A cellulose acetate fiber / plant fiber composite paper and its preparation method and application

Abstract

The present invention provides a cellulose acetate fiber / plant fiber composite paper, its preparation method, and application. Using cellulose acetate fiber and plant fiber as raw materials, the paper is formed by wet-forming, achieving a gradient wettability structure in one step. The resulting cellulose acetate fiber / plant fiber composite paper exhibits a wettability gradient across the thickness. This method, which regulates fiber type and fiber blend ratio to enhance wettability differentiation, offers advantages such as flexibility, cost-effectiveness, environmental friendliness, and ease of processing.

Description

Technical Field

[0001] The present invention belongs to the field of specialty paper, and in particular relates to a cellulose acetate fiber / plant fiber composite paper and a preparation method and application thereof. Background Art

[0002] Liquid adsorption and transport are of great significance in many fields. For example, in biomedicine, liquid adsorption and transport can be used in applications such as diagnostic testing, drug delivery, and biosensors. In environmental engineering, liquid adsorption and transport can be used for wastewater treatment and pollutant removal. In the energy sector, liquid adsorption and transport can be used in adsorption, energy storage, and separation technologies.

[0003] Traditional plant fiber paper has good liquid adsorption capacity. However, the molecular structure of cellulose contains a large number of hydrophilic groups. Therefore, the difference in wettability between the two sides of pure plant fiber paper is small, the surface has relatively uniform wettability, and the diffusion rate is relatively consistent, which is not conducive to controlling the transmission of liquid in the Z direction. To improve the difference in wettability between the two sides of paper, researchers mostly use surface treatment technologies such as plasma treatment, coating, and printing. These surface technologies can improve the difference in wettability between the two sides of paper, but they have disadvantages such as high cost, complex process control, and negative environmental impact. Summary of the Invention

[0004] In order to solve the above-mentioned problems of the prior art, the present invention provides a cellulose acetate fiber / plant fiber composite paper and a preparation method and application thereof, which has the advantages of greater flexibility, economy, environmental friendliness and easy processability.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for preparing cellulose acetate fiber / plant fiber composite paper, comprising:

[0007] (1) cutting cellulose acetate fibers into short fibers, washing, and drying to obtain cellulose acetate short fibers;

[0008] (2) soaking the natural plant fiber pulp sheet in water to dissolve it, and then beating it to obtain plant fiber slurry;

[0009] (3) adding water to the papermaking auxiliary agent to prepare a papermaking auxiliary agent solution;

[0010] (4) After the cellulose acetate short fibers, plant fiber pulp and papermaking auxiliary agent solution are mixed and dispersed, a multi-fiber foaming mixed pulp is prepared, which is papered using a wet forming technology, and the cellulose acetate fiber / plant fiber composite paper is obtained after pressing and vacuum drying.

[0011] Preferably, in step (1), the length of the cellulose acetate staple fibers is 0.5 to 2.0 mm.

[0012] Preferably, in step (2), the beating degree of the plant fiber slurry is 35 to 60°SR.

[0013] Preferably, in step (2), the natural plant fiber pulp board is one or more of hardwood pulp board, softwood pulp board and cotton pulp board.

[0014] Furthermore, the broadleaf pulp board is one or a mixture of poplar pulp board, birch pulp board and eucalyptus pulp board; the coniferous pulp board is one or a mixture of pine pulp board, masson pine pulp board and larch pulp board.

[0015] Preferably, in step (3), the papermaking auxiliary agent is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

[0016] Preferably, in step (4), based on the total mass of the cellulose acetate fibers and the natural plant fiber pulp board, the cellulose acetate fibers account for 30% to 70% of the total mass.

[0017] Preferably, in step (4), the concentration of the papermaking aid in the foamed mixed slurry of multiple fibers is 0.1 to 0.4 g / L.

[0018] The cellulose acetate fiber / plant fiber composite paper is obtained by adopting the preparation method.

[0019] Application of the cellulose acetate fiber / plant fiber composite paper in wet gas power generation.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention uses cellulose acetate fiber and plant fiber as raw materials, and forms paper through a wet-laid process. This creates a gradient wettability structure in a single step. The resulting cellulose acetate fiber / plant fiber composite paper exhibits a wettability gradient across its thickness. From the front to the back of the cellulose acetate fiber / plant fiber composite paper, there is a gradient of cellulose acetate fiber distribution from low to high, pore distribution from large to small, cellulose acetate fiber size from large to small, and hydrophobic functional groups from few to many. These multiple gradients interact with each other, creating a composite paper with a gradient wettability. This is because: the surface wettability and surface charge of cellulose acetate fibers are different from those of plant fibers due to their size. During the water filtration process of paper, due to the effect of gravity and the difference in fiber size, the larger plant fibers first form a filter cake, and the smaller cellulose acetate short fibers then form a small three-dimensional network in the three-dimensional network structure with larger pores, providing more channels and pores. Therefore, the cellulose acetate short fibers eventually gather at the bottom, while the plant cellulose gathers at the top; by adjusting the size of cellulose acetate and the ratio to plant fibers, on the side where cellulose acetate fibers are enriched, due to the close arrangement between fibers and the higher fiber density, a smaller pore structure is formed, which can effectively organize the penetration of liquid, so that this side exhibits a certain low wettability; while on the other side dominated by plant fibers, due to the characteristics and arrangement of plant fibers, a larger pore structure is formed, which is conducive to the penetration and absorption of liquid and exhibits better wettability. The present invention introduces cellulose acetate fibers into plant fiber paper to increase the wettability difference of the paper in the Z direction, and controls the size and content of the cellulose acetate fibers to achieve the control of the wettability difference. The smaller the size of the cellulose acetate fibers, the higher the enrichment on the lower surface of the paper, and the lower the wettability of the surface. By adjusting its gradient, control of liquid adsorption and transmission can be achieved. This gradient wettability structure enables it to achieve directional transmission of liquid inside the paper, control the flow path and speed of the liquid, and demonstrate the potential for moisture power generation, which is of great significance for applications such as microfluidic systems, sensor technology and precision filtration. Compared with other methods, the present invention regulates the fiber type and fiber mixing ratio to increase the wettability difference of paper, which has the advantages of greater flexibility, economy, environmental friendliness and ease of processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 These are scanning electron microscope images of the cellulose acetate fiber / plant fiber composite paper prepared in Example 3 of the present invention: a is a microscopic structure image of the upper surface of the cellulose acetate fiber / plant fiber composite paper; b is a microscopic structure image of the lower surface of the cellulose acetate fiber / plant fiber composite paper.

[0023] Figure 2 The open circuit voltage of the cellulose acetate fiber / plant fiber composite paper of different sizes prepared by the present invention.

[0024] Figure 3 This is the voltage-time variation curve of the cellulose acetate fiber / plant fiber composite paper prepared in the present invention. DETAILED DESCRIPTION

[0025] In order to further understand the present invention, the present invention is described below in conjunction with embodiments. These descriptions are only for further explaining the features and advantages of the present invention and are not intended to limit the claims of the present invention.

[0026] The present invention achieves a gradient wettability structure in one step during the wet-formed composite paper preparation process by adjusting the ratio of cellulose acetate fiber to plant fiber. The mechanically sheared cellulose acetate fiber is then slurried with plant fiber and papermaking additives to form composite paper handsheets.

[0027] The method for preparing the cellulose acetate fiber / plant fiber composite paper comprises the following steps:

[0028] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0029] (2) soaking and disintegrating the natural plant fiber pulp sheet in water, and then beating the pulp to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 35 to 60°SR;

[0030] (3) Weighing a certain amount of papermaking aid and adding water to prepare a certain concentration, wherein the papermaking aid is a surfactant, preferably sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, etc.;

[0031] (4) The cellulose acetate staple fibers, plant fiber slurry, and papermaking auxiliary agent solution in steps (1) to (3) are fully mixed and dispersed to obtain a multi-fiber foaming mixed slurry, which is then papered using a wet forming technology, and then pressed and vacuum-dried to obtain a cellulose acetate fiber / plant fiber composite paper.

[0032] The standard basis weight of the cellulose acetate fiber / plant fiber composite paper of the present invention is 60g / m 2 Based on the total mass of the cellulose acetate fiber and natural plant fiber pulp, the cellulose acetate fiber accounts for 30% to 70% of the total mass, and the natural plant fiber pulp accounts for 30% to 70% of the total mass. The concentration of papermaking additives in the multi-fiber foaming mixed slurry is 0.1 to 0.4 g / L. The thickness of the cellulose acetate fiber / plant fiber composite paper is 0.2 to 0.5 mm, and the contact angle of the paper is 20° to 90°.

[0033] The natural plant fiber pulp board described in the present invention is one or a mixture of hardwood pulp board, softwood pulp board and cotton pulp board; the hardwood pulp board is one or a mixture of poplar pulp board, birch pulp board and eucalyptus pulp board; the softwood pulp board is one or a mixture of pine pulp board, masson pine pulp board and larch pulp board.

[0034] The cellulose acetate fiber is commercial cellulose acetate fiber with a diameter of 12 μm and a length cut to 0.5 to 2.0 mm by a high-speed grinder.

[0035] The concentration of the papermaking auxiliary agent in the foaming mixed slurry of multiple fibers is 0.1-0.4 g / L.

[0036] Example 1

[0037] This embodiment 1 provides a cellulose acetate fiber / plant fiber composite paper and a preparation method thereof, comprising:

[0038] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0039] (2) soaking the hardwood pulp board and the softwood pulp board in water to disintegrate, and further beating the pulp to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 40°SR;

[0040] (3) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0041] (4) The cellulose acetate staple fibers, plant fiber pulp and papermaking auxiliary agent solution in steps (1) to (3) are mixed, dispersed and dispersed to obtain a multi-fiber foaming mixed pulp; in the multi-fiber foaming mixed pulp, the ratio of the absolute dry mass of the cellulose acetate staple fibers to the absolute dry mass of the plant fiber pulp is 3:7, and the concentration of sodium dodecylbenzene sulfonate is 0.2 g / L; wet forming technology is adopted to produce paper, and after pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained.

[0042] Example 2

[0043] This embodiment 2 provides a cellulose acetate fiber / plant fiber composite paper and a preparation method thereof, comprising:

[0044] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0045] (2) soaking the hardwood pulp board and the softwood pulp board in water to disintegrate, and further beating the pulp to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 40°SR;

[0046] (3) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0047] (4) The cellulose acetate staple fibers, plant fiber pulp and papermaking auxiliary agent solution in steps (1) to (3) are mixed, dispersed and dispersed to obtain a multi-fiber foaming mixed pulp; in the multi-fiber foaming mixed pulp, the ratio of the absolute dry mass of the cellulose acetate staple fibers to the absolute dry mass of the plant fiber pulp is 4:6, and the concentration of sodium dodecylbenzene sulfonate is 0.2 g / L; wet forming technology is adopted to produce paper, and after pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained.

[0048] Example 3

[0049] This embodiment 3 provides a cellulose acetate fiber / plant fiber composite paper and a preparation method thereof, comprising:

[0050] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0051] (2) soaking the hardwood pulp board and the softwood pulp board in water to disintegrate, and further beating the pulp to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 40°SR;

[0052] (3) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0053] (4) The cellulose acetate staple fibers, plant fiber pulp and papermaking auxiliary agent solution in steps (1) to (3) are mixed, dispersed and dispersed to obtain a multi-fiber foaming mixed pulp; in the multi-fiber foaming mixed pulp, the ratio of the absolute dry mass of the cellulose acetate staple fibers to the absolute dry mass of the plant fiber pulp is 5:5, and the concentration of sodium dodecylbenzene sulfonate is 0.2 g / L; wet forming technology is adopted to produce paper, and after pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained.

[0054] Example 4

[0055] This embodiment 4 provides a cellulose acetate fiber / plant fiber composite paper and a preparation method thereof, comprising:

[0056] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0057] (2) soaking the hardwood pulp board and the softwood pulp board in water to disintegrate, and further beating the pulp to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 40°SR;

[0058] (3) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0059] (4) The cellulose acetate staple fibers, plant fiber pulp and papermaking auxiliary agent solution in steps (1) to (3) are mixed, dispersed and dispersed to obtain a multi-fiber foaming mixed pulp; in the multi-fiber foaming mixed pulp, the ratio of the absolute dry mass of the cellulose acetate staple fibers to the absolute dry mass of the plant fiber pulp is 6:4, and the concentration of sodium dodecylbenzene sulfonate is 0.2 g / L; wet forming technology is adopted to produce paper, and after pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained.

[0060] Example 5

[0061] This embodiment 2 provides a cellulose acetate fiber / plant fiber composite paper and a preparation method thereof, comprising:

[0062] (1) cellulose acetate fibers are cut into short fibers using a high-speed mill, and then washed and dried to obtain cellulose acetate short fibers, wherein the length of the cellulose acetate short fibers is 0.5 to 2.0 mm;

[0063] (2) soaking the hardwood pulp board and the softwood pulp board in water to disintegrate, and further beating to obtain a plant fiber pulp, wherein the beating degree of the plant fiber pulp is 40°SR;

[0064] (3) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0065] (4) The cellulose acetate staple fibers, plant fiber pulp and papermaking auxiliary agent solution in steps (1) to (3) are mixed, dispersed and dispersed to obtain a multi-fiber foaming mixed pulp; in the multi-fiber foaming mixed pulp, the ratio of the absolute dry mass of the cellulose acetate staple fibers to the absolute dry mass of the plant fiber pulp is 7:3, and the concentration of sodium dodecylbenzene sulfonate is 0.2 g / L; wet forming technology is adopted to produce paper, and after pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained.

[0066] Comparative Example 1

[0067] Pure plant fiber paper without cellulose acetate fiber was used as a blank sample, and the implementation method was as follows:

[0068] (1) tearing bleached hardwood pulp board and bleached softwood pulp board into small pieces with a mass ratio of 3:1, soaking them in deionized water for 24 hours, and then fully deflurring them with a fiber deflurring machine (running at 12000r), and then beating the plant fiber pulp in a trough beater with a beating concentration of 2% and a beating degree of 40°SR to obtain plant cellulose pulp;

[0069] (2) adding water to a papermaking auxiliary agent to prepare a papermaking auxiliary agent solution, wherein the papermaking auxiliary agent is sodium dodecylbenzenesulfonate;

[0070] (3) The plant fiber slurry and the papermaking auxiliary agent solution in step (1) and step (2) are fully mixed and dispersed to obtain a mixed slurry, wherein the concentration of the papermaking auxiliary agent is 0.2 g / L; wet forming technology is used to paper the paper, and pure plant fiber paper is obtained after pressing and vacuum drying.

[0071] The wettability of the cellulose acetate fiber / plant fiber composite papers prepared in Examples 1 to 5 and the pure plant fiber paper of Comparative Example 1 was tested. The results are shown in Table 1.

[0072] Table 1 Wettability of the paper obtained in Examples 1 to 5 and Comparative Example 1

[0073]

[0074] Table 1 shows that the water contact angles of the top and bottom surfaces of the cellulose acetate fiber / plant fiber composite paper obtained in the present invention differ. The top surface exhibits higher wettability than the bottom surface, and the degree of this difference is significantly greater than that observed in the pure plant fiber paper of Comparative Example 1. This demonstrates that the present invention, using cellulose acetate fiber and plant fiber to prepare the composite paper, can improve the wettability gradient across the thickness of the composite paper. Furthermore, a comparison of Examples 1 to 5 shows that as the cellulose acetate fiber content increases, the wettability of both the top and bottom surfaces of the composite paper deteriorates, and the difference in contact angles between the top and bottom surfaces first increases and then decreases. The maximum difference in contact angles between the top and bottom surfaces of the composite paper is achieved when the mass ratio of cellulose acetate fiber to plant fiber is 5:5.

[0075] Figure 1 This is a scanning electron microscope (SEM) image of the cellulose acetate fiber / plant fiber composite paper prepared in Example 3. Figure 1 As can be seen from a, the upper surface of the cellulose acetate fiber / plant fiber composite paper is mainly a plant fiber network, with a small amount of cellulose acetate fibers interspersed among them; Figure 1 As can be seen in b, the lower surface of the cellulose acetate fiber / plant fiber composite paper is mainly a network structure of cellulose acetate interwoven with a small amount of plant fibers interspersed. Figure 1 a and Figure 1The fiber network structure of b shows structural differences between the upper and lower surfaces of the composite paper. This structural difference leads to different properties on the upper and lower surfaces of the paper, particularly wettability. Because the upper surface is primarily composed of plant fibers, it is super-hydrophilic and more easily absorbs liquids, exhibiting excellent water absorption properties upon contact with liquids. The lower surface, on the other hand, is primarily composed of cellulose acetate, a fiber property that may result in strong resistance to moisture upon contact with liquids.

[0076] The cellulose acetate fiber / plant fiber composite paper prepared in Example 5 was cut into rectangles of a certain area (0.5 cm 2 ,1cm 2 ,2cm 2 ,4cm 2 ), attach a copper mesh electrode to the top surface of the composite paper, and a double-conductor copper foil electrode to the bottom surface of the composite paper. Then, connect the positive and negative terminals of a multimeter, or the working and auxiliary electrodes of an electrochemical workstation, to the copper mesh and copper foil electrodes, respectively, to create a CA@Cell wet gas power generation device. Finally, air dry the CA@Cell wet gas power generation device.

[0077] Figure 2 It can be seen that the performance of wet gas power generation is related to the area size of the material. A larger surface area provides more active surface areas and reaction sites, which can promote the ion exchange and charge generation process between water molecules in the moisture and the active functional groups on the surface of the material, thereby increasing the current output. Secondly, a larger surface area can improve the stability and reliability of the system to a certain extent, reducing the risk of early attenuation or failure. However, when the surface area reaches 4cm 2 When the surface area is increased, the lateral diffusion path of water or ions in the material is increased, which may slow down the diffusion of water and ions in the longitudinal direction (i.e., across the thickness), thereby reducing the efficiency of moisture conversion into electrical energy. Therefore, the optimal condition (2cm 2 ) composite paper is connected to an electrochemical workstation to detect the open circuit voltage in real time, such as Figure 3 shown. Figure 3 It can be seen that the open circuit voltage of the cellulose acetate fiber / plant fiber composite paper increases steadily with time, with the maximum output voltage reaching 117mV, and can last for 3600s without attenuation, greatly improving the wet-to-electric conversion performance of the paper-based material.

Claims

1. Application of cellulose acetate fiber / plant fiber composite paper in wet gas power generation, characterized in that: The preparation method of the cellulose acetate fiber / plant fiber composite paper comprises: (1) Cutting cellulose acetate fibers into short fibers, washing, and drying to obtain cellulose acetate short fibers; the length of the cellulose acetate short fibers is 0.5 to 2.0 mm; (2) Soaking the natural plant fiber pulp sheet in water to disintegrate it, and then beating it to a beating degree of 35-60°SR to obtain a plant fiber pulp; (3) Adding water to the papermaking auxiliary agent to prepare a papermaking auxiliary agent solution; (4) After cellulose acetate short fibers, plant fiber pulp and papermaking auxiliary agent solution are mixed and dispersed, a multi-fiber foaming mixed pulp is prepared, which is papered using a wet forming technology. After pressing and vacuum drying, cellulose acetate fiber / plant fiber composite paper is obtained. The obtained cellulose acetate fiber / plant fiber composite paper has a wettability gradient in the thickness direction; among them, based on the total mass of cellulose acetate fiber and natural plant fiber pulp board, cellulose acetate fiber accounts for 30% to 70% of the total mass.

2. The use of the cellulose acetate fiber / plant fiber composite paper in wet gas power generation according to claim 1, characterized in that: In step (2), the natural plant fiber pulp board is one or more of a broadleaf wood pulp board, a coniferous wood pulp board and a cotton pulp board.

3. The use of the cellulose acetate fiber / plant fiber composite paper in wet gas power generation according to claim 2, characterized in that: The broadleaf wood pulp board is one or a mixture of poplar wood pulp board, birch wood pulp board and eucalyptus wood pulp board; the coniferous wood pulp board is one or a mixture of pine wood pulp board, masson pine pulp board and larch wood pulp board.

4. The use of the cellulose acetate fiber / plant fiber composite paper in wet gas power generation according to claim 1, characterized in that: In step (3), the papermaking auxiliary agent is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

5. The use of the cellulose acetate fiber / plant fiber composite paper in wet gas power generation according to claim 1, characterized in that: In step (4), the concentration of the papermaking additive in the multi-fiber foaming mixed slurry is 0.1~0.4 g / L.

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