CN104372608B - A method for preparing superhydrophobic fabrics by sol-gel electrochemical deposition - Google Patents

Abstract

The invention discloses a method for preparing a super-hydrophobic fabric by sol-gel electrochemical deposition, belonging to the technical field of textile chemical industry. Firstly, preparing a silane modified hybrid sol solution containing a hydrophobic long chain, then depositing a fabric between a copper sheet and a platinum sheet by taking the copper sheet as a reaction electrode and the platinum sheet as a counter electrode, so that a hydrophobic component is directionally arranged on the fabric, a fabric contact angle can reach more than 160 degrees, and super-hydrophobicity is realized. The method overcomes the defects of poor adhesion, cracks and the like of a deposited film caused by limited self-reaction driving force of a sol precursor, the thickness of the deposited film is adjustable, residual liquid can be recycled after electrification, no waste water is discharged, meanwhile, the nano-diamond component is added, the friction coefficient of the surface of the deposited film can be obviously reduced, the external force resistance of the deposited film is improved, and KNO does not need to be added in the electrochemical process₃And the like, and is suitable for developing functional textiles.

Description

A method for preparing superhydrophobic fabrics by sol-gel electrochemical deposition

technical field

A method for preparing superhydrophobic fabrics by sol-gel electrochemical deposition belongs to the technical field of textile chemistry.

Background technique

The superhydrophobicity of superhydrophobic materials is achieved through the binary synergy of the lower surface energy of the material surface and the nano-sized rough structure. application. The preparation methods mainly include plasma etching method, template method, mechanical method, phase separation method, etc. However, because many preparation methods are complicated in process, expensive in manufacturing equipment, and the properties of the prepared materials are relatively unstable, they are not suitable for mass industrial production.

The surface of superhydrophobic materials can be prepared by a sol-gel method, in which inorganic nanoparticles such as _SiO2 that have undergone hydrophobic treatment are dispersed in a sol-gel matrix and sprayed on a clean glass or aluminum sheet. By adjusting the content of nanoparticles in the mixture and the type of sol, the static contact angle between the surface and the water droplet can reach 160°. However, the self-reaction driving force of the sol precursor is limited, so the preparation of sol films by dip coating, spray coating and spin coating often has disadvantages such as poor adhesion and cracks, and the film-forming coating has a great influence on the mechanical properties of flexible materials. Suitable for flexible materials such as textiles, paper, polyethylene films, etc. Electrochemical deposition is an important method for the deposition and modification of irregular materials and flexible materials. It can provide additional hydrolysis and condensation reaction driving forces for the sol precursor system when combined with sol-gel technology, so that the resulting sol-gel films can be produced. There are many micropores, and the cohesion between the colloidal particles is good.

Patent CN201110352061.0 discloses a method for preparing a super-hydrophobic and super-oleophilic surface by electrochemical deposition. First, electrochemical deposition is performed on the surface of a copper or copper alloy substrate to form a silver film with a micro-nano structure, and then dodecyl hydroxy stearin is used. After acid modification, the prepared superhydrophobic and superoleophilic surface has a contact angle of 154°-159° for water and 0-5° for oil. In this method, the conductive deposition substrate is directly used as the working electrode, which limits the utilization of non-conductive materials, and requires subsequent immersion treatment after deposition, which is a complicated process.

SUMMARY OF THE INVENTION

The invention discloses a method for preparing superhydrophobic fabric by sol-gel electrochemical deposition, and the specific process is as follows:

1. The sol precursor and hydrophobic silane coupling agent were used to synthesize a hydrophobic hybrid sol solution under acid catalysis, and the non-conductive fabric was electrochemically deposited in a two-electrode electrochemical system to impart superhydrophobicity to the fabric.

2. the preparation method of the hydrophobic hybrid sol solution is:

(1) take by weighing the sol precursor of 4-10 parts by weight and the dehydrated alcohol of 15-35 parts by weight and stir, and add dropwise to the 0.2mol/L HCl of 55-75 parts by weight at room temperature, Prepared into a sol solution;

(2) 1-8 parts by weight of nano-diamonds with a particle size of 200-500nm are ultrasonically dispersed for 80min in 92-99 parts by weight of 8-12% sulfonic anionic surfactant to prepare nano-diamond dispersions liquid;

(3) Add 10-18 parts by weight of the nano-diamond dispersion liquid in (2) dropwise to 82-90 parts by weight of the sol liquid in (1), quickly and uniformly disperse for 3h, and adjust the pH of the system to 4 with ammonia water -5, prepare a hybrid sol solution;

(4) Add 4-12 parts by weight of a hydrophobic silane coupling agent to 88-96 parts by weight of the hybrid sol solution, stir evenly and fully hydrolyze and condense to obtain a hydrophobic hybrid sol solution.

3. The sol precursor is at least one of tetraethyl orthosilicate and tetra-n-butyl titanate.

4. The hydrophobic silane coupling agent has the following structure:

F ₁ —Si(OR) ₃

Wherein R is CH ₃ —, CH ₃ CH ₂ —; F ₁ is a hydrophobic group, which can be CF ₃ (CF ₂ ) _a (CH ₂ ) _b —, CH ₃ (CH ₂ ) _n —, γ-Cl(CH ₂ ) _m— , Ph—, where a, b, m, and n are all natural numbers, a and b can be 1-6; n can be 1-15; m can be 1-5;

5. The hydrophobic silane coupling agent can also have the following structure:

F ₁ —Si(OR) ₂ —F ₂

Wherein R is CH ₃ —, CH ₃ CH ₂ —; F ₁ and F ₂ are both hydrophobic groups, which can be CF ₃ (CF ₂ ) _a (CH ₂ ) _b —, CH ₃ (CH ₂ ) _n —, γ One or both of -Cl(CH ₂ ) _m — and Ph —, where a, b, m, and n are all natural numbers, a and b can be 1-6; n can be 1-15; m can be 1 to 5.

6. The electrochemical deposition conditions of the fabric are voltage 3-20V, deposition time 1-15min, and reaction electrode copper sheet area 4-20cm ² .

7. During the electrochemical deposition of the fabric, the fabric sample is placed vertically between the two electrodes to facilitate deposition uniformity.

8. The fabrics can be cotton fabrics, silk fabrics, wool fabrics, viscose fabrics, polyester fabrics, nylon fabrics, and blended fabrics thereof.

The surface of the modified fabric prepared by this technology is deposited with a layer of micro-nano characteristic structure composed of fabric fiber wrinkles and inorganic oxides (silicon dioxide or titanium dioxide) and nano-diamonds. At the same time, under the synergistic effect of the hydrophobic chain of silane coupling agent, the The contact angle to water can reach more than 160°. Due to the existence of nanodiamonds, the nodularity between the deposited film and the fibers is enhanced under electrochemical action, and the friction coefficient on the surface of the fibers is significantly reduced, so that the wear resistance of the deposited film is enhanced. The hydrophobic hybrid sol solution prepared in the invention has the advantages of easy control of electrochemical deposition experimental conditions, low deposition temperature, simple deposition equipment, and easy realization of industrial production. There is no need to fix the fabric on the working electrode, and there is no need to add salts such as _KNO3 to the electrolyte to increase the conductivity, which greatly simplifies the treatment process.

Description of drawings

1 is a schematic diagram of a kind of sol-gel electrochemical deposition for preparing super-hydrophobic fabrics of the present invention, in the figure 1 is a constant voltage DC power supply; 2 is a nanodiamond; 3 is a hydrophobic chain-containing sol component; 4 is a copper reaction electrode; 5 is hydrophobic hybrid sol solution; 6 is fabric; 7 is platinum electrode.

Detailed ways

The following examples will help to further understand the present invention, but do not limit the content of the present invention.

Example 1

Weigh 6 parts by weight of tetraethyl orthosilicate and 30 parts by weight of dehydrated ethanol and stir evenly, and add dropwise to 64 parts by weight of 0.2mol/L HCl at room temperature to prepare a sol solution; 6 parts by weight of nanodiamonds with a particle size of 250nm are ultrasonically dispersed for 80min in 94 parts by weight of 10% sodium heptadecylbenzimidazole sulfonate to prepare a nanodiamond dispersion; 10 parts by weight of nanodiamonds are dispersed The solution was added dropwise to 90 parts by weight of the sol solution, quickly and uniformly dispersed for 3 hours, and the pH of the system was adjusted to 5 with ammonia water to prepare a hybrid sol solution; 10 parts by weight of octyl was added to 90 parts by weight of the hybrid sol solution. The triethoxysilane coupling agent is uniformly stirred and fully hydrolyzed and condensed to obtain a hydrophobic hybrid sol solution.

The pure cotton woven fabric was placed vertically between the two electrodes of the two-electrode electrochemical system to facilitate deposition uniformity. The electrochemical deposition conditions were voltage 8V, deposition time 8min, and reaction electrode copper sheet area 6cm ² .

The water contact angle of the fabric sample after electrochemical deposition is 164.5°, which realizes the superhydrophobicity of the fabric and has excellent friction resistance.

Example 2

Weigh 4 parts by weight of tetra-n-butyl titanate and 35 parts by weight of absolute ethanol and stir evenly, and add dropwise to 61 parts by weight of 0.2mol/L HCl at room temperature to prepare a sol solution; 1 part by weight of nano-diamond with a particle size of 400nm is ultrasonically dispersed in 99 parts by weight of 11% sodium dibutylnaphthalene sulfonate for 80min to prepare a nano-diamond dispersion; 15 parts by weight of nano-diamond dispersion is dropwise Add dropwise to 85 parts by weight of the sol solution, quickly and uniformly disperse for 3 hours, and adjust the pH of the system to 4 with ammonia water to prepare a hybrid sol solution; add 8 parts by weight of methyltriethoxy to 92 parts by weight of the hybrid sol solution base silane, uniformly stirred and fully hydrolyzed and condensed to obtain a hydrophobic hybrid sol solution.

The polyester-cotton woven fabric was placed vertically between the two electrodes of the two-electrode electrochemical system to facilitate deposition uniformity. The electrochemical deposition conditions were voltage 12V, deposition time 12min, and reaction electrode copper sheet area 10cm ² .

The water contact angle of the fabric sample after electrochemical deposition is 163.7°, which realizes the superhydrophobicity of the fabric and has excellent friction resistance.

Example 3

Weigh 10 parts by weight of tetraethyl orthosilicate and 30 parts by weight of dehydrated ethanol and stir evenly, and add dropwise to 60 parts by weight of 0.2mol/L HCl at room temperature to prepare a sol solution; 5 parts by weight of nanodiamonds with a particle size of 550nm are ultrasonically dispersed for 80min in 95 parts by weight of 12% sodium N-oleoyl-N methyl taurate to prepare a nanodiamond dispersion; 13 parts by weight of nanodiamonds The diamond dispersion was added dropwise to 87 parts by weight of the sol solution, dispersed quickly and uniformly for 3 hours, and the pH of the system was adjusted to 4 with ammonia water to prepare a hybrid sol solution; 7 parts by weight of the hybrid sol solution was added to 93 parts by weight of the hybrid sol solution. Dodecyltriethoxysilane, uniformly stirred and fully hydrolyzed and condensed to obtain a hydrophobic hybrid sol solution.

The cotton wool woven fabric was placed vertically between the two electrodes of the two-electrode electrochemical system to facilitate the deposition uniformity. The electrochemical deposition conditions were voltage 6V, deposition time 13min, and reaction electrode copper sheet area 12cm ² .

The water contact angle of the fabric sample after electrochemical deposition is 161.8°, which realizes the superhydrophobicity of the fabric and has excellent friction resistance.

Example 4

Weigh 7 parts by weight of tetraethyl orthosilicate and 32 parts by weight of dehydrated ethanol and stir evenly, and add dropwise to 57 parts by weight of 0.2mol/L HCl at room temperature to prepare a sol solution; 2 parts by weight of nanodiamonds with a particle size of 500nm are ultrasonically dispersed for 80min in 98 parts by weight of 8% sodium diisooctyl succinate to prepare a nanodiamond dispersion; 11 parts by weight of nanodiamond dispersion Add dropwise to 89 parts by weight of the sol solution, quickly and uniformly disperse for 3h, and adjust the pH of the system to 5 with ammonia water to prepare a hybrid sol solution; add 6 parts by weight of 3-chlorine to 94 parts by weight of the hybrid sol solution C-grade triethoxysilane, uniformly stirred and fully hydrolyzed and condensed to obtain a hydrophobic hybrid sol solution.

The polyester woven fabric was placed vertically between the two electrodes of the two-electrode electrochemical system to facilitate the deposition uniformity. The electrochemical deposition conditions were voltage 15V, deposition time 7min, and reaction electrode copper sheet area 10cm ² .

The water contact angle of the fabric sample after electrochemical deposition is 160.2°, which realizes the superhydrophobicity of the fabric and has excellent friction resistance.

Example 5

Weigh 4.5 parts by weight of tetra-n-butyl titanate and 38 parts by weight of dehydrated ethanol, stir evenly, and add dropwise to 57.5 parts by weight of 0.2mol/L HCl at room temperature to prepare a sol solution; 3.5 parts by weight of nano-diamonds with a particle size of 350nm are ultrasonically dispersed for 80 min in 10% sodium dodecylbenzenesulfonate in a mass concentration of 96.5 parts by weight to prepare a nano-diamond dispersion; 13 parts by weight of nano-diamond dispersion Add dropwise to 87 parts by weight of the sol solution, quickly and uniformly disperse for 3 hours, and adjust the pH of the system to 4.5 with ammonia water to prepare a hybrid sol solution; add 4 parts by weight of hexadecyl to 96 parts by weight of the hybrid sol solution Triethoxysilane is uniformly stirred and fully hydrolyzed and condensed to obtain a hydrophobic hybrid sol solution.

The polyester-cotton woven fabric was placed vertically between the two electrodes of the two-electrode electrochemical system to facilitate deposition uniformity. The electrochemical deposition conditions were voltage 18V, deposition time 10min, and reaction electrode copper sheet area 18cm ² .

The water contact angle of the fabric sample after electrochemical deposition is 169.2°, which realizes the superhydrophobicity of the fabric and has excellent friction resistance.

Claims (1)

1. A method for preparing a super-hydrophobic fabric by sol-gel electrochemical deposition is characterized in that a sol precursor and a hydrophobic silane coupling agent are hybridized into a sol solution under the acid catalysis condition, and simultaneously, a nano-diamond dispersion solution is used for modifying the sol solution to prepare a hydrophobic hybridized sol solution; electrochemically depositing a non-conductive fabric in a two-electrode electrochemical system to impart superhydrophobicity and wear resistance to the fabric;

the preparation method of the hydrophobic hybrid sol solution comprises the following steps:

(1) weighing 4-10 parts by weight of sol precursor and 15-35 parts by weight of absolute ethyl alcohol, uniformly stirring, and dropwise adding the sol precursor and the absolute ethyl alcohol into 55-75 parts by weight of 0.2mol/L HCl at room temperature to prepare sol solution;

(2) carrying out ultrasonic dispersion on 1-8 parts by weight of nano-diamond with the particle size of 200-500nm in 92-99 parts by weight of sulfonic acid group anionic surfactant with the mass concentration of 8-12% for 80min to prepare nano-diamond dispersion liquid;

(3) dropwise adding 10-18 parts by weight of the nano-diamond dispersion liquid in the step (2) into 82-90 parts by weight of the sol liquid in the step (1), rapidly and uniformly dispersing for 3 hours, and adjusting the pH value of the system to 4-5 by using ammonia water to prepare a hybrid sol liquid;

(4) adding 4-12 parts by weight of hydrophobic silane coupling agent into 88-96 parts by weight of hybrid sol solution, uniformly stirring, and fully hydrolyzing and condensing to obtain hydrophobic hybrid sol solution;

the sol precursor is at least one of tetraethyl orthosilicate and tetra-n-butyl titanate;

the hydrophobic silane coupling agent has the following structure:

F₁—Si(OR)₃

wherein R is CH₃—、CH₃CH₂—；F₁Is a hydrophobic group, may be CF₃(CF2)_a(CH2)_b—、CH₃(CH₂)_n—、γ-Cl(CH₂)_mPh-, wherein a, b, m and n are natural numbers, and a and b can be 1-6; n can be 1-15; m can be 1-5;

the hydrophobic silane coupling agent may also have the following structure:

F1—Si(OR)₂—F₂

wherein R is CH₃—、CH₃CH₂—；F₁And F₂Are all hydrophobic groups and may be CF₃(CF₂)_a(CH₂)_b—、CH₃(CH₂)_n—、γ-Cl(CH₂)_mOne or two of Ph < - >, wherein a, b, m and n are natural numbers, and a and b can be 1-6; n can be 1-15; m can be 1-5;

the electrochemical deposition condition of the fabric is 3-20V of voltage, the deposition time is 1-15min, and the area of the copper sheet of the reaction electrode is 4-20cm²；

When the fabric is subjected to electrochemical deposition, a fabric sample is vertically placed between two electrodes so as to facilitate the deposition uniformity;

the fabric can be cotton fabric, silk fabric, wool fabric, viscose fabric, polyester fabric, chinlon fabric and blended fabric thereof.

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