CN103304673B - A kind of method optimized Ascidian nano-cellulose and prepare - Google Patents

Abstract

Ascidian Mierocrystalline cellulose (tunicate? cellulose, TC) there is larger molecular weight and degree of crystallinity, therefore traditional acid-hydrolysis method is adopted to be difficult to prepare the Ascidian nano-cellulose (tunicate of high yield? cellulose? nanocrystals, T-CNs), its maximum output also only has an appointment 20%.For above-mentioned Problems existing, the invention discloses a kind of method prepared by T-CNs of optimization.First, utilize ball mill to Ascidian Mierocrystalline cellulose (tunicate in presence of water? cellulose, TC) grind, then acid hydrolysis is carried out to the TC after grinding.By adopt high-power ultrasonics supersound process is carried out to said hydrolyzed product, can prepare productive rate up to more than 50% T-CNs.Preparation technology's environmental protection of the present invention, method is simple, is conducive to industrialization.

Description

A kind of method optimized Ascidian nano-cellulose and prepare

Technical field

The invention belongs to nano-cellulose liquid crystal material technical field, more particularly relate to Ascidian nano-cellulose and the molten improvement causing cholesteryl liquid crystal preparation method thereof.

Background technology

Cellulose resource is enriched, and is the material of the maximum natural organic high-molecular of reserves.It is composition higher plant (as cotton and trees) and the main component of various alga cells wall, while some fungi, bacterium also can synthetic cellulose.People have also discovered cellulosic existence in some knapsack class animal (as Ascidian) in recent years.Because of its wide material sources, degradable, renewable and excellent physical and chemical performance, in today of fossil fuel shortages, to its abundant processing and utilization, there is important economy and environment benefit.

Since entering 21 century, nanosecond science and technology there has also been significant progress, and nano-cellulose becomes the study hotspot of field of polymer technology, also in the production, life of people, play the part of more and more important role gradually.Nanofiber have multiple preparation method, mainly comprises the method such as hydrolysis method, mechanical process.1949, Rangby [RanbyB.G., ActaChemicaScandinavica1949,3:649] adopted the method for sulphuric acid hydrolysis to prepare nano-cellulose.1992, Revol etc. [RevolJ.F., BradfordH., GiassonJ, GrayD.G., Int.J.Biol.Macromol. [J], 1992:170] found that nano-cellulose suspension can form cholesteryl liquid crystal at low concentrations.2004, Nakagaito etc. [NakagaitoA., YanoH., Appl.Phys.A-Mater.Sci.Proc., 2004,78 (4): 547] beating equipment made the completely thin fibrillation of Mierocrystalline cellulose.2007, fiber dispersion was become nano-cellulose with disintegrator with high pressure homogenizer by Leitner etc. [LeitnerJ., HinterstoisserB., WastynM., Cellulose, 2007,14:419].2010, Zhang Lihong etc. [extract Microcrystalline Cellulose and prepare the method for lyotropic cholesteryl liquid crystal, China, patent of invention in Ascidian, ZL201010217969.6,2012.3.14] adopt the method for sulphuric acid hydrolysis to prepare Styela clava nano-cellulose cholesteryl liquid crystal.

Adopt chemical acid hydrolysis to need strong acid hydrolysis completely, require high to conversion unit, and the more difficult recovery of reacted residue; Adopt mechanical process preparation completely, without the need to chemical reagent, less on the impact of environment, but size distribution prepared by mechanical process is wider, and the equipment needed for mechanical process preparation is simultaneously more special, and energy expenditure is high.

The method preparing the molten N*-LCs of causing of T-CNs reported up to now adopts acid-hydrolysis method to process all completely, and N*-LCs productive rate is very low, and the wasting of resources is comparatively serious.For above-mentioned Problems existing, the invention provides a kind of mechanical mill TC and high-power ultrasonics auxiliary treatment N*-LCs to improve the method for N*-LCs productive rate.Prepare compared with the molten method causing N*-LCs of T-CNs with traditional, processing method is more simple, and reduces the requirement to equipment in commercial process, reduces production energy consumption, and can greatly improve the molten productive rate causing N*-LCs of T-CNs.

Summary of the invention

The present invention utilizes mechanical mill Ascidian Mierocrystalline cellulose (TC) and the molten cholesteryl liquid crystal (N*-LCs) that causes of high-power ultrasonics auxiliary treatment Ascidian nano-cellulose (T-CNs) to improve the new technology of N*-LCs productive rate.The method that traditional raising T-CNs is molten causes N*-LCs productive rate often by extending hydrolysis time, improve temperature of reaction or increase that the methods such as sulfuric acid concentration realize, this several method not only increases the requirement of equipment but also very easily makes Mierocrystalline cellulose generation carbonization.This method more simple and effectively can realize the raising of N*-LCs productive rate by comparison, and processing method is simple, reduces in commercial process the requirement of equipment and production cost.

Mechanical mill TC and high-power ultrasonics auxiliary treatment N*-LCs comprises the following steps with the method improving N*-LCs productive rate:

The white Ascidian cellulose sheaths extracted is cut into small pieces, together adds in ball mill with a certain amount of water; Need to cool after work for some time, repeat for several times; By grinding the TC water slurry centrifugal treating obtained, outwell the limpid liquid in upper strata; Lower floor's centrifugal sediment is mixed according to certain ratio with the vitriol oil, after mixing solutions heated and stirred reaction certain hour, adds a large amount of deionized water termination reactions; Remove acid excessive in solution by centrifugal and dialysis, with the ultrasonic wave of different-energy, it is processed as required, after suitably concentrating, namely obtain having that the T-CNs of different pitch is molten causes N*-LCs suspension.

Accompanying drawing explanation

Fig. 1 is the molten contrast photo causing N*-LCs suspension of T-CNs prepared by classical acid hydrolysis method and the method through improving.

Fig. 2 is the molten POM photo causing N*-LCs suspension of T-CNs prepared by classical acid hydrolysis method.

Fig. 3 is the molten POM photo causing N*-LCs suspension of T-CNs after mechanical mill and high-power ultrasonics auxiliary treatment.

Can be clear that in Fig. 1 that the obtained molten N*-LCs of the causing suspension of T-CNs of classical acid hydrolysis can precipitate after leaving standstill, the T-CNs after mechanical mill and high-power ultrasonics auxiliary treatment is molten, and to cause N*-LCs suspension then highly stable.

Can know the macrobead seeing TC in Fig. 2, size is at 20-200 μm.

A small amount of size is only had to be about the TC particle of 20 μm in Fig. 3.

Embodiment

Embodiment 1

(1) get the block Ascidian Mierocrystalline cellulose of 100g and 1L water is poured in ball mill jointly, after grinding 1h, the friction of shredder internal cause elevates the temperature, and need shut down 15min and be cooled to room temperature, and then grinding, above step repetitive operation three times.

(2) poured out by ground Ascidian Mierocrystalline cellulose water slurry, use centrifuge process, rotating speed is 12000rpm, removes supernatant liquor, retains from precipitation.

(3) get the vitriol oil that 10g throw out and 175ml concentration are 64wt% to mix, oil bath magnetic agitation reacting by heating 5h at 45 DEG C.

(4) add 800ml deionized water termination reaction, use centrifuge process, rotating speed is 12000rpm, removes supernatant liquor, with centrifugal again after washed with de-ionized water, and repetitive operation three times.

(5) centrifugal sediment is loaded in dialysis tubing and dialyse to extraneous solution is neutrality with deionized water.

(6) carry out supersound process with Ultrasonic cell smash to nano-cellulose suspension, ultrasonic power is 25KHz, and ultrasonic power is 600W, and ultrasonic time is 8min, and ultrasonic amplitude of fluctuation shank diameter is 6mm.

(7) polyoxyethylene glycol (PEG) again the dialysis tubing after supersound process being put into 15wt% concentrates, and to be that the T-CNs of 5wt% is molten cause N*-LCs suspension to obtained concentration.

Embodiment 2

In step (1), the cellulosic consumption of block Ascidian is 0.01-10kg, and all the other steps are identical with embodiment 1.

Embodiment 3

In step (1), the consumption of water is 0.1-10L, and all the other steps are identical with embodiment 1.

Embodiment 4

In step (1), the ball mill grinding time is 1-120min, and all the other steps are identical with embodiment 1.

Embodiment 5

Ball mill cooling time is 1-120min in step (1), and all the other steps are identical with embodiment 1.

Embodiment 6

In step (3), the reaction times is 0.5-10h, and all the other steps are identical with embodiment 1.

Embodiment 7

In step (3), hydrolysis temperature is 0-80 DEG C, and all the other steps are identical with embodiment 1.

Embodiment 8

In step (3), sulfuric acid concentration is 40-70wt%, and all the other steps are identical with embodiment 1.

Embodiment 9

In step (6), ultrasonication power is 100-1500W, and operating frequency range is that all the other steps of 21-25KHz are identical with embodiment 1.

Embodiment 10

In step (6), ultrasonic treatment time is 1-180min, and all the other steps are identical with embodiment 1.

Embodiment 11

In step (6), ultrasonication horn diameter is 2-30mm, and all the other steps are identical with embodiment 1.

Embodiment 12

The T-CNs molten N*-LCs of causing suspension concentration obtained in step (7) is that all the other steps of 0.5-12wt% are identical with embodiment 1.

Claims (1)

1. optimize a method prepared by Ascidian nano-cellulose, its feature comprises the following steps:

(1) get the block Ascidian Mierocrystalline cellulose of 100g and 1L water is poured in ball mill jointly, after grinding 1h, the friction of shredder internal cause elevates the temperature, and need shut down 15min and be cooled to room temperature, and then grinding, above step repetitive operation three times;

(2) poured out by ground Ascidian Mierocrystalline cellulose water slurry, use centrifuge process, rotating speed is 12000rpm, removes supernatant liquor, retains from precipitation;

(3) get the vitriol oil that 10g throw out and 175mL concentration are 64wt% to mix, oil bath magnetic agitation reacting by heating 5h at 45 DEG C;

(4) add 800mL deionized water termination reaction, use centrifuge process, rotating speed is 12000rpm, removes supernatant liquor, with centrifugal again after washed with de-ionized water, and repetitive operation three times;

(5) centrifugal sediment is loaded in dialysis tubing and dialyse to extraneous solution is neutrality with deionized water;

(6) carry out supersound process with Ultrasonic cell smash to nano-cellulose suspension, ultrasonic power is 25kHz, and ultrasonic power is 600W, and ultrasonic time is 8min, and ultrasonic amplitude of fluctuation shank diameter is 6mm;

(7) polyoxyethylene glycol (PEG) again the dialysis tubing after supersound process being put into 15wt% concentrates, and to be that the T-CNs of 5wt% is molten cause N*-LCs suspension to obtained concentration.