mounting process of paper containing ink writing,it is shown that nano-chitosan quaternary ammonium can firmly adsorb dye molecules on the fibers by electrostatic adsorption,and immobilize the dye molecules,thus achieving the anti-diffusing effect.The nano-chitosan quatermary almonium salt has perfect anti-diffusing properties for the writing of blue ink.Extending the storage time can improve the anti-diffusing properties of nano-chitosan quaternary ammonium salt for the writing of red ink,thus achieving the better anti-diffusing properties.The simulated lounting process of different types of paper shows that the nano-chitosan quatermary ammonium salt dispersion can not penetrate the dense paper such as printing paper and manuscript paper well,and its anti-diffusing properties will be reduced.3.Study on the conservation effect of nano-chitosan quaternary ammonium salt on paperThe ShengXuan paper samples were treated with the dispersion of nano-chitosan quaternary ammonium salt in isopropanol.The properties of sanples were studied by universal testing machine,tearing tester,folding endurance tester,pH meter,contact angle meter and SEM.The results show that the nano-chitosan quaternary ammonium salt can enhance the mechanical strength of ShengXuan paper.The mechanical properties of the paper after wet-heat aging and dry-heat aging maintain better,and it has not change the hydrophilicity of ShengXuan paper,and will not affect the subsequent paper mounting.By treatment several different types of paper with nano-chitosan quatermary ammonium salt,the results show that it can reinforce the mechanical strength of dense paper such as printing paper and manuscript paper,and the mechanical strength retention rate of paper is better after wet-heat aging and dry-heat aging,and the changes of pH value and color difference are little.4.Study on the conservation effect of nano-chitosan quaternary amnonium salt combined with nano-magnesium oxide on acid paperThe acidic paper was treated with nano-chitosan quatermary ammonium salt combined with nano-magnesium oxide.The deacidification,reinforcement,anti-mildew performance and anti-diffusing properties of nano-chitosan quaternary ammonium salt combined with nano-magnesium oxide on paper were studied by universal testing machine,tearing tester,folding endurance tester,pH meter and ultraviolet-visible absorption spectroscopy separately.The results show that nano-magnesium oxide has good deacidification and reinforcement effect on acid paper,and has good thermal aging resistance,and can reduce the damage of thermal aging to paper and nano-chitosan quaternary ammonium salt.The mechanical strength of acid paper treated with nano-magnesia and nano-chitosan quaternary ammonium salt can be greatly increased.The better treatment method is spraying nano-chitosan quaternary ammonium salt on the acidic paper first,and then spraying nano-magnesium oxide after isopropanol volatilization.This reinforcement method will not affect the anti-diffusing properties of the nano-chitosan quatermary ammonium salt,and has better thermal aging resistance for acid paper.The nano-chitosan quaternary ammonium salt has certain anti-mildew effect,and the addition of nano-magnesium oxide can improve the anti-mildew ability of paper.