| Gummed Canton silk(also known as Xiangyun Silk)is a classic silk product in China.It is made of silk,Dioscorea Cirrhosa Lour,and river mud.It is made by hand under natural conditions by repeated dyeing and exposure,and finally by applying mud.The two key steps in the processing of gummed Canton silk are solarization,which causes the pigment of Dioscorea Cirrhosa Lour to solidify on the silk,and mud coating,which creates a shiny black coating on the surface of the fabric.The production process of gummed Canton silk is tedious and dependent on sunlight and river mud,so it is currently limited to the Foshan area in Guangdong.The fundamental reason for the difficulty of industrial production of gummed Canton silk is that the chemical mechanisms involved in the two key processing steps are not yet clear.In this study,we first investigated the key organic components and their structural characteristics of the river mud used in the production of gummed Canton silk;Then,a quantitative detection method for key organic components in river mud was established;Finally,the effect of solarization on the composition and structure of the pigment extract from Dioscorea Cirrhosa Lour was investigated.The main research conclusions are as follows:Firstly,the alkaline solution acid precipitation method was used to separate the river mud from the two main production areas of gummed Canton silk,Shunde and Xiqiao,and Xiasha river mud with similar physical properties was used as a control.Purified three organic components from river mud.The structure of river mud components attached and not attached to fabrics during the coating process was investigated using UV,FT-IR,XPS.The study showed that the humic acid and fulvic acid in the organic matter of river mud were involved in the construction of the coating of gummed Canton silk,while humin and other insoluble substances were not involved in the reaction.The content of humic acid and fulvic acid in the river mud from Xiqiao and Shunde areas of Foshan was higher,and its aromatization and oxygen-containing functional groups were significantly higher,and its humic acid fraction had a stronger ability to bind iron ions.Secondly,a method for quantitatively analyzing key organic components of river mud based on the Folin-Ciocalten method was created,and key data on the content of river mud coating construction components used in the production of gummed Canton silk was obtained.The optimum reaction conditions for testing 10.0 mg of river mud were 1.0 m L of 1 mol/L Folin-Ciocalten reagent,0.6 m L of 150 mg/m L sodium carbonate solution,3.4 m L of deionized water,and 40 KHz sonication at 40℃for 60min.The standard curve equation was Y=1.30476X+0.26943,R~2=0.99834.The RSD values of stability and reproducibility were 0.68%and 1.43%,respectively,and the average spiked recovery was 102.96%with RSD of 3.41%,indicating that the method is simple,easy to use,and accurate.The contents of key organic fractions(humic acid and fulvic acid)in river mud from Shunde,Xiqiao,and Xiasha were 9.64%,5.61%and1.88%,respectively,measured by this method.Finally,the effect of solarization on the composition and structure of the pigment extract from Dioscorea Cirrhosa Lour was basically clarified.By analyzing the pigment and separated components after solarization,it is clear that solarization did not cause significant changes in the structure of tannin pigments in Dioscorea Cirrhosa Lour,but caused significant changes in the structure of white polysaccharide components in the pigment crude extract. |
PDF Full Text Request