A new strategy aimed at significantly enhancing the anisotropic conductivity of hydrogel materials, along with a simple construction technology and design concept, are proposed. Anisotropic conductive hydrogel materials have attracted much attention from researchers in the field of flexible electronics for their inherent excellent properties. However, the anisotropic conductivity of the existing conductive hydrogels is not high and the preparation methods are complex. Herein, fluorescent-highly conductive anisotropic Janus-type nanoribbon hydrogel array film (named JNHAF) is successfully prepared using a combination of parallel electrospinning and post-polymerization as an example of the study. Highly oriented [2,7-dibromo-9-fluorenone (DF)/gelatin (GE)]// [carbon black (CB)/GE] Janus-type nanoribbon is used as the building block. The composition as well as the arrangement of Janus-type nanoribbons are microscopically designed and regulated to effectively separate the conductive and insulating materials, so that the samples can achieve highly anisotropic conductivity and obvious green fluorescence. When the mass ratio of GE to CB is 1:0.1, the conductive anisotropy ratio of JNHAF can reach 1.12 x 105. The degree of anisotropic conductivity of JNHAF is significantly improved compared with existing reported anisotropic conductive hydrogels, and the preparation method is simple. JNHAF responds quickly to light, tensile strain, and temperature, making it suitable for assembling multi-stimulus responsive sensors. JNHAF has excellent flexibility, degradability, mechanical properties and a certain degree of sensitivity (gauge factor of 4.29), and is used for human joint motion detection with an obvious response signal. The design idea and construction technology of this hydrogel breaks through the technical bottleneck of the low degree of anisotropy of conductive hydrogels, which will lead and expand the scientific frontiers of anisotropic conductive hydrogel materials, and provide novel design ideas and theoretical values for new hydrogel materials.

A new strategy to substantially increase the degree of anisotropic conductivity of hydrogel materials and a new technique to establish the universal construction of multifunctional highly anisotropic conductive hydrogel materials are proposed. The highly oriented [double network]//[single network] Janus nanobelts viz. [Tb (TTA)3(TPPO)2/gelatin (GE)]//[polyaniline (PANI)/GE] Janus nanobelts used as building units are fabricated by parallel electrospinning technology, and the anisotropic conductive-luminescence double-functional Janus nanobelt hydrogel array membrane (recorded as JAHM) is constructed. Using Janus structure as the building unit avoids adverse interactions between conductive and luminescent materials, resulting in excellent green luminescence and high conductivity of JAHM. The conductive side of Janus nanobelt is further cleverly designed as a double network structure with physical cross-linking of PANI and GE chains, which is linked by hydrogen bonding to increase the water content and conductivity, and thus improve the degree of anisotropic conductivity, the insulating side of Janus nanobelt is GE single network structure containing Tb(TTA)3(TPPO)2. The integration of hydrogel single and double network structures is realized in Janus nanobelt and the degree of anisotropic conductivity of JAHM is up to 2.41 x 105. Compared with the reported anisotropic conductive hydrogel, the anisotropic conductivity of JAHM is significantly improved, and the preparation method is simple, which solves the complex problem of complicated preparation method of traditional anisotropic hydrogels. JAHM responded rapidly at different tensile strains and different temperatures, and the assembled strain sensors are sensitive to human joint motion detection (gauge factor of 4.24). This project can help to provide new routes and technical support for the improvement of the anisotropic conductivity of hydrogel materials, and lay the foundation for the development of other multifunctional conductive hydrogel materials.

Luminescent glass is one of the effective candidates for solid-state lighting. Niobate glass systems have rarely been reported in the field of luminescence applications. In this study, a series of Nb-Si-Na-K luminescent glasses were prepared by high-temperature melting quenching technique. By changing the proportion of each component of the glass matrix, the structure of the glass network can be affected to regulate the luminous intensity and time. The existence of a large number of O-Nb-O and Si-O-Si bonds in the glass network ensures the stable structure of Nb-Si-Na-K luminous glass. The luminescence chromaticity stability of the glass is revealed by CIE coordinate diagram, and the high thermal stability is proved by differential thermal analysis curve. 35Nb2O5-35SiO2-10Na2O-20K2O-1Dy2O3 luminous glass has high transmittance (80%) and high quantum efficiency (41.3%). Moreover, 35Nb2O5-35SiO2-10Na2O-20K2O based glass can achieve effective luminescence under the doping of Dy3+/Eu3+/Sm3+/Tb3+ ions. The results show that Nb-Si-Na-K luminescent glass has the potential to be used in solid state lighting.

A series of Tb3+ ions doped sodium magnesium aluminum borosilicate glasses 15Na(2)O-15MgO-15Al(2)O(3)-20SiO(2)-35B(2)O(3) (abbreviated as NMASB):xTb(3+) (x = 0, 0.2, 0.6, 0.8, 1, 1.5 and 2 %) were prepared by the high-temperature melting method. The structural properties of the glass were explored by analyzing the results of X-ray diffractometer (XRD), infrared and Raman spectra. The Delta T value of Differential scanning calorimeter (DSC) showed good thermal stability of the glass. The optical properties of the glass were studied by absorption spectroscopy, photoluminescence (PL) spectroscopy, CIE chromaticity color temperature, fluorescence decay curve, quantum efficiency and thermoluminescence (TL) curve. The absorption spectrum owned four absorption peaks at 351, 368, 377 and 485 nm, and the optical band gap of the glass with different Tb3+ concentrations was from 3.37 to 3.27 eV. Under the excitation at 377 nm, the NMASB:Tb-\ glass showed several sharp emission peaks centered at 485, 543, 582 and 622 nm, corresponding to the transitions of D-5(4) -> F-7(n) (n = 6, 5, 4, 3), respectively. The fluorescence lifetime was fitted by the three-exponential function ranged from 2.89 ms for NMASB:0.2%Tb3+ to 2.66 ms for NMASB:2%Tb3+, indicating that the glass had high charge separation efficiency. Judd-Ofelt theory was used to fit the intensity parameters Omega(i) (i = 2,4,6), and the absorption oscillator strengths, spectral quality factors, spontaneous transition probabilities, and fluorescence branching ratios of the optical transitions were calculated. The TL curves of pure and Tb-doped glasses both owned two peaks, indicating that there were two different depths of traps in the glass. The luminescence intensity was greatly improved after Tb doping, and the TL intensity of the glass was linearly related to the dose. These results indicate that Tb-doped NMASB glass can be a potential material for blue-green laser and thermoluminescence dosimeter(TLD) applications.

A series of Dy 3 + doped niobiosilicate luminescent glasses have been prepared by high temperature melting using the chemical composition of 35SiO 2 - 35Nb 2 O 5 - 10Na 2 O - 20K 2 O-xDy 2 O 3 (x = 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 mol %). Results of differential scanning calorimetry (DCS) show that the glass matrix has good thermal stability. Presence of [SiO 4 ] and [NbO 6 ] structural units in the glass was confirmed by FTIR and Raman spectral analyses. Results of UV - Vis - NIR absorption spectra show that Dy 3 + doped optical glass can be excited by ultraviolet light, and the transmittance curve displays the high transmittance of the glass. Photoluminescence (PL) analysis reveals that there are three emission peaks: 4 F 9/2 -> 6 H 15/2 (blue light), 4 F 9/2 -> 6 H 13/2 (yellow light), and 4 F 9/2 -> 6 H 11/2 (red light); the highest intensity of the samples is obtained at x = 0.8 mol%, and the variable temperature emission spectrum shows that the emission intensity at 423 K remains above 78.85 % that of room temperature. The CIE chrominance coordinate diagram determines that the chrominance coordinate value is close to the standard white light, the correlation color temperature calculation proves that it is located in the cold white light region. The decay curve can be fitted with the double exponential attenuation equation. The above results show that Dy 3 + doped niobiosilicate glass has the potential to be used as W -LED material.

Effect of Fe/Cd/O doping on the physicochemical properties of alpha-NiS nanocrystals (exhibiting useful optical, electronic, and optoelectronic properties) has been studied by preparing the Fe/Cd/O-doped (2.5/5.0 mol%) alpha-NiS nanocrystals using a pulsed microwave heating method and characterizing them chemically and physically using the available standard methods. X-ray diffraction and energy-dispersive X-ray absorption analyses confirm the phase purity. Atomic force microscopic analysis shows the average particle sizes within 19-20 nm; scanning electron microscopic analysis indicates the spherical shape and homogeneity of the nanocrystals prepared. Optical and magnetic measurements indicate that doping has significantly modified the optical absorption coefficient (with bandgap energy values in the range of 3.62-4.73 eV), photoluminescence yield, and ferromagnetic ordering. Electrical (DC/AC) measurements made at various temperatures (40-150 degrees C) and frequencies (10(2)-10(6) Hz) indicate a normal electrical behavior and increase of electrical/electronic conductivity and dielectric constant due to doping. The study indicates that oxygen (anionic) doping makes alpha-NiS nanocrystals a better electrochemical sensing performer and cathode material for use in storage batteries.

In this paper, Sr2SiO4 phosphors with different Sm3+ concentrations and Sr2SiO4:0.006Sm3+ phosphors obtained from the coal gasification slag as raw materials have been synthesized by the high-temperature solid-phase method. The influence of Sm3+ ions and the purity of SiO2 on the structural and optical attributes of Sr2SiO4 have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) spectrum, photoluminescence (PL) spectra and fluorescence lifetime analysis. XRD results showed that the doping ions have entered into the host lattice, and SEM shown the crystallite sizes have been found to vary from 1 to 3 mu m. PL spectra displayed that the emission intensity of the samples increased with the increase in concentrations of Sm3+ ions. At the optimum doping concentration, the luminous intensity and fluorescence lifetime of the sample prepared by the purified silica is much higher than that of the phosphor prepared by the chemical product silica, which is close to that of the pure chemical reagent. Finally, we explored the application of fluorescent powder in pc-WLED devices. Notably, the devices exhibited excellent luminous performance at 20 mA current. The results demonstrate that coal gasification slag (CGS) product can be used to synthesize brilliant materials with potential uses for the pc-WLED technology.

A series of barium-boroaluminosilicate [30SiO(2)-11Al(2)O(3)-44B(2)O(3)-5BaO-(10-x)K2O-xDy(2)O(3) (with x = 0.25, 0.5, 0.75, 1.0, 1.25, 1.5 mol%)] glasses doped with Dy3+ ions were prepared by the high temperature (melt quenching) method. In the glass matrix, the relationship among structure, luminescence properties, and B/Al ratio was analyzed; also studied are the physical properties of glass and influence of Dy3+ concentration on the luminescence properties. Differential Scanning Calorimeter (DSC) results have shown the glass matrix exhibiting good thermal stability and high resistance to crystallization. FTIR and Raman spectra have confirmed the presence of stretching and bending vibrations of [BO3], [AlO4] and [SiO4] structural units in the prepared glass. The observed UV-Vis-NIR spectra have indicated that the existence of thirteen bands corresponding to the transition Dy3+ ions from H-6(15/2) level to different excited levels; the transmittance curves obtained have shown the transmittance up to 91 %. Increase in Dy3+ concentration is found to decrease the optical band gap; the calculated Judd-Oflet parameter is found to follow the trend Omega(2)>Omega(4)>Omega(6). Photoluminescence studies have shown three emission peaks which could be associated to the transitions: F-4(9/2) -> H-6(15/2) (blue light), F-4(9/2) -> H-6(13/2) (yellow light), and F-4(9/2) -> H-6(11/2) (red light); the maximum intensity obtained for the glass with x = 0.75 mol%, with spacing between Dy3+ ions being 1.9137 & Aring;; and the decay curve could be fitted with double exponential function. The CIE results have revealed that the chromaticity coordinates are closer to that of standard white light, and the color temperature located in the region of cold white light.

The commercial LED has the disadvantages of low thermal stability and poor luminous quality at high temperature due to the organic resin encapsulation phosphor, and luminous glass is one of the effective ways to solve this problem. A series of niobium silicate (SiO2-Nb2O5-Na2O-K2O-Dy2O3-Sm2O3, labeled as SNNKDS) luminous glasses have been obtained by melt quenching method. The results of differential thermal analysis prove the existence of high thermal stability. The infrared spectrum, Raman spectrum and the calculation of physical parameters reveal the excellent thermal stability and stable structure of the prepared glass. The optical properties of luminescent glass have been studied in detail, the energy transfer from Dy3+ ions to Sm3+ ions has been observed, the Dy3+/Sm3+ co-doping glasses can achieve warm white light emission by changing the excitation wavelength and the doping amount of Sm3+. The variable temperature emission spectrum of SNNK:0.8D0.4S is analyzed. At 423 K, the comprehensive emission intensity is 79.91% of that at room temperature, the ΔC value of colorimetric shift at 473 K is 2.1×10-2. The warm white light output with excellent correlated color temperature (3746 K) has been achieved using glass samples encapsulated with 395nm LED chip. The analysis shows that Dy3+/Sm3+ co-doped niobium silicate glasses can be regarded as a candidate for the w-LED applications.

Niobium silicate based materials have become a research focus due to their interesting photoelectric properties. In this study, a series of 35SiO2-35Nb2O5-10Na2O-20K2O-xSm2O3 (with x = 0.2/0.4/0.6/0.8/1.0/1.2 mol%) luminous glasses were prepared and characterized. Presence of Si-O-Si and O-Nb-O bonds makes these glass samples to have extremely high thermal stability; and addition of alkali metal ions increases their disorder. The lower optical bandgap and higher Urbach energies obtained prove that it is conducive to the microenvironment of luminescence. They exhibit strong absorption in the ultraviolet region and small chromaticity shift at high temperature. Glass with x = 0.8 mol% has been found to have the highest emission intensity, 84.85% transmittance, and 98.83% color purity, which proves the feasibility of the prepared luminous glass as the red light composition of LED. Concentration quenching can be associated mainly to the nearest neighbor ion interaction; increase of Sm3+ concentration causes decreasing distance of luminescent ions. The temperature range of 298-423 K shows promising application potential in optical temperature measurement, with maximum absolute sensitivity of 0.521% K-1 and maximum relative sensitivity of 0.550% K-1 being observed. Unique properties observed for the Sm3+ doped niobium silicate glasses indicate their development value in the field of multifunctional materials.

Studies have been made to understand the effect of anionic doping (with 2.5 wt% sulfur) on the physicochemical properties and photocatalytic, and antimicrobial activity applications of the interesting and useful (CdO)1- x(Mn3O4)x (x = 0.0/0.25/0.50/0.75/1.0) nanocrystals (synthesized by a microwave-assisted solvothermal method, and annealed at 650 degrees C). X-ray diffraction, electron microscopic (SEM/TEM) and EDX spectral analyses have shown that the synthesized samples are of high phase purity having spherical shaped morphology with crystallite sizes in the range of 11-22 nm. UV-visible spectral (in the wavelength range 200-800 nm) and AC electrical measurements (in the temperature range 40-160 degrees C and with frequency range 100 Hz-1 MHz) have indicated tuning of optical and electrical properties on doping. Capability in photocatalytic degradation (with Methylene Blue dye under UV-visible light irradiation) and antimicrobial activity (against gram positive Bacillus Subtiles, gram negative Escherichia Coli and fungus Candida Albicans) have also been studied for the 10 samples (including the 5 un-annealed samples) considered.

Eu2+ and Ce3+ ions with different concentrations of single/co-doped Sr2SiO4 phosphors have been successfully prepared using a high-temperature solid-state reaction. The influences of Eu2+ and Ce3+ ions on the construction and optical performance behavior of Sr2SiO4 have been investigated by X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), scanning electron microscope (SEM), ultra-violet-visible (UV-vis), and photoluminescence (PL) spectral analyses. XRD results revealed that the doping ions have entered the host lattice, and SEM showed the crystallite sizes have been found to vary from 1 to 6 mu m. The intensity of the absorption spectra for the co-doped samples was larger than that of the single-doped sample. PL spectra displayed that the emission intensity of the samples strengthened as the amount of concentrations of Eu2+ and Ce3+ ions. The concentration quenching of single/co-doped phosphors was related to dipole-dipole interaction, and the energy from the 2F5/2 transition to the 5D level of Ce3+ was effectively transferred to the 4f65d level of Eu2+. The Eu2+ and Ce3+ ions co-doping samples resulted in a light green color. The findings from the study reveal that the Eu2+ and Ce3+ ions single/co-doped Sr2SiO4 phosphors would be potential candidates for the LED application.

The Na-p zeolite using oil shale ash (OSA) as raw material was synthesized by hydrothermal synthesis method. The effects of alkali concentration, acid concentration, crystallization temperature, and crystallization time on the formation of Na-p zeolite were studied. The optimal synthesis conditions for converting oil shale ash into Na-p zeolite are: acid leaching concentration is 10%, NaOH dosage is 7 g, crystallization temperature is 130℃ and crystallization time is 12 h. It is found that adding some coal fly ash to oil shale ash can improve the adsorption performance of zeolite materials. The specific surface and the crystallinity of zeolite prepared from OSA and coal fly ash (CFA) are greater than that of pure OSA. The absorbion experiment results indicate that the zeolite synthesized by adding coal fly ash to the oil shale ash own richer pore structure and higher adsorption efficiency for methylene blue (99.2%). The thermodynamic and kinetic processes of methylene blue adsorption by pure oil shale ash, zeolites synthesized from oil shale ash, and zeolites synthesized from oil shale ash with coal fly ash have been systematically studied. These results reveal that the zeolite synthesized in the present study with high absorption can be used as a promising material for the wast water treatment.

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Alkali halides crystals occur in either NaCl structure or CsCl structure and the crystalline alkali halides are important both purely scientific and technological. The importance and applications in several optical, optoelectronic, and electronic devices led to the preparation and characterization of polycrystalline aggregates (with reduced crystallite sizes at or below micro level) of several pure and hybrid (mixed and/or doped) alkali halides in the recent decades. Polycrystalline aggregates of alkali halides can be cut into any shape and polished for their utility in device applications. There are several reports available in the past about two decades on the polycrystalline aggregates of simple and hybrid alkali halides. Presented herewith is an overview of various studies made on the preparation and properties of polycrystalline aggregates of simple and hybrid alkali halides (both single-phased and multi-phased) focusing the results reported by the present author and his co-workers. The reported results have indicated that the optical (particularly absorption and photoluminescence) and electrical (particularly dielectric) properties can be tuned significantly by reducing the crystallite sizes of the polycrystalline aggregates of alkali halides.

Obtaining spherical shaped Co3O4 nanocrystals/nanoparticles (considered to be a very promising functional material) at low-cost with chemical purity, reduced crystallite size and useful physicochemical properties has been considered to be challenging. The present work (an attempt in this direction) involves the preparation of spherical shaped Co3O4 nanocrystals from cobalt acetate (dissolved in ethylene glycol) by a polyol synthesis route using a domestic microwave oven along with calcination at a suitable temperature (100/200/300/400 °C used to understand the phase evolution). X-ray diffraction (XRD, including Rietveld), infrared spectral, Raman spectral, energy dispersive X-ray absorption spectral and electron microscopic (SEM/TEM, including SAED) analyses have shown good crystallinity, chemical phase purity, spherical shape, reduced crystallite/particle size and narrow size distribution for the Co3O4 nanocrystal sample calcined at 400 °C. UV-Vis-NIR spectral analysis has shown the existence of multiple bandgap energies (1.51–1.98, 2.44–2.61 and 2.81–3.43 eV). Magnetic measurements have confirmed the antiferromagnetic nature possessing considerable magnetization below and above Neel temperature (TN), which indicates the presence of weak ferromagnetic ordering. The crystallite/particle sizes obtained for the sample calcined at 400 °C through XRD analysis, TEM analysis and using TN value (37.3 K) are 32.0, 33.6 and 31.3 nm, respectively. The method of preparation used is highly yielding, low-cost and more advantageous than many other methods used in the past.

Green emitting NaCl:XTb [ X = 0.0, 0.002, 0.004, 0.006, 0.008, 0.01 and 0.02] single crystals were grown by adopting the Czochralski method and their structural, mechanical and optical properties were studied by carrying out X-ray diffraction (XRD), micro-hardness, optical absorption, photoluminescence (PL), thermoluminescence (TL), etc. measurements. XRD results revealed the absence of lattice distortion due to doping with Tb ions. Hardness analysis displayed more hardness for the Tb-doped crystals than for the pure NaCl crystal. Optical absorption spectra confirmed five main peaks corresponding to 4f8 & RARR;4f75 d1(8S) and 7F6 & RARR;5LJ=9,10 transitions of the Tb3+ ions. PL emission spectra (excitated at 372 nm) indicated the maximum intensity peak at 545 nm corresponding to 5D4 & RARR;7F5 transition of the Tb3+ ions. The emission peak intensity was found to increase with the increase in Tb concentration; and the CIE coordinates of NaCl:0.02 Tb were found as x = 0.3008 and y = 0.5000, located in the green region. TL glow curves exhibited higher intense peaks for the NaCl:0.02 Tb crystal irradiated with & gamma;-ray; the peak parameters (E, s, & mu;g and b) were also estimated. Dose response and energy storage stability of the NaCl:0.02 Tb crystal irradiated with & gamma;-ray were studied for dosimetry application. The research results show that the NaCl:Tb crystal would be potential candidates for the WLEDs and TLD applications.

KCl0.5Br0.5:0.01Ce3+,XPr3+ (X = 0.002, 0.004, 0.006, 0.008, 0.01, 0.02 and 0.04) crystals have been successfully grown by using the Czochralski method, and the structural, optical and mechanical properties have been investigated by making X-ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS), optical (UV–Vis) absorption, photoluminescence (PL) and micro-hardness measurements. XRD and XPS studies indicate that Ce and Pr ions have entered into the KCl0.5Br0.5 crystal matrix and created vacancies to satisfy charge conservation. The UV–Vis absorption spectra recorded have shown peaks observed at 207, 246, 282, 334, 445, 469, 483 and 590 nm. The PL emission spectra of the crystals have shown that the peak emission increases with the increase in Pr ion concentration and obtains the maximum at X = 0.006. The energy transfer between Ce3+and Pr3+ ions in the crystals has been investigated. Results of micro-hardness measurement indicate that the elastic stiffness constant and Vickers hardness values increase with the increase in Pr ion concentration.

Pure and O2- (2.5/5.0 wt%) doped (CdS)(1-x)(MnS2)(x) nanocomposites (with x = 0.0/0.25/0.50/0.75/1.0) have been (for the first time) prepared by a simple solvothermal method (with pulsed microwave heating) and characterized structurally, chemically and physically (thermally, electrically, optically and magnetically) by adopting the available techniques. The prepared samples (except the pure and doped CdS) are found to be multi-phased nanocomposites, and are paramagnetic in nature. Average crystallite sizes obtained are within 5.6 and 13.9 nm, and the thermal stability has been found to increase in proportion with the amount of CdS present. Bandgap energies obtained are within 1.8 and 2.2 eV, and significant photoluminescence peaks have been observed; DC and AC electrical measurements along with complex impedance analysis have provided useful results. The present study indicates that the prepared nanocomposites (based on CdS and MnS2) are expected to find utility in optoelectronic and energy devices. (c) 2023 Elsevier B.V. All rights reserved.