Tea extract gel composition with formaldehyde color changing performance

Abstract

The present invention discloses a tea extract gel composition with formaldehyde color changing performance, wherein the tea extract gel composition is composed of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide and the balance by mass of water. Various auxiliary agents may also be added therein. The tea extract gel composition disclosed by the present invention can react with formaldehyde and produce obvious color changes, and thus can be used to absorb and indicate formaldehyde pollutants.

Description

Technical Field

[0001] The invention belongs to the field of daily chemicals, and in particular relates to a tea extract gel composition with formaldehyde color changing performance. Background Art

[0002] Hydrogel is a type of extremely hydrophilic three-dimensional network structure that swells rapidly in water. Due to the presence of a cross-linked network, hydrogel can swell and retain a large amount of water. The amount of water absorbed is closely related to the degree of cross-linking. The water content in the hydrogel can be as low as a few percent or as high as 99%. The aggregated state of the gel is neither completely solid nor completely liquid. Under certain conditions, it can maintain a certain shape and volume, and solutes can diffuse or penetrate from the hydrogel. Hydrogels composed of natural substances are being used more and more widely because of their better biocompatibility, sensitivity to the environment, abundant sources, and low prices.

[0003] In recent years, hydrogel materials based on natural extracts for air purification have been gradually introduced, such as: CN105770945A discloses an enzyme formaldehyde removal and deodorization agent, which is prepared from the culture solution of microorganisms such as oriental yeast, lactic acid bacteria, pentose pediococcus and baker's yeast; CN101804215A uses natural plant aloe as raw material, and amino-derivatizes the polysaccharide in the aloe gel hydrolysate, and then compounding the tool with amino collagen to obtain formaldehyde capture gel; CN111974364A provides a fast and long-lasting air purification gel particle and a preparation method thereof, and the following raw materials are included in the gel particle: lemon oil, aloe extract, rose oil extract, etc., which can adsorb formaldehyde within 10min at room temperature. However, these natural extract hydrogels lack visual indication function for typical indoor air pollutants-formaldehyde, which is not conducive to family promotion and use.

[0004] CN111701439A discloses a color-changing gel for removing formaldehyde with visual perception, which is characterized in that after the alkaline alcohol amine compound reacts with formaldehyde, the pH value of the gel system changes and the acid-base indicator changes color, thereby achieving the purpose of removing formaldehyde and changing color. The color change of formaldehyde in this system is indirect, and it requires nearly equivalent formaldehyde to react with alcohol amine to produce obvious pH value changes and then change the color of the indicator. However, this design is not very useful for the detection of formaldehyde at the actual ppm concentration level in indoor air. The unique amine odor of the alcohol amine compound itself will also bring inconvenience to the use of indoor environment.

[0005] Therefore, the above-mentioned prior art has at least the following technical problems: the formaldehyde purification gel in the prior art has an odor, and has poor indication sensitivity, and is difficult to change color when the formaldehyde concentration is low. Summary of the invention

[0006] The purpose of the present invention is to provide a natural, non-toxic and odorless raw material, which can directly react with formaldehyde to produce a highly sensitive aldehyde-induced color-changing gel.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] The invention discloses a tea extract gel composition with formaldehyde discoloration performance. The tea extract gel composition consists of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide and the balance by mass of water.

[0009] The content of catechins in the tea extract is preferably ≥10%, more preferably above 30%.

[0010] The molecular weight of the polyacrylamide is preferably 5 million to 25 million.

[0011] The present invention also provides a tea extract gel composition with formaldehyde discoloration performance, which consists of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide, 0-10% by mass of an auxiliary agent and the balance by mass of water.

[0012] The 0 here means that it is infinitely close to 0 but not 0.

[0013] Furthermore, the tea extract gel composition is preferably composed of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide, 0.1-10% by mass of an auxiliary agent and the balance of water.

[0014] Furthermore, the auxiliary agent may be a thickener, a catalyst or a mixture of the two.

[0015] The thickener is one or more of agar, hyaluronic acid, polyvinyl alcohol, gelatin, sodium alginate, hydroxypropyl cellulose, and soluble starch.

[0016] The catalyst is one or more of zinc salt, calcium salt, magnesium salt, titanium salt, citric acid, and tartaric acid; the anions of the zinc salt, calcium salt, magnesium salt, and titanium salt are various common inorganic anions such as chloride, sulfate, nitrate, or organic anions such as acetate.

[0017] When there is a thickener in the auxiliary agent, the mass fraction of the thickener is preferably 0.1 to 3%;

[0018] When a catalyst is present in the auxiliary agent, the mass fraction of the catalyst is preferably 0.1 to 3%.

[0019] Furthermore, when the tea extract gel composition contains auxiliary agents, it is more preferably composed of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide, 0.1-3% by mass of thickener, 0.1-3% by mass of catalyst and the balance by mass of water.

[0020] Furthermore, the tea extract gel composition with formaldehyde color changing performance is prepared by the following method: firstly pre-dissolve polyacrylamide in 20-90°C water, stir until clear, then add tea extract and mix, stir evenly to obtain the gel composition.

[0021] When the tea extract gel composition contains a thickener and a catalyst, the tea extract gel composition with formaldehyde color changing performance is prepared by the following method: firstly, polyacrylamide and the thickener are pre-dissolved in 20-90° C. water, stirred until clear, and then the tea extract and the catalyst are added and mixed, and stirred evenly to obtain the gel composition.

[0022] Furthermore, the tea extract gel composition with formaldehyde color changing property provided by the present invention can react with formaldehyde and produce obvious color change, and thus can be used to absorb and indicate formaldehyde pollutants.

[0023] Furthermore, after the gel composition reacts with formaldehyde, the viscosity value increases.

[0024] In the present invention, the tea extract, also known as tea extract, has catechins as its core component, accounting for about 30% of the dry matter, and the main components include catechin, epicatechin, epigallocatechin, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate [Journal of Wuxi University of Light Industry, 2001, 20(2):117].

[0025] Tea extract is rich in phenolic hydroxyl groups, which can scavenge free radicals and inhibit lipid peroxidation. Tea extract can be extracted from tea leaves and their by-products (such as tea powder, tea leaves, rough tea or trimmed leaves). The extraction methods include solvent extraction, steam distillation and sublimation. In most cases, the solvent extraction method is used in industry, and the solvent can be water, ethanol, acetone and ethyl acetate. Tea extract is the most advantageous plant effective extract and is also the inevitable way out for the by-product of tea production - rough old tea. This development of turning waste into treasure makes the health function of tea better benefit mankind and has considerable economic benefits.

[0026] The catechin compounds in the main components of tea extracts contain polyphenol structural units, which can undergo condensation reactions with formaldehyde at multiple locations [J.Appl.Chem, 1959, 9:474], but cannot produce obvious color change effects. However, the applicant has found that in the presence of polyacrylamide, catechin compounds can react with formaldehyde and polyacrylamide as shown in the following example. Figure 1 The ternary synergistic reaction shown in FIG. 1 has the following reaction mechanism: the carbonyl group of formaldehyde reacts with the active NH in polyacrylamide and the active CH in the adjacent position of the phenolic hydroxyl group of the catechin compounds to form an extended conjugated structure under the induced orientation coplanar effect of the intramolecular hydrogen bond to make it color (see attached Figure 1 ), thus achieving the aldehyde-induced color change function (attached Figure 2 ).

[0027] Since the ternary synergistic reaction actually crosslinks the polyacrylamide polymer, in terms of macroscopic performance, the gel composition will have a significant increase in viscosity along with discoloration. Therefore, a rotational viscometer can also be used to measure the viscosity of the gel composition system to characterize the crosslinking effect caused by the ternary synergistic reaction.

[0028] Compared with the prior art, the present invention has the following beneficial effects: the gel composition is based on natural extracts, is friendly and safe to the home environment, has good formaldehyde absorption performance, is sensitive to formaldehyde discoloration, and has a simple and gentle preparation process, which effectively solves the technical problems of poor formaldehyde purification gel indication sensitivity and odor in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the ternary synergistic reaction between catechins in tea extract and formaldehyde and polyacrylamide.

[0030] Figure 2 The following are comparison photos of the formaldehyde discoloration of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0031] The technical solution of the present application is described in detail below through specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0032] Example 1

[0033] A tea extract gel composition with formaldehyde discoloration performance comprises the following components: 5% by mass of tea extract (commercial product, catechin content 50%), 10% by mass of polyacrylamide (molecular weight 10 million) and 85% by mass of water.

[0034] The preparation method is as follows: firstly, polyacrylamide is pre-dissolved in 50°C water, stirred until clear, then tea extract is added and mixed, and stirred evenly to obtain the gel composition.

[0035] The gel composition was placed in an air detection chamber. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition changed from colorless to orange after 24 hours (see attached Figure 2 The viscosity of the gel composition system was measured by a rotational viscometer, and its viscosity value increased from an initial value of 51 (mPa·s) to 1530 (mPa·s) after formaldehyde discoloration.

[0036] The above-mentioned gel composition was placed in an air detection cabin. Under the condition of formaldehyde concentration of 1 mg / L, the color of the gel composition changed from colorless to slightly yellow after 24 hours. The viscosity of the gel composition system was measured by a rotational viscometer, and its viscosity value increased from an initial value of 51 (mPa·s) to 215 (mPa·s) after formaldehyde changed color.

[0037] Example 2

[0038] A tea extract gel composition with formaldehyde discoloration performance comprises the following components: 1% by mass of tea extract (commercial product, catechin content 50%), 20% by mass of polyacrylamide (molecular weight 5 million) and 79% by mass of water.

[0039] The preparation method is as follows: firstly, polyacrylamide is pre-dissolved in 90°C water, stirred until clear, and then tea extract is added and mixed, and stirred evenly to obtain the gel composition.

[0040] The gel composition was placed in an air detection cabin. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition changed from colorless to light yellow after 24 hours, achieving an obvious formaldehyde color change effect.

[0041] The viscosity of the gel composition system was measured by a rotational viscometer, and the viscosity value increased from an initial value of 310 (mPa·s) to 2170 (mPa·s) after formaldehyde discoloration.

[0042] Example 3

[0043] A tea extract gel composition with formaldehyde discoloration performance comprises the following components: 10% by mass of tea extract (commercial product, catechin content 10%), 1% by mass of polyacrylamide (molecular weight 25 million) and 89% by mass of water.

[0044] The preparation method is as follows: firstly, polyacrylamide is pre-dissolved in 20° C. water, stirred until clear, then tea extract is added and mixed, and stirred evenly to obtain the gel composition.

[0045] The gel composition was placed in an air detection cabin. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition changed from light yellow to brown after 24 hours, achieving an obvious formaldehyde color change effect.

[0046] The viscosity of the gel composition system was measured using a rotational viscometer, and the viscosity value increased from an initial value of 32 (mPa·s) to 870 (mPa·s) after formaldehyde discoloration.

[0047] Example 4

[0048] A tea extract gel composition with formaldehyde discoloration performance comprises the following components: 5% by mass of tea extract (commercial product, catechin content 50%), 10% by mass of polyacrylamide (molecular weight 10 million), 0.1% by mass of agar, 3% by mass of citric acid and 81.9% by mass of water.

[0049] The preparation method is as follows: firstly, polyacrylamide and agar are pre-dissolved in 50°C water, stirred until clear, then tea extract and citric acid are added and mixed, and stirred evenly to obtain the gel composition.

[0050] The gel composition was placed in an air detection cabin. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition changed from colorless to orange after 6 hours, achieving an obvious formaldehyde color change effect.

[0051] The viscosity of the gel composition system was measured using a rotational viscometer, and the viscosity value increased from an initial value of 870 (mPa·s) to 3100 (mPa·s) after formaldehyde discoloration.

[0052] Example 5

[0053] A tea extract gel composition with formaldehyde discoloration performance comprises the following components: 5% by mass of tea extract (commercially available product, catechin content 50%), 10% by mass of polyacrylamide (molecular weight 10 million), 3% by mass of polyvinyl alcohol, 0.1% by mass of zinc acetate and 81.9% by mass of water.

[0054] The preparation method is as follows: firstly, polyacrylamide and polyvinyl alcohol are pre-dissolved in 50°C water, stirred until clear, then tea extract and zinc salt (zinc acetate dihydrate) are added, mixed, and stirred evenly to obtain the gel composition.

[0055] The gel composition was placed in an air detection cabin. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition changed from colorless to orange after 12 hours, achieving an obvious formaldehyde color change effect.

[0056] The viscosity of the gel composition system was measured using a rotational viscometer, and the viscosity value increased from an initial value of 1230 (mPa·s) to 19800 (mPa·s) after formaldehyde discoloration.

[0057] Comparative Example 1

[0058] A formaldehyde-removing gel composition comprises the following components: 10% by mass of polyacrylamide (molecular weight of 10 million) and 90% by mass of water.

[0059] The preparation method is as follows: polyacrylamide is pre-dissolved in 50°C water, and stirred until it is clear to obtain a gel composition.

[0060] The gel composition was placed in an air detection chamber. Under the condition of formaldehyde concentration of 10 mg / L, the color of the gel composition remained colorless after 24 hours (see attached for details). Figure 2 Right), no formaldehyde discoloration effect was observed.

[0061] The viscosity of the gel composition system was measured by a rotational viscometer, and the viscosity value slightly increased from an initial value of 53 (mPa·s) to 75 (mPa·s) after absorbing formaldehyde.

[0062] The above is only a preferred embodiment of the present application, and is not any formal or substantial limitation to the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope described in the embodiments of the present application. Any technician familiar with this profession, without departing from the spirit and scope of the present application, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the substantial technology of the present application are still within the scope of the technical solution of the present application.

Claims

1. A tea extract gel composition having formaldehyde discoloration performance, characterized in that: The tea extract gel composition is composed of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide and the balance by mass of water; The tea extract contains catechins that are ≥10%; the molecular weight of the polyacrylamide is 5 million to 25 million.

2. A tea extract gel composition having formaldehyde discoloration performance, characterized in that: The tea extract gel composition is composed of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide, 0-10% by mass of auxiliary agent and the balance by mass of water, wherein 0 represents infinitely close to 0 but not 0; the tea extract has a catechin content of ≥10%; the polyacrylamide has a molecular weight of 5 million to 25 million; the auxiliary agent is a thickener, a catalyst or a mixture of the two; The thickener is one or more of agar, hyaluronic acid, polyvinyl alcohol, gelatin, sodium alginate, hydroxypropyl cellulose, and soluble starch; The catalyst is one or more of zinc salt, calcium salt, magnesium salt, titanium salt, citric acid and tartaric acid.

3. The tea extract gel composition according to claim 2, characterized in that: The tea extract gel composition consists of the following components: 1-10% by mass of tea extract, 1-20% by mass of polyacrylamide, 0.1-10% by mass of an auxiliary agent and the balance of water.

4. The tea extract gel composition according to claim 2, characterized in that: When the auxiliary agent contains a thickener, the mass fraction of the thickener is 0.1-3%; when the auxiliary agent contains a catalyst, the mass fraction of the catalyst is 0.1-3%.

5. Use of the tea extract gel composition with formaldehyde color changing property as claimed in claim 1 or claim 2 in absorbing and indicating formaldehyde pollutants.

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