A laser scattering body based on biomass fiber and a preparation method and application thereof

Abstract

The present application relates to the technical field of optical materials, and particularly relates to a laser scattering body based on biomass fiber and a preparation method and application thereof.The orientation degree of the laser scattering body is less than or equal to 15.0%; the laser scattering body comprises a fluorescent material, biomass fiber and transparent liquid resin; the biomass fiber is fiber from which lignin or a lignin chromophore group is removed; the biomass fiber has a porous structure inside; the diameter of the biomass fiber is 0.1-100 microns, the length is 0.5-5 mm, and the length-diameter ratio is 10-500.The laser scattering body is prepared by selecting biomass fiber of a specific size and fluorescent material and transparent liquid resin, so that the orientation degree of the laser scattering body is less than or equal to 15.0%, and the scattering effect and uniform illumination effect of the laser scattering body are improved.

Description

Technical Field

[0001] This invention relates to the field of optical materials technology, and in particular to a laser scatterer based on biomass fibers, its preparation method, and its application. Background Technology

[0002] Traditional light sources (such as incandescent and fluorescent lamps) have low luminous efficiency, primarily due to significant energy loss caused by high temperatures and large Stokes displacement. Solid-state lighting (SSL), including light-emitting diodes (LEDs) and laser diodes (LDs), has gradually become a competitive alternative to traditional light sources due to its high luminous efficiency, energy saving, and small size, and has been widely adopted. LEDs suffer from "efficiency degradation," limiting their application in high-brightness fields. LDs, however, effectively avoid this problem. LD-driven SSL lighting only requires increasing the input current density to achieve ultra-high brightness. Furthermore, LDs offer advantages such as high beam quality, high color rendering, adjustable chromaticity and color temperature, controllable digital communication sensing, and long lifespan, making them suitable for applications such as automotive headlights, airport lighting, multimedia projectors, and laser televisions. Therefore, LDs hold promise as the next generation of high-brightness solid-state light sources.

[0003] Laser lights (LDs) have a highly concentrated, compact beam structure (focused on a small point) and can only emit monochromatic light, failing to provide uniform 3D light and the full visible spectrum required for certain lighting applications, thus hindering their use in the lighting field. To address this issue, many studies have used near-ultraviolet or blue LDs to illuminate transducers containing colored phosphors to construct multicolor lighting systems. These LD systems are equipped with scattering centers that can disperse the highly concentrated laser beam, thus serving as high-scattering light sources for lighting. However, the brightness of such systems is strongly limited by the Stokes shift and internal quantum efficiency of the phosphor transducer.

[0004] With the development of the field of illumination, research on using scatterers to scatter and focus laser beams to obtain efficient light sources has gradually become a hot topic. Foreign research has demonstrated a macroscopically extended three-dimensional scatterer composed of interconnected hollow hexagonal boron nitride (BN) microtubes with nanometer-scale wall thickness. This highly efficient (>98%) scatterer has a broadband range of 450–640 nm. BN diffusers enable isotropic light distribution from numerous coherent laser sources. However, the interconnected BN microtubes are manufactured at high temperatures in a quartz tube furnace, followed by computer-controlled chemical vapor deposition. This process requires stringent and energy-intensive fabrication conditions. Patent document CN113831837A discloses a laser scatterer with controllable particle size, which uses an organosilane solution as a precursor. A hydrogel is formed through an acid-base catalyst reaction, and the material with a three-dimensional porous structure is obtained after supercritical carbon dioxide drying. This material exhibits superior performance and has made significant contributions to the development of laser lighting technology. However, its application is hindered by its complex and expensive manufacturing process, and the silicon used is non-degradable, which can easily generate a large amount of white pollution after the product is used.

[0005] Therefore, given the high energy consumption in the manufacturing process of existing scatterer materials and their inconsistency with green development requirements, new materials and structural configurations are needed for scatterers. Wood is a renewable natural resource that has been used for construction and furniture for centuries. In recent years, with the development of nanotechnology, many wood-based functional composite materials have been prepared by adjusting the layered porous structure and unique chemical composition to obtain new functions. This method has been used to develop various products, such as transparent wood, dense wood, and photonic wood. Transparent wood is a wood-based composite material made by removing or modifying lignin from wood and then introducing a polymer with a refractive index matching into the cellulose skeleton. This material has characteristics such as high light transmittance, natural degradation, and environmental friendliness, and has potential applications in fields such as construction, solar cells, and quantum dot lighting. However, the complex cellular structure inside wood causes light to scatter within the wood, resulting in transparent wood having a high degree of haze. Researchers have made considerable efforts to reduce haze. However, few researchers have considered how to fully utilize this high haze characteristic to create more functional materials. The higher the haze of a transparent material, the stronger its light scattering effect. This means that when a concentrated beam of light illuminates a highly hazy material, the beam is scattered into three-dimensional space, thus providing illumination. Based on this, it can be inferred that if the haze of transparent wood increases further, its scattering properties will become even more pronounced, which is a natural advantage for scattering laser light and generating uniform 3D light sources for illumination.

[0006] Patent document CN117754678A discloses a wood-based laser scatterer, composed of lignin-removed wood or lignin-removed chromophore wood and a transparent resin whose refractive index is mismatched with that of wood nanocellulose, impregnated into the wood's internal pore structure. It is manufactured through ultraviolet light curing or thermal curing. Compared to the aforementioned laser scatterers, this natural laser scatterer has a simpler preparation process, milder reaction conditions, good mechanical properties and water resistance, and is environmentally friendly with low carbon emissions. However, this wood-based laser scatterer still has certain limitations: (1) the liquid has poor permeability in solid wood, resulting in a long time for lignin removal and uneven lignin removal, leading to low preparation efficiency; (2) the anisotropy of wood itself and the directional arrangement of cells inside the wood result in low scattering uniformity of this scatterer, and the optical illumination performance still needs to be further improved; (3) the anisotropy of solid wood leads to large internal stress in large-sized wood laser scatterers, causing cracking and thus preventing their application; (4) the wood needs to be cut into the required shape, which increases the complexity of the preparation process. These problems hinder the industrial continuous production of wood laser scatterers. Therefore, based on all the problems of existing scatterer materials (including but not limited to high energy consumption in manufacturing processes, complex processes, and anisotropy leading to the inability to achieve uniform illumination), it is urgent to develop new scatterer materials and structural configurations to achieve laser illumination. Summary of the Invention

[0007] This invention provides a laser scatterer based on biomass fibers, its preparation method, and its application, in order to solve the problems of complex manufacturing processes, long time consumption, high energy consumption, and high cost of existing scatterer materials.

[0008] According to a first aspect of the present invention, the present invention provides a laser scatterer based on biomass fibers, characterized in that the orientation degree of the laser scatterer is ≤15.0%; the laser scatterer comprises a fluorescent material, biomass fibers and a transparent liquid resin;

[0009] The biomass fiber is a fiber with lignin or lignin chromophore removed; the biomass fiber has a hollow internal structure; the biomass fiber has a diameter of 0.1μm-100μm, a length of 0.5μm-5mm, and an aspect ratio of 10-500.

[0010] The laser scatterer of this invention is a composite structure composed of fluorescent materials, biomass fibers, and transparent liquid resin. Combining the characteristics of each component, the three work synergistically to enhance the scattering effect and uniform illumination of the laser scatterer. Specifically, the hollow internal structure and specific size range of the biomass fibers (diameter 0.1μm-100μm, length 0.5μm-5mm) provide more scattering interfaces and paths for the laser, enhancing the scattering effect while ensuring the orientation degree of the laser scatterer is ≤15.0%, thus achieving uniform illumination. The fluorescent material can absorb laser light and emit light of a specific wavelength, converting ultraviolet, visible, or infrared light into white light. The transparent liquid resin serves as a matrix, uniformly dispersing and fixing the other components to form a stable scatterer structure, while its transparency ensures effective laser transmission and scattering.

[0011] It should be noted that the method for calculating the orientation degree of the present invention is as follows:

[0012] Wide-angle X-ray scattering (WAXS) is a method for determining fiber orientation, which is the angle between the fiber alignment direction and the main orientation (the main orientation of the material). Utilizing the symmetrical transmission mode of the diffraction pattern, the effective angle range is reduced from 360° to 180° by superimposing the intensities of the two halves of the angle range (1°-180° and 181°-360°). Based on the obtained azimuth intensity distribution spectrum of the fiber diffraction arc in the two-dimensional WAXS pattern of the fiber, the fiber orientation index (fc) is calculated according to formula (1):

[0013] (1).

[0014] FWHM is the full width at half maximum (FWHM) of the azimuth profile derived from the selected equatorial reflection.

[0015] Furthermore, the biomass fiber accounts for 1% to 90% of the total mass of the biomass fiber and the transparent liquid resin. By rationally controlling the content of biomass fiber, the optical properties, mechanical properties, and stability of the laser scatterer are optimized. Specifically, this content range can effectively adjust the scattering path and intensity of the laser within the scatterer, thereby achieving a uniform illumination effect from soft to high intensity, while ensuring that the scatterer has good transmittance, reflectivity, haze, and luminous uniformity. In addition, an appropriate amount of biomass fiber can also enhance the mechanical strength and toughness of the scatterer, improve its thermal stability and water resistance, and enable it to maintain stable performance in complex environments.

[0016] Furthermore, the biomass fiber accounts for 10% to 25% of the total mass of the biomass fiber and the transparent liquid resin, preferably 10% to 15%.

[0017] Furthermore, the fluorescent material accounts for 0.01% to 20% of the total mass of the biomass fiber and the transparent liquid resin. By precisely controlling the content of the fluorescent material, the luminous efficiency and color modulation of the laser scatterer are optimized. Specifically, this content range can effectively adjust the absorption and conversion efficiency of the fluorescent material to the laser, thereby achieving a luminous effect from weak to strong, while ensuring that the scatterer has good color diversity and controllability. In addition, an appropriate amount of fluorescent material can also improve the luminous uniformity of the scatterer, avoiding uneven luminous emission caused by excessive fluorescent material, and further improving the lighting quality.

[0018] Furthermore, the fluorescent material accounts for 0.01% to 5% of the total mass of the biomass fiber and the transparent liquid resin, preferably 0.05% to 2%.

[0019] Furthermore, the biomass fibers have a diameter of 1μm ≤ 80μm, a length of 0.5μm ≤ 1mm, and an aspect ratio of 10 ≤ 500. By precisely controlling the fiber size, the propagation path and scattering intensity of the laser within the scatterer can be adjusted more finely, improving the uniformity of laser illumination and the luminous effect of the laser scatterer.

[0020] Further, by weight, the laser scatterer comprises 0.02-0.04 parts of fluorescent material, 2.5-5 parts of biomass fiber, and 15-25 parts of transparent liquid resin.

[0021] Furthermore, the biomass fiber includes one or more of wood fiber, bamboo fiber, hemp fiber, and seaweed fiber; wherein the wood fiber is made from any one of balsa wood, paulownia, fir, poplar, ash, and pine; the bamboo fiber is made from one or more of moso bamboo, bamboo fern, green bamboo, and moso bamboo; and the hemp fiber is made from one or more of jute, flax, and ramie.

[0022] Furthermore, the density of the biomass fiber is 0.02 g / cm³. 3 ~1.35 g / cm 3 The density of biomass fibers can be controlled to achieve controllable transmittance, controllable reflectance, controllable density, controllable illumination uniformity, excellent thermal stability, and a high laser damage threshold.

[0023] Further, the transparent liquid resin is one or more of polyethylene glycol diacrylate, epoxy acrylate, acrylate derivatives, polyurethane prepolymer, polyurethane modified epoxy resin, polyvinylpyrrolidone, polyethylene glycol, polydimethylsiloxane, tetramethyl orthosilicate, tetraethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and silicone rubber; preferably, the transparent liquid resin is polyethylene glycol diacrylate.

[0024] By selecting a suitable resin, the optimal mechanical properties, water resistance, and optical compatibility of the laser scatterer can be achieved.

[0025] Furthermore, the refractive index of the transparent liquid resin is <1.53 or >1.53, and is different from the refractive index of the biomass fiber; this difference in refractive index can enhance the scattering effect of laser in the scattering body and improve the scattering efficiency.

[0026] Furthermore, the fluorescent material includes one or more of the following: aluminate fluorescent materials, silicate fluorescent materials, nitride fluorescent materials, phosphate fluorescent materials, and sulfide fluorescent materials doped with rare earth elements; the particle size of the fluorescent material is 0.1–100 μm.

[0027] By selecting suitable fluorescent materials, the color of the laser can be controlled, and better synergy can be achieved with biomass fibers and transparent liquid resins, improving the luminous efficiency and uniformity of the laser scatterer. Furthermore, specifying a particle size range of 0.1–100 μm for the fluorescent materials ensures uniform dispersion within the scatterer, guaranteeing sufficient laser excitation and further enhancing the luminous efficiency and uniformity of the scatterer. This leads to broader application prospects and better performance of the laser scatterer in the field of laser lighting.

[0028] Furthermore, the laser scatterer of the present invention includes any one or a combination of two or more of the following morphologies: sphere, cylinder, ellipsoid, cube, cuboid, and cone; the diameter of the spherical biomass fiber laser scatterer is between 1 mm and 100 mm; and the density of the biomass fiber laser scatterer is 0.10 g / cm³. 3 ~1.50 g / cm 3 .

[0029] According to a second aspect of the present invention, the present invention also provides a method for preparing the above-described biomass fiber-based laser scatterer, comprising the following steps:

[0030] Preparation of biomass fiber;

[0031] The fluorescent material and the biomass fiber were added to a transparent liquid resin and stirred to obtain a mixed system; the obtained mixed system was then vacuum impregnated.

[0032] The preparation method of this invention includes steps such as preparing biomass fibers, mixing them with fluorescent materials and transparent liquid resin, and vacuum impregnation. The entire process is simple, straightforward, easy to operate, and easy to control and implement. This preparation method does not require complex equipment or harsh conditions, reducing production costs and difficulty, and facilitating the large-scale industrial production of laser scatterers. By mixing biomass fibers with fluorescent materials and transparent liquid resin and then vacuum impregnating the mixture, laser scatterers with excellent optical and mechanical properties can be prepared, meeting the requirements for laser lighting materials and providing effective material support for the development of laser lighting technology.

[0033] Furthermore, the method for preparing biomass fibers is as follows: wood is ground into fibers; the wood and other raw materials are chipped to a thickness of less than or equal to 1 mm, with no limitation on length and width; the chips are boiled in water at a temperature above 80°C for 10-30 minutes; and the chips are then fed into a hot mill for grinding to obtain fibrous wood.

[0034] The fibrous wood is placed in a lignin removal solution or a lignin modifier solution and then heated to a temperature between 40°C and boiling until all the wood fibers turn white. The solute in the lignin removal solution is selected from one or both of sodium chlorite and sodium hypochlorite, and the mass concentration of the solute is 0.1-20%. The pH value of the water is adjusted to 4-5 using acetic acid. The lignin modifier solution is a mixture consisting of hydrogen peroxide and an alkaline solution, with a mass ratio of hydrogen peroxide to alkaline solution of 10:0.1-10:3. The mass fraction of the alkaline solution is 1%-50%, and the solute is selected from one or both of sodium hydroxide and potassium hydroxide.

[0035] The method for preparing biomass fibers in this invention involves treating wood with a lignin removal solution or a lignin modifier solution. The heating temperature is between 40°C and the solution boiling, providing mild conditions that do not excessively damage the fiber's structure and properties. Simultaneously, by adjusting the solution's composition and pH value, lignin or lignin chromophores in the wood can be effectively removed, turning the fiber white and achieving the desired optical properties. Biomass fibers prepared using this method exhibit excellent optical properties and structural stability, providing a high-quality raw material base for subsequent laser scattering device preparation and ensuring the performance and quality of the final product.

[0036] Furthermore, the stirring speed is ≥500 rpm and the stirring time is ≥5 min.

[0037] The stirring speed can be 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1500 rpm, etc., and the stirring time can be 5 min, 8 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 60 min, etc.

[0038] Furthermore, the vacuum impregnation pressure is -0.02MPa to -0.1MPa, and the time is 1min to 120min.

[0039] This invention uses stirring to uniformly disperse fluorescent materials and biomass fibers in a transparent liquid resin, and then vacuum impregnates the mixture to thoroughly remove air bubbles and allow the resin to fully penetrate the fiber pores, thereby forming a dense and uniform composite structure. Vacuum impregnation at a vacuum level of -0.02 MPa to -0.1 MPa and a time period of 1-120 minutes rapidly and thoroughly eliminates air bubbles in the mixture, allowing the transparent liquid resin to fully penetrate and fill the porous structure of the biomass fibers, eliminating pore defects, and thus obtaining a dense, uniform, and bubble-free composite scatterer, significantly improving the uniformity and optical performance of laser scattering.

[0040] The vacuum impregnation pressure can be -0.02MPa, -0.03MPa, -0.04MPa, -0.05MPa, -0.06MPa, -0.07MPa, -0.08MPa, -0.09MPa, -0.1MPa, etc., and the time can be 1min, 5min, 8min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, etc.

[0041] According to a third aspect of the present invention, the present invention also provides the application of the above-described biomass fiber-based laser scatterer in the preparation of laser lighting materials, the laser lighting materials including lighting materials for use in the fields of seabed lighting, underwater lighting, indoor lighting, outdoor lighting, long-distance non-contact lighting, adjustable light color lighting, laser scattering and laser display.

[0042] The laser scatterer of this invention can uniformly scatter a highly concentrated laser beam into three-dimensional space, providing an efficient and uniform light source. It solves the problems of beam concentration and uneven illumination in traditional laser lighting, provides a new solution for the development of laser lighting technology, expands the application scope of laser lighting, and has important practical application value and market prospects.

[0043] The beneficial effects of this invention are:

[0044] The present invention provides a laser scatterer based on biomass fiber, which is prepared by using biomass fiber of specific size, fluorescent material and transparent liquid resin, so that the orientation degree of the laser scatterer is ≤15.0%, thereby improving the scattering effect and uniform illumination effect of the laser scatterer.

[0045] The method for preparing a biomass fiber-based laser scatterer provided by this invention is simple, has mild reaction conditions, is easy to operate, has low energy consumption, low cost, and is green and pollution-free. The preparation process can also be industrialized through continuous fiberboard manufacturing technology, which can improve production efficiency and realize large-scale continuous industrial production. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a diagram showing the illumination effect of the laser scatterer in Embodiment 1 of the present invention.

[0048] Figure 2 This is a graph showing the illuminance uniformity and illuminance variation coefficient of the laser scatterer in Embodiment 1 of the present invention.

[0049] Figure 3 This is a microstructure diagram of the laser scatterer in Embodiment 1 of the present invention.

[0050] Figure 4 This is a structural orientation diagram of the laser scatterer of Embodiment 1 of the present invention, obtained by wide-angle X-ray testing.

[0051] Figure 5 Figure 1 shows the microstructure of wood fibers in Example 2 of the present invention; wherein, Figure 2a is the microstructure of the original wood fibers in Example 2, Figure 2b is the microstructure of the wood fibers after lignin removal in Example 2, and Figure 2c is the microstructure of the wood fibers after lignin removal by impregnation with polyethylene glycol diacrylate in Example 2.

[0052] Figure 6 This is a diagram showing the illumination effect of the laser scatterer in Embodiment 2 of the present invention.

[0053] Figure 7 This is a structural orientation diagram of the laser scatterer of Embodiment 2 of the present invention, obtained by wide-angle X-ray testing.

[0054] Figure 8 This is a diagram showing the illumination effect of the laser scatterer in Embodiment 3 of the present invention.

[0055] Figure 9 This is a graph showing the illuminance uniformity and illuminance variation coefficient of the laser scatterer in Embodiment 3 of the present invention.

[0056] Figure 10 This is a diagram showing the illumination effect of the laser scatterer in Comparative Example 5 of this invention.

[0057] Figure 11 This is a graph showing the illuminance uniformity and illuminance variation coefficient of the laser scatterer in Comparative Example 5 of the present invention.

[0058] Figure 12 Figure 6 shows a cross-sectional view of the wood microstructure of Comparative Example 6 of the present invention. Figure 1a is a cross-sectional view of the wood microstructure before impregnation with polyethylene glycol diacrylate, and Figure 2b is a cross-sectional view of the wood microstructure after impregnation with polyethylene glycol diacrylate.

[0059] Figure 13 Figure 6 shows a longitudinal section of the wood microstructure of Comparative Example 6 of the present invention. Figure 1a is a longitudinal section of the wood microstructure before impregnation with polyethylene glycol diacrylate, and Figure 2b is a longitudinal section of the wood microstructure after impregnation with polyethylene glycol diacrylate.

[0060] Figure 14 This is a structural orientation diagram of the laser scatterer of Comparative Example 6 of the present invention, obtained by wide-angle X-ray testing.

[0061] Figure 15 This is a graph showing the illuminance uniformity and illuminance variation coefficient of the laser scatterer in Comparative Example 6 of the present invention.

[0062] Figure 16 This is a diagram showing the illumination effect of the laser scatterer in Comparative Example 6 of this invention.

[0063] Figure 17 Figure 7 shows a cross-sectional view of the wood microstructure of Comparative Example 7 of the present invention. Figure 8a is a cross-sectional view of the wood microstructure before impregnation with polyethylene glycol diacrylate, and Figure 9b is a cross-sectional view of the wood microstructure after impregnation with polyethylene glycol diacrylate.

[0064] Figure 18 Figure 7 shows a longitudinal section of the wood microstructure of Comparative Example 7 of the present invention. Figure 8a is a longitudinal section of the wood microstructure before impregnation with polyethylene glycol diacrylate, and Figure 9b is a longitudinal section of the wood microstructure after impregnation with polyethylene glycol diacrylate.

[0065] Figure 19 This is a structural orientation diagram of the laser scatterer of Comparative Example 7 of the present invention, obtained by wide-angle X-ray testing.

[0066] Figure 20 This is a graph showing the illuminance uniformity and illuminance variation coefficient of the laser scatterer in Comparative Example 7 of the present invention.

[0067] Figure 21 This is a diagram showing the illumination effect of the laser scatterer in Comparative Example 7 of this invention. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0069] Example 1

[0070] This embodiment provides a laser scatterer based on biomass fibers, comprising the following raw materials in parts by weight: 0.04 parts fluorescent material, 2.5 parts biomass fibers, and 20 parts transparent liquid resin polyethylene glycol diacrylate. The laser scatterer has a diameter of 3 cm and a density of 1.05 g / cm³. 3 .

[0071] The refractive index of polyethylene glycol diacrylate is 1.45, while that of biomass fiber is 1.53. Biomass fiber is fiber with lignin or lignin chromophores removed. The internal structure of biomass fiber is porous and cellular, with a diameter of 1 μm ≤ diameter ≤ 80 μm, a length of 0.5 μm ≤ length ≤ 1.0 mm, and an aspect ratio of 10 ≤ aspect ratio ≤ 300. The density of biomass fiber is 0.41 g / cm³. 3 The fluorescent material is an aluminate fluorescent material with a particle size of 10-14 μm.

[0072] The preparation method of biomass fiber is as follows: Poplar wood is taken as raw material, and it is chipped into sheets with a thickness of less than or equal to 0.5 mm and a length and width of ≤10 cm. The sheets are boiled in water at 90°C for 15 minutes, and then the sheets are ground in a hot mill to obtain fibrous wood. The fibrous wood is placed in a lignin removal solution or a lignin modifier solution and heated to a temperature between 40°C and boiling until all the wood fibers turn white. The lignin removal solution is a 2.5% sodium chlorite solution, and the pH of the aqueous solution is adjusted to 4-5 with acetic acid. The lignin modifier solution is a mixture consisting of hydrogen peroxide and an alkaline solution, with a mass ratio of hydrogen peroxide to alkaline solution of 1:10. The mass fraction of the alkaline solution is 20%, and the alkaline substance is sodium hydroxide.

[0073] This embodiment also provides a method for preparing the laser scatterer, including the following steps:

[0074] (1) Mix 0.04 g of fluorescent material, 2.5 g of biomass fiber and 20 g of polyethylene glycol diacrylate liquid at a speed of 800 rpm for 20 min to form a mixed system; immerse the resulting mixed system under a pressure of -0.05 MPa for 60 min.

[0075] When the laser scatterer is irradiated with a green laser with a wavelength of 532 nm, the highly concentrated laser light is dispersed.

[0076] like Figure 1 The image shows the illumination effect of laser irradiation on the wood fiber laser scatterer in Example 1. As can be seen from the image, when the laser irradiates the wood fiber laser scatterer, the laser exhibits a significant dispersion effect.

[0077] like Figure 2 The figure shows the illuminance variation coefficient of the wood fiber laser scatterer irradiated by a 532 nm green laser in Example 1. The vertical axis represents the illuminance (lux), with 0 being the point of zero illuminance. The horizontal line intersecting 0 and perpendicular to the vertical axis is the horizontal axis, and the center point of the circle on the horizontal axis is the position of the spherical laser scatterer. The ellipsoidal curve represents the spherical laser scatterer in 360° directions. As can be seen from the figure, the illuminance variation coefficient of the wood fiber laser scatterer is 4.10%, the lowest among all examples. This indicates a high degree of laser dispersion and a maximum enhancement of irradiation uniformity, making it the scatterer with the best three-dimensional uniform irradiation effect and the best luminous illumination effect in this invention. The microstructure of the laser scatterer in this embodiment is as follows: Figure 3 As shown. Figure 4 The orientation degree of the wide-angle X-ray diffraction pattern of the laser scatterer in this embodiment is shown. It can be seen that the orientation degree of this embodiment is very small, only 8.6%, which indicates that it has very good uniformity.

[0078] Example 2

[0079] This embodiment provides a laser scatterer based on biomass fibers, differing from Embodiment 1 only in that the amount of fluorescent material is 0.02 parts and the amount of biomass fibers is 5 parts. The orientation degree of the laser scatterer in this embodiment is 11.2%. The diameter of the laser scatterer is 3 cm, and the density is 1.00 g / cm³. 3 .

[0080] The laser scatterer is prepared using the same method as in Example 1.

[0081] Figure 5 a, Figure 5 b and Figure 5 Figure c shows the microstructure diagrams of the original wood fibers, the lignin-removed wood fibers, and the impregnated polyethylene glycol diacrylate wood fibers from Example 2, respectively. Figure 5As can be seen in image a, the wood fibers have a hollow internal structure; from Figure 5 As shown in b, after lignin removal, the structure of wood fibers remains intact under microscopic conditions, indicating that lignin removal has no significant impact on the wood fiber structure; from Figure 5 As can be seen from c, after impregnation and curing with polyethylene glycol diacrylate, the overall structure of the wood fiber remains intact under microscopic conditions. The polyethylene glycol diacrylate is completely impregnated into the pores, filling them completely, thus preparing a wood fiber laser scatterer.

[0082] like Figure 6 The image shows the illumination effect of laser irradiation on the wood fiber laser scatterer in Example 2. As can be seen from the image, when the laser irradiates the wood fiber laser scatterer, the laser exhibits a significant dispersion effect.

[0083] like Figure 7 The figure shows the illuminance variation coefficient of the wood fiber laser scatterer irradiated by a 532 nm green laser in Example 2. The vertical axis represents the illuminance (lux), with the 0 point on the vertical axis being the point where the illuminance is 0. The horizontal axis is the line that intersects the 0 point and is perpendicular to the vertical axis. The center point of the circle on the horizontal axis is the position of the spherical laser scatterer. The ellipsoidal curve represents the spherical laser scatterer in the 360° direction. As can be seen from the figure, the illuminance variation coefficient of the wood fiber laser scatterer is 6.97%, which is significantly reduced. The illuminance in the 0° direction of the coordinate system is weakened, the laser dispersion is enhanced, and the irradiation uniformity is improved, initially achieving a three-dimensional uniform irradiation effect. Compared with Example 1, the irradiation intensity is slightly reduced.

[0084] Example 3

[0085] This embodiment provides a laser scatterer based on biomass fibers, differing from Embodiment 1 only in that the amount of biomass fibers used is 5 parts. The orientation degree of the laser scatterer in this embodiment is 14.3%. The diameter of the laser scatterer is 3 cm, and the density is 1.08 g / cm³. 3 .

[0086] The laser scatterer is prepared using the same method as in Example 1.

[0087] like Figure 8 The image shown is an illumination effect diagram of laser irradiation on a wood fiber laser scatterer in this embodiment. As can be seen from the image, when the laser irradiates the wood fiber laser scatterer, the laser exhibits a significant dispersion effect.

[0088] like Figure 9The figure shows the illuminance variation coefficient of the wood fiber laser scatterer irradiated by a 532 nm green laser in this embodiment. The vertical axis represents the illuminance (lux), with 0 being the point of zero illuminance. The horizontal axis is the line intersecting 0 and perpendicular to the vertical axis, and the center point of the circle on the horizontal axis is the position of the spherical laser scatterer. The ellipsoidal curve represents the spherical laser scatterer in 360° directions. The figure shows that the illuminance variation coefficient of the wood fiber laser scatterer is 13.53%, which is low, indicating that the laser is dispersed, the irradiation uniformity is strong, and the three-dimensional uniform irradiation effect is good. Compared to Embodiment 1, the irradiation intensity is higher on the left half and lower on the right half in this embodiment, indicating that the transmitted laser intensity is reduced and the reflected intensity is increased.

[0089] Comparative Example 1

[0090] This comparative example provides a laser scatterer based on biomass fibers, differing from Example 1 only in that the amount of biomass fibers used is 10 parts, and the biomass fibers have an outer diameter of 10 μm ≤ outer diameter ≤ 50 μm and a length of 10 μm ≤ length ≤ 5 mm. The orientation degree of the laser scatterer in this comparative example is 20.9%.

[0091] The laser scatterer is prepared using the same method as in Example 1.

[0092] Experimental results: The amount of biomass fiber added was too high. 10 parts of biomass fiber could not be mixed evenly in 20 parts of polyethylene glycol diacrylate. The dispersibility was extremely poor, and it was impossible to make spherical scatterers.

[0093] Comparative Example 2

[0094] This comparative example provides a laser scatterer based on biomass fibers, differing from Example 1 only in that: the amount of phosphor is 0.01 parts, the amount of biomass fibers is 0.5 parts, and the biomass fibers have an outer diameter of 10 μm ≤ 50 μm and a length of 10 μm ≤ 5 mm. The orientation degree of the laser scatterer in this comparative example is 13.9%.

[0095] The laser scatterer is prepared using the same method as in Example 1.

[0096] Experimental conditions: In this comparative example, when the wood fiber laser scatterer was irradiated with laser, the amount of biomass fiber and phosphor was too small. Under microscopic conditions, a large area within the scatterer was pure resin, without any phosphor or biomass fiber. Consequently, the laser light passed through the scatterer without encountering any obstacles, forming a beam-like light path that could not be scattered and therefore could not provide illumination. Although the spherical scatterer had a very small degree of orientation, it still could not provide illumination because it could not scatter the laser.

[0097] Comparative Example 3

[0098] This comparative example provides a laser scatterer based on biomass fibers, differing from Example 1 only in that the amount of biomass fibers used is 5 parts, and the biomass fibers have an outer diameter of 100 μm and an outer diameter of ≤200 μm, and a length of 5 mm and ≤10 mm. The orientation degree of the laser scatterer in this comparative example is 19.8%.

[0099] The laser scatterer is prepared using the same method as in Example 1.

[0100] Experimental results: The outer diameter and length of the biomass fibers were too large, and the fibers formed a disordered strip-like state in the resin, which was not a uniform suspension and could not produce spherical scatterers.

[0101] Comparative Example 4

[0102] This comparative example provides a laser scatterer based on biomass fibers, differing from Example 1 only in that the biomass fibers have an outer diameter of 1 nm < outer diameter ≤ 50 nm and a length of 1 μm < length ≤ 5 μm. The orientation degree of the laser scatterer in this comparative example is 9.5%.

[0103] The laser scatterer is prepared using the same method as in Example 1.

[0104] Experimental results: In this comparative example, when the wood fiber laser scatterer was irradiated with laser, the biomass fibers were too small, reaching nanoscale particle size. Since the particle size was far smaller than the laser wavelength, the laser light passed directly through the scatterer, forming a single beam path that could not be scattered, thus failing to provide illumination. Although the spherical scatterer had a very small degree of orientation, it still could not provide illumination due to its inability to scatter the laser, resulting in an illuminance variation coefficient of 80.4%.

[0105] Comparative Example 5

[0106] This comparative example provides a laser scatterer, which differs from Example 1 only in that it does not include biomass fibers. The preparation method of this laser scatterer is as follows:

[0107] (1) Mix 0.04 g of fluorescent material and 20 g of polyethylene glycol diacrylate liquid to form a mixture system, and pour 5 g of the mixture system into a spherical mold.

[0108] (2) The spherical mold containing the mixed system from step (1) is cured under a UV lamp with a power of 100 W / cm². 2 An illumination time of 60 s was used to obtain a fluorescent material—polyethylene glycol diacrylate laser scatterer. When this scatterer was irradiated with a green laser at a wavelength of 532 nm, the highly concentrated laser light was dispersed in large quantities.

[0109] like Figure 10The image shows the illumination effect of laser irradiation on the fluorescent material-polyethylene glycol diacrylate laser scatterer in this comparative example. As can be seen from the image, when the laser irradiates the fluorescent material-polyethylene glycol diacrylate laser scatterer, the laser exhibits a dispersion effect.

[0110] like Figure 11 The figure shows the illuminance variation coefficient of the fluorescent material-polyethylene glycol diacrylate laser scatterer irradiated by a 532 nm green laser in this comparative example. The vertical axis represents the illuminance (lux), with 0 points representing zero illuminance. The horizontal line intersecting 0 points and perpendicular to the vertical axis is the horizontal axis, and the center point of the circle on the horizontal axis is the position of the spherical laser scatterer. The circular curve represents the spherical laser scatterer in 360° directions. The figure shows that the orientation degree of the fluorescent material-polyethylene glycol diacrylate laser scatterer is 11.8%, and the illuminance variation coefficient is 17.7%.

[0111] Comparative Example 6

[0112] This comparative example provides a laser scatterer, the preparation method of which is as follows:

[0113] (1) The density is 0.15 g / cm³ 3 A 1.5cm diameter spherical balsa wood was placed in a 3.5% sodium chlorite solution (pH adjusted to 4.5 with acetic acid) and boiled at 100°C until the balsa wood turned completely white. The balsa wood was then removed and tested, and the lignin content was found to be 7.52%.

[0114] (2) The white balsa wood skeleton obtained in step (1) was placed in acetone solvent to replace the water, and then placed in polyethylene glycol diacrylate liquid. Under vacuum conditions, polyethylene glycol diacrylate with a refractive index of 1.47 was immersed in the balsa wood skeleton; the soaking time was 3.5h, and the amount of transparent resin applied was 58.5wt.

[0115] (3) Place the balsa wood frame obtained in step (2) under a UV lamp for photocuring. The power of the UV lamp is 100W / cm². 2 A laser scattering body was obtained by illuminating the balsa wood for 20 seconds. The scattering body was then irradiated with a 532nm laser, resulting in highly concentrated laser light that was uniformly scattered into three-dimensional space, achieving the desired illumination effect.

[0116] like Figure 12 a and Figure 12 b are cross-sectional views of the wood microstructure before and after impregnation with polyethylene glycol diacrylate in the comparative example, respectively. Figure 12As can be seen from b, after impregnation and curing with polyethylene glycol diacrylate, the cell structure of the wood remains intact under microscopic conditions. The polyethylene glycol diacrylate completely penetrates and fills the cell cavities, thus preparing a wood laser scatterer; for example... Figure 13 a and Figure 13 b are longitudinal cross-sectional views of the wood microstructure before and after impregnation with polyethylene glycol diacrylate in the comparative example. Figure 13 As can be seen in b, from a longitudinal perspective, the microstructure of wood presents as a series of tightly packed cells, and the wood exhibits a longitudinally arranged cellular structure.

[0117] Figure 14 The orientation diagram of the laser scatterer made of wood is shown. Compared with Example 1, it can be seen that the orientation degree of Example 1 is very small, only 8.6%, while the orientation degree of this comparative example is as high as 47.3%, which inherently determines that it cannot achieve uniform light emission. Figure 15 The illuminance variation coefficient of the wood laser scatterer is 16.83%, which is much higher than that of Example 1.

[0118] like Figure 16 The image shown is an illustration of the illumination effect of laser irradiation on a wood fiber laser scatterer in this comparative example.

[0119] Comparative Example 7

[0120] This comparative example provides a laser scatterer, the preparation method of which is as follows:

[0121] (1) The density is 0.89 g / cm³ 3 A 1.5cm diameter spherical bamboo was placed in a 3.5% sodium chlorite solution (pH adjusted to 4.5 with acetic acid) and boiled at 80℃ until the bamboo turned completely white. The bamboo was then removed and tested, and the lignin content was found to be 8.16%.

[0122] (2) The white bamboo skeleton obtained in step (1) was placed in acetone solvent to replace the water, and then placed in liquid epoxy resin. Under vacuum conditions, epoxy resin with a refractive index of 1.50 was immersed in the bamboo skeleton; the soaking time was 5h, and the amount of transparent resin applied was 452wt.

[0123] (3) Place the bamboo frame obtained in step (2) under a UV lamp for photocuring. The power of the UV lamp is 100W / cm². 2 A laser scattering body was obtained by illuminating the balsa wood for 20 seconds. The scattering body was then irradiated with a 532nm laser, resulting in highly concentrated laser light that was uniformly scattered into three-dimensional space, achieving the desired illumination effect.

[0124] like Figure 17 a and Figure 17b are cross-sectional views of the bamboo microstructure before and after epoxy resin impregnation in this comparative example. Figure 17 As can be seen from b, after impregnation with epoxy resin and curing, the cell structure of bamboo remains intact under microscopic conditions. The epoxy resin is completely impregnated into the cell cavity and fills the cell cavity, thus preparing a bamboo laser scatterer. Figure 18 a and Figure 18 b represents the microstructure of bamboo longitudinal sections before and after impregnation with epoxy resin in this comparative example. The bamboo microstructure shows tightly packed cells. From a longitudinal perspective, the bamboo thin-walled cells and vascular bundles show a longitudinally arranged structure.

[0125] Figure 19 The diagram shows the orientation degree of the laser scatterer made from bamboo. Compared with Example 1, it can be seen that the orientation degree of Example 1 is very small, only 8.6%, while the orientation degree of this comparative example is as high as 65.4%. Figure 20 The illuminance variation coefficient of the bamboo laser scatterer is 16.3%, which is much higher than that of Example 1, which inherently determines that it cannot achieve uniform light emission.

[0126] like Figure 21 The image shown is an illustration of the illumination effect of laser irradiation on a wood fiber laser scatterer in this comparative example.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser scatterer based on biomass fibers, characterized in that, The orientation degree of the laser scatterer is ≤15.0%; the laser scatterer comprises fluorescent material, biomass fiber and transparent liquid resin; the laser scatterer is prepared by uniformly dispersing the fluorescent material and the biomass fiber in the transparent liquid resin to form a mixed system, and then vacuum impregnating the mixed system to allow the transparent liquid resin to penetrate into the porous structure of the biomass fiber; The biomass fiber is a lignin-free fiber; the biomass fiber has a porous internal structure; the biomass fiber has a diameter of 0.1μm-100μm, a length of 0.5μm-5mm, and an aspect ratio of 10-500. By weight, the laser scatterer comprises 0.02-0.04 parts of fluorescent material, 2.5-5 parts of biomass fiber, and 15-25 parts of transparent liquid resin; the density of the biomass fiber is 0.02 g / cm³. 3 ~1.35 g / cm 3 The refractive index of the transparent liquid resin is <1.53 or >1.53, and is different from that of the biomass fiber; the particle size of the fluorescent material is 0.1 to 100 μm.

2. The laser scatterer based on biomass fibers according to claim 1, characterized in that, The biomass fiber includes one or more of wood fiber, bamboo fiber, hemp fiber, and seaweed fiber; wherein the wood fiber is made from any one of balsa wood, paulownia, fir, poplar, ash, and pine; the bamboo fiber is made from one or more of moso bamboo, bamboo fern, green bamboo, and nan bamboo; and the hemp fiber is made from one or more of jute, flax, and ramie.

3. The laser scatterer based on biomass fibers according to claim 1, characterized in that, The transparent liquid resin is one or more of polyethylene glycol diacrylate, epoxy acrylate, acrylate derivatives, polyurethane prepolymer, polyurethane-modified epoxy resin, and polyvinylpyrrolidone. And / or, the fluorescent material includes one or more of the following: aluminate fluorescent materials, silicate fluorescent materials, nitride fluorescent materials, phosphate fluorescent materials, and sulfide fluorescent materials doped with rare earth elements.

4. The method for preparing a laser scatterer based on biomass fibers according to any one of claims 1-3, characterized in that, include: Preparation of biomass fiber; The fluorescent material and the biomass fiber were added to a transparent liquid resin and stirred to obtain a mixed system; The resulting mixture was then subjected to vacuum impregnation.

5. The method for preparing a laser scatterer based on biomass fibers according to claim 4, characterized in that, The method for preparing biomass fiber is as follows: The wood is shaved into chips with a thickness of 1 mm or less, then steamed in water at a temperature of 80°C or higher for 10-30 minutes. The chips are then ground to obtain fibrous wood. Place the fibrous wood in a lignin removal solution or a lignin modifier solution, and then heat it at a temperature between 40°C and the boiling point of the solution until all the wood fibers turn white. The solute in the lignin removal solution is selected from one or both of sodium chlorite and sodium hypochlorite, and the mass concentration of the solute is 0.1-20%; the pH value of the water is adjusted to 4-5 with acetic acid; the lignin modifier solution is a mixture of hydrogen peroxide and alkaline solution, and the mass ratio of hydrogen peroxide to alkaline solution is 10:0.1-10:3; the mass fraction of the alkaline solution is 1%-50%, and the solute is selected from one or both of sodium hydroxide and potassium hydroxide.

6. The method for preparing a laser scatterer based on biomass fibers according to claim 5, characterized in that, The stirring speed is ≥500 rpm and the stirring time is ≥5 min; And / or, the vacuum impregnation pressure is -0.02MPa to -0.1MPa, and the time is 1min to 120min.

7. The application of the biomass fiber-based laser scatterer according to any one of claims 1-3 in the preparation of laser lighting materials, characterized in that, The laser lighting materials include those used in the fields of seabed lighting, underwater lighting, indoor lighting, outdoor lighting, long-distance non-contact lighting, adjustable light color lighting, laser scattering, or laser display.

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