Study On The Surface Structure Design And Coloring Properties Of Alginate Fiber And Its Textiles

Alginate fiber is a green and renewable biomass material,and its raw materials are abundant in nature.The main preparation method of alginate fiber is wet spinning.Alginate fiber can be obtained after the sodium alginate spinning solution is extruded from the spinneret to the solidification bath.Sodium alginate is a natural polymer extracted from the alginate plants,which has many excellent properties.Its non-toxic,pollution-free and biodegradable characteristics make alginate fiber widely used in textile,clothing,medical and health fields.Alginate fiber and its fabric have many excellent properties,but the following problems make it difficult to dye alginate fiber and its fabric:it is not resistant to strong acid and alkali,it is easy to be dissolved in salt solution,its oxidation resistance is relatively low,it is also insoluble in organic solvents,the dye uptake decreases with the increase of dye concentration,and the dye uptake time and temperature also increase.In order to solve the dyeing problem of alginate fiber and its fabric,this paper will start from the perspective of stock solution dyeing and structure coloring,and carry out the following research on the coloring methods of alginate fiber and its fabric:（1）Thermochromic alginate fibers with core-sheath structure were prepared by microfluidic spinning method.The fibers were composed of a layer containing thermochromic powder and a core layer of pure alginate.There is no chemical reaction between the thermochromic powder and the alginate,and the tensile strength of the core-sheath structure alginate fiber decreases with the increase of the powder concentration.For the alginate fiber with thermochromic core-sheath structure,the core-sheath structure does not affect its color saturation and brightness.Thermochromic alginate fibers are sensitive to change color and can accurately change temperature at the critical temperature.The color of thermochromic alginate fibers can be adjusted reversibly with the change of external temperature.（2）The Si O₂ microspheres with good monodispersity were prepared by the stobe method,and the gravity deposition self-assembly method was used to construct the structural color with Si O₂ as the unit on the surface of the polydopamine-treated alginic acid/cotton blended fabric.With the increase of the addition amount of tetraethyl orthosilicate,the particle size of Si O₂ microspheres showed a trend of decreasing first and then increasing.With the increase of the addition of tetraethyl orthosilicate,the reflectance spectrum of the structure color showed a trend of red shift first and then blue shift.After the substrate was treated with polydopamine,a fabric with better durability and saturation was obtained.（3）Fe₃O₄@C microspheres were prepared by solvothermal method with acetone as solvent,ferrocene and hydrogen peroxide as raw materials.The microspheres were mixed with polyethylene glycol diacrylate（PEGDA）and dispersed evenly.The dispersion was coated and fixed on the fabric,and then the fabric was irradiated by ultraviolet light in a magnetic field.Finally,the alginate/cotton blended fabric with structural color was prepared,which has good durability,high color saturation and is not easy to fade.In addition,through the study of Fe₃O₄@C microspheres,it is found that the color of magnetic microsphere dispersion will become weaker with the weakening of magnetic field,and the decrease of dispersion concentration will lead to the decrease of color brightness and color of liquid in the same magnetic field.