Preparation And Properties Of Full Color Thermochromic Fluorescent Fiber

Smart textiles are created by combining traditional textiles with various research disciplines such as nanotechnology,materials science,fashion design,electronics and computer engineering.Globally,the market for smart textiles is expanding and promising.Stimulusresponsive fluorescent materials are a type of smart materials whose fluorescent behavior changes significantly under the action of external stimuli such as force,electricity,and heat.They have huge applications in the fields of biological analysis,encryption anti-counterfeiting,optical switches,and sensing detection potential,among which thermal response has received widespread attention because of its low cost and abundant sources.Thermally responsive fluorescent color-changing fiber materials,as the basic components of smart clothing,have important theoretical research and development and application values.In this paper,the melting/crystallization transition of saturated fatty acids in the heating and cooling process is used to drive the aggregation and dispersion state transition of fluorescent molecules and fluorescent extinguishing molecules,and realize the reversible change of fluorescent color in the off-on state.The mixed color matching of red,green and blue primary color thermochromic fluorescent materials has successfully prepared a full-spectrum thermochromic fluorescent material,combined with wet spinning technology,and finally obtained a full-color thermochromic fluorescent fiber.The specific research content as follows:(1)Select the hexadecanoic acid phase change material with crystallization characteristics,use its melting/crystallization transition to drive the aggregation and dispersion state of fluorescent molecules and fluorescent extinguishing agent molecules,and obtain a thermally driven off-on color-changing three-primary-color fluorescent material,and analyze its thermoluminescent color-changing behavior.Nile red is selected as the fluorophore of the red thermochromic fluorescent material,combined with hexadecanoic acid,it can emit bright red fluorescence in the dispersed state at elevated temperature,and realize the quenching effect in the state of fluorescence aggregation at normal temperature.Two coumarin derivatives with high fluorescence intensity were selected as the blue fluorophore(7-diethylaminocoumarin-3-carboxylic acid)and the green fluorophore(coumarin 6),using Foster Energy resonance transfer,the introduction of fluorescent extinguishing agent methylene blue,obtains blue and green thermochromic fluorescent materials that quench fluorescence in the aggregated state and emit bright blue and green fluorescence in the dispersed state.(2)Using the principle of color addition of three primary colors,the red,green and blue three primary color thermochromic fluorescent materials are mixed and prepared in different proportions to obtain a full-color thermochromic fluorescent material.Three primary color thermochromic fluorescent materials are first paired in pairs,with blue fluorophore: red fluorophore at 10:1,5:1,3:1,2:1,1:1;green fluorophore: red fluorophore 10:1,5:1,3:1,2:1,1:1;blue fluorophore: green fluorophore is 10:1,5:1,3:1,1:1,1:3 mixed in molar ratio,a series of colors such as purple,yellow,blue-green,orange,etc.were obtained,and according to the molar ratio of red fluorophore: green fluorophore: blue fluorophore = 3:2:8,obtained in the light-emitting material The unique white fluorescence realizes the expansion of the color range of fluorescent color-changing materials.(3)Using wet spinning technology,thermochromic fluorescent fibers were prepared based on thermochromic fluorescent powders,and the microscopic morphology,fluorescence characteristics,and mechanical properties of the fibers were studied and analyzed.First,the thermochromic fluorescent material is ground into powder,dispersed into 5 wt% sodium alginate solution,coagulated in 5 wt% calcium chloride solution,and prepared by wet spinning technology with a draw ratio of 1.1 times fiber material.It is divided into four particle size gradients by standard sieving,and test analysis proves the influence of particle size differences on fiber formation,mechanical properties,and fluorescent discoloration behavior.Utilize the good flexibility of the prepared fiber to embroider on the fabric to prepare a flexible colorchanging fabric device.The pattern has the advantages of significant color change and good fluorescence reversibility(> 30 cycles),which can meet different personalized designs.great practical application potential.