Iron powder induction thermochromic polydimethylsiloxane fiber and preparation method thereof

Abstract

The invention discloses an iron powder induction thermochromic polydimethylsiloxane fiber and a preparation method thereof.The preparation method comprises the steps that iron powder and thermochromic microcapsules are added into a mixed emulsion of polydimethylsiloxane and a curing agent, so that the polydimethylsiloxane fiber is endowed with a quick-response thermochromic function; and remote non-contact rapid temperature and color change control is realized. Compared with a traditional temperature change material, the fiber prepared through the method has higher response speed and higher flexibility and plasticity, the application scene is expanded, the fiber can be used in the fields of textiles, intelligent clothes, medicine, temperature control and the like, and the intelligence and application value of the material are increased.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent materials, and in particular relates to an iron powder-induced thermochromic polydimethylsiloxane fiber and a preparation method and application thereof. Background Art

[0002] In the current research context, temperature-variable fiber materials have been widely used in the fields of textiles, medicine, and construction, and can change color according to changes in ambient temperature. However, traditional temperature-variable fibers have certain limitations in terms of temperature response speed and controllability of color conversion. In order to improve the performance of this type of material, the present invention combines iron powder and polydimethylsiloxane (PDMS) as matrix materials, and innovatively applies electromagnetic induction heating technology to the design and manufacture of temperature-variable fiber materials.

[0003] Traditional temperature-variable fibers rely on heat sources, such as human body temperature or ambient heat, to trigger the color change of the material. Due to the lack of effective control of the heat source, such materials often face problems such as slow response to temperature changes and inability to adjust in real time in practical applications. Therefore, improving the response speed of temperature-variable fibers to temperature changes and their application potential in different scenarios have become research focuses. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing iron powder-induced thermochromic polydimethylsiloxane fibers.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0008] The polydimethylsiloxane and the curing agent are mixed evenly, and iron powder with a particle size of 100 to 150 μm is added, and the mixture is stirred and vacuumed to obtain a spinning mother solution;

[0009] Thermochromic microcapsules are added into spinning mother solution, and after being mixed evenly, the iron powder-induced thermochromic spinning solution is obtained;

[0010] The iron powder-induced thermochromic spinning solution is loaded into a syringe and injected into a coagulation bath through a pinhole under the push of a propeller, thereby finally preparing polydimethylsiloxane fibers.

[0011] Wherein, the added amount of the iron powder is 5-10 wt % compared with the polydimethylsiloxane fiber.

[0012] As a preferred solution of the method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention, the addition amount of the iron powder to the polydimethylsiloxane fiber is 5wt%.

[0013] As a preferred solution of the method for preparing the iron powder induced thermochromic polydimethylsiloxane fiber of the present invention, the mass ratio of the polydimethylsiloxane to the curing agent is 9 to 10:1.

[0014] As a preferred solution of the method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention, the stirring time is 8 to 10 minutes, and the vacuuming time is 30 to 50 minutes.

[0015] As a preferred solution of the method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention, the thermochromic microcapsules are red, and the color change temperature is 30-42°C.

[0016] As a preferred solution of the method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention, the content of the chromic microcapsules is 2.5-4wt% of the mass of the spinning solution.

[0017] As a preferred solution of the method for preparing the iron powder induced thermochromic polydimethylsiloxane fiber of the present invention, the specification of the pinhole is 18-19G.

[0018] As a preferred solution of the method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention, the coagulation bath is an oil bath at 100-125°C.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a polydimethylsiloxane fiber prepared by a method for preparing an iron powder-induced thermochromic polydimethylsiloxane fiber.

[0020] Another object of the present invention is to overcome the deficiencies in the prior art and provide an iron powder-induced thermochromic polydimethylsiloxane fiber for use in smart textiles, wearable devices, medical hyperthermia and dynamic visual displays.

[0021] Beneficial effects of the present invention:

[0022] (1) The present invention combines iron powder with temperature-changing pigment and PDMS matrix to develop electromagnetic induction temperature-changing fiber, which realizes remote non-contact rapid control of temperature and color change.

[0023] (2) Compared with traditional temperature-sensitive materials, the fiber prepared by the present invention has faster response speed, higher flexibility and plasticity, and can be used in textiles, smart clothing, medicine and temperature monitoring systems, which greatly expands its application scenarios and improves the intelligent performance and application value of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0025] Figure 1 This is a diagram of the preparation process and color testing process of the iron powder-induced thermochromic polydimethylsiloxane fiber in Example 1 of the present invention.

[0026] Figure 2 This is a diagram of the mechanical properties of the iron powder-induced thermochromic polydimethylsiloxane fiber prepared in Example 1 of the present invention and Comparative Example 1.

[0027] Figure 3 This is a graph showing the electromagnetic induction heating performance of the iron powder-induced thermochromic polydimethylsiloxane fiber prepared in Example 1 and Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] The method for determining the color change performance of the polydimethylsiloxane fiber induced by iron powder thermochromism of the present invention is as follows: the electromagnetic induction heating color change fiber is fixed on a heating platform, the heating platform heating (cooling) speed is set to 1°C / min, and the color change temperature and color change process during the temperature rise and fall of the fiber surface are detected by a thermal infrared imager, and photographed and recorded. The polydimethylsiloxane fiber induced by iron powder thermochromism is placed in an alternating magnetic field, and electromagnetic induction heating is used to heat the iron powder in the fiber to drive the fiber to change color, and the changes on the fiber surface during the magnetic field changes are detected by a thermal infrared imager, and the color changes are photographed and recorded.

[0032] The method for determining the color of the iron powder-induced thermochromic polydimethylsiloxane fiber of the present invention is: under artificial daylight 6500K, using a computer colorimeter and a color matching instrument to measure CIE-1931 chromaticity coordinates, reflectivity and absorptivity.

[0033] The curing agent used in the present invention is SYLGARD 186 silicone curing agent.

[0034] The red thermochromic microcapsules used in the present invention are homemade, with a color change temperature of 31°C and a particle size of 10 μm. The preparation method is as follows: urea and formaldehyde in a molar ratio of 1:1.5 are stirred and mixed evenly, and the pH value of the solution is adjusted to 7-9. The reaction is carried out at a constant temperature of 70°C for 1 hour to form a bone aldehyde resin pre-solution. The thermochromic ternary compound (tetradecanol, bisphenol A, crystal violet lactone) is used as a core material, and a 5% concentration of gum arabic powder solution is gradually added as an emulsifier to form a stable solution. The pre-solution is slowly added to the solution while maintaining air stirring, and the reaction is continued at 70°C for 1 hour, the wall material is gradually formed and coated with the core material to obtain microcapsules, which are cooled to room temperature and centrifuged to obtain red thermochromic microcapsules.

[0035] The Fe powder used in the present invention is high-purity metallic iron powder, and its particle size is 112 μm.

[0036] The raw materials used in the present invention are commercially available unless otherwise specified.

[0037] Example 1

[0038] This embodiment provides a method for preparing iron powder-induced thermochromic polydimethylsiloxane fiber, specifically:

[0039] (1) polydimethylsiloxane (PDMS) and a curing agent were uniformly mixed in a mass ratio of 10:1, 5 wt% of iron powder with a particle size of 100 μm was added, and the mixture was stirred for 10 min and then vacuumed for 30 min to obtain a spinning mother solution;

[0040] (2) adding red thermochromic microcapsules with a color change temperature of 31° C. into a spinning mother solution, and mixing them evenly to obtain an iron powder-induced thermochromic spinning solution, wherein the content of the red thermochromic microcapsules is 4 wt %;

[0041] (3) The electromagnetic induction thermochromic spinning solution is loaded into a syringe and injected into an oil bath at 100° C. through a 19G needle hole under the push of a propeller, thereby finally preparing iron powder induction thermochromic polydimethylsiloxane fibers.

[0042] Example 2

[0043] This embodiment provides a method for preparing an induction thermochromic fiber, which is specifically as follows:

[0044] (1) polydimethylsiloxane (PDMS) and a curing agent were mixed uniformly in a mass ratio of 9:1, 10 wt % of iron powder with a particle size of 150 μm was added, and the mixture was stirred for 8 min and then vacuumed for 50 min to obtain a spinning mother solution;

[0045] (2) adding red thermochromic microcapsules with a color change temperature of 31° C. into a spinning mother solution, and mixing them evenly to obtain an iron powder-induced thermochromic spinning solution, wherein the content of the red thermochromic microcapsules is 3 wt %;

[0046] (3) The iron powder-induced thermochromic spinning solution is loaded into a syringe and injected into an oil bath at 125° C. through an 18G needle hole under the push of a propeller, thereby finally preparing iron powder-induced thermochromic polydimethylsiloxane fibers.

[0047] Example 3

[0048] This embodiment provides a method for preparing an induction thermochromic fiber, which is specifically as follows:

[0049] (1) polydimethylsiloxane (PDMS) and a curing agent were uniformly mixed in a mass ratio of 9:1, 10 wt % of iron powder with a particle size of 150 μm was added, and the mixture was stirred for 8 min and then vacuumed for 45 min to obtain a spinning mother solution;

[0050] (2) adding red thermochromic microcapsules with a color change temperature of 31° C. into a spinning mother solution, and mixing them evenly to obtain an iron powder-induced thermochromic spinning solution, wherein the content of the red thermochromic microcapsules is 2.5 wt %;

[0051] (3) The iron powder-induced thermochromic spinning solution is loaded into a syringe and injected into an oil bath at 125° C. through a 19G needle hole under the push of a propeller, thereby finally preparing iron powder-induced thermochromic polydimethylsiloxane fibers.

[0052] Comparative Example 1

[0053] The difference between this comparative example and Example 1 is that the content of iron powder in step (1) is adjusted to 10wt%, 20wt%, 30wt%, 40wt%, and 50wt% to prepare the iron powder-induced thermochromic polydimethylsiloxane fiber of this comparative example.

[0054] The mechanical properties of the iron powder-induced thermochromic polydimethylsiloxane fibers prepared in Example 1 and Comparative Example 1 were measured. The results are as follows: Figure 2 shown.

[0055] from Figure 2 It can be seen that when the iron powder content is 5-10wt%, the iron powder-induced thermochromic polydimethylsiloxane fiber shows good elasticity and ductility can reach more than 250%. When the iron powder content is 5wt%, the elasticity is the best and the ductility is close to 300%. When the iron powder content is higher than 10%, the elasticity and ductility decrease.

[0056] Comparative Example 2

[0057] The difference between this comparative example and Example 1 is that the particle sizes of the iron powder in step (1) are adjusted to 200 μm and 300 μm, respectively, to prepare iron powder-induced thermochromic polydimethylsiloxane fibers.

[0058] The electromagnetic induction heating performance of the iron powder-induced thermochromic polydimethylsiloxane fiber prepared in Example 1 and Comparative Example 2 was measured. Figure 3 shown.

[0059] from Figure 3 It can be seen that the heating effect of iron powder with a particle size of 100μm is the best, followed by 200μm iron powder, and the heating effect of 300μm is the worst. This is because 100μm iron powder has a smaller particle size, a larger surface area, and good thermal conductivity, so the heating effect is the best. After heating for a fixed time of 20s, the heating temperature of iron powder with a particle size of 100μm can reach 41.8℃.

[0060] Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that the mass ratio of PDMS to curing agent in step (1) is adjusted to 5:1, 6:1, 7:1, 8:1, and 9:1, respectively, to prepare iron powder-induced thermochromic polydimethylsiloxane fibers.

[0062] The mechanical properties of the polydimethylsiloxane fibers prepared in Example 1 and Comparative Example 3 were measured, and the results are shown in Table 1.

[0063] Table 1 Comparison of mechanical properties of polydimethylsiloxane fibers prepared with different mass ratios

[0064]

[0065] It can be seen from Table 1 that when the mass ratio of PDMS to curing agent is relatively low, the prepared polydimethylsiloxane fiber is relatively rigid and brittle. When the mass ratio of polydimethylsiloxane to curing agent is 10:1, the prepared polydimethylsiloxane fiber has the best softness, can undergo large deformation without damage, and has good plasticity.

[0066] Comparative Example 4

[0067] The difference between this comparative example and Example 1 is that the pinhole specifications in step (3) are adjusted to 14G, 18G, 20G, and 25G, and the iron powder-induced thermochromic polydimethylsiloxane fibers are prepared.

[0068] The spinnability of the iron powder-induced thermochromic polydimethylsiloxane fibers prepared in Example 1 and Comparative Example 4 was measured. The results are shown in Table 2.

[0069] Table 2 Comparison of spinnability of polydimethylsiloxane fibers prepared with needles of different specifications

[0070]

[0071] From the comparison of Table 2, it can be seen that needles of different specifications have a significant impact on fiber properties and spinning process. Due to the thick inner diameter of the 14G needle, although the spinning process is relatively smooth, the fiber diameter is too large, reaching 1.65mm, which is difficult to meet the requirements of fine weaving, and the curing effect is not good, so it is not suitable for use. The 18G needle is balanced in fiber diameter and process stability, close to the 19G needle. The 19G needle achieves the best balance between fiber fineness, spinnability and curing effect. It has a moderate fiber diameter, high process stability and excellent curing effect, making it the ultimate optimal choice. In contrast, although 20G and 25G needles can prepare finer fibers, the too small inner diameter causes the spinning solution to easily coagulate in the needle, clogging the needle, significantly reducing the process stability, and even failing to complete normal spinning.

[0072] Comprehensive analysis shows that the 19G needle maintains good process stability while ensuring fiber fineness, taking into account both performance and processing difficulty, and is the best choice in wet spinning.

[0073] Comparative Example 5

[0074] The difference between this comparative example and Example 1 is that the contents of the red thermochromic microcapsules in step (2) are adjusted to 2wt%, 2.5wt%, 3wt%, 5wt% and 6wt%, respectively, to prepare iron powder-induced thermochromic polydimethylsiloxane fibers.

[0075] The comprehensive properties of the polydimethylsiloxane fibers prepared in Example 1 and Comparative Example 5 were measured, and the results are shown in Table 3.

[0076] Table 3 Comparison of comprehensive properties of polydimethylsiloxane fibers prepared with different temperature-dependent powder contents

[0077]

[0078] According to Table 3, after comprehensive evaluation of various factors, the content of thermochromic microcapsules is in the range of 2.5-4wt%, and the prepared fiber has balanced performance in key indicators such as color change, spinnability, spinning solution viscosity and cost. Although the formulations below or above this range have their own characteristics, they all have obvious limitations and cannot meet application requirements.

[0079] In summary, the present invention combines iron powder and temperature-changing pigments with a PDMS matrix to develop electromagnetic induction temperature-changing fibers, which achieves remote non-contact rapid control of temperature and color changes. Moreover, compared with traditional temperature-changing materials, the fibers prepared by the present invention have faster response speed, higher flexibility and plasticity, and can be used in textiles, smart clothing, medicine, and temperature monitoring systems, greatly expanding its application scenarios and improving the intelligent performance and application value of the materials.

[0080] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing iron powder-induced thermochromic polydimethylsiloxane fiber, characterized in that: include, The polydimethylsiloxane and the curing agent are mixed evenly, and iron powder with a particle size of 100 to 150 μm is added, and the mixture is stirred and vacuumed to obtain a spinning mother solution; Thermochromic microcapsules are added into spinning mother solution, and after being mixed evenly, the iron powder-induced thermochromic spinning solution is obtained; The iron powder-induced thermochromic spinning solution is loaded into a syringe and injected into a coagulation bath through a pinhole under the push of a propeller, thereby finally preparing polydimethylsiloxane fibers. Wherein, the added amount of the iron powder is 5-10 wt % compared with the polydimethylsiloxane fiber.

2. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The iron powder is added in an amount of 5 wt % relative to the polydimethylsiloxane fiber.

3. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The mass ratio of the polydimethylsiloxane to the curing agent is 9 to 10:

1.

4. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The stirring time is 8 to 10 minutes, and the vacuuming time is 30 to 50 minutes.

5. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The thermochromic microcapsule is red, and the color changing temperature is 30-42°C.

6. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The content of the thermochromic microcapsules is 2.5-4wt% of the mass of the spinning solution.

7. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The specification of the pinhole is 18-19G.

8. The method for preparing the iron powder-induced thermochromic polydimethylsiloxane fiber according to claim 1, characterized in that: The coagulation bath is an oil bath at 100-125°C.

9. An iron powder-induced thermochromic polydimethylsiloxane fiber prepared by the preparation method according to any one of claims 1 to 8.

10. Application of the iron powder-induced thermochromic polydimethylsiloxane fiber as claimed in claim 9 in smart textiles, wearable devices, medical hyperthermia and dynamic visual display.

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