The Extraction Of Red Cabbage/purple Sweet Potato And Preparation Of Acid-base Indicator Silk Fabric

With the improvement of people’s living and the enhance for awareness of environmentalprotection, dye is becoming increasingly popular. As yet,study on natural dye is concentratedon dyeing performance,and less study on special function.Preparation of excellent acid-baseinstruction effect fabric,and when natural dye which is sensitive to acid/base is applied to thecloth.This study not only would improve the natural dye worthiness,but also would be willaccord with ecological textile and increase the additory value of textile.In this paper，red cabbage （RC） and purple sweet potato （PSP） are the main study object,and extracted by means of pH3-HCl aqueous and pH3-HCl-80%ethanol aqueousrespectively, and optimizing the extraction process.The paper probed into the spectrumcharacter of pigment of red cabbage and purple sweet potato by IR and UV-visiblespectroscopy and research influence of the pigment stability on the pH， metalion,temperature，etc.The preparation and testing acid-base instructions property of silk fabricwere investigated.According to acid-base instructions property, the process parameters wereoptimized.The results were as follows:The optimum extraction process of RCwas pH3-HCl as extractant with ratio of materialto liquid1:10for60min under60℃,extracting2times. The optimum extraction process ofPSP was pH3-HCl-80%ethanol as extractant with ratio of material to liquid1:30for90minunder70℃,extracting2times.The pigment of RC and PSP which have maximum absorption peak in290nm,530nmrespectively, show that RC and PSP are all anthocyan pigments. According to maximumabsorption peak in320nm,322nm respectively and A310/Amax-visratio, gives the result thatpigment of RC and PSP are acylation pigment and acetylation groups more than one．There isno glucosides on5-C of RC and PSP contained a glucosides on3-C according to A440/Amax-visratio.Color and absorbance of RC and PSP were affected by pH value.At pH5～6and pH >8,absorbance of RC and PSP had markedly droppded within3times.RC and PSP were stableunder50℃,the higher the temperature is, the faster the decomposition.Al³⁺have certainprotect effect while Fe²⁺damaged the pigment.The Acid-base instructions performance of silk fabric was perpared by immobilizingBOVC/PSP with metal ion.The Acid-base instructions performance of silk fabric exhibitedremarkbale color change from red to yellowgreen at pH3～9with short response time andecxcellent recycle stablilty.Different acid and base had less effects on acid-base instructions.The effect factors such as type and dosage of metal ion，pigment dosge and temperatureon acid-base indicator performance are investigated, and optimizing conditions wereobtained. The optimum process of RC silk fabric was concentration of RC8%（omf），concentration of ferrous sulfate6%（omf） at60℃，The optimum process of PSP silk fabricwas concentration of RC8%（omf），concentration of ferrous sulfate4%-6%（omf） at60℃.