Photocuring Process Research Articles

Enhancing dental remineralization and antimicrobial properties with Ag nanoparticles-loaded mesoporous bioactive glass in reinforced dental resins: A one-pot synthesis approach

Secondary caries develops between the dental filling and the tooth surface because the filling materials lack antibacterial properties. In our study, we successfully created Ag-mesoporous bioactive glass (MBG) with antibacterial properties using a one-pot synthesis method and modified its surface with bisphenol A-glycidyl methacrylate (Bis-GMA). We tested the antibacterial and remineralizing abilities of the resin matrix. The 10 wt% Bis-GMA-Ag-MBG composite resin showed excellent remineralizing and antibacterial abilities, and the presence of Ag nanoparticles did not affect these properties during the photocuring process. Cell viability experiments confirmed that the 10 wt% Bis-GMA-Ag-MBG composite resin is biocompatible. This study emphasizes the potential of Bis-GMA-Ag-MBG (10 wt%) as a new dental composite resin with bioactive, remineralizing, and antibacterial properties, addressing the critical need for durable and preventive dental materials against secondary caries.

Cationic UV-curing of bio-based epoxidized castor oil vitrimers with electrically conductive properties

The growing appeal of carbon nanotube composites in the contemporary market derives from their exceptional thermal and chemical stability, coupled with electrical conductivity. In this study, we combined these salient features with a biobased epoxy matrix having vitrimeric properties, hence being reprocessable and resheapable, to obtain a biobased conductive coating. Epoxidised castor oil (ECO) was chosen as a monomer precursor for the straightforward synthesis. The synthesis relied on a cationic UV-curing process, embedding the conductive carbon nanotubes in the matrix. Photo DSC and transmission FTIR analysis were conducted to determine the final conversion of the epoxy rings in the cationic photocuring process. Thermo-mechanical properties were evaluated by tensile tests, and DMTA. Thermal stability was assessed by TGA. Dielectric spectroscopy confirmed increased electrical conductivity in the presence of increasing CNT content, reaching a percolation threshold at 0.5 phr of CNTs. Vitrimeric properties were proved by stress relaxation experiments, and the UV-cured composite underwent a thermo-activated transesterification reaction starting from 70 °C, catalysed by dibutyl phosphate. Overall, the ECO-CNT composite showed high thermal resistance (up to 400 °C) electrical conductivity with 0.5 phr CNT concentration, and vitrimeric properties. The study can be, therefore, considered a promising starting point to obtain sustainable biobased and electrically conductive vitrimers.

Effect of silica nanospheres silanized by functional silanes on the physicochemical and mechanical properties of Bis-GMA/TEGDMA dental composite resin by photocuring synthesis

This investigation focused on the contribution of various silane blends, used as coupling agents, to the ultimate performance of dental nanocomposite dimethacrylate photocurable resins. Initially, the surface of silica nanospheres was silanized with three different silane coupling agents: γ-MPS, APTES, and OTMS, with the grafting rate serving as the index. Fourier Transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) verified the modification of nanosilica. Through orthogonal test experiments on the three silane coupling agents, the optimal modifier concentration, temperature, and time were determined. Subsequently, 15 wt% organomodified SiO2 nanospheres were incorporated into Bis-GMA/TEGDMA (70/30 by wt%) based resins via a photocuring process. Scanning electron microscopy (SEM) findings revealed a relatively vague interface between inorganic fillers and resins in the polymer composite, especially when reactive silanes like γ-MPS and their corresponding blends were used. The combination of SiO2 and γ-MPS functional silane blend provided the highest flexural properties and the lowest solubility after storing the nanocomposite in water for 1 week at 37 °C. With these methods, composite resins containing 15 wt% MPS-SiO2 nanospheres in a Bis-GMA/TEGDMA (70/30 by wt%) mixture exhibited the best comprehensive properties, making them a promising choice for achieving long-term durable restorations in clinical therapies.

Preparation and performance of alumina/epoxy-siloxane composites: A comparative study on thermal- and photo-curing process

Although epoxy-based composites that consist of inorganic fillers and matrixes are widely used in “conventional” electronic packaging applications due to their excellent insulation and robust properties, they limit their uses in “advanced electronic packaging” which requires enhanced thermal conductivity. However, conventional thermal curing methods for fabrication of epoxy-based composites do not fulfill sufficient thermal conductivity. Herein, we apply photo-induced curing strategy for fabricating alumina-incorporated epoxy-siloxane composites that consist of sol-gel derived siloxane matrix and bimodal sized alumina particles as a thermally conductive filler. We investigate how curing mechanism (thermal- or UV-curing) and varying the ratios of the alumina particles of two different sizes affect the various physical properties. It is found that photo-curing process makes greatly enhanced thermal conductivity, low thermal expansion, and high mechanical robustness compared to thermally-cured composites. As the results, we can achieve significantly enhanced thermal conductivity (>11 W/m K) with high thermal stability and mechanical robustness.

Triplet Upconversion under Ambient Conditions Enables Digital Light Processing 3D Printing.

The rapid photochemical conversion of materials from liquid to solid (i.e., curing) has enabled the fabrication of modern plastics used in microelectronics, dentistry, and medicine. However, industrialized photocurables remain restricted to unimolecular bond homolysis reactions (Type I photoinitiations) that are driven by high-energy UV light. This narrow mechanistic scope both challenges the production of high-resolution objects and restricts the materials that can be produced using emergent manufacturing technologies (e.g., 3D printing). Herein we develop a photosystem based on triplet-triplet annihilation upconversion (TTA-UC) that efficiently drives a Type I photocuring process using green light at low power density (<10 mW/cm2) and in the presence of ambient oxygen. This system also exhibits a superlinear dependence of its cure depth on the light exposure intensity, which enhances spatial resolution. This enables for the first-time integration of TTA-UC in an inexpensive, rapid, and high-resolution manufacturing process, digital light processing (DLP) 3D printing. Moreover, relative to traditional Type I and Type II (photoredox) strategies, the present TTA-UC photoinitiation method results in improved cure depth confinement and resin shelf stability. This report provides a user-friendly avenue to utilize TTA-UC in ambient photochemical processes and paves the way toward fabrication of next-generation plastics with improved geometric precision and functionality.

Forming deviation coupling model and control method in the photopolymerization process of ceramic slurry

In the process of photocuring using ceramic slurry, the scattering of ceramic particles is widely acknowledged as the primary cause of deviations. However, when aiming to minimize scattering deviations for the production of intricate structures, it is crucial to also consider deviations resulting from resin shrinkage, an aspect that has been overlooked in previous research. This study successfully reduced scattering deviations by incorporating graphite as a light absorber. This approach enabled the evaluation and analysis of the impact of shrinkage deviations on forming deviations. Experimental results investigating deviations in size and shape across various feature structures demonstrated the substantial impact of shrinkage deviations on the final forming deviations. By combining theoretical analysis with empirical findings, this study proposes a coupled model that accounts for the combined effects of scattering deviations and shrinkage deviations. Additionally, a control method is introduced to enhance forming accuracy by compensating for scattering deviations using shrinkage deviations. Moreover, it elucidates the variation curve of forming deviations with the addition of graphite under different photocuring parameters. Ultimately, this model facilitated the enhancement of ceramic slurry formulation and photocuring process parameters, enabling the high-precision printing of intricate ceramic core molds with incorporated grids.

UV-Cured Bio-Based Acrylated Soybean Oil Scaffold Reinforced with Bioactive Glasses.

In this study, a bio-based acrylate resin derived from soybean oil was used in combination with a reactive diluent, isobornyl acrylate, to synthetize a composite scaffold reinforced with bioactive glass particles. The formulation contained acrylated epoxidized soybean oil (AESO), isobornyl acrylate (IBOA), a photo-initiator (Irgacure 819) and a bioactive glass particle. The resin showed high reactivity towards radical photopolymerisation, and the presence of the bioactive glass did not significantly affect the photocuring process. The 3D-printed samples showed different properties from the mould-polymerised samples. The glass transition temperature Tg showed an increase of 3D samples with increasing bioactive glass content, attributed to the layer-by-layer curing process that resulted in improved interaction between the bioactive glass and the polymer matrix. Scanning electron microscope analysis revealed an optimal distribution on bioactive glass within the samples. Compression tests indicated that the 3D-printed sample exhibited higher modulus compared to mould-synthetized samples, proving the enhanced mechanical behaviour of 3D-printed scaffolds. The cytocompatibility and biocompatibility of the samples were evaluated using human bone marrow mesenchymal stem cells (bMSCs). The metabolic activity and attachment of cells on the samples' surfaces were analysed, and the results demonstrated higher metabolic activity and increased cell attachment on the surfaces containing higher bioactive glass content. The viability of the cells was further confirmed through live/dead staining and reseeding experiments. Overall, this study presents a novel approach for fabricating bioactive glass reinforced scaffolds using 3D printing technology, offering potential applications in tissue engineering.

Temperature Changes in Primary and Permanent Teeth Dentine of Varying Thicknesses Following Irradiation by Two Light Curing Units.

This study was performed to determine the temperature rise under human dentin discs of different thicknesses from primary and permanent teeth during the photo-curing process using quartz tungsten halogen (QTH) or light-emitting diode (LED). The current experimental study sample consisted of 160 dentin discs of different thicknesses (0.5, 1, 1.5, and 2 mm), of which 80 dentin discs were prepared from sound lower second primary molars, and the remaining 80 dentin discs were prepared from sound lower third permanent molars extracted surgically for various reasons. A "K" type of thermal tentacle was placed in the center of an acrylic resin base, followed by the placement of a dentin disc. Then, the thermal changes were measured during the photo-curing of the composite using a second LED or QTH light curing unit for 20 s. Statistical evaluation was performed using the IBM SPSS Statistics® Version 20.0 software system (SPSS Inc., Chicago, IL, USA). The current study found that the temperature rise in primary teeth (1.17-2.96°C) is significantly lower compared to the rise in permanent teeth (1.55-3.33°C), regardless of the dentin disc thickness or light curing unit used. The temperature rise decreases significantly when the thickness of dentin discs increases, regardless of the type of teeth or light curing unit used (P<0.05). Furthermore, QTHcauses less temperature rise (1.17-2.65°C) compared to LED (1.61-3.33°C). The temperature rise during polymerization of the resin composite with the second-generation LED appeared to be below 5.5°C. Hence, it appears to be safe for use during the restoration of primary teeth. Primary teeth dentin might be more effective than permanent teeth dentin in protecting the dental pulp.

Self-wrinkling coating for impact resistance and mechanical enhancement

Protective materials are essential for personal, electronic, and military defenses owing to their efficient impact-resistant and energy-absorbing properties. Inspired by the bottom-up fabrication process and energy dissipation mechanism of natural organisms with hierarchical structures, we demonstrated a self-wrinkled photo-curing coating as a new protective material for enhancing the anti-impact property of the substrates. Owing to the self-assembly of polydimethylsiloxane (PDMS) containing polymeric photoinitiator on the surface, the liquid coating formulation was photo-cured by one-step UV irradiation with simultaneous generation of self-wrinkled surface morphology and a gradient cross-linked architecture. The maximum impact resistance height (hmax) of the glass substrate coated with plain coating increased from 120 to 180 cm when coated with wrinkled gradient coating. Furthermore, the Young’s modulus, fracture stress, and toughness of the wrinkled gradient coating film improved from 39.6 MPa, 2.4 MPa, and 74.1 MJ/cm3 to 235.0 MPa (∼5× increase), 18.5 MPa (∼6.6× increase), and 845.0 MJ/cm3 (∼10.8× increase) compared to the pure coating film as reference. The theoretical simulation and experimental results proved that the surface self-wrinkled morphology and intrinsic hierarchical architecture contribute to the energy dissipation and impact resistance of the cured coating. The photo-curing process, a bottom-up strategy, is conducted in a non-contact mode compared with nano-printing and lithography, enabling bulk materials to be engineered.

Incorporating Wireless Strategies to Wearable Devices Enabled by Photocurable Hydrogel for Monitoring Pressure Information.

Advances in emerging technologies for wireless collection and the timely analysis of various information captured by wearable devices are of growing interest. Herein, we propose a crosslinked ionic hydrogel prepared by a facile photocuring process, that allows wearable devices to be further incorporated into two wireless integrated systems for pressure monitoring applications. The device exhibits a simplified structure by effectively sharing functional layers, rather than conventional two separate combinations, offering the salient performance of iontronic sensing and electrochromic properties to simultaneously quantify and visualize pressure. The developed smart patch system was demonstrated to monitor physiological signals in real-time using the user interface of remote portable equipment with Bluetooth protocol and on-site electrochromic displays. Moreover, a passive wireless system based on the magnetic coupling effect was designed, which could operate free from the battery and simultaneously acquire multiple pressure information. It is envisioned that the strategies would hold enormous potential for flexible electronics, versatile sensing platforms and wireless on-body networks. This article is protected by copyright. All rights reserved.

Digital Light Processing of Zirconia Suspensions Containing Photocurable Monomer/Camphor Vehicle for Dental Applications.

This study reports the utility of solid camphor as a novel diluent in photocurable hexanediol diacrylate (HDDA) monomer to manufacture 4 mol% yttria partially stabilized zirconia (4Y-PSZ) components for dental applications by digital light processing (DLP). The use of a 65 wt% HDDA-35 wt% camphor solution allowed 4Y-PSZ suspensions to have reasonably low viscosities (1399 ± 55.8 mPa·s at a shear rate of 75 s-1), measured by a cone/plate viscometer, at a high solid loading of 48 vol%, where 4Y-PSZ particles prepared by calcination of as-received 4Y-PSZ granules, followed by a ball-milling process, were used with assistance of a dispersant. These 4Y-PSZ suspensions could be successfully applied to our custom-made DLP machine for manufacturing 4Y-PSZ components. To this end, several processing parameters, including layer thickness of 4Y-PSZ suspension, UV illumination time for layer-by-layer photocuring process, and initial dimensions of 4Y-PSZ objects, were tightly controlled. As sintering temperature increased from 1300 °C to 1500 °C, relative density and grain size of 4Y-PSZ objects increased, and cubic phase content also increased. Thus, after sintering at the highest temperature of 1500 °C for 3 h, high mechanical properties (biaxial flexural strength = 911 ± 40.7 MPa, hardness = 1371 ± 14.4 Hv) and reasonably high optical transmittance (translucency parameter = 7.77 ± 0.32, contrast ratio = 0.809 ± 0.007), evaluated by a spectrophotometer, were obtained due to a high relative density (97.2 ± 1.38%), which would be useful for dental applications.

Injectable and photocurable macromonomers synthesized using a heterometallic magnesium-titanium metal-organic catalyst for elastomeric polymer networks.

Injectable and in situ photocurable biomaterials are receiving a lot of attention due to their ease of application via syringe or dedicated applicator and ability to be used in laparoscopic and robotic minimally invasive procedures. The aim of this work was to synthesize photocurable ester-urethane macromonomers using a heterometallic magnesium-titanium catalyst, magnesium-titanium(iv) butoxide for elastomeric polymer networks. The progress of the two-step synthesis of macromonomers was monitored using infrared spectroscopy. The chemical structure and molecular weight of the obtained macromonomers were characterized using nuclear magnetic resonance spectroscopy and gel permeation chromatography. The dynamic viscosity of the obtained macromonomers was evaluated by a rheometer. Next, the photocuring process was studied under both air and argon atmospheres. Both the thermal and dynamic mechanical thermal properties of the photocured soft and elastomeric networks were investigated. Finally, in vitro cytotoxicity screening of polymer networks based on ISO10993-5 revealed high cell viability (over 77%) regardless of curing atmosphere. Overall, our results indicate that this heterometallic magnesium-titanium butoxide catalyst can be an attractive alternative to commonly used homometallic catalysts for the synthesis of injectable and photocurable materials for medical applications.

Phase Change Energy Storage Material with Photocuring, Photothermal Conversion, and Self-Cleaning Performance via a Two-Layer Structure.

Compared with the thermal curing process, the photocuring process has advantages such as high efficiency and less energy consumption. However, the preparation of photocurable phase change materials (PCMs) with photothermal conversion and self-cleaning properties is challenging due to the conflict between the transparency required by the photocurable resin system and the opacity deduced by the large number of fillers required by photothermal conversion and the negative effect of filler steric hindrance on the reaction rate and crystallinity. In this work, a "thiol-ene" click chemical reaction induced using UV was used to prepare photocurable PCMs, followed by spraying a carboxylated multiwalled carbon nanotube (CCNT) suspension (with ethyl acetate) onto the surface to achieve an effective two-layer composite of the PCM and CCNTs, by which the rough surface of the PCM and the interaction offered by the hydrogen bonds on the interface of the PCM and the CCNTs provide sufficient adhesion for the two phases. The "thiol-ene" cross-linked polymer network provided shape stability as a support material. 1-Octadectanethiol (ODT) and beeswax (BW) were encapsulated in the cross-linked polymer network as phase change components, providing phase change latent heat. The CCNT layer provided excellent photothermal conversion and self-cleaning properties. The experimental results show that the latent heat of the PCM can reach 124.2 J/g, the water contact angle is 144°, the photothermal conversion efficiency reaches 75%, and it has significant self-cleaning performance. To the best of our knowledge, this is the first report on a photocurable PCM with photothermal conversion and self-cleaning properties.

Hierarchical Porous Structure Fabrication Via Hybrid Stereolithography and Inkjet Printing With Sacrificial Liquid

Abstract Inspired by porous morphology in nature, such as bone and lung tissues, synthetic porous materials are widely adopted in engineering applications that require lightweight, thermal resistance, energy absorption, and structural flexibility. One of the main challenges in the current porous material manufacturing techniques is their limited control over individual pore size, connectivity, and distribution. This paper presents a novel additive manufacturing process to fabricate porosity-embedded structures by integrating stereolithography and inkjet printing using a sacrificial liquid–water. A solenoid-based inkjet nozzle dispenses water droplets onto a layer of liquid photopolymer resin. Then the resin layer is photocured by a mask image projection device using a digital light processing device. The photocuring process defines the layer profile and captures the deposited water droplets in the solidified layer. The refilled fresh resin will further embed water droplets and form a new layer for the subsequent water droplet deposition. Three-dimensional (3D) structures with embedded water droplets can be printed layer-by-layer. The captured water will evaporate when heated, leaving an air-filled porous 3D structure. By selectively depositing water droplets and varying inkjet printing parameters, including pressure, nozzle opening time, and jetting frequency, the micropores whose sizes from 100 µm to 500 µm and distributions within the 3D-printed part can be modulated. This hybrid process can fabricate 3D structures with homogenously distributed pores and graded polymer structures with varying porosities. The elastic modulus of 3D-printed foam structures in different pore distributions has been tested and compared.

Random wrinkle structures for spectrum preserved warm white organic light emitting diodes

Surface wrinkles of mesoscopic size were formed by a single photocuring process of an in-house synthesized linear liquid pre-polymer. The linear relationship between the amplitude and the period of the wrinkles indicates the presence of constant compressive strain during the wrinkling process. The stiffness ratio of the hard film to the soft foundation decreases as the initial film becomes thinner, providing a quantitative measure for estimating the wrinkle size. As an application, mesoscopic wrinkles were investigated as optical structures for enhanced light outcoupling and angular spectral stability of red, green, blue, and white organic light emitting diodes.

Networking of Block Copolymer Nanoassemblies via Digital Light Processing Four-Dimensional Printing for Programmable Actuation

Controls over stimuli-responsive functional materials and programmable shape deformations are key features in the four-dimensional (4D) printing of soft actuators. Instead of using random copolymers, homopolymers, or natural polymers, this paper reports the first use of amphiphilic, photocurable, and pH-responsive block copolymer (BCP) nanoassemblies in digital light processing (DLP) 4D printing to fabricate smart and programmable soft actuators. Programmable actuation was studied via a bottom-up approach: (1) designed synthesis of pH-responsive BCPs, (2) nanoassembly structures of BCPs, and (3) networking of nanoassemblies via the photocuring process in DLP. As a proof-of-concept, bilayered grippers, ring-shaped actuators, and octopus-like actuators were programmed to produce a range of bending angles and actuation patterns. pH-responsive BCP nanoassemblies were also combined with commercially available three-dimensional printing liquid resin (PlasClear) to produce stimulus-responsive printing ink that was successfully used for 4D printing applications. Thus, smart and programmable materials were developed for 4D printing applications.

Influence of the Addition of Sialon and Aluminum Nitride Fillers on the Photocuring Process of Polymer Coatings

This article presents the results of a study on polymer coatings containing poly ethoxylated bisphenol A diacrylate (Bis-AEA10) with aluminum silicon nitride oxide (Sialon) and aluminum nitride (AlN). The polymer coatings were obtained by the photopolymerization technique. Investigations were carried out to determine the effect of the AlN and Sialon content on the UV-curing kinetics, as well as on the mechanical (hardness), thermal (Tg, thermal stability), physicochemical (water contact angle), and structural properties of the polymer coatings. Polymerization rates were characterized as functions of double-bond conversion using the photo-Differential Scanning Calorymetry technique (photo-DSC). The results obtained showed that a small addition of sialon filler (3–5 wt.%) to Bis-AEA10 increases the photopolymerization rate of the varnish, while the addition of more Sialon decreases the rate of photopolymerization. However, for the systems containing AlN filler, the maximum polymerization rate was observed for samples containing 10 wt.% filler. In the case of a varnish composition containing AlN, the maximum polymerization rate is characterized by the system containing 10 wt.% of AlN. This shows that the AlN filler has a good influence on the polymerization process. In either case, the final double bond conversion was high (80%–95%). Mechanical tests have shown that introducing the filler into the polymer matrix increases its hardness. The content of Sialon and AlN in the coatings causes an increase (up to 4–5 wt.%) and a decrease (&gt;4–5 wt.%) in the glass transition temperature. The effect of the addition of fillers on the physicochemical properties of the coating surface has also been investigated and characterized by the water contact angle method. The addition of 20 wt.% Sialon and AlN increased the contact angle of the samples by approximately 40% and 31%, respectively, resulting in coatings with hydrophobic surface properties.

Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect

AbstractThe main goal of this study is to show that photoacoustic spectroscopy (PAS) can be applied in the monitoring of photocuring processes in epoxy diacrylate resins. The resin used was EBECRYL 3720‐TP25 with the photoinitiator Omnirad 808. Comparison between the conventional transmission and absorption photoacoustic spectra of the resin is presented. Amplitude and phase of the photoacoustic signal were used to monitor the photocuring. The wavelength of the modulated photocuring light and the concentration of the photoinitiator were the parameters varied in the monitoring. The novelty was found when the resin was irradiated by a continuous light, centered at the absorption peak of the photoinitiator and simultaneously with the modulated light. In the time window when this continuous light was on (off) the amplitude of the photoacoustic signal increased (decreased). This is called “positive effect,” as it has been observed when PAS was applied to study photosynthesis in leaves. A mechanism is proposed to correlate the positive effect with the oxygen inhibition effect during the photocuring of the epoxy diacrylate resin. The results suggest that the amplitude of the photoacoustic signal and the positive effect can be used as monitoring parameters in the studies of photocuring process in epoxy diacrylate resins.

Tailoring of Optical Properties of Methacrylate Resins Enriched by HPHT Microdiamond Particles.

Diamond particles have great potential to enhance the mechanical, optical, and thermal properties of diamond–polymer composites. However, the improved properties of diamond–polymer composites depend on the size, dispersibility, and concentration of diamond particles. In the present study, diamond–polymer composites were prepared by adding the microdiamond particles (MDPs) with different concentrations (0.2–1 wt.%) into polymers (acrylate resins) and then subjected to a photocuring process. The surface morphology and topography of the MDPs–polymer composites demonstrated a uniform high-density distribution of MDPs for one wt.% MPDs. Thermogravimetric analysis was employed to investigate the thermal stability of the MDPs–polymer composites. The addition of MDPs has significantly influenced the polymers’ thermal degradation. Absorption and emission spectra of thin layers were recorded through UV/Vis spectrophotometry and spectrofluorimetry. The obtained results revealed a significant increase in the fluorescence intensity of MDPs–polymer composites (at 1 wt.% of MDPs, a 1.5×, 2×, and 5× increase in fluorescence was observed for MDPs–green, MDPs–amber daylight, and MDPs–red resin, respectively) compared with the reference polymer resins. The obtained results of this work show the new pathways in producing effective and active 3D-printed optical elements.

Preparation of a water‐dispersible nano‐photoinitiator oriented towards 3D printing hydrogel with visible light

AbstractIn this article, a preparation method of a water‐dispersible photoinitiator, which can be used for three‐dimensional (3D) printing of the hydrogel and can be initiated under visible light is proposed. The oil‐soluble photoinitiator 2,4,6‐trimethylbenzoyl‐diphenylphosphine oxide (TPO) is nano‐wrapped with surfactant Tween 20 to obtain the oil‐in‐water (O/W) miniemulsion, and then it is successfully transformed into water‐dispersible nanospheres without the use of organic solvents or crystallization inhibitors. The morphology and optical properties were characterized by transmission electron microscopy (TEM), particle size analysis and ultraviolet–visible (UV–Vis) spectroscopy. Subsequently, the water‐dispersible nano‐photoinitiator was used to realize the photopolymerization of acrylamide/N,N′‐methylenebisacrylamide hydrogel under visible light (405 nm). Then, the micromorphology of the photocuring process of the hydrogel was observed by TEM and the photocuring activity of the initiator was evaluated. Finally, a viscosifier suitable for AM/MBA hydrogel system was screened out, and the direct ink writing (DIW) 3D printing of the hydrogel was successfully realized by using this nano‐photoinitiator.