Zinc ricinoleate-chitosan electrolyte coacervate, method of making and use thereof
Patent Information
- Application Number
- CN202610818912.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-08
- Publication Date
- 2026-08-21
AI Technical Summary
[0005]针对现有技术中蓖麻油酸锌水溶性差、稳定性不足、除臭谱系有限以及壳聚糖除臭能力弱的缺陷，本发明提供了一种基于静电诱导的蓖麻油酸锌-壳聚糖电解质凝聚体及其制备方法与其在除臭中的应用
[0022]（1）粒径均一，分散稳定性优异：本发明制备的蓖麻油酸锌-壳聚糖聚电解质凝聚体在最佳条件下粒径约为150nm，PDI低至0.10-0.12，在20天内各项指标均无明显变化，表现出优异的长期储存稳定性。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of deodorant technology, specifically relating to an electrostatically induced zinc ricinoleate-chitosan electrolyte condensate, its preparation method, and its application in deodorization. Background Technology
[0002] Zinc ricinoleate (Zn(Ri)2) is a commonly used deodorizing ingredient because its two carboxylate groups can neutralize odor molecules such as ammonia and hydrogen sulfide. However, it has significant drawbacks in practical applications: First, it has poor water solubility and insufficient stability, usually requiring organic solvents or surfactants for dispersion. Its activity is also greatly affected by pH, easily dissociating or agglomerating under weakly acidic or alkaline conditions, and easily precipitating and becoming inactive during long-term storage. Second, its deodorizing spectrum is limited, with weak ability to remove trimethylamine (a major source of sweat odor).
[0003] Chitosan (CS) is a natural cationic polysaccharide with good biocompatibility, film-forming properties, and antibacterial activity. Its amine groups protonate and become positively charged under acidic conditions, allowing it to adsorb negatively charged bacteria or odor molecules through electrostatic interactions. However, chitosan alone has limited neutralization ability against small-molecule odors such as ammonia, and its solubility decreases under near-neutral or alkaline conditions, thus limiting its applications.
[0004] Patent CN114258862A discloses a pet pee pad with deodorizing function, in which zinc ricinoleate is set as a deodorizing agent in the deodorizing layer and chitosan is added as an antibacterial agent in the absorbent layer. Although zinc ricinoleate and chitosan are used in the same product, they are located in different functional layers and play their respective roles independently. However, this still cannot solve the problems of poor water dispersibility, insufficient stability and limited deodorizing spectrum of zinc ricinoleate, as well as the weak deodorizing ability of chitosan when used alone. Summary of the Invention
[0005] To address the shortcomings of existing technologies such as poor water solubility, insufficient stability, limited deodorization spectrum of zinc ricinoleate, and weak deodorization ability of chitosan, this invention provides an electrostatically induced zinc ricinoleate-chitosan polyelectrolyte aggregate, its preparation method, and its application in deodorization. The zinc ricinoleate-chitosan polyelectrolyte aggregate (Zn(Ri)2-CS aggregate) is formed by the electrostatically induced self-assembly of zinc ricinoleate and chitosan; wherein zinc ricinoleate provides a negative charge, and chitosan provides a positive charge, and the two are mixed according to their charge ratio to form the polyelectrolyte aggregate. By controlling the charge ratio, total concentration, pH, and salt concentration of the system, uniformly sized and stably dispersed nanoscale spherical aggregates can be obtained.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] In a first aspect, the present invention provides a method for preparing zinc ricinoleate-chitosan polyelectrolyte aggregates.
[0008] This invention provides a method for preparing zinc ricinoleate-chitosan polyelectrolyte aggregates, the preparation method comprising the following steps:
[0009] S1: Prepare chitosan solution and zinc ricinoleate solution separately;
[0010] S2: Adjust the pH values of the chitosan solution and zinc ricinoleate solution obtained in step S1 respectively;
[0011] S3: Under stirring conditions, the chitosan solution obtained in step S2 and the zinc ricinoleate solution are mixed, and electrolytes are added to adjust the salt concentration. After standing, the mixture is allowed to self-assemble to obtain zinc ricinoleate-chitosan polyelectrolyte aggregate (hereinafter referred to as aggregate).
[0012] In some specific embodiments, in step S3, the chitosan solution and zinc ricinoleate solution are mixed at a charge ratio of 1:9 to 9:1, more preferably at a charge ratio of 2:3 to 3:2, and even more preferably at a charge ratio of 1:1.
[0013] In some specific embodiments, in step S3, the electrolyte is sodium chloride, and the salt concentration is 2-30 mM, preferably 2-10 mM, and more preferably 5 mM.
[0014] In some specific embodiments, in step S1, the concentration of the chitosan solution is 5-20 mM, more preferably 10 mM; the concentration of the zinc ricinoleate solution is 5-20 mM, more preferably 10 mM.
[0015] In some specific embodiments, in step S2, the pH of the chitosan solution and the zinc ricinoleate solution is adjusted to 2.0-5.5 by hydrochloric acid or sodium hydroxide, more preferably to 4.0-5.0, and even more preferably to 4.5.
[0016] In some specific embodiments, in step S3, the chitosan solution and zinc ricinoleate solution are mixed by adding one solution dropwise to the other solution while continuously stirring.
[0017] Secondly, the present invention provides a zinc ricinoleate-chitosan polyelectrolyte aggregate prepared by the above-described preparation method.
[0018] In some specific embodiments, the average particle size of the zinc ricinoleate-chitosan polyelectrolyte aggregate is 100–250 nm, preferably 140–150 nm.
[0019] Thirdly, the present invention provides a deodorizing article comprising the above-mentioned zinc ricinoleate-chitosan polyelectrolyte aggregate, and an acceptable carrier or excipient.
[0020] Fourthly, the present invention provides the application of the above-mentioned deodorizing products in air purification, textile deodorization, daily chemical products and environmental governance.
[0021] The beneficial effects of this invention are as follows:
[0022] (1) Uniform particle size and excellent dispersion stability: The zinc ricinoleate-chitosan polyelectrolyte aggregate prepared by this invention has a particle size of about 150 nm under optimal conditions and a PDI as low as 0.10-0.12. There are no significant changes in various indicators within 20 days, which shows excellent long-term storage stability.
[0023] (2) Significantly improves deodorization performance: At the same concentration, the adsorption rate of ammonia by the zinc ricinoleate-chitosan polyelectrolyte aggregate of the present invention can reach up to 82%, while that of zinc ricinoleate alone is only 55%, and the deodorization efficiency is improved by about 49%, showing the synergistic effect of chitosan and zinc ricinoleate.
[0024] (3) The preparation process is simple and the conditions are mild: the zinc ricinoleate solution and chitosan solution are simply mixed to form aggregates, without the need for complex equipment or harsh conditions, and are easy to scale up.
[0025] (4) Environmentally friendly: All raw materials used are biodegradable materials, and no organic solvents or emulsifiers need to be added during the preparation process, which meets the requirements of green environmental protection. Attached Figure Description
[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:
[0027] Figure 1 Figure A shows the particle size and PDI variation curves of aggregates prepared under different charge ratios. Figure 1 B is the normalized light scattering intensity variation curve of condensates prepared under different charge ratios.
[0028] Figure 2 Figure A shows the particle size and PDI variation curves of aggregates prepared at different total concentrations. Figure 2 B represents the normalized light scattering intensity variation curves of condensates prepared at different total concentrations.
[0029] Figure 3 Figure A shows the particle size and PDI variation curves of aggregates prepared at different pH values. Figure 3Figure B shows the normalized light scattering intensity variation curves of condensates prepared at different pH values.
[0030] Figure 4 Figure A shows the particle size and PDI variation curves of aggregates prepared at different salt concentrations. Figure 4 Figure B shows the normalized light scattering intensity variation curves of condensates prepared under different salt concentrations.
[0031] Figure 5 This is a transmission electron microscope image of the condensate under optimal conditions.
[0032] Figure 6 The results are from the stability test of the condensate under optimal conditions (20 days). Figure 6 In section A, the curves show the changes in particle size and PDI of the aggregate over time. Figure 6 B is the curve showing the change of normalized light scattering intensity of the condensate over time.
[0033] Figure 7 Figure A shows a comparison of the adsorption rates of Zn(Ri)2-CS aggregates and Zn(Ri)2 at different adsorption times. Figure 7 Figure B is a comparison of the adsorption rates of Zn(Ri)2-CS condensates and Zn(Ri)2 for different odors.
[0034] Figure 8 The ammonia absorption rate is that of Zn(Ri)2-CS condensates with different particle sizes. Detailed Implementation
[0035] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0036] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0037] This invention provides a method for preparing zinc ricinoleate-chitosan polyelectrolyte aggregates, the preparation method comprising the following steps:
[0038] S1: Prepare chitosan solution and zinc ricinoleate solution separately;
[0039] S2: Adjust the pH values of the chitosan solution and zinc ricinoleate solution obtained in step S1 respectively;
[0040] S3: Under stirring conditions, the chitosan solution obtained in step S2 and the zinc ricinoleate solution are mixed, and electrolytes are added to adjust the salt concentration. After standing, the mixture is allowed to self-assemble to obtain the zinc ricinoleate-chitosan polyelectrolyte aggregate.
[0041] In a preferred embodiment of the present invention, in step S3, the chitosan solution and the zinc ricinoleate solution are mixed at a charge ratio of 1:9 to 9:1, more preferably at a charge ratio of 2:3 to 3:2, and even more preferably at a charge ratio of 1:1.
[0042] In a preferred embodiment of the present invention, in step S3, the electrolyte is sodium chloride, and the salt concentration ranges from 2 to 30 mM, preferably from 2 to 10 mM, and more preferably from 5 mM.
[0043] In a preferred embodiment of the present invention, in step S1, the concentration of the chitosan solution is 5-20 mM, more preferably 10 mM; and the concentration of the zinc ricinoleate solution is 5-20 mM, more preferably 10 mM.
[0044] As a preferred embodiment of the present invention, in step S2, the pH of the chitosan solution and the zinc ricinoleate solution is adjusted to 2.0-5.5 by hydrochloric acid or sodium hydroxide, more preferably to 4.0-5.0, and even more preferably to 4.5.
[0045] As a preferred embodiment of the present invention, in step S3, the chitosan solution and zinc ricinoleate solution are mixed by adding one solution dropwise to the other solution while continuously stirring.
[0046] Secondly, the present invention provides a zinc ricinoleate-chitosan polyelectrolyte aggregate prepared by the above-described preparation method.
[0047] As a preferred embodiment of the present invention, the average particle size of the zinc ricinoleate-chitosan polyelectrolyte aggregate is 100–250 nm, preferably 140–150 nm.
[0048] Thirdly, the present invention provides a deodorizing article comprising the above-mentioned zinc ricinoleate-chitosan polyelectrolyte aggregate, and an acceptable carrier or excipient.
[0049] Fourthly, the present invention provides the application of the above-mentioned deodorizing products in air purification, textile deodorization, daily chemical products and environmental governance.
[0050] The present application is described below by way of specific embodiments, the purpose of which is to provide a better understanding of the content of the present application. It should be understood that these embodiments are merely illustrative and not restrictive. The reagents used in the embodiments, unless otherwise stated, are commercially available. The methods and conditions used in the embodiments, unless otherwise specified, are conventional methods and conditions.
[0051] Example 1: Effect of monomer charge ratio on condensates
[0052] S1: Weigh out chitosan with a degree of deacetylation of 95% and a molecular weight of about 30kDa to prepare a 10 mM stock solution. Separately, take zinc ricinoleate with a purity of ≥98% and prepare a 10 mM stock solution.
[0053] S2: Adjust the pH of the chitosan solution and zinc ricinoleate solution obtained in step S1 to 4.5 respectively;
[0054] S3: Under stirring conditions, the chitosan solution and zinc ricinoleate solution obtained in step S2 were mixed at charge ratios of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1, respectively. NaCl electrolyte was added to adjust the salt concentration to 5 mM. After standing for 30 minutes to allow self-assembly, the particle size, polydispersity index (PDI), and scattered light intensity were measured using a dynamic light scattering instrument. The measurement results are as follows: Figure 1 As shown.
[0055] Figure 1 The results showed that the scattered light intensity of the system reached its maximum when the charge ratio was 5:5, at which point the particle size was approximately 150.3 nm and the PDI was 0.12. When the ratio deviated from this, the particle size increased significantly, and the PDI rose to over 0.2. Therefore, the optimal charge ratio was determined to be 1:1, at which point the positive and negative charges were nearly completely neutralized, forming a uniform and stable nanoaggregate.
[0056] Example 2: Effect of total monomer concentration on aggregates
[0057] S1: Weigh chitosan with a degree of deacetylation of 95% and a molecular weight of about 30kDa to prepare stock solutions of 5, 10, 15 and 20 mM respectively. Separately, take zinc ricinoleate with a purity of ≥98% and prepare stock solutions of 5, 10, 15 and 20 mM respectively.
[0058] S2: Adjust the pH of the chitosan solution and zinc ricinoleate solution obtained in step S1 to 4.5 respectively;
[0059] S3: Under stirring conditions, the chitosan solution and zinc ricinoleate solution of the same concentration obtained in step S2 were mixed at a charge ratio of 1:1 (i.e., the total monomer concentrations of the mixed solution were 5, 10, 15, and 20 mM, respectively). NaCl electrolyte was added to adjust the salt concentration to 5 mM. After standing for 30 minutes for self-assembly, the particle size, polydispersity index (PDI), and scattered light intensity were measured using a dynamic light scattering instrument. The measurement results are as follows: Figure 2 As shown.
[0060] Figure 2 The results showed that at a total concentration of 10 mM, the system had the smallest particle size (approximately 150.2 nm), the lowest PDI (0.11), and the highest scattered light intensity. At too low a concentration (5 mM), the light intensity was weak; at too high a concentration (15 mM and above), the particle size increased, the PDI rose to above 0.25, and significant aggregation occurred. Therefore, the optimal total concentration was determined to be 10 mM.
[0061] Example 3: Effect of solution pH on aggregates
[0062] S1: Weigh out chitosan with a degree of deacetylation of 95% and a molecular weight of about 30kDa to prepare a 10 mM stock solution. Separately, take zinc ricinoleate with a purity of ≥98% and prepare a 10 mM stock solution.
[0063] S2: Adjust the pH of the chitosan solution and zinc ricinoleate solution obtained in step S1 to 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, and 5.5 respectively by adding hydrochloric acid or sodium hydroxide;
[0064] S3: Under stirring conditions, the chitosan solution and zinc ricinoleate solution with the same pH obtained in step S2 were mixed at a charge ratio of 1:1, and NaCl electrolyte was added to adjust the salt concentration to 5 mM. After standing for 30 minutes for self-assembly, the particle size, polydispersity index (PDI), and scattered light intensity were measured using a dynamic light scattering instrument. The measurement results are as follows: Figure 3 As shown.
[0065] Figure 3 The results showed that the particle size was smallest (approximately 148.8 nm), the PDI was lowest (0.11), and the scattered light intensity was highest at pH 4.5. Too low a pH would disrupt the negative charge balance of zinc ricinoleate, while too high a pH would reduce the protonation degree of chitosan; both were detrimental to the orderly assembly of the aggregates. Therefore, the optimal pH was selected as 4.5.
[0066] Example 4: Effect of solution salt concentration on aggregates
[0067] S1: Weigh out chitosan with a degree of deacetylation of 95% and a molecular weight of about 30kDa to prepare a 10 mM stock solution. Separately, take zinc ricinoleate with a purity of ≥98% and prepare a 10 mM stock solution.
[0068] S2: Adjust the pH of the chitosan solution and zinc ricinoleate solution obtained in step S1 to 4.5 respectively;
[0069] S3: Under stirring conditions, the chitosan solution and zinc ricinoleate solution obtained in step S2 were mixed at a charge ratio of 1:1, and NaCl electrolyte was added to adjust the salt concentration to 0, 5, 10, 20, and 30 mM, respectively. After standing for 30 minutes for self-assembly, the particle size, polydispersity index (PDI), and scattered light intensity were measured using a dynamic light scattering instrument. The measurement results are as follows: Figure 4 As shown.
[0070] Figure 4 The results showed that without salt, the aggregate particle size was approximately 148.8 nm, and the PDI was 0.11. At a salt concentration of 5 mM, excess electrostatic repulsion was shielded, promoting the formation of more compact and uniform aggregates. The particle size decreased to approximately 145.5 nm, the PDI dropped to 0.10, and the scattered light intensity reached its maximum. When the salt concentration continued to increase to 10 mM and above, the particle size gradually increased to over 160 nm, and the PDI increased to over 0.2. Therefore, the optimal salt concentration was 5 mM.
[0071] Example 5: Morphology and stability of condensates under optimal conditions
[0072] Based on the optimization results of Examples 1-4, aggregates were prepared under the conditions of a charge ratio of 1:1, a total monomer concentration of 10 mM, pH=4.5, and a NaCl concentration of 5 mM. The freshly prepared samples were observed using transmission electron microscopy. Figure 5 The results showed that the aggregates were regular spherical with uniform particle size, well dispersed, and without aggregation, which was consistent with the results of dynamic light scattering.
[0073] The above samples were stored at room temperature in the dark, and samples were taken on days 0, 1, 3, 5, 7, 10, 15 and 20 to measure particle size, PDI and light intensity. Figure 6 The results showed that the initial particle size was about 145.5 nm and the PDI was 0.10. After 20 days, the particle size was still around 147 nm and the PDI was 0.12. All indicators showed no significant changes, proving that the aggregate has excellent long-term storage stability.
[0074] Example 6:
[0075] The zinc ricinoleate-chitosan polyelectrolyte aggregate prepared under the optimal conditions in Example 5 was used as the experimental group, a zinc ricinoleate solution of the same concentration was used as the control group, and deionized water (pH=4.5) was used as the blank control to determine the adsorption rate of ammonia. Figure 7The results showed that the adsorption rate of zinc ricinoleate alone was 55.0%, while the adsorption rate of ammonia by the aggregates of this invention reached 82.0%, an improvement of 27.0% compared with zinc ricinoleate alone; the removal rate of hydrogen sulfide reached 74.4%; and the removal rate of trimethylamine reached 72.1%. Compared with single components, the aggregates of this invention exhibited a broad-spectrum and highly efficient synergistic removal ability for both alkaline and sulfur-containing odors.
[0076] Example 7: The effect of aggregate particle size on deodorization effect
[0077] Aggregates were prepared under the optimal conditions optimized in Examples 1 to 4 (charge ratio of 1:1, total monomer concentration of 10 mM, and pH of 4.5). Aggregates with different particle sizes (145 nm, 170 nm, 190 nm, and 220 nm) were obtained by adjusting the salt concentration to 5 mM, 10 mM, 20 mM, and 30 mM, respectively. The absorption rate of ammonia was tested using zinc ricinoleate alone at the same concentration as a control. Figure 8 The results showed that zinc ricinoleate alone had an absorption rate of 55.0% for ammonia. The highest absorption rate was achieved by aggregates with a particle size of 145 nm, reaching 82.0%, which was 49.1% higher than that of zinc ricinoleate alone. As the particle size increased, the absorption rate decreased slightly, with aggregates of 170 nm, 190 nm, and 220 nm having absorption rates of 80.5%, 77.0%, and 74.5%, respectively. This indicates that smaller aggregates, due to their larger specific surface area, can more fully contact ammonia molecules, resulting in a more significant synergistic effect and superior ammonia absorption.
[0078] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for preparing zinc ricinoleate-chitosan polyelectrolyte aggregates, characterized in that, The preparation method includes the following steps: S1: Prepare chitosan solution and zinc ricinoleate solution separately; S2: Adjust the pH values of the chitosan solution and zinc ricinoleate solution obtained in step S1 respectively; S3: Under stirring conditions, the chitosan solution and zinc ricinoleate solution obtained in step S2 are mixed, and electrolytes are added to adjust the salt concentration. After standing, the mixture is allowed to self-assemble to obtain zinc ricinoleate-chitosan polyelectrolyte aggregate.
2. The preparation method according to claim 1, characterized in that: In step S3, the chitosan solution and zinc ricinoleate solution are mixed at a charge ratio of 1:9 to 9:1, preferably 2:3 to 3:
2.
3. The preparation method according to claim 1, characterized in that: In step S3, the electrolyte is sodium chloride, and the salt concentration ranges from 2 to 30 mM, preferably from 2 to 10 mM.
4. The preparation method according to claim 1, characterized in that: In step S1, the concentration of the chitosan solution is 5-20 mM; the concentration of the zinc ricinoleate solution is 5-20 mM.
5. The preparation method according to claim 1, characterized in that: In step S2, the pH of the chitosan solution and zinc ricinoleate solution is adjusted to 2.0-5.5, preferably 4.0-5.0, by using hydrochloric acid or sodium hydroxide.
6. The preparation method according to claim 1, characterized in that: In step S3, the chitosan solution and zinc ricinoleate solution are mixed by adding one solution dropwise to the other while continuously stirring.
7. Zinc ricinoleate-chitosan polyelectrolyte aggregate prepared by the preparation method according to any one of claims 1 to 6.
8. The zinc ricinoleate-chitosan polyelectrolyte aggregate according to claim 7, characterized in that: The average particle size of the zinc ricinoleate-chitosan polyelectrolyte aggregate is 100–250 nm, preferably 140–150 nm.
9. A deodorizing product, characterized in that, The deodorizing product comprises a zinc ricinoleate-chitosan polyelectrolyte aggregate prepared by the method of any one of claims 1 to 6 or a zinc ricinoleate-chitosan polyelectrolyte aggregate as described in any one of claims 7 to 8, and an acceptable carrier or excipient.
10. The application of the deodorizing product according to claim 9 in air purification, textile deodorization, daily chemical products and environmental governance.