Light Transmission Properties Research Articles

Stable Radicals in Dihydrophenazine Derivatives-Doped Epoxy Resin for High Photothermal Conversion.

Organic radicals exhibit great potential in photothermal applications, however, their innate high reactivity with oxygen renders the preparation of stable organic radicals highly challenging. In this work, a series of co-doped radical polymers ares prepared by doping dihydrophenazine derivatives (DPPs) into the epoxy resin matrix. DPPs can form radical species through the electron transfer process, which are further stabilized by the complex 3D network structure of epoxy resin. Experimental results show that the photothermal conversion efficiency is as high as 79.9%, and the temperature can quickly rise to ≈130°C within 60 s. Due to the excellent visible light transmittance and mechanical properties of co-doped systems, this study further demonstrates their practical applications in energy-saving solar windows and thermoelectric power generation.

Effect of Light Sources on Transmittance of Commercially Available Contact Lenses.

Previous studies have suggested that light rays may interact with contact lenses, potentially affecting their transmittance. This study aimed to investigate the effects of visible and ultraviolet (UV)-A light sources on the transmittance of some commercially available daily, weekly, and monthly contact lenses. Nine commercially available soft contact lenses were irradiated with a solar simulator, light-emitting diode (LED) source, laser source, and UV-A source. The average transmittance of the tested lenses before and after irradiation in the UV, visible, and infrared light wavelength ranges was determined using an Agilent UV-visible spectrophotometer, model 8453. The results showed a partial or complete block of UV transmission at the UV-B region (300 nm) and the UV-A region (355 nm) by the Bio true daily contact lens, as well as the Acuvue Oasys, Avaira, and Biomedics 55 weekly lenses. At the visible region (555 nm), irradiation of the contact lenses by different light sources resulted in reduced light transmittance. At the infrared region (900 nm), the weekly and monthly contact lenses partially blocked infrared transmission, while the daily lenses showed either increased or decreased infrared transmission. Solar and artificial lighting, as well as high-powered lasers, constitute a major concern on the contact lenses' light transmission and optical properties. It is essential to develop soft contact lenses that have photoprotective properties while maintaining visible light transmittance.

Sustainable pectin-based film for carrying phenolic compounds and essential oil from Citrus sinensis peel waste

Currently, food science faces the challenge of finding methods to deliver functional and nutritional compounds in ready-to-eat products. Biopolymeric films enriched with essential oils are an emerging strategy for incorporating valuable components into edible carrier matrices. This study investigated the wastewater from orange peel hydrodistillation as a source of phenolic compounds and an innovative ingredient to develop bioactive limonene-loaded pectin-based films, addressing waste disposal challenges by developing a multi-functional packaging material. The objective was to evaluate the effects of formulation synergies, particularly pectin-phenolic interactions, on the physicochemical, rheological properties, and essential oil retention capacity of film-forming emulsions, and then assess the effects on the physicochemical and mechanical properties of the films. Films were analyzed for morphology, water vapor permeability, light transmittance, mechanical, chemical, and physical properties, and encapsulation efficiency. Three formulations were evaluated: pectin control (PC), pectin with Tween-80 surfactant (PT), and pectin with phenolic-rich wastewater (PPW). PPW emulsions displayed higher viscosity, consistency, kinetic stability, and essential oil retention compared to PC. The resulting environmentally-friendly films exhibited increased thickness, improved oil droplet distribution, a more crystalline structure, lower clarity, better flexibility, and increased water vapor permeability. Altered FTIR spectrum bands suggested potential pectin-phenolic interactions, influencing film physicochemical properties through mechanisms such as enhanced crosslinking. The PT film-forming emulsion demonstrated lower kinetic stability and less homogeneity than PC and PPW, showing that the use of the commercial surfactant (0.1g/100 g of film-forming emulsion) led to less favorable performance in terms of emulsion stability and film properties compared to PPW and PC. Conclusively, utilizing orange residue for bioactive pectin-based films offers valuable insights for promoting shelf life, reducing the need for formulation surfactants, and adding nutritional value in food applications, while simultaneously repurposing underutilized waste. This research also contributes to insights into the development of more stable emulsions for creating uniform films.

A Smart Window with Passive Radiative Cooling and Switchable Near-Infrared Light Transmittance via Molecular Engineering.

Smart windows with synergetic light modulation have heightened demands for applications in smart cars and novel buildings. However, improving the on-demand energy-saving efficiency is quite challenging due to the difficulty of modulating sunlight with a broad bandwidth in an energy-saving way. Herein, a smart window with switchable near-infrared light transmittance and passive radiative cooling is prepared via a monomer design strategy and photoinduced polymerization. The effects of hydrogen bonds and fluorine groups in acrylate monomers on the electro-optical properties as well as microstructures of polymer-dispersed liquid crystal films have been systematically studied. Some films show a high contrast ratio of 90.4 or a low threshold voltage (Vth) of 2.0 V, which can be roll-to-roll processed in a large area. Besides, the film has a superior indoor temperature regulation ability due to its passive radiative cooling and controllable near-infrared light transmittance properties. Its radiative cooling efficiency is calculated to be 142.69 W/m2 and NIR transmittance could be switched to below 10%. The introduction of a carboxylic monomer and fluorinated monomer into the system endows the film with a highly efficient temperature management capability. The film has great potential for applications in fields such as flexible smart windows, camouflage materials, and so on.

The Influence of Thickness on Light Transmission for Pre- and Fully Crystallized Chairside CAD/CAM Lithium Disilicate Ceramics.

This in vitro study aimed to compare the light-transmission properties of two chairside CAD/CAM lithium disilicate (LD) ceramics (a novel fully crystallized and a traditional pre-crystallized) across varying thicknesses. One hundred flat specimens were obtained from precrystallized (e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) and fully crystallized (LiSi GC Block; GC, Tokyo, Japan) LD at five different thicknesses (0.5, 0.75, 1.0, 1.50 and 2.0 mm). All specimens were polished with a polishing system for lithium disilicate restorations following recommendations from the manufacturer. Light transmission was evaluated with a radiometer. The statistical analysis between e.max CAD and LiSi GC Block was performed using a Mann-Whitney test for each thickness at a significance level of 0.05 (p < 0.05), followed by a Kruskal-Wallis test to compare the light transmission between the thicknesses of e.max CAD and LiSi GC Block. Light transmittance was significantly affected by ceramic thickness. The 0.5 mm thick specimens exhibited the highest transmittance values compared to all other groups, while a light transmittance of 0.00 was observed in the 2.0 mm thick specimens for both e.max CAD and LiSi GC Block. In the comparison between e.max CAD and LiSi GC Block according to thickness, there was a statistically significant difference exclusively between groups with a thickness of 1.50 mm (p = 0.002). Light transmission for pre- and fully crystallized CAD/CAM lithium disilicate ceramics only showed a statistical difference at the thickness of 1.50 mm (p = 0.002). E.max CAD demonstrated acceptable light transmission up to a thickness of 1.5 mm. A thickness of 2 mm for chairside CAD/CAM lithium disilicate ceramics, whether pre-crystallized or fully crystallized, necessitates the use of dual-cure resin luting cement due to reduced light transmission.

Characterization of plastic scintillator samples produced by a university-SME Collaboration

Scintillator samples are synthesized by a university-SME collaboration and the light yield, light emission and light transmission properties are studied with the aim of determining the fluor content that gives the highest light yield. Three plastic scintillator samples with different fluor additives are produced and their optical properties are found to be comparable with a high-light-yield EJ-204 reference sample. Amongst the three, the sample with 0.75% PPO + 0.75 %PTP and 0.04% POPOP + 0.04% Bis-MSB provides the highest light yield. The authors plan to use the same fluor additive concentration to produce application-specific scintillators that are not commercially available for nuclear reactor monitoring and medical applications.

Research on A Kind of Lightweight Heat-insulating, Sound-insulating and Light-transmitting Concrete Interior Partition Wall Block

The new composite concrete with both lightweight, thermal insulation, heat insulation and light transmission properties is a new type of building The new composite concrete with both lightweight, thermal insulation, heat insulation and light transmission properties is a new type of building material with energy saving and consumption reduction functions. This paper integrates the research status of scholars in this field at home and abroad, realises the lightweight of blocks by studying the properties of lightweight aggregate concrete and porous concrete, and selects suitable light- transmitting materials, tests the light transmittance and mechanical properties of concrete blocks after adding light-transmitting materials, then analyzes the advantages and disadvantages of the sound insulation effect produced by adding soundproofing materials made from different materials to concrete blocks, and selects the best sound insulation effect by adding soundproofing materials to concrete blocks. concrete blocks, and selects the best soundproofing material for the comprehensive performance. Then we analyze the advantages and disadvantages of Then we analyze the advantages and disadvantages of adding different sound insulation materials into concrete blocks, and select the best sound insulation material with comprehensive performance. the same time of realising the three properties of light weight, sound insulation and light transmittance, we further study the effect of adding different thermal insulation materials on the thermal insulation effect of the blocks, and select the concrete blocks with the best thermal insulation performance.

Controllable preparation of VO2@m-SiO2 and its light transmittance and thermal insulation properties of PVB composite films

In this study, a hybrid approach using the Stöber and solvent extraction techniques was employed to synthesize mesoporous silicon-coated VO2 nanomaterials (VO2@m-SiO2, VmS) with controllable pore sizes and shell thicknesses. This synthesis was aimed at elucidating the influence of mesoporous silicon coatings on the thermochromic effect and optical properties of VO2. Experimental findings reveal that the mesoporous silica architecture markedly improve the phase-transition hysteresis of VO2 while mitigating the Mie effects attributable to particle coarsening, under the appropriate shell thickness. Furthermore, concomitant with the enlargement of the mesoporous aperture, the Tlum and ΔTsol of the VmS/PVB films also exhibit upward trends. Tlum reaches 73.33% and 62.24% in VmS3/PVB and VmS5/PVB, peak ΔTsol reaches 5.16% in VmS5/PVB. The facile synthesis procedure of VmS, in conjunction with its superior performance across phase transition, optics, and thermal insulation metrics, offers a viable pathway for industrial-scale deployment of VO2(M) in smart window applications.

Sustained Delivery of Olopatadine from Vitamin-E Loaded Contact Lenses.

Purpose: Topical antihistamines, such as olopatadine hydrochloride, an H1 receptor antagonist, are commonly prescribed for treating allergic conjunctivitis. Drug delivery via eye drops has many deficiencies including a short residence time due to tear drainage via the nasolacrimal duct, which results in a low bioavailability and potential for side effects. These deficiencies could be mitigated by a drug-eluting contact lens such as the recently approved ACUVUE® THERAVISION™ WITH KETOTIFEN which is a daily disposable etafilcon, a drug-eluting contact lens with ketotifen (19 μg per lens). Here, we investigate the feasibility of designing a drug-eluting lens with sustained release of olopatadine for treating allergies using an extended wear lens. Methods: Nanobarrier depots composed of vitamin-E (VE) are formed through direct entrapment by ethanol-driven swelling. The drug-loaded lenses are characterized for transparency and water content. In vitro release is measured under sink conditions and fitted to a diffusion control release model to determine diffusivity and partition coefficient. Results: In vitro studies indicate that ACUVUE OASYS® and ACUVUE TruEye™ lenses loaded with ∼0.3 g of VE/g of hydrogel effectively prolong olopatadine dynamics by 7-fold and 375-fold, respectively. Incorporation of VE into the lenses retains visible light transmission and other properties. Conclusion: The VE incorporation in commercial lenses significantly increases the release duration offering the possibility of antiallergy extended wear lenses.

The Effect of Polyamide 11 on the Thermal Stability and Light Transmittance of Silicone-Based Thermoplastic Vulcanizates.

The effect of polyamide 11 (PA11) on the thermal stability and light transmittance properties of silicone-based thermoplastic vulcanizates (TPVs) has been investigated. The blends were prepared through a dynamic vulcanization process by adding 15, 30, and 45 wt% PA11 to the silicon-based TPVs, respectively. The effect of PA11 on the dispersion of silicone rubber in the TPVs after dynamic vulcanization was characterized by a scanning electron microscope (SEM), the thermal stability of the compounds was evaluated through the changes in mechanical performance in the thermo-oxidative aging process, and the light transmittance of TPVs was measured by a haze meter. The results showed that adding PA11 to silicone-based TPVs caused a decrease in the size of the silicone rubber particles after dynamic vulcanization, resulting in improved dispersion. Due to this, by increasing the compatibility between the segments through silicone's effective dispersion, the amount of light absorption was reduced, and the amount of light transmittance was increased. Finally, according to the results of the thermal aging test, it was found that TPVs with 30 and 45 wt% PA11, respectively, showed outstanding thermal resistance after aging at 160 °C and 168 h and did not melt down.

Asynchronous topological phase transition in trimer lattices

We propose a model of a non-reciprocal double-layer trimer photonic lattice. In this model, two types of topological phases are presented. By adjusting the imaginary coupling coefficients and intra-cell coupling coefficients in this model, two topological phases appear in different coefficient ranges. They exhibit asynchronous topological phase transitions as the coupling coefficients change. We discover that these asynchronous topological phase transitions can impact the light transmission properties of the system. When the coupling coefficients are adjusted to put the system in a topologically non-trivial state, the injected light beam tends to localize at the edge. Moreover, before and after the phase transition, the lowest energy band exhibits oscillatory and non-oscillatory behavior in the evolution of the light beam at the boundary. Asynchronous topological phase transitions can be utilized to manipulate the light transmission properties of the system, offering potential applications in optical communication and the development of photonic integrated circuits.

Natural polymer fillers instead of dye and pigments: Pumice and scoria in PDMS fluid and elastomer composites

Abstract The electrical and thermal conductivities and light transmittance properties of silicone oil and polydimethylsiloxane (PDMS) elastomer composites were investigated. Pumice, scoria, nano-Ag, and multi-walled carbon nanotube (MWCNT) particles were used as fillers. An effective, clean, and easy method was used to prepare nanosized particles from pumice and scoria rocks. Only MWCNT–PDMS composites showed electrical conductivity. The highest electrical conductivity of 24.7 S·m−1 was obtained with the 25% pumice–10% MWCNT–silicone oil composite. All filler particles increased the thermal conductivity of the PDMS elastomer. MWCNTs were more effective than pumice and scoria, and the thermal conductivity reached 0.62 W·(m·K)−1 with an addition of 3 wt% MWCNTs. All filler particles decreased the transparency of the PDMS elastomer. The sample with 5 wt% pumice particles reached zero transmittance. Pumice and scoria naturally colored the PDMS elastomer. The powders of these natural volcanic rocks could be used as a suitable coloring filling material instead of dyes and pigments for polymers without waste. However, it was concluded that pumice and scoria particles are not suitable for making composites with silicone oil due to the possibility of catalyzing the degradation of linear PDSM.

Investigation of the Efficacy of Horizontal Hollow Light Tubes for Energy Conservation in Illuminating Buildings

This study investigates the properties of light transmission and distribution, examining how incident light angles impact illuminance distribution and daylight factor. Light tubes are acknowledged as promising tools to enhance lighting conditions and reduce energy consumption in building design. The study involved installing horizontal hollow light tubes, each measuring 0.5 m in length and 0.30 m in diameter, on a wooden test model. A 20-watt LED lamp was employed as the light source, and an illuminance meter recorded the values at various horizontal and elevation angles. The study’s assessment included calculating the average illuminance and daylight factor to obtain light transmission efficiency and energy-saving potential. The findings revealed that both aluminum alloy and zinc alloy tubes experienced a decrease in illuminance as incident elevation angles increased, with the most effective light transmission occurring at a horizontal angle of 90°. Notably, the aluminum alloy tube outperformed the zinc alloy tube, demonstrating more than a 15% increase in light transmission efficiency. Furthermore, the daylight factor values from both types of tubes aligned with established standards for residential and office activities, underscoring their potential as energy-efficient lighting solutions for spaces lacking natural light or with limited illumination.

A Comparative Thermodynamic Study of AlF3, ScF3, Al0.5Sc0.5F3, and In0.5Sc0.5F3 for Optical Coatings: A Computational Study

Optical coatings are thin layers of materials applied to optical components in order to modify the transmission, reflection, or polarization properties of light. The common materials used for optical coatings include magnesium fluoride (MgF2), scandium trifluoride (ScF3), and aluminum trifluoride (AlF3), owing to their desirable optical properties, spectral range, and compatibility with substrates. However, each of these materials has its own drawbacks. For instance, AlF3 has been found to exhibit limited resistance to attack by chemicals, as well as poor thermal stability, while MgF2 has low durability, as well as being hygroscopic. In this study, we undertook ab initio calculations in order to compare the thermal properties of AlF3, ScF3, Al0.5Sc0.5F3, and In0.5Sc0.5F3 in order to obtain the best material for optical coatings. MgF2 was also included in the study as a reference. The calculations used PBE pseudopotentials and the extended generalized gradient approximation within the quantum espresso algorithm. The study demonstrated that the computed results agree with the information found in the literature. ScF3 exhibited a negative coefficient of thermal expansion, unlike the other four. Moreover, AlF3 was found to be the best candidate for optical coatings that are used in high-power laser systems with high thermal dissipation, due to its superior thermal expansion coefficient as well as its better response to thermal stress. The large variation between the cp and cv of ScF3 is not desirable. Moreover, due to its negative thermal expansion coefficient, ScF3 is not thermally stable. The highest thermal stability was exhibited by In0.5Sc0.5F3. Since Al0.5Sc0.5F3 and In0.5Sc0.5F3 have been modeled in this study for the first time, experimental determination of their crystal structures needs to be investigated.

Preparation and characterization of egg white protein film incorporated with epigallocatechin gallate and its application on pork preservation.

The aim of this study was to develop the composite films with antioxidant and biodegradable activity based on egg white protein (EWP) and epigallocatechin gallate (EGCG). Water susceptibility, light transmittance, microstructure and antioxidant properties of the composite films without and with EGCG were fully characterized. It was noted that the addition of EGCG might decrease the moisture content, water solubility and swelling capacity. SEM micrographs revealed that discontinuous blocks and rough surfaces were caused by increasing concentration of EGCG, whereas compact and homogeneous particles appeared when the concentration of EGCG reached to 80μmol/L. Moreover, the biodegradability of the composite films was demonstrated by the soil degradation properties that they can be almost completely degraded within ten days. Experimental results on the application in chilled fresh pork showed that the EWP-based films could play an antioxidant role when incorporated with EGCG, indicating their great potential for food packaging.

Polymer and photo‐selective covers on plant and fruit development: A review

AbstractGrowers have increasingly adopted protected cropping in tunnels or greenhouses to ensure sustainability and continuous crop productivity against a backdrop of climate change. The predominant types of covers used in controlled‐environment agriculture are polymer‐based shade nets or structures covered with polymer sheets. These have three main functions: (1) physical protection from birds, hail, and excessive radiation; (2) modification of the environment by controlling humidity, shade, and temperature; and (3) increasing the proportion of diffuse light. In order to address concerns regarding the amounts of useful light potentially blocked by these covers, researchers and growers have suggested several innovative solutions that involve altering the light received by plants. This includes supplementation of artificial illumination, filtering solar radiation with colored films, or altering the incident spectrum with spectral‐shifting covers containing light‐emitting fluorescent compounds embedded within a polymer matrix. In principle, any of these methods have the potential to selectively modify the spectrum of incident light and subsequently induce plant physiological responses, resulting in increased crop yield, improved fruit quality, and reduced susceptibility to pests and diseases. This review focuses on the benefits offered by passive covers in terms of their variable shading and light transmittance properties and their effects on vegetative growth and fruit development in various crops. It is anticipated that through a better understanding of photo‐selective covers in protected cropping, primary producers will be better equipped to make informed decisions regarding their deployment and thereby achieve better yields and more nutritious produce from their crops.

A novel active packaging film containing citronella oil: Preparation, characterization, antimicrobial activity and application in grape preservation

In this study, citronella oil (CO) was incorporated into soy protein isolate (SPI) to prepare antimicrobial protein films capable of inhibiting the growth of spoilage microorganisms on food packaging and providing effective preservation of food products. The morphological, physical and functional properties of the antimicrobial protein films were characterized and investigated by different characterization tools. The SEM results showed that the surface of the films was relatively smooth and flat. FTIR and XRD analyses indicated that CO was uniformly distributed in SPI with good compatibility. Under UV light, the films containing CO showed moderate light transmission and better UV-blocking properties than the SPI-based films. The addition of CO improves the hydrophobic property of the films, and the water content of the film containing 3 % CO is reduced to 20 % compared with that of the SPI film with 27.5 %. The DMA showed that the prepared films had good tensile, swelling and relaxation properties. Antimicrobial protein films containing 3 % CO showed high antimicrobial activity against S. aureus and E. coli. It was also found that the film with 3 % CO had a survival rate of more than 70 % and an apoptosis rate of 5.3 % for BEAS-2B cells after 48 h, indicating that such films are safe. Moreover, the film with 3 % CO showed good freshness and storage capacity with a weight loss of 44.16 % after the grapes had been packed for 7 days. These good physical properties and functional properties suggest that films containing CO have great potential for food packaging applications.

Assessment and ANN model development of natural light transmittance of light-transmitting concrete

This study aims to reveal the potential of Light-transmitting concrete (LTC) in transmitting natural light or sunlight, and to investigate the relationship between fibre diameter, fibre spacing, solar incidence angle, surface area, and light transmittance properties. The artificial neural network model as well as explicit equations from the model were developed to predict the light transmittance of LTC. The surface area was altered by varying LTC block arrangements from one to six. It was found that light incidence angle significantly affected the light transmittance of LTC. The highest light transmittance of LTC was achieved near solar noon, but it decreased drastically as soon as the solar incidence angle exceeded the acceptance angle. The effect of the LTC surface area and solar incidence angle on light transmittance diminished with a smaller fibre diameter or larger fibre spacing. The ANN model and explicit equations developed from the network provide good accuracy in predicting light transmittance of LTC.

Synthesis, optimization via response surface methodology, and structural properties of carboxymethylcellulose/curcumin/graphene oxide biocomposite films/coatings for the shelf-life extension of shrimp

In this study, carboxymethylcellulose (CMC), curcumin (Cur), and graphene oxide (GO) were used to prepare a novel biocomposite film (CMC-Cur-GO). A central composite design under response surface methodology was employed to optimize the films in terms of water vapor permeability (WVP) and swelling percentage (SP). Under the optimum conditions, which the rates of CMC, GO and curcumin were found to be 1350 mg, 29.99 mg, and 0.302 g, respectively, WVP and SP of CMC-Cur-GO were obtained 0.902 × 10−8 (g/m·h·Pa) and 13.62 %, respectively. The biocomposite films (CMC, CMC-Cur, CMC-GO and CMC-Cur-GO) were characterized by Fourier transform infrared spectroscopy, field-emission scanning electron microscope, thermal gravimetric analysis, X-ray diffraction analysis, ultraviolet-vis light transmittance, moisture content, and mechanical properties. Compared with pure CMC film, the tensile strength, elongation at break and Young's modulus of CMC-Cur-GO were significantly improved by up to 75 %, 41 % and 23 %, respectively (p < 0.05). Then, CMC-Cur-GO was applied as a coating solution for the shrimps. The coated shrimps with the CMC-Cur-GO significantly (p < 0.05) showed a noteworthy improvement in microbial quality (total and psychrotrophic bacterial count), chemical deterioration and lipid oxidation (pH and total volatile basic nitrogen, peroxide value and thiobarbituric acid) and physical characteristic (weight loss) as compared to other samples. The CMC-Cur-GO coating could increase the shelf life of shrimp under refrigerated storage.

Study on optical coupling characteristics of a high-radial-tolerance thick-lens beam expanding fiber collimator

In this paper, a high-radial-tolerance fiber collimator (HRTFC) consisting of beam expanding fiber (BEF) and thick-lens (T-lens) is designed. The HRTFC uses BEF to reduce coupling loss, while T-lens are used to increase the outgoing spot to enhance the tolerance of radial mismatch. Firstly, the Gaussian beam ABCD optical transmission matrix is used to analyze transmission properties of light in the T-lens. Then, a beam transmission coupling model is constructed to explore the coupling losses of radial, angular, and axial mismatches under different spots. Finally, a static experimental platform is built to verify the influence of spot size on the coupling mismatch, and a dynamic experimental platform is built to monitor the temperature without contact. The experimental results show that the coupling loss decreases from 1.808 dB to 0.368 dB in the HRTFC, with the fiber mode field diameter (MFD) increasing from 10μm to 28μm. Increasing the spot of the HRTFC to a certain extent can reduce the tolerance of angular mismatch but can significantly increase the tolerance of radial mismatch.