Inorganic all-solid-state electrochromic devices with reversible color change between yellow-green and emerald green

2020 ◽  
Vol 56 (69) ◽  
pp. 10062-10065
Author(s):  
Xiang Zhang ◽  
Wenjie Li ◽  
Xi Chen ◽  
Yingming Zhao ◽  
Lebin Wang ◽  
...  

All-solid-state ECDs prepared by evaporation exhibit bright color changes between yellow-green and emerald green.

Author(s):  
Boris S. Tanaseichuk ◽  
Margarita K. Pryanichnikova ◽  
Alexey A. Burtasov

Asymmetric conjugate diynes are of considerable interest because of their ability to solid state polymerization to form polymers with an ordered tough polyene structure. The capacity of conjugated diynes to such polymerization is determined by the presence and nature of the substituents in the side chain diynes and the degree of their distance from the diacetylenic fragment. To evaluate the effect of the distance a bulky substituent of conjugate diyne′s fragment for ability of asymmetric diacetylenes ordered solid state polymerization were prepared 4 alkildiinil′s ether of p-hydroxybenzaldehyde with varying degrees of distance diyne′s fragment from the benzene ring.Synthesis of alkildiinil′s esters of p-hydroxybenzaldehyde was carried out in two stages. At the first stage by alkylation of p-hydroxybenzaldehyde of corresponding of toluenesulfonate′s terminal alkynol or ω-bromalkines in the presence of sodium ethoxide was prepared monoalkinil′s ether of p-hydroxybenzaldehyde, in which the terminal triple bond is separated from the phenoxyl′s fragment 1, 2, 3 and 4 methylene′s groups. Use as a alkylating agent of toluenesulfonate′s terminal alkynols, which differ in low volatility compared ω-bromalkines, gives a fairly high (~ 60%) the yield of desired products. At the second stage according to the method of Kadio-Chodkiewich the condensation-3-brompropin-2-ol with the corresponding monoalkinil′s esters of p-hydroxybenzaldehyde were alkildiynil′s ethers of p-hydroxybenzaldehyde, which have a terminal triple bond is separated from the benzene′s ring 1, 2, 3 and 4 methylene′s groups. The effect of the degree of remoteness of the conjugate diyne′s fragment from the bulk p-formilfenoksil′s substituents on these compounds ability to solid state polymerization under UV irradiation was studied by the asymmetric diynes. About the polymerization rate was judged visually by a color change. All investigated diynes exhibited the ability to solid state polymerization. The rate of it was largely dependent of the number of methylene′s fragments, separating p-formilfenoksil′s ring from diyne′s fragment. If the irradiation of diynes containing 3 or 4 methylene′s fragments, color change of almost colorless to dark brown occurred within 5-6 h, then diynes containing 1 or 2 of the methylene′s fragments was required for 24 h. It goes to show that the increase the length of the methylene′s chain, postpones surround p-formilfenoksil′s fragment from a paired diyne′s fragment, eases  the solid state polymerization. However, the absence of the bright color of the polymer characteristic polydiacetylene′s ordered structures indicates that, polymerization was not well-ordered in out case.Thus, the results showed that administration of methylene′s fragments, causing varying degrees of remoteness of the conjugate diyne′s fragment from the bulk p-formilfenoksil′s fragment, has a significant impact on the ability of asymmetric conjugate diynes to solid state polymerization under UV irradiation. The increase in the degree of remoteness promotes their solid state polymerization, those namely the structure of asymmetric diynes determines their behavior in the polymerization process.


RSC Advances ◽  
2017 ◽  
Vol 7 (15) ◽  
pp. 9373-9380 ◽  
Author(s):  
Yoshiaki Yoshida ◽  
Takeshi Endo

The alternating PVEC and PMI copolymers with various composition ratios exhibited reversible color changes such as halochromism in solution and in the solid-state.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiyu Sun ◽  
Wei Wu ◽  
Limei Tian ◽  
Wei Li ◽  
Fang Zhang ◽  
...  

AbstractNot only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2569
Author(s):  
Mia Kurek ◽  
Nasreddine Benbettaieb ◽  
Mario Ščetar ◽  
Eliot Chaudy ◽  
Maja Repajić ◽  
...  

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.


2021 ◽  
pp. 138700
Author(s):  
Olivia Bouvard ◽  
Maxime Lagier ◽  
Luc Burnier ◽  
Anna Krammer ◽  
Andreas Schüler

2021 ◽  
Vol 224 ◽  
pp. 110992
Author(s):  
Wenjie Li ◽  
Xiang Zhang ◽  
Xi Chen ◽  
Yingming Zhao ◽  
Wenhai Sun ◽  
...  

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.


1996 ◽  
Vol 8 (10) ◽  
pp. 808-811 ◽  
Author(s):  
Shawn A. Sapp ◽  
Gregory A. Sotzing ◽  
Jerry L. Reddinger ◽  
John R. Reynolds

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5574-5585
Author(s):  
Intan Fajar Suri ◽  
Jong Ho Kim ◽  
Byantara Darsan Purusatama ◽  
Go Un Yang ◽  
Denni Prasetia ◽  
...  

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.


2016 ◽  
Vol 10 (1) ◽  
pp. 516-521 ◽  
Author(s):  
Vanessa Dias da Silva ◽  
Eduardo Martinelli S de Lima ◽  
Caroline Dias ◽  
Leandro Berni Osório

Proposition: The purpose of this study was to evaluate in vitro the color changes of esthetic orthodontic elastomeric ligatures of different shades when exposed to four food colorings commonly found in the diet of patients. Materials and Methods: The sample consisted of esthetic orthodontic elastomeric ligatures in the colors pearl, pearl blue, pearl white and colorless, which were immersed for 72 hours in five different solutions: distilled water (control group), coffee, tea, Coca-Cola ® and wine. The color changes of the esthetic orthodontic elastomeric ligatures were measured with the aid of a spectrophotometer, at T1 - as provided by the manufacturer; and T2 - after colorings process. Results: The results indicated that the esthetic orthodontic elastomeric ligatures of all initial hues are susceptible to pigmentation. Among the evaluated colors, all changed the finished look and the color of the samples tested. In ascending order, the color of the samples was as follows: distilled water, Coca-Cola®, black tea, wine and coffee. Conclusion: The substances that have a greater potential for pigmentation in esthetic orthodontic elastomeric ligatures were black tea, wine and coffee, respectively. All shades of esthetic orthodontic elastomeric ligatures are susceptible to color change.


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