Liquid crystal elastomer fabric and preparation method thereof

Abstract

The invention belongs to the technical field of intelligent textiles, and discloses a liquid crystal elastomer (LCE) fabric and a preparation method thereof. According to the method, an LCE polymer is dissolved in a mixed solvent of dimethyl sulfoxide and dichloromethane, a precursor solution with the concentration of 8%-23% is prepared, the surfaces of various blended fabrics are coated with the precursor solution in a single face mode, a uniform coating is formed through ultraviolet curing and thermocuring processes, and molecular orientation is optimized in combination with pre-stretching sizing. Experiments show that the coating significantly improves the breaking strength of the fabric and endows the fabric with a thermal response characteristic. By adjusting the LCE concentration and base material adaptability, the problems that a traditional LCE process is high in cost and complex in operation are solved. Preferably, under the concentration of 18%, the breaking strength CV of 90% polyester + 10% spandex knitted fabric is 3.46%, the air permeability is reserved by 14%, and the knitted fabric has high thermal responsiveness and mechanical stability. The method is suitable for the fields of flexible electronics, soft robots, self-adaptive protective clothing and the like, and an intelligent functional textile compatible with multiple scenes is realized through a low-cost brushing process.

Description

Technical Field

[0001] The present invention belongs to the technical field of smart textiles, and specifically relates to a liquid crystal elastomer (LCE) fabric and a preparation method thereof, which is particularly suitable for achieving smart functional textiles with high interface bonding strength and multi-scenario compatibility through a simple coating process. Background Art

[0002] In recent years, smart textiles have demonstrated tremendous potential in wearable devices, medical monitoring, and adaptive protection. Traditional smart fabric coatings rely on shape memory alloys or electroactive polymers (EAPs). These coatings sacrifice fabric flexibility to maintain conductivity. For example, polypyrrole coatings can increase fabric bending stiffness by over 50%, resulting in reduced wearer comfort. Shape memory alloy coatings rely on external heating (>100°C) to trigger deformation, which consumes high energy and can easily damage the fabric.

[0003] Liquid crystal elastomers (LCEs), as an emerging stimuli-responsive material, are considered an ideal candidate for overcoming existing technological bottlenecks due to their high energy density, reversible actuation, molecular programmability, high strain and stimuli-responsive properties. However, existing LCE-to-fabric integration techniques often rely on composite fiber weaving or sandwich encapsulation, which present complex processes, high costs, and compromised breathability. For example, processing LCE into fibers and then blending them with matrix yarns requires custom spinning equipment, increasing costs by 300%-500% and reducing fabric porosity by 40%-60%, significantly impairing breathability. Currently, mainstream LCE coating processes (such as 3D printing and electrospinning) are expensive, making direct application on common textiles difficult. Their preparation is complex and costly. Existing spray or spin coating methods often result in uneven distribution of the coating on the fabric surface. Spray coating can easily lead to edge accumulation, while spin coating is more suitable for rigid, flat substrates. The centrifugal force during spin coating can cause the coating thickness to decrease from the center to the edge, and this uneven coating can affect thermal response and durability.

[0004] Most studies have focused on a single type of substrate (such as nylon or polyester), lacking systematic research on different blended textiles. Due to differences in surface roughness, hydrophilicity, and elastic modulus, LCE adhesion, deformation behavior, and mechanical stability can vary significantly across fabrics.

[0005] The traditional LCE fiber preparation method is complicated, but this study uses a direct brushing process, which can greatly reduce production costs and is suitable for large-scale textile manufacturing. By optimizing the concentration and viscosity of the LCE solution, it can be evenly coated on the surface of different blended fabrics, ensuring the stability of thermal response performance. At the same time, the present invention is applicable to a variety of blended fabrics, broadening the scope of application. Current LCE research mostly focuses on a single material, while the method of the present invention can be applied to at least seven different blended fabrics, systematically evaluating the mechanical properties and temperature response characteristics of LCE, and providing data support for LCE in actual textile applications. By adjusting the concentration of the LCE solution and the curing conditions, its deformation rate at low temperatures (such as 80°C) is optimized, avoiding the defects of traditional LCE high-temperature drive, and improving wearability and comfort. Summary of the Invention

[0006] This invention proposes a brush-coating method for LCE coating, aiming to prepare a liquid crystal elastomer fabric. This method can achieve stable adhesion of LCE on a variety of blended fabrics (including viscose, polyester, spandex, cotton, etc.), while optimizing the process to provide broader applications in smart textiles, flexible electronics, soft robotics, and other fields. The technical solutions adopted by this invention are as follows: According to a specific embodiment of the present invention, a method for preparing a liquid crystal elastomer fabric comprises the following steps: The LCE polymer is soaked and dissolved in an organic solvent to obtain an LCE precursor solution.

[0007] Cut the prepared fabric into small pieces, then evenly apply the LCE precursor solution on one side of the fabric and cure it with a UV lamp. The fabric cured by ultraviolet irradiation in the ultraviolet light box is placed in an oven, dried, pre-stretched and shaped, and then placed in the oven again for orientation and fixation, ultimately obtaining a liquid crystal elastomer fabric with high elasticity, high recovery and thermal responsiveness.

[0008] In the above technical solution, further, the organic solvent used in step 1) is a mixed solvent of dimethyl sulfoxide and dichloromethane, and the two are mixed in equal volume proportions to dissolve the LCE crystals.

[0009] Furthermore, in step 1), LCE crystals are immersed in a mixed solvent at a concentration of 8% to 23% by mass, stirred in a magnetic stirrer at 50°C for 4 to 6 hours, and after the LCE crystals are completely dissolved and the mixed solution is uniform, it is placed in an oven to evaporate the remaining solvent. The LCE liquid crystal monomer used in this invention is RM82, a thermotropic elastomer. Its combination with fabrics is primarily intended to explore its potential applications in smart textiles.

[0010] Furthermore, the fabric samples described in 2) are mainly organic fabrics and knitted fabrics. The specific fabrics can be single fabrics, or they can be viscose + polyester + spandex blended woven fabrics, polyester filament + cotton + spandex blended woven fabrics, cotton + polyester blended woven fabrics, 96% polyester + 4% spandex blended knitted fabrics, 92% cotton + 8% spandex blended knitted fabrics, 95% viscose + 5% spandex blended knitted fabrics, and 90% polyester + 10% spandex blended knitted fabrics.

[0011] Furthermore, in step 2), the fabric is coated with the LCE precursor solution, and the base fabric is preferably a blended knitted fabric, and most preferably a 90% polyester + 10% spandex blended knitted fabric.

[0012] Furthermore, in step 3), the film is cured in a UV light box at a wavelength of 365 nm for 15 minutes; Furthermore, in step 3), after light curing, the fabric is placed in an oven and dried at 60°C for 20 to 30 minutes. The actual state is observed. After drying, the fabric is taken out and pre-stretched to 1.2 to 1.8 times (the specific situation depends on the type of fabric), and then placed in an oven and dried at 60°C to 80°C for another 2 hours to obtain the finished product.

[0013] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: 1) In the present invention, LCE crystals are dissolved in a 1:1 volume mixture of dimethyl sulfoxide and dichloromethane, and can be completely dissolved to prepare a uniform LCE precursor solution. At the same time, energy consumption is low and the dissolution effect is better.

[0014] 2) When preparing LCE fabrics, considering the fabric structure and the influence of yarn type on the coating, a fabric density of 15 to 22 yarns / cm is optimal. Within this range, the interstices between the yarns are moderate, allowing the LCE solution to penetrate through the interstices, resulting in a tight and uniform coating and a more pronounced effect on the fabric. However, denser fabrics, such as woven fabrics, have higher densities and smaller pores, making it difficult for the LCE solution to penetrate between the yarns, and only a thin film forms on the surface, resulting in a less pronounced coating effect. Based on experimental and literature analysis, a yarn thickness of 16s to 24s is optimal. Coarser yarns result in noticeable unevenness on the fabric surface, leading to uneven coating thickness. Finer yarns, however, result in insufficient penetration of the coating through the fabric pores, resulting in a thin film on the surface, similarly leading to a less pronounced effect on the fabric. The present invention successfully produces LCE fabrics with excellent uniformity by using a brush coating process. The brush coating process operates at fixed points and in fixed quantities according to the fabric structure, and can control the coating direction and strength along the fabric texture, reducing dead corners and accumulation. Compared with spraying and spin coating, which are sensitive to changes in solution viscosity, the brush coating process has a wider applicability.

[0015] 3) Within the LCE concentration range of 8% to 23%, as the concentration increases, the thicker the coating, the more significant the improvement in the fabric's breaking strength, and the greater the thermal response deformation and expansion rate, but the breathability also gradually deteriorates. Experiments have found that a concentration between 13% and 18% is a relatively good choice, with a moderate coating thickness, coating ratio, and breathability, achieving good thermal response and improved breaking strength while also ensuring comfortable wear. Compared to existing technologies, this invention, through an innovative combination of overall structure, material selection, and processing technology, comprehensively improves the performance of liquid crystal elastomer-coated fabrics at a lower cost.

[0016] 4) At 80°C, the best thermal response shrinkage of the best coated fabric obtained in the experimental group of the present invention can reach about 21%, with relatively obvious thermal response deformation; there are many groups with deformations between 5% and 10%, indicating that LCE coating is feasible and effective for coating on fabrics of most common materials. However, due to the low elasticity of the fabric itself, the thermal response shrinkage change is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a viscose + polyester + spandex blended woven LCE coated fabric; Figure 2 It is a polyester + cotton + spandex blended woven LCE coated fabric; Figure 3 It is a cotton + polyester blend woven LCE coated fabric; Figure 4 It is a 96% polyester + 4% spandex blended knitted LCE coated fabric; Figure 5 It is a 92% cotton + 8% spandex blended knitted LCE coated fabric; Figure 6 It is a 95% viscose + 5% spandex blended knitted LCE coated fabric; Figure 7 It is a 90% polyester + 10% spandex blended knitted LCE coated fabric; Figure 8 The 90% polyester + 10% spandex blended knitted LCE coated fabric of Example 8; Figure 9 The 90% polyester + 10% spandex blended knitted LCE coated fabric of Example 9; Figure 10 The 90% polyester + 10% spandex blended knitted LCE coated fabric of Example 10; Figure 11 It is the LCE used in the embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical method of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0019] According to some specific embodiments of the present invention, the coating preparation process used for liquid crystal elastomer fabrics includes adding LCE polymer to a mixed solvent of equal volumes of dimethyl sulfoxide and dichloromethane to prepare an LCE solution, fixing the base fabric, i.e., the base cloth, on cardboard for brushing, then brushing the LCE precursor solution onto the base cloth, placing it in a UV light box for UV curing, and then placing it in an oven for drying. After removing the fabric and pre-stretching it, it is dried and post-cured. This allows the LCE elastic liquid crystals to lock their internal arrangement structure under high-temperature stretching, ensuring high reversibility and stability in subsequent thermal drive cycles. The base fabric described in the present invention can be a single base fabric or a mixed fabric, and is particularly effective for blended knitted fabrics. For single base fabrics with good elasticity, the LCE liquid crystal elastomer coating of the present invention can also improve its various properties.

[0020] Example 1

[0021] like Figure 1 The fabric shown is a viscose, polyester, and spandex blend woven LCE-coated fabric. The preparation method includes the following steps: An 18% LCE precursor solution (made by mixing dimethyl sulfoxide and dichloromethane in a 1:1 ratio by volume and stirring at 50°C for 4–6 hours to fully dissolve) is applied to one side of the viscose, polyester, and spandex blend woven fabric. After UV curing, the fabric is dried at 60°C, pre-stretched 1.5 times, and then post-cured at 80°C for 2 hours.

[0022] The original weight was 0.5263 g, but after coating, it reached 0.6595 g, resulting in a coating weight increase of 0.1332 g, approximately a 25% increase. This indicates that the LCE solution formed a certain load on the fabric surface, but due to the denseness of the woven fabric, only a thin layer formed on the surface. The fabric thickness increased from 0.746 mm to 0.844 mm (a 13% increase), reflecting a significant increase in the coating thickness on the fabric surface. The dense structure of the woven fabric caused the LCE solution to adhere primarily to the surface, with limited penetration. This resulted in an increase in both thickness and weight, but also an uneven coating distribution. The air permeability decreased by 67% from 426.2 mm / s to 139.2 mm / s, indicating that the LCE coating sealed the fabric pores and provided a high density. The breaking strength increased significantly from approximately 64.45 N to 198.74 N, but the CV value (coefficient of variation) was high (approximately 11%), indicating uneven distribution of the coating on the fabric and possible inconsistent adhesion. In terms of temperature response and expansion rate, the longitudinal expansion rate reaches 11% at 80°C, while the transverse expansion rate is almost zero. The main reason is that the pre-stretching is mainly concentrated in the longitudinal direction. The fabric has poor transverse elasticity and cannot be stretched.

[0023] In general, this embodiment is reasonable in improving mechanical properties, but has deficiencies in air permeability and isotropic uniformity. The transverse thermal response deformation is almost zero, and the LCE coating has little effect on the base fabric.

[0024] Example 2

[0025] like Figure 2 The fabric shown is a polyester + cotton + spandex blended woven LCE-coated fabric. The preparation method includes the following steps: an 18% LCE precursor solution (mixed with dimethyl sulfoxide and dichloromethane in a 1:1 volume ratio and stirred at 50°C for 4–6 hours to fully dissolve) is coated on one side of a low-weight fabric (polyester + cotton + spandex blended woven fabric base weight 0.3037g), followed by UV curing, drying at 60°C, pre-stretching 1.5 times, and secondary curing at 80°C.

[0026] The original weight is 0.3037g, and it reaches 0.4514g after coating. The coating accounts for 49%, indicating that the coating adhesion is relatively high.

[0027] The thickness increased from 0.368 mm to 0.464 mm (a 26% increase), indicating a significant coating effect. Air permeability decreased significantly from 811.5 mm / s to 213.3 mm / s (a 74% decrease), indicating that the LCE coating almost completely sealed the fabric pores. The breaking strength increased from approximately 92–93 N to approximately 110–111 N, with an extremely low CV value, indicating a uniform coating distribution. However, the temperature responsiveness, with a shrinkage of only approximately 4.1% at 80°C, suggests a weak LCE effect. Furthermore, the breaking strength enhancement effect was poor, indicating that the LCE coating had little effect on the base fabric.

[0028] Example 3

[0029] like Figure 3 The figure shows a cotton + polyester blended woven LCE-coated fabric. The preparation method includes the following steps: an 18% LCE precursor solution (mixed with dimethyl sulfoxide and dichloromethane in a volume ratio of 1:1 and stirred at 50°C for 4–6 hours to fully dissolve) is coated on one side of a cotton + polyester blended fabric (base weight 0.1503), followed by UV curing, drying at 60°C, 1.5x pre-stretching, and secondary curing at 80°C.

[0030] The original weight is 0.1503g, and after coating, it is 0.2886g. The coating accounts for as much as 92%, indicating that the solution adheres more to the lightweight fabric. The thickness change increases from 0.19 mm to 0.22 mm (an increase of 16%). The coating is thin but the adhesion amount is large. The air permeability decreases from 2183.4 mm / s to 1173.1 mm / s (a decrease of 46%), which is lower than that of other embodiments, and the air permeability of the fabric is partially retained. Mechanical properties: The breaking strength is slightly improved, but the CV value is slightly higher after coating, indicating that the adhesion uniformity needs to be improved. Temperature response: The expansion rate changes little, reflecting that the lightweight fabric has less elasticity and limited pre-stretching. The thermal responsiveness of LCE has limited effect on the base fabric, which does not meet the ideal standard. The lightweight fabric base makes it easy for the LCE solution to adhere in large quantities, and the coating accounts for a high proportion, which may cause the fabric to feel hard.

[0031] Example 4

[0032] like Figure 4 Shown is a polyester + spandex blended knitted LCE-coated fabric. The same LCE precursor solution (18%) as above is used to coat one side of a 96% polyester + 4% spandex blended knitted fabric. The subsequent steps are UV curing, drying at 60°C, 1.5x pre-stretching, and secondary curing at 80°C.

[0033] The original weight was 0.3434g, and after coating, it was 0.5166g, with the coating accounting for a relatively moderate 50% of the fabric. The thickness changed minimally, increasing from 0.484 mm to 0.488 mm (only a 1% increase), suggesting that most of the LCE had penetrated the fabric rather than forming a noticeable surface layer. Air permeability, however, increased from 1596.7 mm / s to 1949.4 mm / s (a 22% increase), likely due to pre-stretching improving the fabric's pore structure. Mechanical properties: Breaking strength was significantly improved (originally low, rising to approximately 92–93 N after curing). After pre-stretching, temperature responsiveness exhibited shrinkage of approximately 9% in the longitudinal direction and 4% in the transverse direction, representing relatively low shrinkage rates that do not meet ideal standards. The fabric surface was observed to be relatively thinly coated, and the coating had poor adhesion, indicating that the LCE coating had little effect.

[0034] Example 5

[0035] like Figure 5 Shown is a cotton + spandex blended knitted LCE-coated fabric. The same LCE precursor solution (18%) as above was used to coat one side of a 92% cotton + 8% spandex blended knitted fabric. The fabric was then UV-cured, dried at 60°C, pre-stretched 1.5 times, and post-cured at 80°C.

[0036] The original sample weighed 0.3497g, and after coating, it weighed 0.5952g, with the coating accounting for 70%, indicating a high coating adhesion. Thickness change: increased from 0.62 mm to 0.64 mm (only an increase of 3%), indicating that the coating is thinner and more uniform. The air permeability decreased from 1673.9 mm / s to 611.0 mm / s (a decrease of 63%), a significant decrease, indicating that the pores of the knitted fabric are partially closed. Among the mechanical properties, the breaking strength increased from the extremely low original value (2.43–2.23 N) to about 46–49 N, with a significant reinforcement effect, and the CV value was low, indicating that the coating was more evenly distributed. Temperature response: The longitudinal shrinkage rate reached 12% at 80°C, and there was almost no change in the transverse direction, mainly concentrated in the pre-stretching effect in one direction. In this solution, cotton has good water absorption, so it helps to improve the adsorption of the coating to a certain extent. Therefore, the coating is thinner and more uniform, and has a significant effect on enhancing the breaking strength of the fabric. However, the base fabric has no elasticity in the horizontal direction, so the thermal responsiveness of LCE cannot be reflected. Overall, this solution is feasible and can be used in specific occasions.

[0037] Example 6

[0038] like Figure 6 The figure shows a viscose + spandex blended knitted LCE-coated fabric. The same LCE precursor solution (18%) as above was used to coat one side of a 95% viscose + 5% spandex blended knitted fabric. The fabric was then UV-cured, dried at 60°C, pre-stretched 1.5 times, and post-cured at 80°C.

[0039] The original sample weighs 0.369g, and after coating, it weighs 0.5978g. The coating accounts for 62%, which is a medium level. The thickness increases from 0.45mm to 0.47mm (an increase of 4%), and the coating is relatively thin. The air permeability decreases from 1965.8mm / s to 409.3mm / s (a decrease of 79%), indicating that the coating has a significant effect on sealing the pores of the fabric. Mechanical properties: The breaking strength increases from about 8.63–9.36N of the original sample to about 30–32N after coating, and the CV value is low, indicating an improvement in uniformity. Temperature response: The changes in the expansion and contraction rates at room temperature and 80°C are balanced (about 4% in the longitudinal direction and about 4–6% in the transverse direction). The thermal responsiveness is low and is not an ideal standard.

[0040] Example 7

[0041] like Figure 7 Shown is a polyester + spandex blended knitted LCE-coated fabric. The same LCE precursor solution (18%) as above is used to coat one side of a 90% polyester + 10% spandex blended knitted fabric. The subsequent steps are UV curing, drying at 60°C, 1.5x pre-stretching, and secondary curing at 80°C.

[0042] The original weight was 0.1773g, but after coating, it reached 0.4579g, with the coating comprising a significant 158% of the total weight, indicating that the LCE deposition significantly outweighs the lightweight substrate load. Thickness change: From 0.34 mm to 0.36 mm (6% increase), the coating significantly penetrated the fabric interior, resulting in minimal surface thickening. Air permeability: The air permeability decreased from 6211.3 mm / s to 896.8 mm / s (86% decrease), almost completely sealing most of the fabric's pores. The breaking strength increased from approximately 4.7–5.7 N to approximately 28–30 N, with a CV value of 3.46%, indicating good coating uniformity. The fabric exhibited excellent temperature responsiveness and high shrinkage, reaching 15% in the longitudinal direction and 13% in the transverse direction. Pre-stretching reached 1.5 times in both the longitudinal and transverse directions, indicating good elasticity and sufficient pre-stretching. The coated fabric exhibited a high degree of thermal responsiveness, indicating a significant LCE influence. It is an ideal LCE coating material. The coated fabric can be used in flexible wearables and soft robots, but its air permeability varies greatly and it is not suitable for applications that require good air permeability.

[0043] Example 8

[0044] like Figure 8 Shown is a polyester + spandex blended knitted LCE-coated fabric. An 8% LCE precursor solution (mixed with dimethyl sulfoxide and dichloromethane in a 1:1 volume ratio and fully dissolved by stirring at 50°C for 4–6 hours) was coated on one side of a 90% polyester + 10% spandex blended knitted fabric. The fabric was then UV-cured, dried at 60°C, pre-stretched 1.5 times, and post-cured at 80°C.

[0045] The original sample weighed 0.1773g, but after coating, it weighed 0.3311g, with the coating accounting for 87%. The thickness increased from 0.34 mm to 0.35 mm (a mere 3% increase), indicating an extremely thin coating. The air permeability decreased from 6211.3 mm / s to 2063.1 mm / s (a 67% decrease), which is consistent with the knitted fabric's inherent pore structure. The breaking strength increased from approximately 4.7–4.9 N to approximately 10.7–11.4 N. The thin coating suggests that the LCE coating has little effect on the fabric's breaking strength. Regarding temperature responsiveness, the shrinkage was 10% in the longitudinal direction and 5% in the transverse direction. Overall, the low LCE concentration suggests that the LCE coating has minimal impact on all aspects of the fabric's performance, so this sample does not meet the requirements.

[0046] Example 9

[0047] like Figure 9Shown is a polyester + spandex blended knitted LCE-coated fabric. A 13% LCE precursor solution (mixed with dimethyl sulfoxide and dichloromethane in a 1:1 volume ratio and fully dissolved by stirring at 50°C for 4–6 hours) was coated on one side of a 90% polyester + 10% spandex blended knitted fabric. The fabric was then UV-cured, dried at 60°C, pre-stretched 1.5 times, and post-cured at 80°C.

[0048] The original weight was 0.1773g, while the coated weight was 0.406g. The coating percentage was 129%. The thickness increased from 0.34 mm to 0.35 mm (a 3% increase), indicating an extremely thin coating. The air permeability decreased from 6211.3 mm / s to 1462.4 mm / s (a 76% decrease), which is consistent with the inherent pore structure of the knitted fabric. The breaking strength increased from approximately 4.7–4.9 N to approximately 23.8–27.1 N, but the CV value was slightly higher after coating, indicating localized adhesion differences. Temperature responsiveness demonstrated an 11% longitudinal shrinkage and a 9% transverse shrinkage at 80°C, indicating moderate overall deformation. Taking into account the changes in weight, thickness, air permeability, breaking strength, and thermal responsiveness, this sample exhibits moderate air permeability and good thermal responsiveness. Furthermore, the significant increase in breaking strength makes it suitable for flexible wearable textiles requiring less demanding strength.

[0049] Example 10

[0050] like Figure 10 Shown is a polyester + spandex blended knitted LCE-coated fabric. A 23% LCE precursor solution (mixed with dimethyl sulfoxide and dichloromethane in a 1:1 volume ratio and fully dissolved by stirring at 50°C for 4–6 hours) was coated on one side of a 90% polyester + 10% spandex blended knitted fabric. The fabric was then UV-cured, dried at 60°C, pre-stretched 1.5 times, and post-cured at 80°C.

[0051] The original weight was 0.1773g, while the coated weight was 0.6766g. The coating accounted for 282% of the total weight. The thickness increased from 0.34 mm to 0.42 mm (a 3% increase), indicating a noticeable coating. The air permeability dropped sharply from 6211.3 mm / s to 616.7 mm / s (a 90% decrease), almost completely blocking the fabric's pores and potentially significantly affecting comfort. The breaking strength increased from approximately 4.7–4.9 N to approximately 42.1 N, but the CV value after coating was around 20%, indicating localized unevenness. Temperature responsiveness was demonstrated with a longitudinal shrinkage of 21% and a transverse shrinkage of 17% at 80°C, indicating significant thermal responsiveness. However, the significant thickness variation significantly compromised flexibility and comfort, and the air permeability was also poor. This is because the high concentration and viscosity of the LCE solution made coating difficult, resulting in uneven coating. While suitable for applications requiring high thermal responsiveness and fabric strength, it is not well-suited for flexible smart fabrics.

[0052] In summary, the coating of the present invention significantly improves the breaking strength of fabrics, particularly from 4.7N to 30N, a 540% increase, as demonstrated in Example 7. It also imparts thermal responsiveness (maximum longitudinal shrinkage of 21% at 80°C). By adjusting the LCE concentration and substrate compatibility, the high cost and poor air permeability of traditional LCE processes are addressed. A preferred 90% polyester + 10% spandex knit (as demonstrated in Example 7) achieves a breaking strength CV of 3.46% at an 18% concentration and retains 14% air permeability, combining high thermal responsiveness (15% longitudinal shrinkage) with mechanical stability.

[0053] The embodiments described above are merely some preferred embodiments of the present invention and are not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A method for preparing a liquid crystal elastomer fabric, characterized in that: The following steps are involved: Dissolving liquid crystal elastomer polymer particles in an organic solvent to prepare an LCE precursor solution; The LCE precursor solution is coated on the surface of the base fabric to form a film on the surface of the base fabric to form a coating; After curing with near-ultraviolet light, place in oven for drying; Then, the coated part is stretched and fixed, and then placed in an oven for another orientation and fixation; A liquid crystal elastomer fabric with thermal response is obtained.

2. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The organic solvent used in the LCE precursor solution is a mixed solvent of dimethyl sulfoxide and dichloromethane in a volume ratio of 1:

1.

3. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The mass concentration of the liquid crystal elastomer in the LCE precursor solution is in the range of 8% to 23%, preferably in the range of 13% to 18%.

4. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The base fabric is a viscose + polyester + spandex blended woven fabric, a polyester filament + cotton + spandex blended woven fabric, a cotton + polyester blended woven fabric, a 96% polyester + 4% spandex blended knitted fabric, a 92% cotton + 8% spandex blended knitted fabric, a 95% viscose + 5% spandex blended knitted fabric or a 90% polyester + 10% spandex blended knitted fabric.

5. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The base fabric surface is a single-sided surface.

6. The method for preparing liquid crystal elastomer fabric according to claim 1, characterized in that: The dissolving step is performed by stirring at 50° C. for 4-6 hours, and the curing step is performed by curing with a near-ultraviolet lamp at a wavelength of 365 nm for 15-30 minutes.

7. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The drying temperature is 60°C, and the treatment temperature for re-orientation and fixing is 60°C to 80°C.

8. The method for preparing liquid crystal elastomer fabric according to claim 1, wherein: The stretching is fixed at 1.2 to 1.8 times.

9. A liquid crystal elastomer fabric, characterized in that: The method is prepared by the method according to any one of claims 1 to 8.

10. The liquid crystal elastomer fabric according to claim 9, wherein: Combines thermal responsiveness and force stability.

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