Light Transmission Properties Research Articles

Facile Fabrication of Multifunctional Transparent Flame-Retarded Hydrogel for Fire-Resistant Glass with Excellent Transparency, Fire Resistance and Anti-Ageing Property.

Acrylamide-methacrylic acid copolymer named P (AM-co-MAA) was synthesized via aqueous solution polymerization, and then mixed with crosslinker, flame retardants and initiators to prepare multifunctional transparent flame-retarded hydrogels with transparency, fire resistance and anti-ageing property. The results show that the application of multifunctional transparent flame-retarded hydrogel imparts high level of transparency and excellent fire resistance to the fire-resistant glass, and the light transmittance and fire resistance of the flame-retarded hydrogel increases with the increasing mass ratio of AM to MAA in P(AM-co-MAA). When the mass ratio of AM to MAA is 4:1, the obtained P(AM-co-MAA) imparts the lowest backside temperature of 130 °C at 3600 s and highest light transmittance of 86.1% to the transparent flame-retarded hydrogel. TG and DSC analysis show that the addition of P(AM-co-MAA) increases the thermal stability of the transparent flame-retarded hydrogels due to the formation of numerous hydrogen bonds via the complexation between amide and carboxyl groups. Accelerated ageing test indicates that the transparent flame-retarded hydrogel containing P(AM-co-MAA) exerts durable fire resistance and transparency, and the ageing resistance of the transparent flame-retarded hydrogel depends on the mass ratio of AM to MAA in P(AM-co-MAA). Therefore, this study provides a promising strategy to prepare a novel multifunctional transparent flame-retarded hydrogel with excellent light transmittance, fire resistance and anti-ageing properties.

Mechanical and light transmittance properties of high-performance translucent concrete

High-Performance Translucent Concrete (HPTC) is an innovative energy-saving building material, as it is a high-quality translucent concrete with high workability, superior mechanical properties, and good light transmittance. This paper investigates the performance of HPTC incorporated with plastic optical fibers (POF), its fresh properties, mechanical properties, and light transmittance performance. The data presented here refer to specimens of 21 mixtures divided into six main groups, the latter group upgraded to be ultra-high performance translucent concrete (UHPTC). Besides fresh concrete tests, bulk density, all-ages compressive strength, splitting tensile strength, flexural strength, bond strength, modulus of elasticity strength, and light transmittance as well as relations between light transmittance and mechanical properties were investigated in the HPTC hardened phase. Although the HPTC mechanical properties increase with increasing POF volume ratios and diameters, the light transmittance significantly increases with increasing POF volume ratios. In this paper, HPTC performs up to 21.35% light transmittance for specimens with a volume ratio of 4% POF and 2 mm POF diameter as well as good mechanical properties such as compressive strength of 54.30 MPa at 91 days. In addition, UHPTC performs up to 154.2 MPa compressive strength, 13.8 MPa tensile strength, 23 MPa flexural strength, 25.7 MPa bond strength, and 49.71 GPa modulus of elasticity, as well as 10.31 % light transmittance.

Effect of Cooling Rate on Mechanical Properties, Translucency, Opalescence, and Light Transmission Properties of Monolithic 4Y-TZP during Glazing.

A standard cooling rate has not been established for glazing; therefore, the effects of the cooling rate on the properties of zirconia need to be evaluated to predict outcomes in clinical practice. 4Y-TZP glazed at three different cooling rates was analyzed to estimate the effect of cooling rate during glazing on the mechanical and optical properties. Hardness tests, field-emission scanning electron microscopy analysis, X-ray diffraction analysis, flexural strength measurement, and optical property evaluations were performed. When 4Y-TZP was glazed at a higher cooling rate (Cooling-1) than the normal cooling rate (Cooling-2), there was no significant difference in grain size, flexural strength, average transmittance, and translucency parameters. The hardness was slightly reduced. The opalescence parameter was reduced for the 2.03 mm thick specimens. When 4Y-TZP was glazed at a lower cooling rate (Cooling-3) than the normal cooling rate, there was no significant difference in hardness, grain size, flexural strength, and translucency parameters. In addition, the average transmittance and opalescence parameters were slightly reduced for the 0.52 and 2.03 mm specimens, respectively. The effects of the cooling rate during glazing on the mechanical and optical properties of 4Y-TZP appear to be minimal and clinically insignificant. Therefore, even if the cooling rate cannot be strictly controlled during glazing, the clinical outcomes will not be significantly affected.

Evaluation of Color and Spectral Behavior of a Novel Flowable Resin Composite after Water Aging: An In Vitro Study.

Background: This study aimed to evaluate the color matching, light transmittance, and reflectance characteristics of the novel flowable resin composite OCF-001 (OCF). Methods: Fifty-four resin composite molds were made with simulated class I cavities of A2, A3, and A4 shades by filling the rubber mold interspace with Estelite Sigma Quick (ESQ), Gracefil Putty (GP) and Filtek Supremme Ultra (FSU). After applying the adhesive, three different flowable resin composites (n = 6), OCF, Gracefil LoFlo (GLF), and Supreme Ultra Flowable (SUF), were used to fill the cavities. A colorimeter was used to measure the color parameters (CIEDE2000). The color measurements were taken immediately and after 28 days. Data were analyzed using the nonparametric Kruskal–Wallis (α = 0.05) and Wilcoxon tests. The light transmittance and reflection characteristics were measured with a black background using a spectrophotometer under D65 illumination. Results: The ΔE00, and ΔC of OCF was lower than other tested materials in A2 and A3 shades both immediately and after 28 days. OCF showed the highest transmittance characteristic, and a relatively stable reflectance curve in all the wavelengths. Conclusions: OCF showed better shade matching with the surrounding shades of A2 and A3, a relative uniform reflectance and higher light transmission properties.

1D randomized photonic crystals: influence as single- and dual-channel narrowband filter

Nowadays, optical filters with high-level performance are highly demanded. While examining the light transmission properties of both periodic and random one-dimensional (1D) photonic crystals, it is observed that random 1D photonic structures have more favorable properties to meet these demands. With the influence of randomness, novel single- and dual-channel narrowband filters at a 1550 nm wavelength for optical telecommunication are presented in this study. For designing narrowband filters, the central wavelength precision, quality factor and peak transmission are of great importance. Randomness can be attained by permuting the refractive indices of two dielectric materials through the binomial coefficient method, wherein the light transmission properties are calculated using the transfer matrix method. The proposed filters show a minimum full width at half maximum of 0.24 nm in the single-channel narrowband filter and 0.08 and 0.095 nm in the dual-channel narrowband filter at the chosen spectral region. This filters have ultra-narrowband transmission peaks compared with those of existing narrowband filters based on defective 1D photonic structures.

Micro/nano particles reinforced polymer composites as greenhouse films for heat retention purposes

AbstractThe aim and objective of this review is to intensively summarize composite film materials that can achieve thermal radiation insulation without affecting visible light transmittance, in order to reduce the heat loss in greenhouses and thus save energy. Eight kinds of composite films, which could be used for radiation insulation, were finally determined and intensively reviewed by searching the key words including insulation film, insulation agent, and infrared insulation. These materials can be divided into two categories: silica/poly and zinc oxide/poly composites. The radiation thermal insulation property and light transmission property of these materials were experimentally tested by spectrometry. The key finding of this article includes that phonon resonance and Anderson localization could be used to block thermal infrared radiation by generalizing material properties. The conclusion of this review is that those materials have at least a 10% increase in infrared thermal radiation blocking, but only a small decrease in visible light transmittance.

Development of New Biodegradable Agar-Alginate Membranes for Food Packaging.

The paper analyzes the possibility of replacing the polyethylene packaging from food products with biodegradable packaging obtained from biopolymers. The proposed packaging materials were obtained from polysaccharides (alginate, agar), glycerol as plasticizer. To improve the properties necessary for the coating materials, two groups of membranes were made, one with ascorbic acid (AA, 0.1–0.45 g) in 150 mL filmogenic solution and the other with calcium chloride (CaCl2, 0.02–0.1 g) in 150 mL filmogenic solution. The membranes were analyzed for mechanical properties, light transmission, transparency and barrier properties (water vapor, oxygen, or fatty substances). The results demonstrated that the addition of AA (0.1 g), increases tensile strength, transparency, oxygen and water barrier properties. On the other hand, the addition of calcium chloride (0.08 g) increased the hardness, tensile strength and opacity of the membranes. Moreover, it ensured a uniform distribution of the mixture components. The uniformization of the mixture components in the presence of AA and CACl2 was observed by SEM and roughness analysis. Hydrogen bonding interactions between the biopolymers and the additives used were highlighted by FTIR analysis. All membranes have shown very good UV absorption. The results suggest that agar/alginate/glycerol membranes with AA and CaCl2 have the potential to be used in an active food packaging system.

Thermal, flammability, and antimicrobial properties of arrowroot (Maranta arundinacea) fiber reinforced arrowroot starch biopolymer composites for food packaging applications

Using the solution casting method, a novel biodegradable thermoplastic arrowroot (Maranta arundinacea) starch (TPAS) films containing arrowroot fiber (AF) at different concentrations (0, 2, 4, 6, 8, and 10 wt%) were developed and characterized in terms of thermal, antibacterial activity, water vapor permeability (WVP), biodegradability, and light transmittance properties. The TPAS/AF-10 biocomposite film revealed a higher degradation temperature (313.02 °C) than other biocomposite films, indicating better thermal stability. Furthermore, increasing AF concentration led to a significant (p < 0.05) reduction in the linear burning rate and WVP of the biocomposite films from 248.9 to 115.2 mm/min and 8.18 × 10−10 ×g. s−1.m−1. Pa−1 to 5.20 × 10−10 ×g. s−1.m−1. Pa−1, respectively. The addition of fibers in the surface structure had a significant impact on remarkable drop in opacity (91.1 to 74.1%). In addition, the incorporation of AF and control film showed an insignificant effect against three pathogenic bacteria, including Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922), and Bacillus subtilis (B29). The soil burial findings demonstrated that the weight loss of TPAS/AF biocomposite films was significantly higher than TPAS film. Overall, the reinforcement of arrowroot fiber with TPAS film improved the properties of biocomposites for environmentally friendly food packaging applications.

Effects of various cleaning agents on polypropylene and copolyester thermoplastic orthodontic retainer materials

ObjectivesThis study aimed to evaluate and compare the effects of four cleaning agents on the flexural modulus and light transmittance properties of polypropylene and copolyester thermoplastic retainer materials after long-term exposure. MethodsA total of 120 pieces of standardized copolyester and polypropylene retainer materials were tested after being thermoformed. They were divided equally into six subgroups: as-received, artificial saliva, chlorhexidine, alcohol-based and alcohol-free mouthwashes, and Retainer Brite®. The pieces were subjected to a cleaning process involving 15 minute immersion three times weekly for 3 months. The flexural modulus and light transmittance were then measured for all specimens with three point bending tests and spectrophotometry, respectively. One-way ANOVA and independent samples t-test were applied to compare the means, and Tukey's post hoc test was used in cases of significant differences. The threshold for significance was 0.05. ResultsFor each retainer type, the statistical results revealed that the flexural modulus values of the copolyester retainer material significantly differed from those of polypropylene material under chlorhexidine mouthwash, alcohol-based mouthwash, and Retainer Brite® conditions. Copolyester and polypropylene showed significant differences in light transmittance under all conditions. No significant difference in flexural modulus values was observed among conditions, whereas significant differences in light transmittance were observed between alcohol-based mouthwash and the other conditions for copolyester material. ConclusionsAccording to our results, any cleaning agent can be safely used for both materials without affecting the elastic modulus. However, alcohol-based mouthwash decreases the light transmittance of copolyester retainer material.

Photothermal and energy performance of an innovative roof based on silica aerogel-PCM glazing systems

The glazing systems are considered as the critical components in terms of the building energy consumption owing to the undesired insulation performance and poor thermal inertial mass. To overcome those challenges, the glazing systems integrated with silica aerogel and PCM (SA-PCM) are confirmed as a promising technology to improve photothermal performance. However, the inevitable conflict remains between the energy saving and daylighting performance when the PCM and silica aerogel are filled into two different layers. Therefore, an innovative roof based on SA-PCM glazing systems is proposed, in which the original PCM layer is divided into five cavities for filling PCM and air. A numerical model to investigate the thermal performance and energy efficiency of the innovative roof is developed. The evaluation of the thermal performance of the innovative roof is conducted by the indicators of temperature decrement factor and temperature time lag, while the energy efficiency is evaluated by the total heat loss through the inner surface of the innovative roof. To evaluate the optical performance of the innovative roof, the dynamic optical properties (transmittance, absorptance, and reflectance) are obtained in conditions of different PCM fill ratios. The photothermal and energy performance of the innovative roof are investigated over a 24-hour period in the severe cold region of the city Daqing (China). The results show that the thermal performance of the innovative roof is improved with the addition of PCM amount embodied in the decrease in magnitude and the increase in phase shift of temperature waves on the inner surface. Besides, both the transmittance and absorptance of the innovative roof change significantly along with the PCM fill ratio over the course of the day, while the change in reflectance is slight. Additionally, the optimal energy performance of the innovative roof occurs at 80% fill ratio of PCM, in which the total heat loss and the energy saving rate account for 2595 kJ/m2·d-1 and 11.37%, respectively. Based on the principle of prioritizing the energy efficiency while considering the demand for light transmission properties of the innovative roof, the fill ratio of PCM is recommended as 60%.

Gelatin/Chitosan Films Incorporated with Curcumin Based on Photodynamic Inactivation Technology for Antibacterial Food Packaging.

Photodynamic inactivation (PDI) is a new type of non-thermal sterilization technology that combines visible light with photosensitizers to generate a bioactive effect against foodborne pathogenic bacteria. In the present investigation, gelatin (GEL)/chitosan (CS)-based functional films with PDI potency were prepared by incorporating curcumin (Cur) as a photosensitizer. The properties of GEL/CS/Cur (0.025, 0.05, 0.1, 0.2 mmol/L) films were investigated by evaluating the surface morphology, chemical structure, light transmittance, and mechanical properties, as well as the photochemical and thermal stability. The results showed a strong interaction and good compatibility between the molecules present in the GEL/CS/Cur films. The addition of Cur improved different film characteristics, including thickness, mechanical properties, and solubility. More importantly, when Cur was present at a concentration of 0.1 mM, the curcumin-mediated PDI inactivated >4.5 Log CFU/mL (>99.99%) of Listeria monocytogenes, Escherichia coli, and Shewanella putrefaciens after 70 min (15.96 J/cm2) of irradiation with blue LED (455 ± 5) nm. Moreover, Listeria monocytogenes and Shewanella putrefaciens were completely inactivated after 70 min of light exposure when the Cur concentration was 0.2 mM. In contrast, the highest inactivation effect was observed in Vibrio parahaemolyticus. This study showed that the inclusion of Cur in the biopolymer-based film transport system in combination with photodynamic activation represents a promising option for the preparation of food packaging films.

Development mechanism of aging depth of bitumen with increasing UV aging time

The UV aging of bitumen has a significant influence on the pavement service life, therefore, the research on UV aging has attracted increasing attention recently. It is known that the aging of bituminous pavements does not occur instantly through the full depth, instead, the aging depth of the bitumen increases gradually with the increasing aging time. The limitation of the research is that the development mechanism of the aging depth of bitumen is not clearly known. Various thicknesses of bituminous membranes were prepared and the UV light transmission and absorption properties of bituminous membranes were investigated by UV–visible spectrophotometric, aiming to determine the penetration depth of UV light in bitumen after UV aging. It is concluded that, for the same bituminous membrane, the transmittance of UV light increases with the increase of the light wavelength; while the transmittance of UV light decreases significantly with the increase of bituminous membrane thickness. The penetration depth of UV light in bitumen increases gradually with increasing UV aging time. The relationship between UV light penetration depth in bitumen and aging depth of bitumen was analyzed, and UV aging models of three parts of bitumen were established to reveal the development mechanism of the UV aging depth of bitumen during UV aging. The increasing aging depth of bitumen is due to the increase of UV light penetration depth in bitumen, and the diffusion action of aging products from surface bitumen to deeper bitumen. During the UV aging, the bitumen actually comprises three parts, namely, the surface direct aging part (UV light can reach), the deeper diffusion aging part (aged by the diffusion action) and the internal unaged part (UV light and diffusion action can not affect).

The Effect of Light-Curing Stains on Composite Basis on The Light Transmittance Properties of Composites

The Effect of Light-Curing Stains on Composite Basis on The Light Transmittance Properties of Composites

The Effect of Light-Curing Stains on Composite Basis on The Light Transmittance Properties of Composites

The Effect of Light-Curing Stains on Composite Basis on The Light Transmittance Properties of Composites

Drug-free contact lens based on quaternized chitosan and tannic acid for bacterial keratitis therapy and corneal repair

Bacterial keratitis (BK) and related inflammatory diseases causes irreversible damage to the corneal tissue. In this study, a novel polyacrylamide semi-interpenetrating network hydrogel including quaternized chitosan and tannic acid (PAM-QCS-TA) were used to construct a novel antibacterial and antioxidant contact lens. The obtained hydrogels showed high water content (>85%), swelling resistance, light transmittance (>90%) and adjustable mechanical property. Both quantitative and qualitative antibacterial experiments against Staphylococcus aureus and Escherichia coli (E. coli) indicated excellent sterilization function especially against E. coli (almost 100%). Due to the presence of tannin acid, it showed obvious antioxidant properties, which relieved oxidative stress and protect cells from reactive oxygen species-induced cytotoxicity. Animal experiments also indicated the shortened treatment time of BK (only 3 days) as well as the protection of eye tissue structure. Therefore, such drug-free antibacterial and antioxidant contact lens avoiding the development of drug resistance is a potential candidate in ocular infectious and inflammatory diseases treatment.

Study of photonic band gap robustness in disordered polymer photonic crystals under hydrostatic pressure

Transmission properties of light through disorder polymeric photonic crystals have been studied. The photonic crystals made of polymeric multilayers with Gaussian distribution of layer thickness are found to exhibit robust photonic bandgap (PBG). The transmission characteristics of different random structures starting from periodic to gradually perturbed structures have been systematically investigated. The numerical examples illustrate that the photonic structure can sustain its PBG for a large range of disorder up to σ = 100 nm, which is nearly equal to 15% of the layer thickness calculated from the quarter wavelength condition for a normal incidence of light. It also quantitatively demonstrates the average transmission of the PBG region is becomes flatter due to the random nature of the structure. The proposal provides that the polymeric photonic crystal may be employed for potential applications for robust integrated photonic devices and optical communication systems.

NaLaMo2O8:Yb3+, Er3+ transparent glass ceramics: Up-conversion luminescence and temperature sensitivity property

A novel transparent Yb3+/Er3+ co-doped NaLaMo2O8 glass ceramics (GCs) with borosilicate glass as the matrix were prepared via glass melting and subsequent controlled crystallization method, and the light transmission property, phase structure, microstructure and up-conversion (UC) performance were characterized by XRD, TEM, transmittance spectroscopy and photoluminescence spectrum. A decrease in the lattice parameter of NaLaMo2O8 in GC sample was verified by XRD Rietveld method, indicating the successful incorporation of Yb3+/Er3+ ions in the Na/La-site of NaLaMo2O8 phase. The UC emission intensity of transparent GCs was significantly enhanced compared to precursor glass. The green light emission in the UC is a three-photon absorption process. The 2.0Yb3+/0.1Er3+(mol%) co-doped GC sample shows the maximum absolute sensitivity of 1.406% K−1 at 473 K, which implies that the as-prepared GC exhibits potential application prospects in the field of optical temperature sensing.

Optical characterization and emission enhancement property of Ag nanomesh structure fabricated by nanosphere lithography

A metal nanomesh structure with regularly arranged nanosized holes has a light transmission property at a certain wavelength region and good conductivity; therefore, it can be applied to the wavelength-selective electrode of optical devices such as organic light-emitting diodes (OLEDs) and solar cells. In this study, Ag nanomesh structures with hole arrays of different sizes and periods were fabricated, and their electrical and optical properties were evaluated. Alq3, a green light-emitting material for OLEDs, was deposited on the fabricated Ag nanomesh, and its transmission, scattering, and photoluminescence (PL) spectra were investigated. The PL intensity of Alq3 was approximately four times higher than that without the Ag nanomesh. Time-resolved PL measurements showed the presence of a short-lived component in all samples with Ag nanomesh, indicating plasmonic emission enhancement. These results indicate that Ag nanomeshes can be applied as plasmonic electrodes in optical devices.

Mechanical, light transmittance properties and simulation study of sustainable translucent lightweight aggregate concrete

To investigate the engineering feasibility of translucent lightweight aggregate concrete (TLAC) in sustainable buildings, this paper focuses on testing the light transmission properties and mechanical performance of TLACs, the light transmission effect in building interiors is simulated and evaluated using automated steps seamlessly integrated with REVIT software and Radiance software. The preparation process of TLACs and the mixture proportions of raw materials were designed by combining translucent concrete technology with self-compacting mortar. The results indicate that the light transmission of TLAC increases with the volume of polymethylmethacrylate optical fiber (POF) incorporated and the diameter of POF, while the compressive strength tends to increase first and then decrease with the increasing volume fraction of POF in the TLAC samples. Moreover, the building lighting simulations show that indoor illuminance will improve significantly with the use of TLACs, which further illustrates the energy savings and structural performance improvements owing to the application of TLAC as a modern construction material.

Optical Properties of Lentil Seed Coats Using Fiber-Optic Spectroscopy

HighlightsA fiber-optic spectroscopy system was set up and validated for measurement of optical properties of lentil seed coat.Light transmission properties of major lentil seed coat types were measured to evaluate their protective ability.Light transmission was detected mainly in the UVA and visible regions in all seed coat types except zero tannin.The protective abilities differed depending on seed coat type (important in breeding for cotyledon protection).Abstract. The light transmission of 20 lentil genotypes, representing six color classes (black, green, tan, brown grey, and zero tannin) was investigated to determine the degree to which seed coats prevent light transmission and possible photodegradation of cotyledon color. A fiber-optic spectroscopy system was set up for measurement; it consisted a deuterium-halogen light source, spectrometer, fiber-optic incidence and transmission probes, and sample holders. The nadir-aligned transmission spectra were measured in wavelength ranges of 250 to 850 nm. To study variability in light transmission of the different seed coat types, the curves were integrated in three wavelength regions to obtain Cumulative UV Transmission (CUVT, 250 to 400 nm), Cumulative VIS Transmission (CVIST, 401 to 700 nm), and Cumulative NIR Transmission (CNIRT, 701 to 850 nm), respectively. Tests for significant differences in light transmission were then done using analysis of variance (ANOVA) via General Linear Modelling and Posthoc GLM Tukey tests. Results showed that all the seed coat types, except zero tannin, showed no detectable transmission of UV light from 250 to 315 nm. Black seed coats showed detectable transmission from 615 to 850 nm, while other seed coat types transmitted varying percentages of light from 315 to 850 nm. The results of ANOVA showed that there were significant (p&amp;lt;0.05) differences in light transmission properties of the major seed coat types. Keywords: Fiber optics, Lentils, Light transmission, Pulse quality, Spectroscopy, Seed coat.