High-precision 3D printing emulsion gel as well as preparation method and application thereof

Abstract

The invention relates to the technical field of material chemistry, in particular to high-precision 3D printing emulsion gel as well as a preparation method and application thereof. The high-precision 3D printing emulsion gel is prepared from an emulsion formed by taking a mixed solution of cellulose nanocrystals and bovine serum albumin as a water phase and vegetable oil as an oil phase. The cellulose nanocrystal and bovine serum albumin are adopted as raw materials to prepare the 3D printing milk gel, and the 3D printing milk gel is green, safe and free of pollution to the environment. By adjusting the ratio and the concentration of the cellulose nanocrystals and the bovine serum albumin, the rheological property of the milk gel can be adjusted, and meanwhile, the prepared milk gel can not generate demulsification and other instability changes within the storage period of one month. Test results show that the 3D printing emulsion gel provided by the invention has a relatively high internal phase volume fraction, so that the viscosity and the storage modulus of the emulsion are increased, and the 3D printing emulsion gel is in a solid state and has the characteristic of shear thinning, so that the 3D printing emulsion gel can be directly used as a 3D printing material without further treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of material chemistry, and in particular to a high-precision 3D printing latex gel and a preparation method and application thereof. Background Art

[0002] 3D printing technology, also known as additive manufacturing, is a new manufacturing technology that integrates rapid automatic forming, image processing, digital control and other processes. It has been widely used in construction, aerospace, biomedicine, materials and food and other fields.

[0003] Food emulsion gel is a soft solid material with a cross-linked polymer network structure filled with oil droplets. Due to its biodegradability, biocompatibility and the dual properties of emulsion and biopolymer gel, it can be combined with 3D printing technology.

[0004] Currently, the main problem facing food 3D printing is that most food raw materials have poor rheological response properties, resulting in low shape accuracy and poor aesthetics of the printed food. It is difficult to maintain its shape after printing, which greatly limits its development in the field of food processing.

[0005] Applying emulsion gel as a new type of food ink to 3D printing technology can be used to develop easy-to-swallow foods, low-fat foods, differentiated nutritional foods, and customized foods for special dietary needs, laying the foundation for its application in personalized and precise nutrition, and has broad application value and prospects. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a high-precision 3D printing latex gel and a preparation method and application thereof, wherein the latex gel can print 3D printing shapes with high precision.

[0007] The invention provides a high-precision 3D printing latex gel, which is made of an emulsion formed by a mixed solution of cellulose nanocrystals and bovine serum albumin as an aqueous phase and vegetable oil as an oil phase.

[0008] Specifically, a mixed solution of cellulose nanocrystals and bovine serum albumin is used as the water phase, and vegetable oil is used as the oil phase. The emulsion is prepared by an emulsification method, and the excess water phase in the emulsion is removed to obtain the latex gel.

[0009] The present invention has no special limitation on the vegetable oil, which may be a generally applicable vegetable oil known in the art. Preferably, the vegetable oil includes but is not limited to one or more of corn oil, rapeseed oil, peanut oil, soybean oil, etc.

[0010] Preferably, the oil phase also includes fat-soluble nutrients.

[0011] The high-precision 3D printed latex gel provided by the present invention can be used in the field of easy-to-swallow foods. Fat-soluble nutrients can be loaded through the oil phase to provide soft, nutritious and visually attractive foods for people with dysphagia.

[0012] The fat-soluble nutrients include, but are not limited to, one or more of β-carotene, curcumin, lycopene, and the like.

[0013] The added amount of the above-mentioned fat-soluble nutrients is preferably 0.05wt%~1.00wt%.

[0014] The present invention provides a method for preparing the above-mentioned high-precision 3D printing latex gel, comprising the following steps:

[0015] The cellulose nanocrystal solution and the bovine serum albumin solution are mixed as the water phase; the vegetable oil is used as the oil phase to form an emulsion through emulsification;

[0016] The excess water phase in the emulsion is removed to obtain a high-precision 3D printing latex gel.

[0017] The preparation method can adjust the rheological properties of the latex gel by adjusting the concentrations of cellulose nanocrystals and bovine serum albumin.

[0018] Preferably, the mass concentration of the cellulose nanocrystal solution is 1% to 3%.

[0019] The solvent of the solution is preferably water.

[0020] Preferably, the pH value of the cellulose nanocrystal solution is less than 4; more preferably, it is 2.5-3.5.

[0021] Preferably, the mass concentration of the bovine serum albumin solution is 1% to 3%.

[0022] The solvent of the solution is preferably water.

[0023] Preferably, the pH value of the bovine serum albumin solution is less than 4; more preferably 2.5-3.5.

[0024] Preferably, the mass ratio of the cellulose nanocrystal solution to the bovine serum albumin solution is 1:1 to 1:3, more preferably 1:1.

[0025] The volume ratio of the water phase to the oil phase is 1:(1-3).

[0026] The present invention has no particular limitation on the emulsification method, which may be an emulsification method well known to those skilled in the art, including but not limited to one or more of high-speed shearing, high-pressure homogenization, and ultrasonic emulsification.

[0027] Preferably, the high-speed shearing rate is 8000-15000 rpm, and the time is 1-5 min.

[0028] Preferably, the pressure of the high-pressure homogenization is 10-60 MPa.

[0029] Preferably, the power of the ultrasonic emulsification is 100-600W, and the time is 5-10 min.

[0030] Preferably, the ultrasonic emulsification is performed intermittently, preferably ultrasonicating for 1 to 3 seconds and stopping for 1 to 3 seconds.

[0031] The present invention has no particular limitation on the method for removing the excess water phase in the emulsion, and the method may be a method well known to those skilled in the art, including but not limited to a centrifugal method.

[0032] Preferably, the centrifugation condition is 4000~15000g, more preferably 8000~12000g.

[0033] The present invention provides the use of the high-precision 3D printing latex gel or the high-precision 3D printing latex gel prepared by the above preparation method as a 3D printing material.

[0034] The present invention does not specifically limit the method for 3D printing the high-precision 3D printing latex gel, and may be a method well known to those skilled in the art. It includes but is not limited to the following steps:

[0035] The high-precision 3D printing latex gel is loaded into the barrel of the 3D printing device, and a printing pattern is input for printing, so that the latex gel is printed into a three-dimensional shape.

[0036] Preferably, the printing parameters of the 3D printing material are:

[0037] Printing temperature is 20~30℃, extrusion rate is 10~30 mm / s, and nozzle diameter is 0.3~1.0 mm.

[0038] The present invention provides a 3D printed food, which is obtained by 3D printing the high-precision 3D printed latex gel or the high-precision 3D printed latex gel prepared by the above preparation method.

[0039] By 3D printing the high-precision 3D printed latex gel, food with a high-precision three-dimensional structure can be obtained.

[0040] In some specific embodiments of the present invention, the printed food may be an easy-to-swallow food.

[0041] Compared with the prior art, the present invention provides a high-precision 3D printing latex gel, which is made of an emulsion formed by a mixed solution of cellulose nanocrystals and bovine serum albumin as an aqueous phase and vegetable oil as an oil phase.

[0042] The present invention uses cellulose nanocrystals and bovine serum albumin as raw materials to prepare 3D printing latex gel, which is green and safe, has biosafety and biocompatibility, and is pollution-free to the environment. The rheological properties of the latex gel can be adjusted by adjusting the ratio and concentration of cellulose nanocrystals and bovine serum albumin. At the same time, the latex gel prepared by the present invention can be stored for 1 month without undergoing unstable changes such as demulsification. The test results show that the 3D printing latex gel provided by the present invention has a higher internal phase volume fraction, which leads to an increase in the viscosity and storage modulus of the emulsion, presents a solid state and has shear-thinning characteristics, and can therefore be directly used as a 3D printing material without further processing, and can be used to develop easy-to-swallow foods, low-fat foods, differentiated nutritional foods, and customized foods with special dietary needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is the apparent viscosity curve of latex gel at different composite particle concentrations;

[0044] Figure 2 The dynamic modulus and tan δ of latex gel at different composite particle concentrations vary with angular frequency;

[0045] Figure 3 Bar graphs of appearance, high fidelity, and collapse ratio of latex gel printed cubic structures for different composite particle concentrations;

[0046] Figure 4 High-precision 3D printing renderings of latex gels in different shapes;

[0047] Figure 5 This is a swallowing test image of the 3D printed latex gel loaded with β-carotene. DETAILED DESCRIPTION

[0048] In order to further illustrate the present invention, the following is a detailed description in conjunction with the embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0049] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0050] Example 1

[0051] The preparation method of high-precision 3D printing latex gel, the steps are as follows:

[0052] (1) Weigh an appropriate amount of cellulose nanocrystal powder and disperse it in ultrapure water. Stir it magnetically at room temperature for 4 h and treat it with an ultrasonic cell disruptor for 3 min (amplitude 30%, 3 s on, 2 s off) to prepare a cellulose nanocrystal dispersion with a mass fraction of 1.0 wt%. Weigh an appropriate amount of bovine serum albumin powder and dissolve it in ultrapure water. Stir it magnetically at room temperature for 4 h to prepare a bovine serum albumin solution with a mass fraction of 1.0 wt%. Use 0.1 M HCl to adjust the pH of the above solution to 3. Mix the above solutions in equal volumes and masses and stir them magnetically for 1 h to obtain a composite particle dispersion with a composite particle concentration of 1.0 wt%.

[0053] (2) Corn oil was used as the oil phase and the composite particle dispersion was used as the water phase. The mixture was mixed at a volume ratio of 2:1. The mixture was mixed using a high-speed shearing machine at 13600 rpm for 2 min to obtain a coarse emulsion. The coarse emulsion was then cyclically homogenized five times at 50 MPa using a high-pressure homogenizer to obtain a fine emulsion.

[0054] (3) The miniemulsion was centrifuged at 10,000 g for 5 min to remove the lower aqueous phase to obtain the final composite latex gel.

[0055] Example 2

[0056] The preparation method is the same as that of Example 1, except that the concentration of the composite particles in step (1) is 0.50 wt %.

[0057] Example 3

[0058] The preparation method is the same as that of Example 1, except that the concentration of the composite particles in step (1) is 0.75 wt %.

[0059] Example 4

[0060] The preparation method is the same as that of Example 1, except that the concentration of the composite particles in step (1) is 1.25 wt %.

[0061] The steady-state shear rheological test was performed on the latex gel prepared in Examples 1-4. The results are as follows: Figure 1 As shown by Figure 1 It can be seen that the composite latex gel has good shear thinning properties.

[0062] The composite latex gel prepared in Examples 1-4 was subjected to large-scale oscillation scanning detection, and the results were as follows: Figure 2 As shown, Figure 2 The left figure in the middle shows the dynamic modulus curve of latex gel at different composite particle concentrations, where G' represents the storage modulus and G" represents the loss modulus; the right figure shows the curve of tan δ of latex gel at different composite particle concentrations with angular frequency. Figure 2It can be seen that the storage modulus of the latex gel is greater than the loss modulus, indicating that the composite gel has excellent viscoelasticity and can quickly recover to a solid state after printing.

[0063] Example 5

[0064] The latex gels obtained in Examples 1-4 were respectively loaded into the barrel of the 3D printing equipment, and the printing parameters were set as follows: needle diameter 0.42 mm, printing speed 12 mm / s, printing pressure 0.16 MPa, printing layer height 0.4 mm, printing spacing 0.8 mm, and the latex gel was printed into a three-dimensional shape.

[0065] The cube printed in this embodiment has good resolution and shape fidelity, and the height collapse ratio after 4 hours is about 98.6%.

[0066] Figure 3 Appearance image (A), high-fidelity bar graph (B) and collapse ratio bar graph (C) of cubic structures printed with different particle concentrations stabilized latex gel.

[0067] The height collapse ratio in this application is calculated as: actual height measurement value / system setting value×100%.

[0068] Embodiment 6-8

[0069] The same printing method as in Example 5 is adopted, except that the printing pressure in Example 6 is 0.12 MPa; the printing pressure in Example 7 is 0.16 MPa; and the printing pressure in Example 8 is 0.12 MPa.

[0070] Figure 4 This is a high-precision 3D printing effect diagram of using 0.75% particle-stabilized latex gel for different shapes. It can be seen that the printed products have good resolution and shape fidelity.

[0071] Application Example 1

[0072] β-carotene was dispersed in corn oil (0.10 wt%) and stirred overnight at room temperature in the dark to ensure that the β-carotene was fully dissolved. Then, the method described in Example 1 was used to prepare emulsion gels stably loaded with β-carotene at different concentrations of composite particles (concentrations were 0.50 wt%, 0.75 wt%, 1.00 wt% and 1.25 wt%). 3D printing was performed at the optimal pressure (0.12, 0.16, 0.16 and 0.12 MPa), with a needle diameter of 0.42 mm, a printing speed of 12 mm / s, a printing layer height of 0.4 mm, and a printing spacing of 0.45 mm. The printed shapes were round tablets with a diameter of 1.5 cm and squares with a side length of 2.0 cm for subsequent experiments. The results of the easy swallowing test of different groups of samples are shown in Figure 5 , where the left picture shows the fork pressure test of 3D printed latex gel; the right picture shows the spoon tilt test of latex gel. Figure 5 It can be seen that the latex gel has good swallowability.

[0073] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A high-precision 3D printing latex gel, characterized in that: The invention is prepared by using a mixed solution of cellulose nanocrystals and bovine serum albumin as a water phase and vegetable oil as an oil phase to form an emulsion.

2. The high-precision 3D printing latex gel according to claim 1, characterized in that: The vegetable oil includes one or more of corn oil, rapeseed oil, peanut oil and soybean oil.

3. The high-precision 3D printing latex gel according to claim 1, characterized in that: The oil phase also includes fat-soluble nutrients; The fat-soluble nutrients include one or more of beta-carotene, curcumin, and lycopene.

4. The method for preparing the high-precision 3D printing latex gel according to any one of claims 1 to 3, comprising the following steps: The cellulose nanocrystal solution and the bovine serum albumin solution are mixed as the water phase; the vegetable oil is used as the oil phase to form an emulsion through emulsification; The excess water phase in the emulsion is removed to obtain a high-precision 3D printing latex gel.

5. The preparation method according to claim 4, characterized in that: The mass concentration of the cellulose nanocrystal solution is 1% to 3%; The pH value of the cellulose nanocrystal solution is less than 4; The mass concentration of the bovine serum albumin solution is 1% to 3%; The pH value of the bovine serum albumin solution is less than 4; The mass ratio of the cellulose nanocrystal solution to the bovine serum albumin solution is 1:1 to 1:3; The volume ratio of the water phase to the oil phase is 1:(1-3).

6. The preparation method according to claim 4, characterized in that: The pH value of the cellulose nanocrystal solution is 2.5-3.5; The pH value of the bovine serum albumin solution is 2.5-3.

5.

7. The preparation method according to claim 4, characterized in that: The emulsification method includes one or more of high-speed shearing, high-pressure homogenization, and ultrasonic emulsification; The method of removing the excess water phase in the emulsion is centrifugation.

8. Use of the high-precision 3D printing latex gel according to any one of claims 1 to 3 or the high-precision 3D printing latex gel prepared by the preparation method according to any one of claims 4 to 7 as a 3D printing material.

9. The use according to claim 8, characterized in that: The printing parameters of the 3D printing material are: Printing temperature is 20~30℃, extrusion rate is 10~30 mm / s, and nozzle diameter is 0.3~1.0 mm.

10. A 3D printed food, obtained by 3D printing the high-precision 3D printed latex gel according to any one of claims 1 to 3 or the high-precision 3D printed latex gel prepared by the preparation method according to any one of claims 4 to 7.

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