CN107460759B - Rapid purification method of nano-cellulose suspension - Google Patents
Rapid purification method of nano-cellulose suspension Download PDFInfo
- Publication number
- CN107460759B CN107460759B CN201710709661.5A CN201710709661A CN107460759B CN 107460759 B CN107460759 B CN 107460759B CN 201710709661 A CN201710709661 A CN 201710709661A CN 107460759 B CN107460759 B CN 107460759B
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- CN
- China
- Prior art keywords
- nano
- cellulose
- cellulose suspension
- suspension
- ammonium bicarbonate
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- 239000000725 suspension Substances 0.000 title claims abstract description 54
- 229920002678 cellulose Polymers 0.000 title claims abstract description 48
- 239000001913 cellulose Substances 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000000746 purification Methods 0.000 title claims abstract description 17
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000001099 ammonium carbonate Substances 0.000 claims abstract description 41
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims abstract description 21
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims abstract description 21
- 235000012501 ammonium carbonate Nutrition 0.000 claims abstract description 20
- 229920001046 Nanocellulose Polymers 0.000 claims abstract description 19
- 238000005119 centrifugation Methods 0.000 claims abstract description 16
- 239000002244 precipitate Substances 0.000 claims abstract description 13
- 150000002500 ions Chemical class 0.000 claims abstract description 12
- 239000012535 impurity Substances 0.000 claims abstract description 10
- 238000010438 heat treatment Methods 0.000 claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 238000009835 boiling Methods 0.000 claims description 12
- 239000008367 deionised water Substances 0.000 claims description 9
- 229910021641 deionized water Inorganic materials 0.000 claims description 9
- 238000007865 diluting Methods 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 239000011259 mixed solution Substances 0.000 claims description 4
- 238000000354 decomposition reaction Methods 0.000 claims 1
- 238000000502 dialysis Methods 0.000 abstract description 7
- 238000005903 acid hydrolysis reaction Methods 0.000 abstract description 4
- 239000000835 fiber Substances 0.000 abstract description 4
- 239000012498 ultrapure water Substances 0.000 abstract description 4
- 239000000084 colloidal system Substances 0.000 abstract description 2
- 229920000168 Microcrystalline cellulose Polymers 0.000 abstract 1
- 235000019813 microcrystalline cellulose Nutrition 0.000 abstract 1
- 239000008108 microcrystalline cellulose Substances 0.000 abstract 1
- 229940016286 microcrystalline cellulose Drugs 0.000 abstract 1
- 239000006228 supernatant Substances 0.000 abstract 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 239000007788 liquid Substances 0.000 description 3
- 230000001502 supplementing effect Effects 0.000 description 3
- 239000002002 slurry Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000003513 alkali Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- GDOPTJXRTPNYNR-UHFFFAOYSA-N methyl-cyclopentane Natural products CC1CCCC1 GDOPTJXRTPNYNR-UHFFFAOYSA-N 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
Landscapes
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
The invention discloses a rapid purification method of a nano-cellulose suspension. Adding ammonium bicarbonate or ammonium carbonate into a nano-cellulose suspension to precipitate nano-cellulose, and repeatedly centrifuging for multiple times to remove original impurity ions in the nano-cellulose. Then decomposing ammonium bicarbonate or ammonium carbonate into gas by a heating method to escape, and obtaining pure nano cellulose suspension. According to the invention, ammonium bicarbonate or ammonium carbonate is added into the nano-cellulose suspension to destroy the stable colloid state of the nano-cellulose suspension, and the nano-cellulose precipitate is separated from the original impurity ions in the supernatant by centrifugation. Newly introduced ammonium bicarbonate or ammonium carbonate can be decomposed into gas to escape from the fiber suspension by a simple heating method, and high-purity nano cellulose suspension is obtained. The purification method can also replace the dialysis process in the process of preparing the nano microcrystalline cellulose by acid hydrolysis, thereby not only saving a large amount of high-purity water required in the dialysis process, but also saving the dialysis time of 3-7 days.
Description
Technical Field
The invention belongs to the field of natural high polymer materials, and particularly relates to a rapid purification method of a nano-cellulose suspension.
Background
Due to the tiny size of nanocellulose, ions doped in nanocellulose cannot be removed by filtration or centrifugation. Nowadays, dialysis is generally used to remove impurity ions from nanocellulose suspensions, which requires a large amount of highly pure water and is time-consuming. For example, the conventional process for preparing nanocellulose by acid hydrolysis requires a long-term dialysis of the slurry after acid hydrolysis with a large amount of high-purity water for 3 to 7 days to remove the ions remaining in the fiber slurry after acid hydrolysis. Not only is time-consuming, but also causes a great deal of waste of high-purity water.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a rapid purification method of a nano-cellulose suspension, namely, ammonium bicarbonate or ammonium carbonate is added into the nano-cellulose suspension, so that the stable colloid state of the nano-cellulose suspension is destroyed, and the nano-cellulose suspension can be separated and purified by a simple centrifugal method. The introduced ammonium bicarbonate or ammonium carbonate can be decomposed into gas by adopting a heating and boiling method to escape, and the high-purity nano cellulose suspension is prepared.
The invention is realized by the following technical scheme.
A method for rapid purification of a nanocellulose suspension, comprising the steps of:
(1) adding ammonium bicarbonate or ammonium carbonate into the cellulose suspension, and uniformly mixing to obtain a mixed solution;
(2) centrifuging the mixed solution obtained in the step (1) by using a high-speed refrigerated centrifuge, taking the cellulose precipitate obtained by centrifuging, diluting the cellulose precipitate by using deionized water, repeatedly adding ammonium bicarbonate or ammonium carbonate, uniformly mixing, centrifuging, and repeatedly centrifuging for multiple times until the original impurity ions are completely removed;
(3) diluting the precipitate obtained by the last centrifugation with deionized water, heating and boiling to completely decompose ammonium bicarbonate or ammonium carbonate into gas to escape, and thus obtaining the high-purity nano cellulose suspension.
Preferably, the cellulose suspension in step (1) is a nano-cellulose suspension or a cellulose suspension that cannot be separated by ordinary centrifugation.
Preferably, the amount of the ammonium bicarbonate or ammonium carbonate used in the step (1) is 0.5 to 3 percent of the mass of the cellulose suspension.
Preferably, the rotation speed of the high-speed freezing centrifuge in the step (2) is 4000-.
Preferably, the time of each centrifugation in step (2) is 5-30 min.
Preferably, the centrifugation in step (2) is repeated 4 to 6 times.
Preferably, the heating and boiling time for completely decomposing the ammonium bicarbonate or ammonium carbonate in the step (3) is 20-120 min.
Preferably, the conductivity of the nanocellulose suspension after purification in step (3) is less than 800 us/cm.
Preferably, the method for rapidly purifying the nanocellulose suspension specifically comprises the following steps:
adding ammonium bicarbonate or ammonium carbonate with the mass of 0.5-3% of the nano-cellulose suspension into the nano-cellulose suspension, uniformly mixing, and centrifuging for 5-30min at the speed of 4000-12000rpm by using a high-speed refrigerated centrifuge. And (3) taking the cellulose precipitate obtained by centrifugation, diluting the cellulose precipitate with deionized water, repeatedly adding ammonium bicarbonate or ammonium carbonate, mixing uniformly, and centrifuging. The centrifugation process is repeated for a plurality of times until the original impurity ions are removed completely. Diluting the precipitate obtained by the last centrifugation with deionized water, heating and boiling for 20-120min to completely decompose ammonium bicarbonate or ammonium carbonate into gas, and then obtaining the high-purity nano cellulose suspension.
Compared with the prior art, the invention has the following advantages and beneficial effects:
in the method, impurity ions in the nano-cellulose suspension can be removed by a simple and rapid centrifugal method. Compared with the commonly used dialysis method, the method saves a large amount of high-purity water, saves 3-7 days of dialysis time, and has very high economic value and practical value.
Detailed Description
The following examples further illustrate specific embodiments of the present invention, but the embodiments of the present invention are not limited thereto.
Example 1
To 100g of a fiber suspension (concentration: 5wt%, conductivity: 50 ms/cm) obtained by hydrolyzing a plant fiber raw material with concentrated sulfuric acid and neutralizing with alkali, 1.75g of ammonium bicarbonate was added and mixed uniformly. The centrifugation was repeated 6 times by centrifuging for 10min at 4000rpm using a high-speed refrigerated centrifuge. Adding 100ml of deionized water into the obtained cellulose precipitate, boiling for 20min (continuously supplementing water during the boiling period, and maintaining the liquid level of 100 ml), to obtain high-purity cellulose suspension.
The conductivity of the high purity cellulose suspension obtained in this example was 600us/cm, indicating that impurity ions in the nanocellulose suspension can be removed simply and rapidly by the purification process of the present invention.
Example 2
To 100g of a 2 wt% strength nanocrystallme cellulose suspension containing 3g of NaCl (conductivity 55 ms/cm) was added 3g of ammonium bicarbonate and mixed homogeneously. The centrifugation was repeated 5 times by centrifuging for 10min at 12000rpm with a high-speed refrigerated centrifuge. Adding 300ml of deionized water into the obtained cellulose precipitate, boiling for 120min (continuously supplementing water during the boiling period, and maintaining the liquid level at 300 ml), and obtaining the high-purity cellulose suspension.
The conductivity of the high purity cellulose suspension obtained in this example was 150us/cm, indicating that impurity ions in the nanocellulose suspension can be removed simply and rapidly by the purification process of the present invention.
Example 3
To 100g of a 1 wt% strength nanocellulose suspension (conductivity 20 ms/cm) obtained by oxidation of 1g NaCl-containing TEMPO, 0.5g of ammonium carbonate was added and mixed homogeneously. The centrifugation was repeated 4 times by centrifuging at 8000rpm for 10min using a high-speed refrigerated centrifuge. Adding 200ml of deionized water into the obtained cellulose precipitate, boiling for 70min (continuously supplementing water during the boiling period, and maintaining the liquid level at 200 ml), to obtain high-purity cellulose suspension.
The conductivity of the high purity cellulose suspension obtained in this example was 80.5us/cm, indicating that impurity ions in the nanocellulose suspension can be removed simply and rapidly by the purification process of the present invention.
Claims (7)
1. A rapid purification method of a nano-cellulose suspension is characterized by comprising the following steps:
(1) adding ammonium bicarbonate or ammonium carbonate into the cellulose suspension, and uniformly mixing to obtain a mixed solution;
(2) centrifuging the mixed solution obtained in the step (1) by using a high-speed refrigerated centrifuge, taking the cellulose precipitate obtained by centrifuging, diluting the cellulose precipitate by using deionized water, repeatedly adding ammonium bicarbonate or ammonium carbonate, uniformly mixing, centrifuging, and repeatedly centrifuging for multiple times until the original impurity ions are completely removed;
(3) diluting the precipitate obtained by the last centrifugation with deionized water, heating and boiling to completely decompose ammonium bicarbonate or ammonium carbonate into gas to escape, and thus obtaining high-purity nano cellulose suspension;
the dosage of the ammonium bicarbonate or ammonium carbonate in the step (1) is 0.5 to 3 percent of the mass of the cellulose suspension.
2. The method for rapidly purifying nano-cellulose suspension as claimed in claim 1, wherein the cellulose suspension of step (1) is nano-cellulose suspension or cellulose suspension that can not be separated by ordinary centrifugation.
3. The method as claimed in claim 1, wherein the rotation speed of the high-speed refrigerated centrifuge in step (2) is 4000-12000 rpm.
4. The method for rapid purification of nano-cellulose suspension as claimed in claim 1, wherein the time of each centrifugation in step (2) is 5-30 min.
5. The method for rapid purification of nano-cellulose suspension as claimed in claim 1, wherein the number of times of repeated centrifugation in step (2) is 4-6.
6. The method for rapid purification of nano-cellulose suspension as claimed in claim 1, wherein the heating boiling time for complete decomposition of ammonium bicarbonate or ammonium carbonate in step (3) is 20-120 min.
7. The method for rapid purification of a nanocellulose suspension according to claim 1, characterized in that the conductivity of the nanocellulose suspension after purification in step (3) is less than 800 μm/cm.
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| CN201710709661.5A CN107460759B (en) | 2017-08-18 | 2017-08-18 | Rapid purification method of nano-cellulose suspension |
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| CN201710709661.5A CN107460759B (en) | 2017-08-18 | 2017-08-18 | Rapid purification method of nano-cellulose suspension |
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| CN107460759A CN107460759A (en) | 2017-12-12 |
| CN107460759B true CN107460759B (en) | 2020-12-22 |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP6933056B2 (en) * | 2017-08-29 | 2021-09-08 | 東亞合成株式会社 | Manufacturing method of cellulose nanofiber powder |
| CN108165094B (en) * | 2017-12-15 | 2021-07-16 | 华南理工大学 | Nano cellulose-based pen core water-based ink and preparation method thereof |
| CN109609036A (en) * | 2018-12-06 | 2019-04-12 | 武汉科丝力纤维制造有限公司 | A kind of environment-friendly modified foamed ceramics adhesive and its preparation process |
| CN109457524B (en) * | 2018-12-29 | 2023-10-20 | 珠海市东辰制药有限公司 | Purification method and purification equipment of nano microcrystalline cellulose |
| CN110656526B (en) * | 2019-10-08 | 2021-10-01 | 齐鲁工业大学 | Method for preparing nano-cellulose from fiber slurry |
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