A method for enhancing modification effect of a silica@polycaffeic acid composite on cotton fabric

Abstract

A method for enhancing the modification effect of silica@polycaffeic acid composite on cotton fabrics, characterized by the following process: (1) Adding a certain amount of silica and chitosan quaternary ammonium salt to deionized water, with concentrations of 5 g / L and 0.0125 g / L respectively, mixing evenly and letting stand for 20 min, centrifuging and washing with water to obtain pretreated silica; (2) Adding the pretreated silica to a pH 8.5 buffer aqueous solution containing caffeic acid, copper sulfate pentahydrate and hydrogen peroxide, with concentrations of 5 g / L, 2 g / L, 7.5 mmol / L and 29.4 mmol / L respectively, mixing evenly and reacting at room temperature for 60 min, centrifuging and washing with water to obtain silica@polycaffeic acid composite; (3) Immersing the cotton fabric in a 5 g / L chitosan quaternary ammonium salt solution for 5 min. (3) The bath ratio was 100:1, then rinsed with deionized water and dried at 60°C to obtain cationic cotton fabric; (4) A dispersion containing silica@polycaffeic acid composite and binder was prepared with concentrations of 2 g / L and 15 g / L, respectively, and deposited onto the surface of cationic cotton fabric at 60°C with a bath ratio of 100:1. Tests showed that the silica@polycaffeic acid composite obtained in this invention contains more polycaffeic acid, which can significantly enhance the modification effect on cotton fabric.

Description

Technical Field

[0001] This invention relates to a method for enhancing the modification effect of silica@polycaffeic acid composites on cotton fabrics, belonging to the field of textile printing and dyeing technology. Background Technology

[0002] Caffeic acid is widely distributed in plants such as coffee beans, grapes, blueberries, dandelions, and honeysuckle. It possesses various uses, including antibacterial, preservative, antioxidant, UV absorption, and photothermal conversion properties, and has applications in food, medicine, cosmetics, and textiles. Structurally, caffeic acid is a typical hydroxycinnamic acid polyphenol, containing both a catechol group and an acrylic acid side chain. The former endows it with broad-spectrum adhesion similar to dopamine, while the latter provides double bond sites for participation in free radical polymerization reactions, serving as molecular anchors for further grafting functional components, showing broad application prospects in the field of material surface modification. Caffeic acid can be converted into polycaffeic acid through chemical oxidation, electrochemical methods, and enzyme-catalyzed oxidative polymerization. Chemical oxidative polymerization is the most commonly used method. For example, using a hydrogen peroxide / CuSO4 system, the catechol group of the caffeic acid monomer can be oxidized to a semiquinone or quinone structure in a very short time, significantly improving the initiation rate and chain growth efficiency of oxidative polymerization.

[0003] Silica is a commonly used inorganic industrial raw material. By introducing silica particles into textile finishing processes using appropriate methods, it is possible to achieve diverse functions such as controlling the wettability of fabric surfaces, UV protection, and structural color enhancement. For example, when silica particles are used in conjunction with low surface energy materials, air can be effectively trapped in the valleys of the rough structure of the fabric surface, achieving a superhydrophobic state with a contact angle greater than 150°. By changing the particle size parameters of silica particles, the scattering and interference behavior of visible light can be adjusted, thereby enabling the construction of structural colors on the fabric surface.

[0004] Silica's surface is rich in silanol groups (Si-OH), allowing it to interact with polar substrates through hydrogen bonds and van der Waals forces. It is also easily chemically modified by various active agents, thus regulating its properties and functions. Forming composite systems with silica particles and bisphenol polymers such as polycaffeic acid is a novel approach to constructing functional composite particles that has emerged in recent years. In the environmental field, researchers have used silica-polycaffeic acid composites to achieve deep treatment of pollutants such as heavy metal ions and organic dyes. In the biomedical field, silica-polycaffeic acid composites can be used for drug delivery. In the textile printing and dyeing field, researchers have prepared silica@polycaffeic acid composite microspheres and constructed robust structural colors on fabric surfaces through deposition and spraying methods. Summary of the Invention

[0005] This invention utilizes chitosan quaternary ammonium salt to pretreat silica, and then adds it to a mixture of caffeic acid, copper sulfate pentahydrate, and hydrogen peroxide for polymerization. This can improve the effective bonding between silica and polycaffeic acid, resulting in a silica@polycaffeic acid composite with better performance, thereby enhancing the modification effect on cotton fabrics.

[0006] This invention relates to the following processes: (1) Add a certain amount of silica and chitosan quaternary ammonium salt to deionized water, with concentrations of 5 g / L and 0.0125 g / L, respectively. After mixing evenly, let stand for 20 min, centrifuge, and wash with water to obtain pretreated silica. (2) Pretreated silica was added to a buffer solution containing caffeic acid, copper sulfate pentahydrate and hydrogen peroxide at a pH of 8.5, with concentrations of 5 g / L, 2 g / L, 7.5 mmol / L and 29.4 mmol / L, respectively. After mixing evenly, the mixture was reacted at room temperature for 60 min. After centrifugation and washing with water, silica@polycaffeic acid composite was obtained. (3) Immerse the cotton fabric in a 5 g / L chitosan quaternary ammonium salt solution for 5 min at a bath ratio of 100:1, then rinse with deionized water and dry at 60°C to obtain cationic cotton fabric. (4) Prepare a dispersion containing silica@polycaffeic acid complex and adhesive, with concentrations of 2 g / L and 15 g / L respectively, and deposit it onto the surface of cationic cotton fabric at 60°C with a bath ratio of 100:1.

[0007] A certain amount of silica and chitosan quaternary ammonium salt were added to deionized water at concentrations of 5 g / L and 0.0125 g / L, respectively. After mixing thoroughly, the mixture was allowed to stand for 20 min, centrifuged, and washed with water to obtain pretreated silica. The chitosan quaternary ammonium salt used was a commercially available product with a substitution degree of 98%. The pretreated silica was then added to a pH 8.5 buffer solution containing caffeic acid, copper sulfate pentahydrate, and hydrogen peroxide at concentrations of 5 g / L, 2 g / L, 7.5 mmol / L, and 29.4 mmol / L, respectively. After mixing thoroughly, the mixture was reacted at room temperature for 60 min. After centrifugation and washing with water, a silica@polycaffeic acid composite was obtained. The surface properties of silica changed after pretreatment with chitosan quaternary ammonium salt, which enhanced its binding ability with caffeic acid, thereby strengthening the effective composite with the polycaffeic acid formed after polymerization. Cotton fabric was immersed in a 5 g / L chitosan quaternary ammonium salt solution for 5 min at a bath ratio of 100:1, then rinsed with deionized water and dried at 60 °C to obtain cationic cotton fabric. The chitosan quaternary ammonium salt used was a commercially available product with a substitution degree of 98%. Finally, dispersions containing silica@polycaffeic acid composites and adhesives at concentrations of 2 g / L and 15 g / L, respectively, were prepared and deposited onto the surface of the cationic cotton fabric at a bath ratio of 100:1 at 60 °C. The adhesive used was a commercially available anionic adhesive. Detailed Implementation

[0008] The present invention will now be described in detail through examples and comparative examples.

[0009] Example 1 (1) Add a certain amount of silica and chitosan quaternary ammonium salt to deionized water, with concentrations of 5 g / L and 0.0125 g / L, respectively. After mixing evenly, let stand for 20 min, centrifuge, and wash with water to obtain pretreated silica. (2) Pretreated silica was added to a buffer solution containing caffeic acid, copper sulfate pentahydrate and hydrogen peroxide at a pH of 8.5, with concentrations of 5 g / L, 2 g / L, 7.5 mmol / L and 29.4 mmol / L, respectively. After mixing evenly, the mixture was reacted at room temperature for 60 min. After centrifugation and washing with water, silica@polycaffeic acid composite was obtained. (3) Immerse the cotton fabric in a 5 g / L chitosan quaternary ammonium salt solution for 5 min at a bath ratio of 100:1, then rinse with deionized water and dry at 60°C to obtain cationic cotton fabric. (4) Prepare a dispersion containing silica@polycaffeic acid complex and adhesive, with concentrations of 2 g / L and 15 g / L respectively, and deposit it onto the surface of cationic cotton fabric at 60°C with a bath ratio of 100:1.

[0010] Comparative Example 1 (1) Untreated silica was added to a buffer solution containing caffeic acid, copper sulfate pentahydrate and hydrogen peroxide at a pH of 8.5, with concentrations of 5 g / L, 2 g / L, 7.5 mmol / L and 29.4 mmol / L, respectively. After mixing evenly, the mixture was reacted at room temperature for 60 min. After centrifugation and washing with water, silica@polycaffeic acid composite was obtained. (2) Immerse the cotton fabric in a 5 g / L chitosan quaternary ammonium salt solution for 5 min at a bath ratio of 100:1, then rinse with deionized water and dry at 60°C to obtain cationic cotton fabric. (3) Prepare a dispersion containing silica@polycaffeic acid composite and adhesive, with concentrations of 2 g / L and 15 g / L respectively, and deposit it onto the surface of cationic cotton fabric at 60°C with a bath ratio of 100:1.

[0011] The color L-values ​​of the cotton fabrics obtained in Example 1 and Comparative Example 1 were tested, and were 50.53 and 62.42, respectively. Both were significantly lower than the L-value (94.45) of the cotton fabric without silica@polycaffeic acid deposition, which is attributed to the color exhibited by polycaffeic acid. The decrease in L-value of the fabric obtained in Example 1 was more significant than that in Comparative Example 1, indicating that more polycaffeic acid was bound in the resulting composite.

[0012] The photothermal heating properties of the cotton fabrics obtained in Example 1 and Comparative Example 1 were tested. Under the same illumination conditions, the surface temperatures of the two fabrics reached 56.7°C and 51°C, respectively, which are significantly higher than the surface temperature of the cotton fabric without silica@polycaffeic acid deposition (31.1°C). This is because polycaffeic acid has broad-spectrum light absorption characteristics, which can effectively absorb light energy and convert it into heat energy. In comparison, the photothermal heating capacity of the fabric obtained in Example 1 is stronger than that in Comparative Example 1, indicating that more polycaffeic acid is bound in the resulting composite.

[0013] The photothermal evaporation capacity of the cotton fabrics obtained in Example 1 and Comparative Example 1 was tested. Under the same light conditions, the water evaporation rates of the two fabrics were 1.056 kg / m²·h and 0.942 kg / m²·h, respectively, which were significantly higher than the water evaporation rate of the cotton fabric without silica@polycaffeic acid deposition (0.808 kg / m²·h). This is also due to the photothermal conversion properties of polycaffeic acid. In comparison, the photothermal evaporation capacity of the fabric obtained in Example 1 was stronger than that in Comparative Example 1, indicating that more polycaffeic acid was incorporated into the resulting composite.

Claims

1. A method for enhancing the modification effect of silica@polycaffeic acid composites on cotton fabrics, characterized in that... The following process is adopted: (1) Add a certain amount of silica and chitosan quaternary ammonium salt to deionized water, with concentrations of 5 g / L and 0.0125 g / L, respectively. After mixing evenly, let stand for 20 min, centrifuge, and wash with water to obtain pretreated silica. (2) Pretreated silica was added to a buffer solution containing caffeic acid, copper sulfate pentahydrate and hydrogen peroxide at a pH of 8.5, with concentrations of 5 g / L, 2 g / L, 7.5 mmol / L and 29.4 mmol / L, respectively. After mixing evenly, the mixture was reacted at room temperature for 60 min. After centrifugation and washing with water, silica@polycaffeic acid composite was obtained. (3) Immerse the cotton fabric in a 5 g / L chitosan quaternary ammonium salt solution for 5 min at a bath ratio of 100:1, then rinse with deionized water and dry at 60°C to obtain cationic cotton fabric. (4) Prepare a dispersion containing silica@polycaffeic acid complex and adhesive, with concentrations of 2 g / L and 15 g / L respectively, and deposit it onto the surface of cationic cotton fabric at 60°C with a bath ratio of 100:1.