AU2020101696A4

AU2020101696A4 - Self-cleaning intelligent temperature control nanocellulose film, preparation method and application thereof

Info

Publication number: AU2020101696A4
Application number: AU2020101696A
Authority: AU
Inventors: Haocun Huang; Fangong KONG; Guodong Li; Wenxia Liu; Xia MENG; Yabin YANG; Ruhe Zhao
Original assignee: Qilu University of Technology
Current assignee: Qilu University of Technology
Priority date: 2019-11-18
Filing date: 2020-08-06
Publication date: 2020-09-10
Anticipated expiration: 2028-08-06
Also published as: CN110818929B; CN110818929A

Abstract

The invention relates to a self-cleaning intelligent temperature control nanocellulose film, a preparation method and application thereof, belonging to the technical field of preparing green functional materials and eco-friendly and energy-saving materials. 5 The method of this invention is to prepare a nanocellulose film material with flexible phase transition and temperature control function, by firstly adding tungsten-doped vanadium dioxide (W@V02 ) nanoparticles into a nanocellulose dispersion liquid, and then using processes such as vacuum filtering, scraper (scraper) coating, mold casting. This material may be applied to a surface such as a switchable glass window of a 10 building, screen glass of an automobile and an aircraft, for selectively absorbing or reflecting external thermal radiation and preventing internal thermal diffusion, and reducing the large amount of energy consumed by buildings or means of transportation for heat preservation, with the advantage of thermochromic effects of nanomaterials. The technology has the advantages such as simple production process 15 and good intelligent temperature control effect, and has great application potential in the fields of smart home, transportation and electronics. 4/4 100°' 90% haze 3° degree (%)% C 20°C 60% 15°C 50% 300 400 500 600 700 800 wavelength (cm-) FIG. 7

Description

4/4

100°'

90%

haze 3° degree (%)% C

20°C

60%

15°C

50%

300 400 500 600 700 800

wavelength (cm-)

FIG. 7

SELF-CLEANING INTELLIGENT TEMPERATURE CONTROL NANOCELLULOSE FILM, PREPARATION METHOD AND APPLICATION THEREOF

Technical Field

The present invention belongs to the technical field of preparing green functional

materials and eco-friendly and energy-saving materials, and in particular, relates to a

self-cleaning intelligent temperature control nanocellulose film, and a preparation

method and application thereof.

Background Art

Increasing shortage of energy makes it an urgent worldwide problem to be solved to

improve energy efficiency and develop and utilize renewable energy. Among various

types of energy consumption, building energy consumption cannot be ignored, which

mainly includes ventilation, coal burning and electric heating in winter, and cooling

with electrical appliances and air conditioners in summer, etc. In addition, manual

temperature control consumes a large amount of non-renewable fossil fuels, increasing production cost, and producing a large amount of harmful gases that

pollute the environment. Research on new energy-saving building materials can not

only alleviate contradiction between energy supply and demand and waste in China,

but also protect the natural environment and provide more economic and comfortable

living conditions for people, which is of positive practical significance and important

research value, and is in line with global development trends.

Vanadium dioxide (V 2) is a metal oxide with a phase transition property, with a

phase transition temperature of 68°C. A structural change before and after the phase

transition leads to a reversible change from transmission to reflection of infrared light.

Based on such a property, vanadium dioxide is applied to the field of intelligent

temperature control films. However, since its phase transition temperature is relatively high, which is much higher than the environment temperature suitable for human survival, if vanadium dioxide is applied to temperature control materials for buildings, a phase transition point thereof have to be lowered.

Patent application CN107188426A discloses a tungsten-doped vanadium dioxide

thermochromic film and a preparation method thereof, in which, a layer of vanadium

pentoxide is firstly deposited on a surface of a substrate by magnetron sputtering, and

then a metal tungsten layer is deposited thereon, and finally, a layer of vanadium

pentoxide is deposited on the tungsten layer, to form a mixed film of vanadium

pentoxide/metal tungsten/vanadium pentoxide; and then an inert atmosphere is used to

oxidize the metal tungsten into high-valent tungsten, and the vanadium pentoxide is

reduced to vanadium dioxide, to obtain the tungsten-doped vanadium dioxide

thermochromic film. Patent application CN105543810B discloses a nano V02 film

with super-hydrophilic, self-cleaning and intelligent temperature control functions and

a preparation method thereof, in which, a precursor solution of vanadium dioxide is

firstly prepared by a sol-gel method, and then uniformly coated on a substrate, and

finally a step of annealing is carried out to obtain the nano vanadium dioxide film.

Patent application CN106957456A dislcoses a method for synthesizing

temperature-sensitive materials using tungsten-doped vanadium dioxide, which makes

uses of a change of crystal form of the tungsten-doped vanadium dioxide at different

temperatures to simultaneously implement a change of hydroxymethyl cellulose

LCST, thereby causing the difference in light transmittance, to achieve the purpose of

reducing a temperature of the hydroxymethyl cellulose LCST to 32-35°C.

On the whole, most of the existing patent applications are based on researches of the

tungsten-doped vanadium dioxide film, and the phase transition point of the prepared

material is quite different from the environment temperature suitable for human

survival, so that it is difficult to achieve the actual temperature control effect when

directly applied to building glass. Moreover, as people's requirements for aesthetics

and quality of life increase, glass is more and more favored in the fields of buildings, automobiles, etc. However, while glass brings people brightness and beauty, it also brings many problems, such as cleaning of glass curtain walls of large buildings.

Summary of the Invention

An objective of the present invention is to provide a method for preparing a

self-cleaning intelligent temperature control nanocellulose film. The prepared

nanocellulose film material has good temperature control and thermochromic effects

and strong environmental adaptability, and thus has great application potential in the

clean glass market.

1. A preparation method of a self-cleaning intelligent temperature control

nanocellulose film, comprises the steps of:

(1) adding tungsten-doped vanadium dioxide nanoparticles and paraffin emulsion to a

nanocellulose dispersion liquid, turning on a stirrer with a rotation speed adjusted to

300 r/min to stir for 15 mins, and mixing evenly; wherein, the nanocellulose

dispersion liquid has a medium of water, and has a concentration of 0.05-3wt.%; and a

mass ratio of the tungsten-doped vanadium dioxide nanoparticles: the paraffin

emulsion: the nanocellulose dispersion liquid is (0.01-0.5 ): (0.1-5): 100; and

(2) vaccum filtering materials evenly mixed above at 0.1 MPa for 1 h and hot-press

drying the same at 100°C for 8 mins, to obtain a self-cleaning intelligent temperature

control nanocellulose film with a thickness of 10-300 [m.

A mixing mode of the tungsten-doped vanadium dioxide nanoparticles, paraffin

emulsion, and nanocellulose in the step (1) is at least one of mechanical stirring,

magnetic stirring and ultrasonic dispersion.

A concentration of nanocellulose in the step (1) is 0.05-1.50wt.%.

Preferably, an amount of the tungsten-doped vanadium dioxide nanoparticle is

0.05-0.2%.

Preferably, an amount of the paraffin emulsion is 0.5-3%.

The prepared nanocellulose film has a thickness of 10-300 m; preferably, the

nanocellulose film has a thickness of 30-100 [m.

The prepared nanocellulose film has a quantity of 10-200 g/m2 , preferably, 30-100

g/m 2 .

The self-cleaning intelligent temperature control nanocellulose film is prepared by

using the above method.

The nanocellulose film has a phase transition temperature of 25-40°C. Preferably, the

phase transition temperature is 28-35°C.

The self-cleaning intelligent temperature control nanocellulose film prepared by the

above method is applied on a glass film.

The present invention has advantegeous effects as follows:

1. Simple process

The present invention takes pure natural plant cellulose nanofibers as raw materials,

loads tungsten-doped vanadium dioxide nanoparticles with phase transition and

temperature control effects onto the surface of a nanocellulose film by using a

mechanical mixing method, and then prepares a nanocellulose film with an intelligent

temperature control effect.

2. Self-cleaning, and low phase transition temperature

Through interaction of tungsten-doped vanadium dioxide nanoparticles, paraffin

emulsion and nanocellulose, the present invention achieves ultra-high hydrophobicity

and an effect that external temperature changes can intelligently regulate transparency,

haze and color changes of the nanocellulose film.

3. High application potential

The product has the advantages such as good intelligent temperature control effect,

and strong environmental adaptability, and has great application potential in the fields

of smart home, transportation and electronics.

Brief Description of the Drawings

FIG. 1 shows a physical image of an intelligent temperature control nanocellulose film

(a: added with W@V0 2 ; b: W@VO 2 accounts for 0.05%; c: W@VO 2 accounts for

0.1%; and d: W@VO 2 accounts for 0.2%);

FIG. 2 shows an atomic force microscope image of the intelligent temperature control

nanocellulose film;

FIG. 3 shows a differential scanning calorimetry (DSC) diagram of the nanocellulose

film before and after treatment;

FIG. 4 shows a contact angle (150 degrees) of the intelligent temperature control

nanocellulose film;

FIG. 5 shows X-ray diffraction patterns of the intelligent temperature control

nanocellulose film before and after treatment;

FIG. 6 shows transparency changes of nanocellulose films with different amounts of

tungsten-doped vanadium dioxide; and

FIG. 7 shows haze changes of the intelligent temperature control nanocellulose film at

different temperatures.

Detailed Description of the Invention

The present invention will be further explained below in connection with specific

examples. Unless otherwise specified, the quantities in the examples are all by mass.

Example 1

A preparation method of a self-cleaning intelligent temperature control nanocellulose

film, comprises the steps of: dispersing 5 parts of cellulose nanofibers in 95 parts of

water, adding 0.01 parts of tungsten-doped vanadium dioxide nanoparticles and 0.1

parts of paraffin emulsion, turning on a stirrer with a rotation speed adjusted to 300

r/min to stir for 15 mins, and preparing the film by vacuum filtering (0.1 MPa, 1 h)

and hot-press drying (100C, 8 min).

Example 2

film, comprises the steps of: dispersing 10 parts of cellulose nanofibers in 90 parts of

water, adding 0.1 parts of tungsten-doped vanadium dioxide nanoparticles and 2 parts

of paraffin emulsion, turning on a stirrer with a rotation speed adjusted to 300 r/min to

stir for 15 mins, and preparing the film by vacuum filtering (0.1 MPa, 1 h) and

hot-press drying (100C, 8 min).

Example 3

film, comprises the steps of: dispersing 15 parts of cellulose nanofibers in 85 parts of

water, adding 0.05 parts of tungsten-doped vanadium dioxide nanoparticles and 0.5

and hot-press drying (100C, 8 min).

Example 4

water, adding 0.2 parts of tungsten-doped vanadium dioxide nanoparticles and 3 parts

of paraffin emulsion, turning on a stirrer with a rotation speed adjusted to 300 r/min to stir for 15 mins, and preparing the film by vacuum filtering (0.1 MPa, 1 h) and hot-press drying (100°C, 8 min).

Example 5

film, comprises the steps of: dispersing 30 parts of cellulose nanofibers in 70 parts of

water, adding 0.5 parts of tungsten-doped vanadium dioxide nanoparticles and 5 parts

of paraffin emulsion into a reaction kettle, turning on a stirrer with a rotation speed

adjusted to 300 r/min to stir for 15 mins, and preparing the film by vacuum filtering

(0.1 MPa, 1 h) and hot-press drying (100°C, 8 min).

Comparative example 1

water, adding 0.3 parts of paraffin emulsion, turning on a stirrer with a rotation speed

(0.1 MPa, 1 h) and hot-press drying (100°C, 8 min).

Comparative example 2

water, adding 0.05 parts of tungsten-doped vanadium dioxide nanoparticles, turning

on a stirrer with a rotation speed adjusted to 300 r/min to stir for 15 mins, and

preparing the film by vacuum filtering (0.1 MPa, 1 h) and hot-press drying (100°C, 8

min).

Implementation effect example

The properties of the materials prepared in Examples 1-5 and Comparative examples

1 and 2 are compared and analyzed in a table below:

Table 1: Comparison between the properties of the materials prepared in Examples

1-5 and Comparative examples 1 and 2

Items Film Phase Transparency Haze Contact Filtration thickness transition (%) degree angle time ([tm) temperature (%) (0) (min) ( 0 C) Example 1 37 19.5 91 55 91 126 Example 2 62 18.8 85 60 124 85 Example 3 83 19.2 81 75 105 91 Example 4 58 18.3 78 81 138 82 Example 5 102 18.0 73 83 150 63 Comparative 61 20.5 81 62 83 115 example 1 Comparative 56 20.1 76 74 55 185 example 2

Although the implementation modes of the present invention have been disclosed as above, they are not limited to the applications listed in the description and examples, and can be applied to various fields suitable for the present invention. For those familiar with the field, it is easy to achieve other modifications. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to specific details.

Claims

1. A preparation method of a self-cleaning intelligent temperature control

nanocellulose film, comprising the steps of:

(1) adding tungsten-doped vanadium dioxide nanoparticles and paraffin emulsion

to a nanocellulose dispersion liquid with a concentration of 0.05-3wt.%, turning on a

stirrer with a rotation speed adjusted to 300 r/min to stir for 15 mins, and mixing

evenly; a mass ratio of the tungsten-doped vanadium dioxide nanoparticles: the

paraffin emulsion: the nanocellulose dispersion liquid being (0.01-0.5) : (0.1- 5) : 100;

and

(2) vaccum filtering materials evenly mixed above at 0.1 MPa for 1 h and

hot-press drying the same at 100 °C for 8 mins to obtain the self-cleaning intelligent

temperature control nanocellulose film with a thickness of 10-300 [m.

2. The preparation method according to claim 1, wherein, a medium of the

nanocellulose dispersion liquid is water.

3. The preparation method according to claim 1, wherein, a concentration of the

nanocellulose dispersion liquid is 0.05-1.50wt.%.

4. The preparation method according to claim 1, wherein, an amount of the

tungsten-doped vanadium dioxide nanoparticles is 0.05-0.2%.

5. The preparation method according to claim 1, wherein, an amount of the paraffin

emulsion is 0.5-3%.

6. The preparation method according to claim 1, wherein, a thickness of the

nanocellulose film is 30-100 [m.

7. A self-cleaning intelligent temperature control nanocellulose film, prepared by the

method according to claim 1.

8. The self-cleaning intelligent temperature control nanocellulose film, prepared by

the method according to claim 1, having a phase transition temperature of 25-40°C.

9. An application of the self-cleaning intelligent temperature control nanocellulose

film, prepared by the method according to claim 1, on a glass film.

a b 1/4

FIG. 2 FIG. 1 c d