Qing Guo , Zuzheng Shang , Weiguo Chen , Dongming Qi , Pu Gao , Zhihua Cui , Sateesh Bandaru
{"title":"In situ generation of azo dyes on silk fibroin through three-step chemical modification","authors":"Qing Guo , Zuzheng Shang , Weiguo Chen , Dongming Qi , Pu Gao , Zhihua Cui , Sateesh Bandaru","doi":"10.1016/j.dyepig.2024.112245","DOIUrl":null,"url":null,"abstract":"<div><p>To enhance the efficiency and reduce the environmental footprint of silk dyeing, this study introduces a novel method that synthesizes azo dyes directly on silk fibroin (<strong>SF</strong>) using a three-step chemical modification at room temperature. Initially, <strong>SF</strong> undergoes modification with isatoic anhydride to yield aromatic primary amino-modified silk fibroin (<strong>SF–NH</strong><sub><strong>2</strong></sub>). Subsequently, <strong>SF-NH</strong><sub><strong>2</strong></sub> is treated with nitrous acid to produce diazotized silk fibroin (<strong>SF–N</strong><sub><strong>2</strong></sub><sup><strong>+</strong></sup>). In the final step, <strong>SF-N</strong><sub><strong>2</strong></sub><sup><strong>+</strong></sup> is combined with coupling components to directly form azo chromophores on the <strong>SF</strong>, culminating in the creation of coloured silk fibroin (<strong>SF–N</strong><img><strong>N-CC</strong>). The efficacy of the three-step dyeing method was validated using infrared spectroscopy and colour development analysis. The modification sites on <strong>SF-NH</strong><sub><strong>2</strong></sub> were identified as the hydroxyl and amino groups of amino acid residues, confirmed through simulated reactions. <strong>SF-N</strong><sub><strong>2</strong></sub><sup><strong>+</strong></sup> demonstrated excellent storage and thermal stability under dry conditions; however, its stability decreased in wet environments. Various coupling components were then reacted with <strong>SF-N</strong><sub><strong>2</strong></sub><sup><strong>+</strong></sup> to synthesize in situ yellow, red, crimson, and green azo dyes on <strong>SF</strong>. The formation of covalent bonds between the dyes and <strong>SF</strong> was verified using DMF stripping methods. The dyed <strong>SF-N</strong><img><strong>N-CC</strong> fabrics underwent testing for fastness, revealing wet fastness rating above grade 4. These findings demonstrate that the three-step modification process represents an innovative, energy-efficient, and fast-reacting dyeing method for <strong>SF</strong>.</p></div>","PeriodicalId":302,"journal":{"name":"Dyes and Pigments","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dyes and Pigments","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0143720824003103","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
To enhance the efficiency and reduce the environmental footprint of silk dyeing, this study introduces a novel method that synthesizes azo dyes directly on silk fibroin (SF) using a three-step chemical modification at room temperature. Initially, SF undergoes modification with isatoic anhydride to yield aromatic primary amino-modified silk fibroin (SF–NH2). Subsequently, SF-NH2 is treated with nitrous acid to produce diazotized silk fibroin (SF–N2+). In the final step, SF-N2+ is combined with coupling components to directly form azo chromophores on the SF, culminating in the creation of coloured silk fibroin (SF–NN-CC). The efficacy of the three-step dyeing method was validated using infrared spectroscopy and colour development analysis. The modification sites on SF-NH2 were identified as the hydroxyl and amino groups of amino acid residues, confirmed through simulated reactions. SF-N2+ demonstrated excellent storage and thermal stability under dry conditions; however, its stability decreased in wet environments. Various coupling components were then reacted with SF-N2+ to synthesize in situ yellow, red, crimson, and green azo dyes on SF. The formation of covalent bonds between the dyes and SF was verified using DMF stripping methods. The dyed SF-NN-CC fabrics underwent testing for fastness, revealing wet fastness rating above grade 4. These findings demonstrate that the three-step modification process represents an innovative, energy-efficient, and fast-reacting dyeing method for SF.
期刊介绍:
Dyes and Pigments covers the scientific and technical aspects of the chemistry and physics of dyes, pigments and their intermediates. Emphasis is placed on the properties of the colouring matters themselves rather than on their applications or the system in which they may be applied.
Thus the journal accepts research and review papers on the synthesis of dyes, pigments and intermediates, their physical or chemical properties, e.g. spectroscopic, surface, solution or solid state characteristics, the physical aspects of their preparation, e.g. precipitation, nucleation and growth, crystal formation, liquid crystalline characteristics, their photochemical, ecological or biological properties and the relationship between colour and chemical constitution. However, papers are considered which deal with the more fundamental aspects of colourant application and of the interactions of colourants with substrates or media.
The journal will interest a wide variety of workers in a range of disciplines whose work involves dyes, pigments and their intermediates, and provides a platform for investigators with common interests but diverse fields of activity such as cosmetics, reprographics, dye and pigment synthesis, medical research, polymers, etc.