CN102924740B

CN102924740B - Preparation method of sea squirt cellulose cholesteric liquid crystal film and products thereof

Info

Publication number: CN102924740B
Application number: CN201210453397.0A
Authority: CN
Inventors: 朴光哲; 张青; 李健荣; 张大为
Original assignee: Qingdao University of Science and Technology
Current assignee: Qingdao University of Science and Technology
Priority date: 2012-10-31
Filing date: 2012-10-31
Publication date: 2015-10-21
Anticipated expiration: 2032-10-31
Also published as: CN102924740A

Abstract

The invention discloses preparation and there is selective reflection infrared light and the technology and products thereof through Ascidian Mierocrystalline cellulose cholesteric liquid crystal (N*-LCs) film of visible ray function.This invention utilizes the molten N*-LCs of the causing suspension of Ascidian nano-cellulose to prepare N*-LCs film by dry masking technique.Can obtain having different pitch and thickness by factor such as adjustment concentration, solvent, hydrolysis temperature or externally-applied magnetic field etc. and the N*-LCs film of different wave length infrared light can be reflected.Film in the present invention is when through visible ray, selects reflects infrared light (heat energy).Therefore, this film is expected the pad pasting being applied to building and automobile window glass, effectively can stop " arch-criminal "---the infrared light of heating in summer building, reduce indoor temperature, reach the object of energy-saving and emission-reduction, and abundant raw materials, cheap, environmental protection, processing method is simply controlled, can be used for suitability for industrialized production.

Description

Preparation method of sea squirt cellulose cholesteric liquid crystal film and products thereof

Technical field

The invention belongs to the film material with function field of Ascidian Mierocrystalline cellulose N*-LCs.

Background technology

20 beginnings of the century, people appreciate the day by day exhausted and non-renewable of the resource such as oil, coal, and environment is to the importance of health, so start visual cognitive ability to arrive on wide material sources and eco-friendly cellulose materials.

Over more than 100 year, people are studied in detail the structure of plant cellulose, chemistry and physical properties.1976, [the Werbowyj R.S. such as D.G.Gary, Gray D.G., Mol.Cryst.Liq.Cryst. (Lett.), 1976,34 (4): 97-103.] on open source literature, report molecular weight is first that 20% ~ 50% aqueous solution of the hydroxypropylcellulose of 100000 can form the N*-LCs solution with rainbow color, strong double refraction and opticity; 1992, Sugiyama etc. [Sugiyama J, Chanzy H, Maret G, Macromolecules, 1992,25 (16): 4232-4234.] extracted Mierocrystalline cellulose first from true Ascidian; 2005, [the Kimura F such as Kimura, Kimura T, Tamura M, et al, Magnetic alignment of the chiral nematicphase of a cellulose microfibril suspension [J], Langmuir, 2005,21 (5): 2034-2037.] the true Ascidian Mierocrystalline cellulose after reporting acid hydrolysis can form N*-LCs; 2007, [Berg O.V.D, the Capadona R.J such as Berg, Weder C, Biomacromolecules, 2007,8 (4): 1353-1357]. from Styela clava, extract Mierocrystalline cellulose first, and obtain Styela clava cellulose whiskers by acid-hydrolyzed method.Utilize Ascidian Mierocrystalline cellulose N*-LCs to prepare film in the present invention, film forming still keeps the distinctive spirane structure of N*-LCs later, can select reflects infrared light.

N*-LCs has unique selection reflecting properties.In reflected wavelength range, the N*-LCs with left-turn spiral structure allows right-hand circular polarization light transmission and reflects left circularly polarized light, and vice versa.Outside reflected wavelength range, left-handed and right-circularly polarized light all can pass through.The wavelength region of reflection can represent with Δ λ=Δ nP formula, wherein: P, Δ n are respectively the pitch of spirane structure, the birefringence index of liquid crystal.Select the wavelength of reflected light to change along with the change at visual angle, make it have color as rainbow.The spirane structure of N*-LCs determines the distinctive optical characteristics of itself, such as opticity, polarisation dichroism, Bragg reflection etc.Therefore, Ascidian Mierocrystalline cellulose N*-LCs not only in traditional natural fiber material field, and can be with a wide range of applications in the field such as anti-fake material, reflective type color Electronic Paper, decoration coating, display material and infrared light shielding energy-saving material.Ascidian Mierocrystalline cellulose N*-LCs film is less in visible region (400-700nm) reflection, and has very strong reflection near infrared region (700-2200nm).Therefore, Ascidian Mierocrystalline cellulose N*-LCs film can be applicable to material of construction for the purpose of usable reflection infrared light, trap heat or automobile industry.

According to the literature, in high-rise building, the energy of about 19% comes from through window and enters indoor solar radiation energy, this part thermal radiation mainly refers to the energy that infrared light (750-2500nm wave band) region produces, and this is the overheated major cause of Summer Indoor.The film of reflects infrared light can make Summer Indoor air-conditioning economize on electricity more than 5%, calculating in 100 hours is used by annual, a domestic air conditioning can economize on electricity 24 kilowatt-hours, 1.4 hundred million domestic air conditionings are had to calculate by the whole nation, every year can brownout 3,300,000,000 kilowatt-hour, be equivalent to the fuel-burning power plant building 600,000 kilowatts less, GHG (Greenhouse Gases) emissions mitigation 3,300,000 tons.

But there is the shortcomings such as expensive, raw material is non-renewable, non-degradable in such film at present on the market, and the N*-LCs film adopting Ascidian Mierocrystalline cellulose to prepare in the present invention has aboundresources, renewable, degradable, the simple environmental protection of technique, and can application techniques film forming be passed through, technique is simple, the features such as efficient energy-saving.

Summary of the invention

The present invention be preparation have select reflects infrared light and make visible ray smoothly through the technology and products thereof of Ascidian Mierocrystalline cellulose N*-LCs film.Ascidian Mierocrystalline cellulose N*-LCs film can effectively stop infrared light heat energy, so, will be widely used in building anti-infrared light pad pasting, anti-fake material and chiral template field with vehicle glass.It has energy-conserving and environment-protective, and raw material resources are enriched, cheap, and reactant and by product nontoxic, environment is not polluted, meet the theme of environmental protection and blueness economy, and operating process simple possible, production cost are low, easily realize industrialization.

The preparation method of Ascidian Mierocrystalline cellulose N*-LCs film comprises the following steps:

Ascidian cellulose powder is mixed according to certain ratio with the vitriol oil, after by mixing solutions, at 45 DEG C, heated and stirred reacts certain hour, add a large amount of deionized water termination reactions, remove acid excessive in solution by centrifugal and dialysis again, after concentrated also supersound process, namely obtain N*-LCs suspension.Then uniform suspension is coated on horizontal glass substrate or other base materials, at room temperature seasoning or vacuum-drying, namely obtains Ascidian Mierocrystalline cellulose N*-LCs film, can film be taken off when weight no longer changes.

By the film thickness and the pitch that regulate Ascidian cellulose suspension concentration and consumption to control Ascidian Mierocrystalline cellulose N*-LCs film, and then reflected wavelength range can be regulated and controled.

Accompanying drawing explanation

Fig. 1 is the energy-conservation schematic diagram of Ascidian Mierocrystalline cellulose N*-LCs film.

Fig. 2 is polarizing microscope (POM) photo of Ascidian Mierocrystalline cellulose N*-LCs suspension.

Fig. 3 is the photo of Ascidian Mierocrystalline cellulose N*-LCs film.

By being clear that the molten fingerprint texture causing N*-LCs of Ascidian Mierocrystalline cellulose in Fig. 2, from fingerprint texture, the pitch P of this molten N*-LCs of causing is about 16 μm.

Fig. 3 a, b are the photos of Ascidian Mierocrystalline cellulose N*-LCs film, and wherein the thickness of Fig. 3 a film is about 112 μm, so the transparency is poor; The thickness of Fig. 3 b film is about 41 μm, so the transparency better.Fig. 3 c shows Ascidian Mierocrystalline cellulose N*-LCs film good snappiness, can adapt to difform base material.

Embodiment

Embodiment 1

(1) get 5g Ascidian Mierocrystalline cellulose, the vitriol oil being 64% with 175ml concentration mixes, with heat collecting type constant-temperature heating magnetic stirring apparatus oil bath heating also stirring reaction 10h at 45 DEG C.

(2) add 500ml deionized water cooling termination reaction, remove supernatant liquor with centrifuge, rotating speed is 12000rad/min, and with centrifugal again after washed with de-ionized water, repeatable operation is to the muddiness of upper strata.

(3) to load in dialysis tubing with deionized water dialysis to extraneous solution is neutrality, then dialysis tubing is put into 15% polyoxyethylene glycol (PEG) concentrated.

(4) ultrasonic suspension is uniformly dispersed after, PS culture dish horizontal substrate to be coated with, and at room temperature drying and forming-film, carefully to take off and namely obtain Ascidian Mierocrystalline cellulose N*-LCs film.

Embodiment 2

In step (1), Ascidian Mierocrystalline cellulose can use dimethyl sulfoxide (DMSO) (DMSO) pre-treatment, adds DMSO stirring reaction 4h at 75 DEG C of 40ml, and then carries out aftertreatment with the vitriol oil of 64%.All the other steps are identical with embodiment 1.

Embodiment 3

In step (1), the reaction times is 5-20 hour, and the molten N*-LCs of the causing pitch obtained is 10-20nm, and the reaction times, longer pitch was larger.

Embodiment 4

First can remove macrobead with the rotating speed of 2000rad/min in step (2), then it is centrifugal that supernatant liquid is carried out washing.All the other steps are identical with embodiment 1.

Embodiment 5

Dripping of Ascidian Mierocrystalline cellulose N*-LCs uniform suspension is carried out drying and forming-film by step (4) on the glass sheet or in glass culture dish.All the other steps are identical with embodiment 1.

Embodiment 6

Vacuum-drying at the base material that Ascidian Mierocrystalline cellulose N*-LCs suspension is housed is placed on 30 DEG C by step (4), when weight no longer changes, film is taken off in cooling.The thickness of the film of suspension concentration preparation different from consumption is also different, and the thickness of the more films of the larger consumption of concentration is larger, otherwise thickness is less.All the other steps are identical with embodiment 1.

Embodiment 7

With glass stick, spreading upon on glass substrate of obtained nano-cellulose uniform suspension is carried out drying in step (4), the film that thickness is less can be prepared, after drying, obtain N*-LCs glass.All the other steps are identical with embodiment 1.

Embodiment 8

Appropriate additive can being added in step (4) to improve the performance of film, improving the toughness of cellulosefilm as added the toughner such as polyvinyl alcohol; Add the plasticizing rate that the fluidizer such as glycerol, sorbyl alcohol increases cellulosefilm; By the fluorinated modified hydrophobic nature etc. improving cellulosefilm of arabinoxylan.

Embodiment 9

Add tetraethoxy in step (4), methyl silicate, the inorganic reagents such as titanium dioxide, utilize the spirane structure of Ascidian Mierocrystalline cellulose N*-LCs suspension to have the functional organic/inorganic composite material film of N*-LCs structure for Template preparation.

Claims

1. a preparation method for Ascidian Mierocrystalline cellulose N*-LCs film, is characterized in that comprising the following steps:

(1), by 5g Ascidian Mierocrystalline cellulose add in 40ml dimethyl sulfoxide (DMSO) at 75 DEG C after stirring reaction 4h with 175ml concentration be 64% the vitriol oil mix, with heat collecting type constant-temperature heating magnetic stirring apparatus at 45 DEG C oil bath heating and stirring reaction 10h;

(2), add 500ml deionized water cooling termination reaction, remove supernatant liquor with centrifuge, rotating speed is 12000rad/min, and with centrifugal again after washed with de-ionized water, repeatable operation is to the muddiness of upper strata;

(3), to load in dialysis tubing with deionized water dialysis to extraneous solution is neutrality, then dialysis tubing is put into 15% polyoxyethylene glycol concentrated;

(4), ultrasonic suspension is uniformly dispersed after, PS culture dish horizontal substrate to be coated with, and at room temperature drying and forming-film, carefully to take off and namely obtain Ascidian Mierocrystalline cellulose N*-LCs film.