2-phenoxyethyl Acrylate Research Articles

Barnacle inspired strategy combined with solvent exchange for enhancing wet adhesion of hydrogels to promote seawater-immersed wound healing

Hydrogels are promising materials for wound protection, but in wet, or underwater environments, the hydration layer and swelling of hydrogels can seriously reduce adhesion and limit their application. In this study, inspired by the structural characteristics of strong barnacle wet adhesion and combined with solvent exchange, a robust wet adhesive hydrogel (CP-Gel) based on chitosan and 2-phenoxyethyl acrylate was obtained by breaking the hydration layer and resisting swelling. As a result, CP-Gel exhibited strong wet adhesion to various interfaces even underwater, adapted to joint movement and skin twisting, resisted sustained rushing water, and sealed damaged organs. More importantly, on-demand detachment and controllable adhesion were achieved by promoting swelling. In addition, CP-Gel with good biosafety significantly promotes seawater-immersed wound healing and is promising for use in water-contact wound care, organ sealing, and marine emergency rescue.

Stereolithographic Rapid Prototyping of Clear, Foldable, Non-Refractive Intraocular Lens Designs: A Proof-of-Concept Study

Purpose A cataract is a cloudy area in the crystalline lens. Cataracts are the leading cause of blindness and the second cause of severe vision impairment worldwide. During cataract surgery, the clouded lens is extracted and replaced with an artificial intraocular lens, which restores the optical power. The fabrication of intraocular lenses using existing molding and lathing techniques is a complex and time-consuming process that limits the development of novel materials and designs. To overcome these limitations, we have developed a stereolithography-based process for producing models of clear lens designs without refractive function, serving as a proof of concept. This process has the potential to contribute toward new lens development, allowing for unlimited design iterations and an expanded range of materials for scientists to explore. Methods Lens-like 3D objects without refractive function were fabricated by using stereolithography. A photopolymerizable resin containing 2-phenoxyethyl acrylate, poly (ethylene glycol) dimethacrylate, and a suitable photoinitiator was developed for the production of lens-like 3D object prototypes. The morphology of the printed devices was characterized by scanning electron microscopy. The transparency and thermal properties were analyzed using spectrophotometry and differential scanning calorimetry, respectively. The biocompatibility of the devices was investigated in a cultured human lens cell line (FHL-124), using a standard lactate dehydrogenase assay, and the lenses were folded and implanted in the human capsular bag model. Results One-piece lens-like 3D objects without refractive function and with loop-haptic design were successfully fabricated using Stereolithography (SLA) technique. The resulting 3D objects were transparent, as determined by UV spectroscopy. The lactate dehydrogenase test demonstrated the tolerance of lens cells to the prototyping material, and apparent foldability and shape recovery was observed during direct injection into a human capsular bag model in vitro. Conclusions This proof-of-principle study demonstrated the potential and significance of the rapid prototyping process for research and development of lens-like 3D object prototypes, such as intraocular lenses.

Preparation of hydrophobic acrylic intraocular lens materials using various crosslinking agents to reduce glistening

Glistening is the condensation of water that forms within the intraocular lens (IOL) materials. In this study, a new approach was attempted to reduce the glistening using various types and content of crosslinking agents. Hydrophobic acrylic IOL materials were prepared from 2-phenoxyethyl acrylate using three different crosslinking agents: ethylene glycol dimethacrylate (EGDMA), 1,4-butanediol diacrylate (BDDA), and glycerol 1,3-diglycerolate diacrylate (GDGDA). The IOL material cross-linked with the GDGDA showed the least amount of glistening. However, the IOL materials exhibited the largest amount of glistening when cross-linked with the EGDMA, indicating that the glistening decreased in the order of GDGDA > BDDA > EGDMA.

Polymeric Surfactants Bearing Divalent Carboxy Pendants for Stable Color Dispersions with High Redispersibility

Inkjet printing of ink requires dyes or pigments insoluble in water but uniformly dispersing as fine particles for a long period. In addition, redispersibility after solidification by solvent vaporization around the jetting heads is also important for performance. In this study, thus, a series of amphiphilic copolymers were prepared for a dispersant of inkjet using reversible addition fragmentation chain-transfer copolymerization of styrene (St), benzyl acrylate (BnA), and phenoxyethyl acrylate (PEA) as a hydrophobic monomer with acrylic acid (AA) and itaconic acid (IA) as a hydrophilic monomer. To understand the fundamental properties and potentials as a polymer dispersant, the surface parameters and rheology of the copolymers and their color dispersions in aqueous media were investigated. The aqueous solutions were typical Newtonian fluids, whereas the color dispersions were non-Newtonian fluids with shear-thinning properties and yield values ranging from 0.57 to 1.04 Pa. Although the surface parameters, such as surface tension (γ), molecular occupied area (Amin), and zeta potential (ζ), did not show clear correlation with polymer structures, their behaviors as a dispersant were significantly different. The color dispersants containing the copolymer of St or BnA as a hydrophobic monomer and IA and AMPS as hydrophilic monomers exhibited sufficient redispersion both for yellow and cyan inks, even after the aging test at 60 °C for 5 days, whereas other copolymers did not exhibit such superior performances. In addition, the color dispersions of the copolymer of St, IA, and AMPS (St-IA-AMPS) showed lower viscosity and yield value and became closer to Newtonian fluid compared with that of St, AA, and AMPS (St-AA-AMPS). Thus, St-IA-AMPS provided good redispersibility and avoided sedimentation. These results suggest that the most suitable dispersant for inkjet inks among the polymers investigated was the copolymer of St, IA, and AMPS.

Synthesis and characteristics of cardanol-based acrylates as reactive diluents in UV-curing coatings

Two types of cardanol epoxy acrylates (CAR1 and CAR2) were synthesized from bio-based cardanol and used as a reactive diluent. Their dilution effect, curing properties, and thermal and physical properties of UV-cured films as a reactive diluent were compared to those of commercial reactive diluent, 2-phenoxyethyl acrylate (PHEA). CAR series showed a lower dilution effect due to their relatively high viscosity compared to PHEA. However, 10 wt% CAR-diluted films showed similar reactivity and high thermal stability compared to 10 wt% PHEA diluted film, indicating CAR series can be used as partial alternatives to PHEA.

Bio-Inspired Instant Underwater Adhesive Hydrogel Sensors.

Underwater adhesion plays an essential role in soft electronics for the underwater interface. Although hydrogel-based electronics are of great interest, because of their versatility, water molecules prevent hydrogels from adhering to substrates, thus bottlenecking further applications. Herein, inspired by the barnacle proteins, MXene/PHMP hydrogels with strong repeatable underwater adhesion are developed through the random copolymerization of 2-phenoxyethyl acrylate, 2-methoxyethyl acrylate, and N-(2-hydroxyethyl) acrylamide with the presence of MXene nanosheets. The hydrogels are mechanically tough (elastic modulus of 32 kPa, fracture stress of 0.11 MPa), and 2-phenoxyethyl acrylate (PEA) with aromatic groups endows the hydrogel with nonswelling property and prevents water molecules from invading the adhesive interface, rendering the hydrogels an outstanding adhesive behavior toward various substrates (including glass, iron, polyethylene terephthalate (PET), porcine). Besides, dynamic physical interactions allow for instant and repeatable underwater adhesion. Furthermore, the MXene/PHMP hydrogels exhibit a high conductivity (0.016 S/m), fast responsiveness, and superior sensitivity as a strain sensor (gauge factor = 7.17 at 200%-500% strain) and pressure sensor (0.63 kPa-1 at 0-70 kPa). The underwater applications of bionic hydrogel-based sensors have been demonstrated, such as human motion, pressure sensing, and holding objects. It is anticipated that the instant and repeatable underwater adhesive hydrogel-based sensors extend the underwater applications of hydrogel electronics.

Photoelastic Organogel with Multiple Stimuli Responses.

The photoelastic effect has many uses in mechanics today, but it is usually disregarded in flexible materials. Using 2-phenoxyethyl acrylate as a monomer and 4-cyano-4'-pentylbiphenyl (5CB) as a solvent, a multiple responsive photoelastic organogel (PO) with strong birefringence but low modulus is created. 5CB is a liquid crystal molecule that does not participate in the polymerization process and is always present as tiny molecules in the polymer. It endows the PO low modulus and high birefringence, as well as the ability to drive the birefringence using an electric field. This PO not only has high sensitivity and fast response as a photoelastic strain sensor, but also has a very sensitive response to heat, especially in the range of human body temperature. It also has a high dielectric constant and a strong correlation between the interference color and the applied electric field, allowing for easy writing and erasure of encrypted data. This unique multisignal response feature and low modulus that mimics human skin bring up new opportunities in the potential applications such as multiple information encryption, anticounterfeiting, and multifunctional wearable sensors.

Polyacrylate resins containing fluoroalkyl groups for powder clear coatings

This work focuses on the synthesis of polyacrylate resins containing fluoroalkyl groups, which are used to prepare powder clear coatings. The resin synthesis was carried out using 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), n-butyl acrylate (BA), 2-phenoxyethyl acrylate (PhEA) as well as two acrylate monomers containing fluoroalkyl groups, i.e. 2,2,2-trifluoroethyl methacrylate (TFEMA) and 2,2,2-trifluoroethyl acrylate (TFEA). The presence of fluorine in the resin was confirmed by 19F NMR spectroscopy, while at the coating surface by polarized optical microscopy equipped with a laser elemental analyzer. Gel permeation chromatography (GPC) was used to determine the average molecular mass and molecular mass distribution of the synthesized resins. Additionally, the viscosity measurement of the resins was performed using a Brookfield viscometer. The thermal behavior of the powder coatings was investigated using differential scanning calorimetry (DSC). Moreover, FT-IR spectra were performed to confirm the crosslinking reaction between hydroxyl groups of the resin and polyisocyanate curing agent. The properties of the cured coatings were tested, such as: roughness, gloss, adhesion to the steel surface, hardness, cupping, scratch resistance and water contact angle. The obtained coatings were characterized by good properties: gloss, adhesion to the steel surface, scratch resistance, and hydrophobicity.

Impact of hydrophobic pendant phenyl groups on transport and co-transport of methanol and acetate in PEGDA-SPMAK cation exchange membranes

CO2 reduction cells are innovative devices that reduce CO2 into valuable chemicals (i.e. methanol (MeOH) and acetate (OAcˉ)) on the cathode. A major challenge with such devices is to develop ion exchange membranes that allow ion-selective transport (i.e., protons for cation exchange membranes, CEM) and suppress the crossover of CO2 reduction products. To design such membranes, it is important to understand multi-solute transport behavior of these solutes. Previously, our group reported acetate diffusivities in co-transport with MeOH increase in sulfonated CEMs, where we speculated charge screening of the electrostatic interactions by co-diffusing MeOH has an impact. Here, crosslinked membranes fabricated by photopolymerization of poly(ethylene glycol) diacrylate (PEGDA), 3-sulfopropyl methacrylate potassium (SPMAK, SO3ˉ-containing ionomer), and a phenyl-containing comonomer either phenoxyethyl acrylate (PEA) or poly(ethylene glycol) phenyl ether acrylate (PEGPEA)) are investigated. We observe OAcˉ diffusivities to both (1) PEGDA-SPMAK and (2) PEGDA-PEGPEA increase in co-diffusion with MeOH and those to (3) PEGDA-SPMAK/PEGPEA decrease. To rationalize this emergent co-transport behavior, we speculate (1) electrostatic interactions are interfered with by co-diffusing MeOH, (2) chain mobility (segmental dynamics) increases in the presence of MeOH and (3) for films with both hydrophobic (PEGPEA) and hydrophilic (SPMAK) comonomers chain mobility (segmental dynamics) decrease due to interactions between the comonomer sidechains depressing overall solute diffusivities. While further investigations are needed, this work contributes to improving our fundamental understanding of the relationships between polymer film chemistry, solute chemistry, and emergent cotransport behavior observed and described in this work (and others) towards enabling the design of improved membrane materials.

Amphiphilic Polymers for Color Dispersion: Toward Stable and Low-Viscosity Inkjet Ink.

Amphiphilic random and block copolymers were synthesized as potential inkjet inks. This study evaluated the potential of these polymers for color dispersion by examining the following factors: surface tension, zeta potential, viscosity, and particle size. Acrylic acid and (ethoxyethoxy)ethyl acrylate were used as the hydrophilic molecular units. Styrene, butyl acrylate, and phenoxyethyl acrylate were used as hydrophobic units. Color dispersions were prepared by using organic dye and these amphiphilic polymers. The color dispersions containing random copolymers exhibited low viscosity, which is preferable for jetting, but the dye particles tended to sediment after the thermal aging test. In contrast, those containing block copolymers showed high viscosity, which was unsuitable for jetting. However, they retained their initial dispersion state after the aging test. The advantages and disadvantages of each monomer arrangement (random or block) were demonstrated, providing a future outlook on the molecular design of polymer dispersants for color dispersions.

Adsorbed Water Structure on Acrylate-Based Biocompatible Polymer Surface.

The role of water in the excellent biocompatibility of the acrylate-based polymers widely used for antibiofouling coating material has been realized previously. Here, we report femtosecond mid-infrared pump-probe spectroscopy of the OD stretch band of HOD molecule adsorbed on highly biocompatible poly(2-methoxyethyl) acrylate [PMEA] and poorly biocompatible poly(2-phenoxyethyl) acrylate [PPEA], both of which reveal that there are two water species with significantly different vibrational lifetime. PMEA interacts more strongly with water than PPEA through the H-bonding interaction between carbonyl (C═O) and water. The vibrational lifetime of the OD stretch in PPEA is notably longer by factors of 3 and 7 than those in PMEA and bulk water, respectively. The IR-pump visible-probe photothermal imaging further unravels substantial spatial overlap between polymer CO group and water for hydrated PMEA and a significant difference in surface morphology than those in PPEA, which exhibits the underlying relationships among polymer-water interaction, surface morphology, and biocompatibility.

Effect of types of hydrophilic acrylic monomers in reducing glistenings of hydrophobic acrylic intraocular lenses

To reduce the glistenings in the hydrophobic acrylic intraocular lens (IOL) materials, various types of hydrophilic acrylic monomers of 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HPA), 4-hydroxybutyl acrylate (HBA), and 2-hydroxyethyl methacrylate (HEMA) were copolymerized with a hydrophobic acrylic monomer, 2-phenoxyethyl acrylate (POEA). In this process, the effect of the types and amounts of hydrophilic acrylic monomers on the physical properties, such as glistenings, equilibrium water content (EWC), refractive index, and glass transition temperature of the resulting hydrophobic acrylic IOL materials was investigated. As the amounts of hydrophilic acrylic monomers (HEA, HPA, HBA and HEMA) increased, glistenings in the IOL materials were significantly decreased in all monomers. At the same amount of the hydrophilic acrylic monomers, the IOL materials from HEA showed the least number of glistenings, but those from HBA exhibited the largest number of glistenings, resulting in a reduction of glistenings in the following order of HEA > HPA > HEMA > HBA. The EWCs of the IOL materials decreased in the order of HEA > HPA > HEMA > HBA with the same amount of hydrophilic monomers. From the above results, it can be seen that the greater the degree of hydrophilicity, such as the amounts and EWCs of the hydrophilic acrylic monomers, the greater the effect of glistening reduction of the resulting IOL materials.

Flexible Materials for High-Resolution 3D Printing of Microfluidic Devices with Integrated Droplet Size Regulation.

We develop resins for high-resolution additive manufacturing of flexible micromaterials via projection microstereolithography (PμSL) screening formulations made from monomer 2-phenoxyethyl acrylate, the cross-linkers Ebecryl 8413, tri(propyleneglycol) diacrylate or 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, the photoabsorber Sudan 1, and the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide. PμSL-printed polymer micromaterials made from this resin library are characterized regarding achievable layer thickness depending on UV exposure energy, and for mechanical as well as optical properties. The best-candidate resin from this screening approach allows for 3D-printing transparent microchannels with a minimum cross section of approximately 35 × 46 μm2, which exhibit proper solvent resistance against water, isopropanol, ethanol, n-hexane, and HFE-7500. The mechanical properties are predestined for 3D-printing microfluidic devices with integrated functional units that require high material flexibility. Exemplarily, we design flexible microchannels for on-demand regulation of microdroplet sizes in microemulsion formation. Our two outlines of integrated droplet regulators operate by injecting defined volumes of air, which deform the droplet-forming microchannel cross-junction, and change the droplet size therein. With this study, we expand the library of functional resins for PμSL printing toward flexible materials with micrometer resolution and provide the basis for further exploration of these materials, e.g., as microstructured cell-culturing substrates with defined mechanics.

Concomitant positive patch test reactions in FreeStyle-allergic patients sensitized to isobornyl acrylate.

Concomitant positive patch test reactions in patients sensitized to isobornyl acrylate (IBOA) have rarely been documented. To report concomitant sensitizations in patients with allergic contact dermatitis (ACD) from the glucose sensor FreeStyle Libre and sensitized to IBOA. In 2019, 26 patients with suspected ACD from FreeStyle Libre were patch tested to a baseline series and to a (meth) acrylate series containing IBOA and 2-phenoxyethyl acrylate (PEA) 0.1% pet. Diabetes devices and patch test preparations were analyzed with gas chromatography - mass spectrometry (GC-MS) for the presence of IBOA and PEA. Of the 26 patients, 18 (69%) were sensitized to IBOA, and eight (44%) and 11 (61%) of these were co-sensitized to sesquiterpene lactones and fragrances, respectively. Ten patients (56%) were co-sensitized to PEA, which, contrary to IBOA, could not be detected in any device. The PEA test material was shown to be contaminated with IBOA. Contact allergy to IBOA appears to be declining and IBOA-sensitized patients are most often co-sensitized to sesquiterpene lactones and fragrances. Vigilance is required when patch testing (acrylate) materials obtained from industry, as these might be contaminated and, hence, alter the results and their interpretation.

Swelling and thermal behavior of a cross-linked polymer networks poly(2-phenoxyethyl acrylate): exploitation by the Voigt viscoelastic model

The response-ability to the external and internal environmental condition qualifies the smart polymer material to be successfully applied in artificial muscle, drug delivery and water treatment. A three-dimensional polymer network based on the phenyl monomer, 2-phenoxy ethyl acrylate (PEA), was polymerized under ultraviolet (UV) radiation using the Darocur 1173 as an initiator of the polymerization reaction, and the 1,6-hexane-diol diacrylate (HDDA) as a chemical cross-linker. The analysis of the thermophysical properties of this elaborated polymeric material represents the main goal of the present work. The infrared spectroscopy (FTIR) and the dynamic scaling calorimetry (DSC) were used to examine, respectively, the vibration of the carbon double bond (C=C) and the glass transition temperature Tg. It is found that parameters, the rate of reticulation and monomer composition have a remarkable effect on the variation of Tg. The swelling behavior of the cross-linked poly(PEA/HDDA) was investigated; the effects of solvent nature, the degree of cross-linking, temperature and chemical structure have a significant influence on material swelling properties. The theoretical investigation based, especially on the Voigt model, Flory–Rehner theory and solubility approximation, permits to give much information about several parameters such as the swelling time constant, swelling equilibrium constant, solubility prediction, entropy and enthalpy. It ended interestingly that the Voigt model shows a good agreement with swelling experimental results.

Highly Tough Hydrogels with the Body Temperature-Responsive Shape Memory Effect.

Shape memory hydrogels (SMHs), a promising class of smart materials for biomedical applications, have attracted increasing research attention owing to their tissue-like water-rich network structure. However, preparing SMHs with high mechanical strength and body temperature-responsiveness has proven to be an extreme challenge. This study presents a facile and scalable methodology to prepare highly tough hydrogels with a body temperature-responsive shape memory effect based on synergetic hydrophobic interactions and hydrogen bonding. 2-Phenoxyethyl acrylate (PEA) and acrylamide were chosen as the hydrophobic monomer and the hydrophilic hydrogen bonding monomer, respectively. The prepared hydrogels exhibited a maximum tensile strength of 5.1 ± 0.16 MPa with satisfactory stretchability, and the mechanical strength showed a strong dependence on temperature. Besides, the hydrogel with 60 mol % PEA shows an excellent body temperature-responsive shape memory behavior with almost 100% shape fixity and shape recovery. Furthermore, we applied the hydrogels as a shape memory embolization plug for simulating vascular occlusion, and the embolism performance was preliminarily explored in vitro.

Preparation of highly dispersed and concentrated aqueous suspensions of nanodiamonds using novel diblock dispersants

HypothesisFinding an efficient dispersant for obtaining a good dispersion of 5-nm detonation nanodiamond (DND) is always a challenge. Two newly designed diblock copolymers, both poly(ammonium methacrylate)-block-poly(2-phenoxyethyl acrylate) (PMA-b-PBEA) but with different molar ratios of PMA to PBEA, were proposed to be efficient dispersants in stabilizing the concentrated aqueous suspensions of DND. ExperimentsThe dispersion efficiency of dispersants for DND in aqueous suspensions was studied by the measurements of particle size, sedimentation property, and rheological behavior. The interactions between the added dispersants and DND were identified by the zeta potential and adsorption analyses. Calculations based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory were conducted for clarifying the dominant parameters relating to the dispersion efficiency of dispersants. FindingsCompared with the commercially popular dispersant ammonium polyacrylate, these two diblock dispersants exhibited superior efficiency in the stabilization of DND suspensions. Using the diblock copolymers as dispersants, good dispersion stability in a DND suspension with an extremely high solid content of 30 wt% was achieved. According to experimental analyses and based on DLVO calculations, a low number of accompanied counter-ions, high adsorption capability, and thick PMA-b-PBEA adsorption layer are the main reasons for the extremely high dispersion efficiency of the two new dispersants.

Newly designed diblock dispersant for powder stabilization in water-based suspensions

A newly designed dispersant for water-based suspensions, ammonium poly(methacrylate)-block-poly(2-phenoxyethyl acrylate) (PMA-b-PBEA), is proposed in this study. According to the results of rheological analysis, the dispersion efficiency of this new dispersant is superior to that of the commercially available ammonium polyacrylate (PAA-NH4). The diblock structure of PMA-b-PBEA, which simultaneously contains a low-polar anchoring head group and a water-dissociable stabilizing moiety, is the main cause for its extremely high efficiency for powder dispersion. The unique structure not only results in effective adsorption approximately double that of PAA-NH4, but also produces a low number of counter-ions that compress the electrical double layer and ruin powder stabilization. Based on Derjaquin-Landau-Verwey-Overbeek calculations, the large adsorbance of PMA-b-PBEA gives the powder, titania (TiO2) in this study, a high steric stabilization energy. In addition, PMA-b-PBEA provides TiO2 with a remarkably high electrostatic energy because it generates fewer counter-ions. This energy provides excellent dispersity of powder in the suspensions with a high solid content of 60wt% without showing any rheological hysteresis.

Effect of Composition of Mixed Reactive Diluent on Thermal Stability of UV Cured Urethane Acrylate/MMT Nanocomposite

The incorporation of montmorillonite (MMT) into urethane acrylate resin were prepared by mixing two reactive diluent based on different composition, 1,6-hexanediol diacrylate (HDDA) and 2-phenoxy ethyl acrylate (PEA) with rigid phenyl group in order to improve the thermal stability. The effect of MMT concentration and reactive diluent composition on mechanical properties and thermal stability of nanocomposite were investigated. The tensile strength and storage modulus were increased in nanocomposite with low PEA concentration, which may be attributed to the lower glass transition temperature of PEA molecule. The thermal stability of nanocomposite was improved with increasing PEA content due to the thermally stable aromatic structure introduced to the polymer matrix.

Preparation of dye-doped polymer-dispersed liquid crystals using acrylic monomers, and enhancement of contrast by using THF solvent as a cleaning agent

Polymer-dispersed liquid crystal (PDLC), with characteristics of high contrast and low driving voltage, has found many product applications and is an important material for new generations. In this experiment, we used 2-phenoxy ethyl acrylate (2-PEA) and tripropylene glycol diacrylate, two acrylic monomers, to prepare PDLC, and we compared various preparation conditions in order to investigate the impact of structural properties on the optical behavior of PDLC. While maintaining the low driving voltage and high contrast of a PDLC, a dichroic dye was added to turn the device into a dye-doped PDLC. Using a polarized light microscope, it was observed that direct injection of the dye resulted in an overflow of the dichroic dye outside the thin film, reducing the contrast of the PDLC. Therefore, we utilized tetrahydrofuran solvent to wash away the liquid crystal (LC) from the PDLC, followed by re-addition of the dye-containing LC. This successfully solved the dye overflow problem and was found to enhance the PDLC contrast effectively.