CN-121974389-A - Super-hydrophobic nano titanium dioxide and preparation method and application thereof

CN121974389ACN 121974389 ACN121974389 ACN 121974389ACN-121974389-A

Abstract

The invention belongs to the technical field of modification of nano materials, and relates to super-hydrophobic nano titanium dioxide, a preparation method and application thereof, the invention realizes the remarkable improvement of the modified TiO 2 in the aspect of dispersion stability by regulating and controlling the dosage of the long-chain siloxane, the pH value of deionized water, the ultrasonic reaction time and using the long-chain siloxane with more bonding points. The long-chain siloxane has good flexibility, the chain segments can adjust spatial arrangement in a rotating and stretching mode, the inter-winding probability among molecules is reduced, the chain segments can be fully attached to the surface of titanium dioxide to form a compact hydrophobic layer, the problem of uneven coating caused by steric hindrance in the modification process is effectively avoided, the problem of interfacial coverage integrity commonly existing in the surface modification of nano particles is solved from the molecular level, the ultrahigh silicon hydroxyl density can be interacted with hydroxyl groups on the surface of nano titanium dioxide in a high-efficiency and large quantity, and the coating stability is improved.

Inventors

Chu Xianglong
Wumanjiang. Aili
NIU YADI
ZHANG RUILI
ZHANG YANHUI

Assignees

新疆师范大学

Dates

Publication Date: 20260505
Application Date: 20260128

Claims (7)

1. The preparation method of the super-hydrophobic nano titanium dioxide is characterized by comprising the following steps of: Adjusting the pH value of deionized water by adopting an inorganic alkaline solution and an inorganic acidic solution to enable the pH value of the deionized water to be 5-6; Mixing deionized water with the pH value of 5-6 with long-chain siloxane to obtain siloxane pretreatment liquid; after ultrasonic mixing modification of the siloxane pretreatment liquid and nano titanium dioxide, obtaining the super-hydrophobic nano titanium dioxide after centrifugation, cleaning and drying; The addition mass of the long-chain siloxane in the siloxane pretreatment liquid is 5% -60% of the mass of the nano titanium dioxide; Long chain siloxanes are Wherein m is 3-20, n is 3-20, and R is alkyl.
2. The method for preparing the super-hydrophobic nano titanium dioxide according to claim 1, wherein the concentration of the siloxane pretreatment liquid is 4 g/L-5 g/L.
3. The method for preparing superhydrophobic nano-titania according to claim 1, wherein the inorganic acidic solution is a hydrochloric acid solution, and the inorganic alkaline solution is ammonia water.
4. The method for preparing superhydrophobic nano-titania according to claim 1, wherein the particle size of the titania is 20nm.
5. The preparation method of the super-hydrophobic nano titanium dioxide according to claim 1, wherein the ultrasonic frequency is 40KHz, and the ultrasonic mixing modification time is 15-40 min.
6. The superhydrophobic nano titanium dioxide according to any one of claims 1-5.
7. The use of the superhydrophobic nano titanium dioxide according to claim 6 as a hydrophobic material and a thermally conductive material as a thermally conductive oil.

Description

Super-hydrophobic nano titanium dioxide and preparation method and application thereof Technical Field The invention belongs to the technical field of modification of nano materials, and particularly relates to super-hydrophobic nano titanium dioxide, a preparation method and application thereof. Background Nano TiO 2, which is a typical inorganic nanomaterial, has become a research hot spot due to its excellent photocatalytic activity, chemical stability and environmental friendliness. However, nano-TiO 2 has a serious agglomeration problem in practical applications, mainly due to the fact that multiple hydroxyl groups on its surface cause the enhancement of van der waals forces, thereby causing strong interactions between neighboring particles. The agglomeration phenomenon may cause the specific surface area of the nano-TiO 2 to be reduced, thereby affecting the photocatalytic performance and thermal stability thereof. In addition, the agglomeration can also change the pore structure and size distribution of the material, and further influence the application effect of the material in the fields of photocatalytic degradation of pollutants, water treatment, solar cells and the like. To solve the agglomeration problem, organic surface modification is a key strategy. The strategy is to change the surface characteristics (such as chemical composition, charge state, wettability) of nano TiO 2 by chemical grafting of siloxane without significantly affecting the bulk structure. At present, although the agglomeration problem is reduced by adopting siloxane coating, the coating layer of the conventional siloxane (such as KH-550, KH-570 and KH-560) is fragile due to few bonding points, and the problem of steric hindrance is caused by easy entanglement of short-chain silane, so that grafting is uneven and the hydrophobicity of the material is poor. Therefore, it is necessary to provide a method capable of solving the problem that conventional siloxanes have weak coating layers due to few bonding points and short-chain silanes are easy to intertwine to cause steric hindrance, thereby resulting in poor hydrophobicity. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide the super-hydrophobic nano titanium dioxide, the preparation method and the application thereof, which solve the problems that the coating layer is fragile and the short-chain silane is easy to intertwine and cause steric hindrance caused by less bonding points of the conventional siloxane, remarkably improve the dispersion stability of modified TiO 2 and improve the hydrophobicity. In order to solve the technical problems, the invention provides a preparation method of super-hydrophobic nano titanium dioxide, which comprises the following steps: Adjusting the pH value of deionized water by adopting an alkaline solution and an acidic solution to enable the pH value of the deionized water to be 5-6; Mixing deionized water with the pH value of 5-6 with long-chain siloxane to obtain siloxane pretreatment liquid; after ultrasonic mixing modification of the siloxane pretreatment liquid and nano titanium dioxide, obtaining the super-hydrophobic nano titanium dioxide after centrifugation, cleaning and drying; The addition mass of the long-chain siloxane in the siloxane pretreatment liquid is 5% -60% of the mass of the nano titanium dioxide; Long chain siloxanes are Wherein m is 3-20, n is 3-20, and R is alkyl. Preferably, the concentration of the siloxane pretreatment liquid is 4 g/L-5 g/L. After siloxane with the concentration of 4 g/L-5 g/L reacts, the obtained modified nano titanium dioxide has the best dispersing effect in a dispersing experiment. Preferably, the inorganic acidic solution is hydrochloric acid solution, the concentration of the hydrochloric acid solution is 0.1mol/L, the alkaline solution is ammonia water, and the concentration of the ammonia water is 0.1mol/L. Preferably, the particle size of the titanium dioxide is 20nm. Preferably, the ultrasonic frequency is 40KHz, and the ultrasonic mixing modification time is 15-40 min. At this ultrasonic frequency, when the reaction time is too short, the coupling agent cannot completely cover the surface of the nano TiO 2, which results in insufficient reaction and no significant change in the surface characteristics of the nano TiO 2. At this ultrasonic frequency, when the reaction time is too long, silanol molecules have enough time to get close to each other and form hydrogen bonds, and the siloxane and polysilane can directly affect the modification of the nano TiO 2 by the coupling agent. The invention provides the super-hydrophobic nano titanium dioxide prepared by the preparation method of the super-hydrophobic nano titanium dioxide. The invention provides application of super-hydrophobic nano titanium dioxide in a heat conducting material serving as a hydrophobic material and a heat conducting oil Compared with the prior art, the invention has the be