Study on the Role of Sizing Agent in Ancient Calligraphy & Painting and the Development of Neutral Aluminum Salt Sizing Precipitator

Author:He Qiu Ju

Supervisor:wang li qin


Degree Year:2019





Chinese ancient calligraphy and painting are an important traditional arts in China.There are a large number of collections in museums and folks.Due to the large amount of pores between the paper fibers of calligraphy painting,it is easy to dizzy and diffuse ink when writing and drawing,which affects the effect of writing and painting.Therefore,the ancients often used a certain proportion of glue and alum solution as surface sizing agent usually,so as to improve the hydrophobicity of paper.The alum gelatin solution was also often used for repair and reinforce painting colors.However,the alum was easy to hydrolyze and produce acid in high humidity,which will accelerate the hydrolysis and aging of cellulose,with the reduction of the storage life of ancient paintings.The scientific connotation of alum gelatin solution was discussed in this paper,based on the understanding of the hydrophobicity and color fixing mechanism,aiming at"seeking advantages and avoiding disadvantages",and developed new materials with excellent performance for painting and calligraphy restoration and protection.The main contents of this research include:(1)Study on application mechanism of alum gelatin solution curing xuan paper and fixing color.The effects of gelatin and alum for paper hydrophobicity were studied through the experiments of glue solidification,ink droplet halo and writing.The dominant factors to improve the hydrophobicity of paper in alum gelatin system were studied by uniform experiment.And the species distribution of aluminium after hydrolysis,mixing with glue and sizing on the surface of xuan paper were studied by Al-Ferron complex timed spectrophotometric method(Al-Ferron)and high-field 27Al-NMR spectroscopy(27Al-NMR).In order to study the synergistic reaction of glue and alum,the surface condition after sizing,including the chemical bonding of alum with gelatin and fibers were tested by scanning electron microscopy(SEM)and attenuated total reflectance infrared spectroscopy(ATR-FTIR).Furthermore,the self-deconvolution and second derivative curve fitting techniques of ATR-FTIR were used to analyze the change of secondary structures of gelatin.The scientific connotation of color fixing was discussed by using the changes of color,color fastness and micro-pore variation.The results showed that alum played a role in drying agents,softeners and sizing retention aids when curing xuan paper,and gelatin played a leading role to enhance hydrophobicity of paper.Alum promotedγ-random of the secondary structure of gelatin,which making the protein structure was more loose,thus the surface hydrophobicity of the protein increased.The hydrolysis products of alum solution were mainly monomeric aluminum Al(H2O)63+(Al1),AlSO4+and polymeric aluminum([Al30O8(OH)56(H2O)24]18+)(Al30).The results of ATR-FTIR showed that the reduced positive monomeric and polymeric aluminum were probably bonded with hydroxyl(-OH)or carboxyl(-COOH)of gelatin and formed network complexes,thus the water resistance of xuan paper improved.When reinforcing the color,the alum prompted gelatin particles depositing on the negatively charged pigments,and filled the pores on the surface of the pigment particles,and reduced the light scattering phenomenon,thereby increased the brightness of the pigment.(2)The impact of alum on the acidification of xuan paper in different aging environments.The changes of molecular structure and micro-morphology of xuan paper fibers treated with alum were analyzed by fourier transform attenuated total reflection infrared spectroscopy(ATR-FTIR),X-ray diffraction(XRD)and scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS)before and after aging at high temperature of 105℃,wet-heat of 50℃and 85%RH and high humidity of 44%85%RH.And the effect of alum on the filler of xuan paper was preliminarily discussed.The results showed that the alum content threshold of high temperature aging was 0.5%,the threshold of damp heat aging was 0.1%,the humidity threshold of acidification of paper at normal temperature was 55%,and the threshold of alum content was 0.6%.The surface of fibers treated with alum gelatin solution shrivelled after wet-heat aging,and when alum concentration exceeded 4%,the fibers twisted and fractured.With the increase of alum content,the infrared absorption peak intensity of cellulose decreased gradually.The analysis of chemical composition showed that alum reduced the content of cellulose and hemicellulose and increased the ash content.The acid precipitated from alum promoted the decomposition of cellulose glycoside bond and dissolved the basic filler calcium carbonate of xuan paper.(3)Study on the application effect and mechanism of different maturity soybean water in painting and calligraphy restoration.For the first time,the 8-aniline-1-naphthlene sulfonic acid(ANS)fluorescence probe and sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)were applied to cultural relics protection.The change of surface hydrophobicity of xuan paper treated by soybean milk in the heating process was analyzed,and(SDS-PAGE)was adopted to sort out the differential bands of soybean protein which later were identified by LC-MS/MS.Last but not least,the self-deconvolution and second derivative curve fitting techniques of ATR-FTIR were used to analyze the change of secondary structures of soybean protein in different heating temperatures.The analysis showed that there was a disappearance of globulin glycinin G3 and glycoprotein lectin under high temperature.The soybean water achieved its largest hydrophobicity when the temperature rose to 80℃.The increase of heating temperature of soybean water raisedβ-sheet content from 41.4%to 48.87%.There was a positive correlation between the structural content ofβ-sheet and the surface hydrophobicity.The research showed that heating temperature of 80℃and a heating time of no more than 30min was most suitable for paper sizing in painting restoration.(4)The development of neutral aluminum salt sizing precipitator for paper sizing and pigment reinforcement.The common natural animal and plant sizing materials and the most potential sizing precipitants were screened by the changes of pH value,chroma,hydrophobicity and mechanical properties of xuan paper before and after sizing.The results showed that the gelatin-treated xuan paper was neutral and had good thermal stability.Among the sizing precipitants,the Alb content of polyaluminium polychloride was the highest.The polynuclear aluminium[AlO4Al12(OH)24(H2O)12]7+(Al13)showed high cationic charge and reaction activity.It was suitable to replace alum as sizing precipitator,playing a role of a drying promoter and bonding with gelatin and form network complex.It was confirmed that polyaluminium chloride was prepared by acid-dissolving method.(5)Application and effect evaluation of neutral aluminum salt sizing precipitator.The results showed that the content of polynuclear aluminium Alb in the solution could reach more than80%.The pH value of xuan papers after sizing could reach more than 7,and it also showed weak alkaline after wet-heat aging for 28 days.The sizing material improved the hydrophobic property and mechanical strength of the paper and made the pigments have good color and no shading.The research and development of neutral aluminum salt sizing precipitator will improve the acidification of ancient paintings and paintings,and it is of great significance for the effective protection of ancient painting and calligraphy.