Transparent State Research Articles

Effects of thiols on electro-optical properties of reverse polymer-stabilised liquid crystal films

ABSTRACT Reverse-mode polymer stabilised liquid crystal (RPSLC) can maintain a transparent state without voltage and exhibit excellent light scattering haze performance when voltage is applied, making it suitable for long-term use in smart windows. However, the high operating voltage of polymer stabilised liquid crystal devices necessitates efforts to reduce the driving voltage and enhance the contrast ratio to improve their optical properties. In this paper, we demonstrate that the introduction of a small amount of the thiol monomer into acrylate polymer monomer during UV-induced homopolymerisation and copolymerisation significantly affects the crosslinking density of the polymer network, thereby influencing the electro-optic performance of RPSLC devices. As a result, we have developed a high-contrast RPSLC device with a saturation voltage below 10 V. These findings are crucial for guiding practical improvements in the performance of RPSLC device.

Cholesteric liquid crystal mixtures for the switchable smart windows and light shutters: Electro-optical and dielectric behaviour

Abstract Cholesteric liquid crystal (CLC) mixtures with variable pitch lengths were prepared for the electrical switchable smart window and light shutter applications by taking varied concentrations (2.6, 3.0, 4.0, and 5.0 wt%) of chiral dopant (R1011) having helical twisting power (HTP) 37.6 μm−1 and nematic E7 liquid crystal (LC). The morphological and electro-optical analysis of these CLC mixtures filled in 10µm thick cells were observed and reported herein, the switching of initial planar (P) and initial focal conic (FC) to homeotropic (H) states as well as vice-versa. The operating voltage of the 2.6 wt% of chiral doped CLC cell was relatively lower among all the sample cells compared with other concentrations. The maximum contrast ratio (CR) was observed for 5.0 wt% chiral doped CLC cell with initial planar state. However, the best CR was observed in 2.6wt% CLC cell with initial FC state. The comparative macroscopic views of the P, FC, and H states in the OFF and ON conditions of applied voltage for prepared CLC cells were observed for transparent and opaque states. Further, UV-visible spectroscopy was performed in the P, FC, and H states under the application of an externally applied field to observe the absorbance and band gap behavior of the fabricated CLC cells. Additionally, chiral concentration-dependent dielectric parameters with variable frequency in initial P and FC states of the fabricated cells were also reported. The temperature-dependent phase behavior of all the prepared cells exhibited a slight decrease in the isotropic phase of LC due to the doping of chiral dopants.

Electrically Switchable Multi-Stable Topological States Enabled by Surface-Induced Frustration in Nematic Liquid Crystal Cells.

In liquid crystal (LC) cells, the surface patterning directs the self-assembly of the uniaxial building blocks in the bulk, enabling the design of stimuli-response optical devices with various functionalities. The combination of different anchoring patterns at both substrates can lead to surface induced frustration, preventing a purely planar and defect-free configuration. In cells with crossed assembly of rotating anchoring patterns, elastic deformations allow to obtain a defect-free bulk configuration, but an electrical stimulus can induce disclination lines. The disclination network is preserved without applied voltage. Depending on the electric field treatment and geometrical parameters, different multi-stable states with and without disclinations are obtained. This is demonstrated with the help of dual-frequency LCs, for which the frequency dependent dielectric properties allow repeatable switching between multi-stable states. Topological protection and the associated energy barrier between different states explains the observed metastability. The obtained configurations are retrieved with Q-tensor simulations and the validity is confirmed by matching optical simulations with experimentally obtained microscopy images. The realized multi-stable topological states interact differently with light, resulting in distinct optical properties. Optimization allows to switch between a highly transparent state and an opaque state, opening up opportunities for smart windows with low energy consumption.

A bifunctional self-powered electrochromic and thermochromic smart window with enhanced privacy protection ability

A bifunctional self-powered chromic smart window can achieve four distinct states: a highly transparent state, a milky white state (thermochromic), a blue color state (electrochromic), and a nontransparent state (the dual-color private state).

Directly Grown Polyimide Covalent Organic Framework Films with High Electrochromic and Energy-Storage Performance.

Two dimensional covalent organic framework (2D COF) films based on triphenylamine are considered to be promising electrochromic and energy-storage materials owing to their interlayer π-π electron delocalization, one-dimensional (1D) nanopores, and stable chemical structures. Triphenylamine-based 2D COF electrochromic films, nevertheless, rarely exhibit transparency and high optical contrast, which severely limited the scope of their application. In this work, two directly grown triphenylamine-based polyimide 2D COF films, TAPA-PMDA and TAPA-NTCDA PI COF, were prepared through solvothermal technology. Their morphologies were assembled into hierarchical nanoporous structures in the form of strips and gravel-like nanograins, respectively. Both the TAPA-PMDA and TAPA-NTCDA PI COF films exhibited a transparent bleached state and high optical contrast. Their optical contrasts were 77.6% at 752 nm and 60.4% at 708 nm, respectively. Interestingly, the TAPA-NTCDA PI COF film could exhibit multicolors (transparent, red-gray, and blue-gray) through regulating the contributions of the electron transition from HOMO to SOMO and HOMO-1 to SOMO of TPA+•. In addition, the TAPA-PMDA and TAPA-NTCDA PI COF films also displayed fast switching and colored/bleached times of 7.3/2.7 and 5.3/8.1 s, respectively. Remarkably, the TAPA-PMDA PI COF film also demonstrated large specific capacitance and excellent charge-discharge rate capabilities. The directly grown polyimide 2D COF films are enormously promising for high-performance electrochromic and energy-storage materials.

Aqueous Solution-Based Switchable Silver Mirror Devices

Dimming glass using electrochromic materials that can control the amount of transmitted light by switching between the colored and transparent states. At the colored state, light is absorbed and is changed to heat resulting in increasing temperature. Meanwhile, a switchable metal mirror between mirror and transparent states, is expected not to absorb light but to reflect light. In the previous study, the switchable silver mirror based on reversible electroplating and electrodissolving on the ITO electrode has been realized. The ionic liquid has been used as a solvent for the silver plating bath. It’s unique solvent, which has the melting salt in room temperature, nonvolatility and ionic electrolyte whereas it’s expensive. Furthermore, aqueous solution is usually employed in the metal plating bath whereas toxic cyanide ion is containing in the bath for stabilizing metal ion. Therefore, in this study, we investigated switchable mirror characteristics using an aqueous solution-based Ag plating bath instead of ionic liquids and wihtout containing cyanide ions.First, an Ag plating bath was prepared by dissolving silver nitrate, sodium sulfate as an electrolyte, sodium citrate as an additive, and ammonia as ligand for silver ion in pure water. Using the Ag plating bath, Ag plating was performed on the ITO modified by a Pd catalyst by applying a constant current of -4 mA/cm2 for 20 sec and the formation of a mirror surface was confirmed. However, the average transmittance in the visible light region is high at about 10%, and the Ag surface looks whitish. This is thought to be due to light scattering caused by the presence of unevenness on the electroplated Ag surface. The surface irregularities would be caused by the lack of dense modification of Pd catalyst, which is the core of silver for smooth plating of silver, so that the conditions to make more highly dispersed Pd catalyst were investigated. Pd strike plating was performed by changing the current density at the same charge. When the current density increased from -5 to -40 mA/cm2, the grain size of Pd catalyst gradually decreased from 130 nm to 61.6 nm. The dispersibility of Pd catalyst also increased with decrease in particle size. When the Pd-modified ITO at the current density of -40 mA/cm2 was plated with Ag by applying a constant current of -4 mA/cm2, a mirror surface with a low transmittance of less than 1% was successfully formed.After Ag plating, Ag dissolution was also investigated by applying a constant current of +4.0 mA/cm2 under the potential of +0.25 V vs. Ag/Ag+ and then a constant potential of +0.25 V vs. Ag/Ag+ . However, black residue was remained on the ITO after dissolving the plated Ag on the Pd-modified ITO. Therefore, the catalyst was changed from Pd to platinum in order to complete Ag dissolution from the ITO. Pt has the advantage of catalytic property and electrochemical stability compared to Pd. Complete dissolution was achieved by plating and dissolution using Pt-modified ITO under the same conditions as those for Pd-modified ITO.The repeating cycle of Ag plating and dissolution was carried out on the Pt-modified ITO until three cycles. At the three cycles, the un-plated region appeared on the upper part of the mirror surface. In order to resolve this problem, we changed the configuration of the equipment to prevent the influence of the Ag plating bath interface, and succeeded in disappearing the un-plated region. Therefore, it is considered that the Ag plating is affected by the oxygen at the plating bath interface during Ag plating.Switchable silver mirror device will be fabricated using an aqueous Ag plating bath. The device shape would prevent the influence of atmospheric oxygen because of the closed system. The device will be repeatedly switched between the transparent and mirror states to evaluate the cycling characteristics of the aqueous solution-based switchable silver mirror device.

Effect of Pt Catalyst Instead of Pd on Switchable Ag Mirror Devices

Electrochromic devices can control the transmittance of incident light between transparent state and color state under electrical bias, and has already been put into practical use in airplane windows and other applications. However, it has some drawback that the temperature rises due to absorption of light in the color state, and the heat is radiated inside. Meanwhile, the Ag mirror device that reversibly switches between transparent state and mirror state has attractive attention due to suppressing heat radiation. Since specular reflection is used in the mirror state, the Ag mirror device has an advantage over electrochromic device in that it does not emit heat and can suppress increases in room temperature.In the previous study, Ag mirror device based on reversible silver plating on Pd-modified ITO electrodes has been reported. The Pd-modified ITO electrode is prepared by electrochemical reduction of palladium ion to get highly dispersed Pd nanoparticles on ITO surface. Pd becomes a nucleation site for Ag plating, resulting in formation of a smooth mirror surface. The Ag plating bath consists of silver nitrate, and citric acid in the mixture of acetonitrile and ionic liquid. When a negative voltage is applied in this plating liquid, the Ag⁺ is reduced to Ag metal on the ITO electrode, forming a mirror surface of Ag. Conversely, when a positive voltage is applied, the plated Ag is oxidized and dissolved in the Ag plating bath, resulting in return to a transparent state. A problem with the Pd catalyst used in this device is that Pd gradually dissolves as the number of cycles increases. In this study, in order to solve this problem and to improve cycle durability, we will consider change of the catalyst from Pd to Pt, which is a noble metal with catalytic property and electrochemical stability.We prepared a new Pt plating bath consisting of hexachloroplatinic acid(IV) hexahydrate and hydrochloric acid in pure water. Pt modification on the ITO electrode was performed by applying a constant current of -10 mA/cm2 for 1.0 sec. Although the Pt-modified ITO electrode succeeded in switching between the mirror state and the transparent state, the switching characteristics degraded with increasing number of cycles. We assume that the degradation was caused by that the amount of modification of the Pt catalyst could not be controlled because the reducing current for Pt metal formation was also used for hydrogen generation in the acid solution. Thus we changed from acidic condition to basic condition in the Pt plating bath. We will conduct SEM image analysis and transmittance measurements to clarify the amount and form of Pt modification. After that, we will search for suitable Pt modification conditions for application to the silver mirror device, and examine whether it is possible to switch between a mirror state and a transparent state, and to improve the number of cycles.

Development of New Light-Dimming Film Using Black Electrochromic Inks

Windows serve the purpose of allowing people to see outside from inside. However, excessive sunlight and heat can enter through windows, disrupting the indoor thermal environment. In the case of vehicles, heat can accumulate quickly in the enclosed space, and temperatures on dashboards can exceed 80°C in summer, jeopardizing the comfort and safety of passengers and drivers without proper heat shielding measures. Our research group is developing a new light-dimming film that can be used for automotive applications. This light-dimming film uses electrochromic principles to produce color change and heat shielding properties through electrochemical effects caused by the application of voltage. This light-dimming film can be fabricated using a wet coating process, which is expected to be highly productive, low-cost, and easily applicable to large-area applications. We are developing a complementary device by combining Prussian blue (PB)-type complex nanoparticles and tungsten oxide (WO3) nanoparticles (NPs). In this prototype device configuration, the electrochemical response produces a colorless transparent state and a dark blue color change, and when colored, the transmittance in the near-infrared region can be reduced to 1% or less. When applied to automobile windows, the performance of cutting heat rays contained in sunlight under hot weather can reduce the air conditioning load, which is expected to reduce fuel consumption or electricity costs in EV vehicles. On the other hand, this dark blue colored state has design issues such as matching with car body color and luxury. To solve these issues, this research is exploring and developing new black electrochromic material such as CuO nanoparticles, etc. In PRiME, we report on the progress in the development of the black electrochromic materials.

Water-Vapor-Triggered Dual-Mode Optical Responses in Rare-Earth-Doped Hollow Nanospheres.

Multimode responsive optical materials are garnering ever-increasing attention due to their diverse applications. This work showcases a film assembled with rare-earth-doped CaF2 hollow nanospheres that exhibit water-vapor-triggered dual-mode optical responses. Upon exposure to flowing water vapor, the film rapidly (less than 1.5 s for a 7.7 μm thickness) transitions to a transparent state and simultaneously undergoes a sharp decrease in the photoluminescence intensity. Both of these changes fully reverse upon water evaporation, demonstrating an impressive reversibility over at least 200 cycles. The water-vapor-induced dual-mode responses are attributed to the altered incident light propagation path stemming from the similar refractive indices between CaF2 and water, coupled with the water-induced energy loss of the rare-earth ions. The fabrication of encryption patterns displaying separate signals in multiple channels, as well as the demonstration of noncontact sensing for water vapor distribution, underscore the promising application potential of this dual-mode responsive system.

Public Information Disclosure in Village Governance

One of the objectives of public information disclosure, in accordance with Law No. 14 of 2008, is to realize transparent, effective, efficient, and accountable state administration. The purpose of this research is to describe the implementation of public information disclosure in village governance. The research locus is Tonsewer Village, West Tompaso District, Minahasa. The research method used is descriptive qualitative, with data collection techniques including observation, interviews, and documentation. The results indicate that Tonsewer Village has the potential to become a role model for other villages in implementing good governance and e-governance, particularly in digital public information disclosure in Minahasa. However, there are several challenges, such as the lack of public understanding of the importance of information disclosure, limited technological infrastructure, insufficient human resource capacity within the village government, and low public participation in accessing public information. Although the village already has a website containing public information, it is not yet optimal and needs further improvement. This study concludes that it is necessary to enhance the capacity of village officials, develop technological infrastructure, and improve community digital literacy to enhance public information disclosure in Tonsewer Village.

An optimal transformation method for inferring ocean tracer sources and sinks

Abstract. The geography of changes in the fluxes of heat, carbon, freshwater and other tracers at the sea surface is highly uncertain and is critical to our understanding of climate change and its impacts. We present a state estimation framework wherein prior estimates of boundary fluxes can be adjusted to make them consistent with the evolving ocean state. In this framework, we define a discrete set of ocean water masses distinguished by their geographical, thermodynamic and chemical properties for specific time periods. Ocean circulation then moves these water masses in geographic space. In phase space, geographically adjacent water masses are able to mix together, representing a convergence, and air–sea property fluxes move the water masses over time. We define an optimisation problem whose solution is constrained by the physically permissible bounds of changes in ocean circulation, air–sea fluxes and mixing. As a proof-of-concept implementation, we use data from a historical numerical climate model simulation with a closed heat and salinity budget. An inverse model solution is found for the evolution of temperature and salinity that is consistent with “true” air–sea heat and freshwater fluxes which are introduced as model priors. When biases are introduced into the prior fluxes, the inverse model finds a solution closer to the true fluxes. This framework, which we call the optimal transformation method, represents a modular, relatively computationally cost-effective, open-source and transparent state estimation tool that complements existing approaches.

Surface-induced nano-generator utilizing a thermo-responsive smart window based on ionic liquid aqueous solution that exhibits lower critical solution temperature type phase separation

We demonstrate a surface-induced nano-generator utilizing a thermo-responsive smart window based on ionic liquid aqueous solution that exhibits lower critical solution temperature (LCST) type phase separation. This smart window was fabricated by filling an aqueous solution of [nBu4P][CF3COO] between the glass substrates coated with two different polymers: a polyimide with an alkyl side chain and an amorphous fluoropolymer. Below the LCST, the transmittance of the smart window was 87 %, nearly identical to that of a glass substrate. In contrast, when heated above the LCST, the [nBu4P][CF3COO] aqueous solution undergoes phase separation, causing the [nBu4P] cations and [CF3COO] anions to adsorb onto the polyimide with the alkyl side chain and the amorphous fluoropolymer facilitated by the surface pinning effect. This adsorption process results in the smart window generating electricity while transitioning to an opaque state. Therefore, the proposed smart window functions as an electricity-generating thermo-responsive device that can switch between transparent and opaque states in response to temperature changes.

A Multimode Dynamic Color-Changing Device for Smart Windows Based on Integrating Thermochromic and Electrochromic Properties.

Electro- and thermochromic materials have been greatly applied in smart windows and displays due to the excellent properties of color variation and solar radiation. However, the mono color and single response to voltage and temperature hinder their application and development. Here, a multimode dynamic color-changing device (T/ECD) was developed by integrating the electrochromic property of synthetic viologen dyes and the thermochromic properties of hydroxypropyl acrylate (HPA). The T/ECD achieves four modes of optical regulation, namely, colorless transparent state, tinted transparent state, colorless opaque state, and tinted opaque state, which can be regulated independently/coordinately using heat and voltage. The optimized T/ECD switched color at 1.2 V with 15 s or adjusted the transparent/opaque state at >34 °C with 46 s. In addition, based on the red viologen (ViO-R), green viologen (ViO-G), and blue viologen (ViO-B) dyes, colorful T/ECDs were successfully designed and fabricated, and T/ECDs have excellent cycling properties, expanding the application requirement. Moreover, we demonstrated their application in smart windows and privacy protection. The design philosophy and successful exploration have great prospects for energy-saving buildings, displays, and information masking/storage systems.

Influence of Corporate Information Transparency on Foreign Institutional Investors' Shareholding Behavior: Evidence from Public Listed Companies in China

In 2003, China implemented the Qualified Foreign Institutional Investor (QFII) system, which has garnered considerable interest from international institutional investors in the mainland market. As global investors, QFIIs depend significantly on precise, thorough information to bolster their investing criteria. Consequently, the transparency of corporate information becomes a crucial factor for QFIIs. However, due to the relatively late development of the Chinese market, an imbalanced structure of listed companies and information asymmetry, the information disclosure of listed companies has been subject to certain degrees of distortion. Therefore, to better facilitate the development of China's securities market and to help QFIIs fully realize their advanced value investment strategies, this paper aims to study the impact of corporate information transparency on the stockholding behavior of foreign institutional investors. This paper begins by reviewing the literature on the factors influencing institutional investor holdings, corporate transparency, and the characteristics of foreign institutional investors' stockholding. It then defines the concepts of corporate information transparency and foreign institutional investors, analyzes the current state of information transparency in Chinese listed companies, and examines the development of the QFII system in China. The theoretical framework explores the mechanisms through which corporate information transparency influences the stockholding behavior of foreign institutional investors. In the empirical analysis, the paper plans to measure the information transparency of listed companies from three perspectives: earnings quality, information ratings by the Shenzhen Stock Exchange, and the number of analyst followings, to investigate how corporate information transparency influences QFII stockholding behavior.

Robustly Flexible, Highly Transparent, and Polymerization-Regulated Polyimide Aerogel Membranes as Efficient Thermal Insulators for Solar Collection.

Efficient thermal insulators that can maintain their efficacy at extreme temperatures are in pressing demand, particularly in fields such as energy saving, aerospace, and sophisticated equipment. Herein, a novel and facile polymerization-regulated optimal strategy is adapted to realize the comprehensive performance of polyimide (PI) aerogel membranes with mechanical robustness, high flexibility, hydrophobicity, light transmittance, and efficient thermal insulation. Benefiting from the hydrolysis of monomers and chemical imidization reaction process verified by a thermo-chemo-mechanically coupled theoretical model, the viscosity of precursors, shrinkage rate, and microstructure of aerogels are precisely controlled, leading to a low thermal conductivity range of 0.023-0.044 W/(m·K). The fabricated PI aerogel membranes, which undergo a remarkable transformation from their initial brittle and opaque nature to a state of high flexibility and transparency, exhibit a 3.0 times increase in tensile strength (4.6 MPa) and a 8.4 times improvement in elongation at break (20.6%) over previous studies while demonstrating an exceptional light transmittance of 92.5% across a wide spectral range from 500 to 2500 nm. Additionally, the PI aerogel membranes possess superior mechanical properties and a wide temperature resistance range extending from -196 to 300 °C. These flexible PI aerogel membranes can be effectively adjusted to meet the practical application of a circular ring solar thermal collector, which displayed a high solar heat collection temperature of 135 °C at a thickness of 0.5 mm. The coordination between the thermophysical properties and mechanical properties of the PI aerogel membranes in this work holds great promise for application requirements of thermal insulators in optical elements under harsh environments.

Scattered-fields-induced tunable narrow resonance in low-index dielectric meta-lattices for transflective display

The development of a transflective display is important for reducing the energy consumption of an outdoor display-device. Currently, it is desirable to have a transflector which can be switched between its reflective and transparent states. The present work provides a novel yet simple route for the development of such a transflector based on one-dimensional (1D) meta-lattice systems. The system studied is shown capable of exciting tunable narrow resonance in the reflectance spectra through the generation of the scattered-field-induced polarizing-field in the system. Surprisingly, while most work on dielectric metasurface relies on high-index material, here it is found that the phenomenon can be achieved with common low-index material. Hence, it is a promising alternative for the development of future display technology with more economical operational cost.

Low-voltage and high-contrast polymer dispersed liquid crystals enabled by ferroelectric fluoro-copolymer doped polyimide film

Smart windows incorporating polymer dispersed liquid crystal (PDLC) technology provide user-friendly operation and play a significant role in intelligent buildings and building energy conservation. Long standing issues of the PDLCs such as high driving voltage, low contrast ratio, and narrow viewing angle hinder their applications. Here PDLCs are sandwiched between the hybrid substrates composed of the ferroelectric polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE)) copolymer and the homogeneous polyimide. The high dielectric constant and ion-trapping ability of ferroelectric copolymers increase the effective voltage drop in the PDLCs. Concurrently, the local electric field created by large dipole moment of ferroelectric copolymers triggers the alignment of liquid crystals (LCs) along the applied field. These synergistic effects contribute to a substantial decrease in the driving voltage of PDLCs. In the opaque state, the random dipole moments in ferroelectric copolymers disrupt the LC orientations near hybrid substrates, thereby increasing the light scattering and reducing the transmission of PDLCs. Consequently, the proposed PDLCs exhibit a contrast ratio ∼2× higher compared to the conventional PDLCs at normal incident. Moreover, the proposed PDLCs demonstrate a wider viewing angle in the transparent state compared to conventional PDLCs. This development promises energy-efficient, eco-friendly, and cost-effective smart windows.

Highly insulated hydrogen powered vacuum gasochromic smart windows for energy-efficient buildings

Switchable active hydrogen powered gasochromic smart windows present an appealing option for energy-efficient building integration, offering two controllable transparencies between ON and OFF states compared to traditional windows. Implementing such glazing in cold-climate buildings requires minimizing the total heat transfer across the glazing, achievable through vacuum-insulated glazing resulting in the retrofitting to obtain energy efficient building. This study investigates the potential of vacuum gasochromic (VGC) windows to enhance the energy efficiency of buildings in diverse climatic conditions, focusing on London, UK, and New Delhi, India. Comparing traditional single-glazing and double-glazing windows with vacuum-gasochromic windows in terms of thermal performance, energy demand, and dynamic control over solar heat gain and visible light transmission are evaluated using advanced simulation techniques with SketchUp, OPTICS6, WINDOW 7.8 and EnergyPlus 9.6. Results reveal that vacuum gasochromic windows exhibit superior thermal insulation with significantly lower U-values of 1.559W/m2K, reducing heat transfer and energy demand for heating and cooling. Vacuum gasochromic opaque states demonstrate exceptional performance in minimizing energy transfer, making them the most energy-efficient option, especially in warm climates like New Delhi with 9544.4 kWh. Conversely, vacuum gasochromic transparent state shows promise in reducing heating demand in London's cold climate by 9.43 %, highlighting their adaptability. Moreover, vacuum gasochromic windows allow dynamic control over solar heat gain and visible light transmission, enabling occupants to adjust transparency based on weather conditions and preferences.

Hierarchical crystalline/defective NiO nanoarrays with (111) crystal orientation for effective electrochromic energy storage

Developing high performance electrochromic materials with energy storage function is essential for next generation smart display devices. Here, a double-layer NiO film (NiO-dl) was prepared by compositing the defective NiO (d-NiO) with the crystalline NiO (c-NiO), with a unique prismatic nanosheet array structure. The synergistic effect as well as the large active area with defect sites and valence modulation brought about by the (111) crystal plane-oriented growth of the sputtering process can promote the intercalation and extraction of OH− and Li+, which greatly enhances the electrochemical properties. Specifically, the NiO-dl film achieves a prominent optical modulation covering visible region (89.5 % in KOH and 64.8 % in Li+ electrolyte at 550 nm) and near-infrared region (54.5 % in KOH and 37.2 % in Li+ electrolyte at 1000 nm), a high transparent bleached state (92.7 %), a superior coloring efficiency (44.7 cm2 C−1) and robust stability (95.1 % retention after 1000 cycles). A high area capacitance of 99.5 mF cm−2 at 0.14 mA cm−2 with the promising cycling performance exhibits the supercapacitor characteristics. The comprehensive evaluation of the NiO-dl film demonstrated its exploitative potential application in electrochromic energy storage fields.

Reverse Mode Polymer Stabilized Cholesteric Liquid Crystal Flexible Films with Excellent Bending Resistance.

The reverse-mode smart windows, which usually fabricated by polymer stabilized liquid crystal (PSLC), are more practical for scenarios where high transparency is a priority for most of the time. However, the polymer stabilized cholesteric liquid crystal (PSCLC) film exhibits poor spacing stability due to the mobility of CLC molecules during the bending deformation. In this work, a reverse-mode PSCLC flexible film with excellent bending resistance was fabricated by the construction of polymer spacer columns. The effect of the concentration of the polymerizable monomer C6M and chiral dopant R811 on the electro-optical properties and polymer microstructure of the film were studied. The sample B2 containing 3 wt% of C6M and 3 wt% R811 presented the best electro-optical performance. The electrical switch between transparent and opaque state of the flexible PSCLC film after bending not only indicated the excellent electro-optical switching performance, but also demonstrated the outstanding bending resistance of the sample with polymer spacer columns, which makes the PSCLC film containing polymer spacer columns have a great potential to be applied in the field of flexible devices.