Multifunctional Glass Research Articles

Self-reducing induced Eu2+/Eu3+ dual-emitting glasses for anti-counterfeiting and optical thermometry

Eu3+/Eu2+ co-doped glasses possess extensive application potential in diverse fields, including light-emitting diodes and sensors, due to their distinctive luminescent characteristics. To date, numerous strategies have been devised to facilitate the coexistence of Eu3+ and Eu2+ in materials. Among them, adjusting the composition of the glass matrix stands out as a straightforward and reproducible approach. Herein, a series of Eu2+/Eu3+ co-doped borosilicate aluminate glasses were successfully synthesized via a high-temperature melting method. By elevating the ratios of B2O3/MgO and Al2O3/BaO in the matrix, a remarkable self-reduction of Eu3+ in ambient air was achieved because of the structural weakness and lower optical basicity for the designed glass matrix. The reduction of Eu3+ is also related to the formation of EuZn• and VΖn′′ defects. Furthermore, by fine-tuning the melting duration and Eu content, we achieved comparable violet and red emission intensities for both Eu2+ and Eu3+ ions. Under UV irradiation with various wavelengths, anti-counterfeiting patterns fabricated from glass powder exhibited precise and pronounced color changes. Notably, the emission intensity ratio of Eu2+/Eu3+ exhibited a consistent decrease as temperature increased, enabling precise temperature determination with exceptional absolute sensitivity (1.22 % K−1) producibility, and discrimination. These findings hold significant implications for the design of Eu3+/Eu2+ co-doped inorganic multifunctional glasses.

Cross-Scale Industrial Manufacturing of Multifunctional Glass Fiber/Epoxy Composite Tubes via a Purposely Modified Filament Winding Production Line.

In the present research work is demonstrated a cross-scale manufacturing approach for the production of multifunctional glass fiber reinforced polymer (GFRP) composite tubes with a purposely redesigned filament winding process. Up until now, limited studies have been reported towards the multiscale reinforcement direction of continuous fibers for the manufacturing of hierarchical composites at the industrial level. This study involved the development of two different multi-walled carbon nanotube (MWCNT) aqueous-based inks, which were employed for the modification of commercial glass fiber (GF) reinforcing tows via a bath coating unit in a pilot production line. The obtained multifunctional GFRP tubes presented a variety of characteristics in relation to their final mechanical, hydrothermal aging, electrical, thermal and thermoelectric properties. Results revealed that the two individual systems exhibited pronounced differences both in crushing behavior and durability performance. Interestingly, for lateral compression the MWCNT coatings comprising a polymeric dispersant minorly affected the mechanical response of the produced tubes. The crashworthiness indicators of the multifunctional tubes displayed a slight 5% variation to the respective reference values, combined with a more ductile behavior. Moreover, regarding the bulk electrical and thermal conductivity values, as well as the Seebeck coefficient factor, the corresponding tubes displayed a variance of 233% and 19% and an opposite semi-conducting sign denoting a p- and n-type character, respectively.

NIR regeneration and visible luminescence modification in photochromic glass: A novel encryption and 3D optical storage medium

AbstractPhotochromic glass shows great promise for 3D optical information encryption and storage applications. The formation of Ag nanoclusters by light irradiation has been a significant development in the field of photochromic glass research. However, extending this approach to other metal nanoclusters remains a challenge. In this study, we present a pioneering method for crafting photochromic glass with reliably adjustable dual‐mode luminescence in both the NIR and visible spectra. This was achieved by leveraging bimetallic clusters of bismuth, resulting in a distinct and novel photochromic glass. When rare‐earth‐doped, bismuth‐based glass is irradiated with a 473 nm laser, and it undergoes a color transformation from yellow to red, accompanied by visible and broad NIR luminescence. This phenomenon is attributed to the formation of laser‐induced (Bi+, Bi0) nanoclusters. We achieved reversible manipulation of the NIR luminescence of these nanoclusters and visible rare‐earth luminescence by alternating exposure to a 473 nm laser and thermal stimulation. Information patterns can be inscribed and erased on a glass surface or in 3D space, and the readout is enabled by modulating visible and NIR luminescence. This study introduces a pioneering strategy for designing photochromic glasses with extensive NIR luminescence and significant potential for applications in high‐capacity information encryption, optical data storage, optical communication, and NIR imaging. The exploration of bimetallic cluster formation in Bi represents a vital contribution to the advancement of multifunctional glass systems with augmented optical functionalities and versatile applications.image

Fabrication of a robust zwitterionic coating on glass with anti-fogging, anti-frosting, self-cleaning and antibacterial properties via UV-induced grafting polymerization

In this work, glass slides were separately silanized by silane coupling agents, 3-(trimethoxysilyl) propyl methacrylate (TPM) and 3-(mercaptopropyl) trimethoxysilane (MPS). Then, in presence of a photoinitiator, multifunctional hydrophilic coatings were fabricated facilely on these silanized glasses via UV-induced grafting polymerization of zwitterionic acrylic monomer methacryloxyethyl sulfobetaine (SBMA). The results showed that both TPM and MPS silanized glasses could participate in the UV-induced grafting polymerization of SBMA, while more SBMA could be grafted to the former glass to gain a little bit higher hydrophilicity. The structure, morphology and properties of the multifunctional glasses were investigated fully. As the hydrophilic polymer brushes poly(SBMA) (pSBMA) covalently attached to the glass surface, the glasses could render a series of excellent performances, including underwater superoleophobicity, anti-fogging, anti-frosting, abrasion resistance, self-cleaning and antibacterial adhesion, and especially high stability even after being immersed in water for 20 days. The strong interaction of pSBMA and water was confirmed via differential scanning calorimeter (DSC) and Raman spectrum analysis, to explicit the anti-fogging mechanism. Therefore, it is promising that the scalable multifunctional glass fabricated via UV-induced grafting polymerization could be potentially applied in the fields of automobile, bathroom, medical, etc.

Multifunctional Glass Microfluidic Microwave Sensor Attenuator for Detection of Permittivity and Conductivity With Device Protection

Multifunctional Glass Microfluidic Microwave Sensor Attenuator for Detection of Permittivity and Conductivity With Device Protection

A shield of defense: Developing ballistic composite panels with effective electromagnetic interference shielding absorption

The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference (EMI) shielding capabilities through absorption. Six fiber-reinforced epoxy composite panels, each with a different fabric material and stacking sequence, have been fabricated using a hand-layup vacuum bagging process. Two panels made of Kevlar and glass fibers, referred to as (K-NIJ) and (G-NIJ), have been tested according to the National Institute of Justice ballistic resistance protective materials test NIJ 0108.01 Standard-Level IIIA (9 mm × 19 mm FMJ 124 g) test. Three panels, namely, a hybrid of Kevlar and glass (H–S), glass with ceramic particles (C–S), and glass with recycled rubber (R–S) have been impacted by the bullet at the center, while the fourth panel made of glass fiber (G-S) has been impacted at the side. EMI shielding properties have been measured in the X-band frequency range via the reflection-transmission method. Results indicate that four panels (K-NIJ, G-NIJ, H–S, and G-S) are capable of withstanding high-velocity impact by stopping the bullet from penetrating through the panels while maintaining their structural integrity. However, under such conditions, these panels may experience localized delamination with variable severity. The EMI measurements reveal that the highest absorptivity observed is 88% for the K-NIJ panel at 10.8 GHz, while all panels maintain an average absorptivity above 65%. All panels act as a lossy medium with a peak absorptivity at different frequencies, with K-NIJ and H–S panels demonstrating the highest absorptivity. In summary, the study results in the development of a novel, cost-effective, multifunctional glass fiber epoxy composite that combines ballistic and electromagnetic interference shielding properties. The material has been developed using a simple manufacturing method and exhibits remarkable ballistic protection that outperforms Kevlar in terms of shielding efficiency; no bullet penetration or back face signature is observed, and it also demonstrates high EMI shielding absorption. Overall, the materials developed show great promise for various applications, including the military and defense.

Electro-mechanical behavior of multi-functional glass fiber composites under dynamic Mode-I fracture loading

An experimental study was performed to investigate damage sensing and fracture toughness of multifunctional conductive glass fiber composites under dynamic mode-I fracture loading. Carbon nanotubes (CNTs) were dispersed within the epoxy matrix using a shear mixing and sonicating process. An electrostatic wet flocking process was used to reinforce milled short PAN-based carbon fibers onto each of the layers of glass fiber fabric along the thickness direction in the composites. These layers of flocked fabric were stacked, and a vacuum infusion process was employed to fabricate the composites. The parametric study consisted of two carbon fiber lengths (80 μm and 150 μm) and two fiber densities (1000 fibers/mm2 and 2000 fibers/mm2) and was performed to investigate the damage sensing capabilities of a three-dimensional conductive network generated through CNTs and carbon fibers. A double cantilever beam (DCB) configuration was considered, and a modified Hopkinson pressure bar setup along with a high-speed camera was used to investigate dynamic fracture toughness of the composites. The piezo-resistance response of the composites during dynamic fracture was measured using a modified system of four probes. For comparison, composites were also characterized for fracture toughness and piezo-resistance under quasi-static fracture loading conditions. The addition of short, milled PAN-based carbon fibers significantly increased the fracture toughness of glass/epoxy composites. The piezo-resistance response of the composites was easily correlated with instances of sudden crack growth during static fracture loading.

Multi-Functional Glasses for the Blind and Visually Impaired: Design and Development

This paper presents the design of a glasses system for the blind and visually impaired that incorporates various technologies to enhance their daily living experience. The glasses are equipped with a speaker and haptic feedback, allowing users to receive audible and tactile notifications about their surroundings. We also implemented image understanding for identifying multiple unique objects, people, and environmental obstacles. Additionally, the glasses can read signs and printed materials via text recognition technology. Finally, the glasses incorporate navigation tools, helping users to find their way in unfamiliar environments. The system has the potential to significantly improve the independence and quality of life of those with visual impairments, as it could be a valuable assistive technology tool for a wide range of applications.

Formation of Porosity toward Acetylene upon Vitrification of Non-porous Photochromic Coordination Polymer Crystals

Designing permanent microporosity in a glassy state of coordination polymer (CP) and metal–organic framework (MOF) has been challenging due to densification of the structures upon vitrification. Here, we propose a new approach to create porosity in CP/MOF glasses derived from nonporous 1D crystal structures. Glassy states of two dense 1D crystal structures [Ag2(cis-dbe) (CF3SO3)2] and [Ag2(cis-dbe) (CF3CO2)2], where cis-dbe = cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene, were prepared by ball milling. Glass structures and dynamics were characterized by synchrotron X-ray, solid-state NMR, and thermal analyses. Loosened assembly of 1D chains through glass formation enabled representation of permanent microporosity and resulted in selective gas sorption behaviors of acetylene over CO2. It elucidated that the property of gas uptake is affected by the glass dynamics and interaction with anions. Reversible photochromism of cis-dbe is preserved in the glasses, leading to multi-functional glass materials.

A perfect pair: Niobium- and gallium-doped ceramic biomaterial enabled by coupled synthesis method with potential application for bone regeneration and cancer-targeted therapy

In this work, we report the synthesis and characterization of sol-gel bioactive glasses containing niobium (Nb) and gallium (Ga), a multifunctional glass that synergistically combines the respective effects of these species in potentiating bone repair and regeneration, concomitantly with a bone cancer targeted therapy. We found that the entry of Ga3+ into the vitreous network promotes an increase in the network connectivity, contributing to an increase in the degree of polymerization of the glass, since part of the calcium ions that behave as network modifying agents were replaced by gallium ions that act as network formers, and hence a replacement of part of the Si-O−…Ca2+…−O-Si by Si-O-Ga-O-Si bonds. Such results confirmed an increase in bridging oxygen bond density associated with a decrease in the number of bonds per unit volume of the glass due to the expansion of the glassy network. Furthermore, the incorporation of Ga2O3 at the expense of CaO in the composition of SNb3Ga3 decreased the ionicity of the chemical bonds. The study of pH variation revealed that the presence of Ga decreases the solubility of the glass influenced by a reduction in non-bridging oxygens (NBOs) concentration, which in turn is associated with an increase in glass network connectivity.

Integration of Screen Printed Piezoelectric Sensors for Force Impact Sensing in Smart Multifunctional Glass Applications

Screen printed piezoelectric polyvinylidene fluoride–trifluoro ethylene (PVDF–TrFE)‐based sensors laminated between glass panes in the temperature range 80–110 °C are presented. No degradation of the piezoelectric signals is observed for the sensors laminated at 110 °C, despite approaching the Curie temperature of the piezoelectric material. The piezoelectric sensors, here monitoring force impact in smart glass applications, are characterized by using a calibrated impact hammer system and standardized impact situations. Stand‐alone piezoelectric sensors and piezoelectric sensors integrated on poly(methyl methacrylate) are also evaluated. The piezoelectric constants obtained from the measurements of the nonintegrated piezoelectric sensors are in good agreement with the literature. The piezoelectric sensor response is measured by using either physical electrical contacts between the piezoelectric sensors and the readout electronics, or wirelessly via both noncontact capacitive coupling and Bluetooth low‐energy radio link. The developed sensor concept is finally demonstrated in smart window prototypes, in which integrated piezoelectric sensors are used to detect break‐in attempts. Additionally, each prototype includes an electrochromic film to control the light transmittance of the window, a screen printed electrochromic display for status indications and wireless communication with an external server, and a holistic approach of hybrid printed electronic systems targeting smart multifunctional glass applications.

Multifunctional glass fibre filter modified with vertical graphene for one-step dynamic water filtration and disinfection

An electric field (EF)-assisted multifunctional one-step dynamic water filtration and disinfection system is developed based on a vertical graphene-modified glass fibre filter (EF-VG-GFF). The EF-VG-GFF purification system can achieve 99.99% disinfection.

Bioinspired Multifunctional Glass Surfaces through Regenerative Secondary Mask Lithography.

Nature-inspired nanopatterning offers exciting multifunctionality spanning antireflectance and the ability to repel water/fog, oils, and bacteria; strongly dependent upon nanofeature size and morphology. However, such patterning in glass is notoriously difficult, paradoxically, due to the same outstanding chemical and thermal stability that make glass so attractive. Here, regenerative secondary mask lithography is introduced and exploited to enable customized glass nanopillars through dynamic nanoscale tunability of the side-wall profile and aspect ratio (>7). The method is simple and versatile, comprising just two steps. First, sub-wavelength scalable soft etch masks (55-350nm) are generated through an example of block copolymer micelles or nanoimprinted photoresist. Second, their inherent durability problem is addressed by an innovative cyclic etching, when the original mask becomes embedded within a protective secondary organic mask, which is tuned and regenerated, permitting dynamic nanofeature profiling with etching selectivity >1:32.It is envisioned that such structuring in glass will facilitate fundamental studies and be useful for numerous practical applications-from displays to architectural windows. To showcase the potential, glass features are tailored to achieve excellent broadband omnidirectional antireflectivity, self-cleaning, and unique antibacterial activity toward Staphylococcus aureus.

Facile fabrication of multifunctional transparent glass with superhydrophobic, self-cleaning and ultraviolet-shielding properties via polymer coatings

Glass is widely used in outdoor living areas such as buildings and optical sensors to pursuit people's expected living standards. However, the hydrophilic nature of traditional glass makes the dust in the air is easy to deposit on the surface, and the poor ultraviolet (UV) shielding efficiency will limit the application areas. In this work, the multifunctional glass with hydrophobicity, self-cleaning and UV-shielding properties was fabricated by coating a transparent styrene-ethylene-butylene-styrene triblock copolymer (SEBS) coating on the glass. Herein, SiO2 particles and UV absorber (UV326) were used to ensure the multifunctional properties. Properties of a series of weight ratios of SiO2 and UV326 were analyzed separately to ensure the appropriate content. Then, the multifunctional glass was fabricated and compared with the traditional glass. Results indicate that the water contact angle was enhanced from hydrophilic (14°) to superhydrophobic state (163°) and the prepared glass can present excellent self-cleaning and antifouling effect. The water droplet bouncing test shows the multifunctional glass was suiting Cassie state. Meanwhile, the multifunctional glass can shield 98% UV light and still retains 34.9% visible light transmittance. Thus, the multifunctional glass with superhydrophobicity, self-cleaning and UV-shielding properties is fabricated and can be used in relevant application areas.

Parametric Study of Environmental Conditions on The Energy Harvesting Efficiency for The Multifunctional Composite Structures

This paper presents a parametric study of the efficacy of an integrated vibration energy harvesting device under the environmental condition representative of an offshore wind turbine. A multifunctional glass fibre composite with an integrated Micro Fibre Composite (MFC) energy harvesting device was tested by swept sine vibration under environmental conditions that ranged from −40 °C to 70 °C in temperature and 10%RH to 90%RH in humidity in order to characterise the sensitivity and dependence of energy harvesting on environmental conditions. Experimental vibration testing was complemented with theoretical analysis to investigate the relative contributions to the temperature dependence of energy harvesting. This included mechanical properties of the stiffness and strength of the cantilever structure and the electrical properties of the MFC transducer, including its dielectric constants and charge coefficients. An inverse proportionality was observed between the magnitude of harvested energy and the climatic temperature. The efficiency of energy harvesting was dominated by the stiffness of the cantilever, which displayed viscoelastic temperature dependence. The sample was also tested with a vibration profile obtained from a wind turbine in order to validate the temperature influence under typical service conditions. Numerical modal analysis was used to determine the shapes of resonance modes, the frequencies of which were temperature dependent. Humidity was observed to have a secondary influence on energy harvesting, with no significant short-term effect on the structural properties of the samples within the limits of the experimental method.

Graphite-like C3N4-coated transparent superhydrophilic glass with controllable superwettability and high stability

In this study, transparent superhydrophilic glass is prepared by doping g-C3N4(g-C3N4-TSG) using a facile evaporation process. The obtained g-C3N4-TSG exhibited excellent superhydrophilicity, transmittance with high stability, wearability, and weatherability, and novel features including photocatalytic and antibacterial activity, anti-ultraviolet and adsorption properties, and electrical conductivity. This material is promising for use in diverse everyday scenarios. The high surface energy of 78.4 mN·m−1 and thinness (2 μm) of the deposited g-C3N4 film endow the glass with exceptional performance, but also cause rapid performance decay in high-dust environments due to adsorbate contamination. Lowering the surface energy and roughening the surface microstructure can effectively extend the service life of g-C3N4-TSG to more than 120 days. This multifunctional glass is a useful material and provides a novel strategy for preparing superhydrophilic surfaces.

Damage sensing in multi-functional glass fiber composites under mode-I fracture loading

A detailed experimental study is performed for piezo resistance damage sensing on conductive glass fiber/epoxy composites under mode-I fracture conditions. The conductive composites are fabricated by homogeneously dispersing carbon nanotubes (CNTs) within the epoxy matrix and electro-flocking short carbon fibers onto the laminates along with a vacuum infusion process. A parametric study is done on the in-situ damage sensing properties by varying the carbon fiber lengths (150 µm and 350 µm) and the carbon fiber areal densities (500, 1000, 1500, and 2000 fibers/mm2). The change in resistance is captured with a four-point probe measuring methodology by measuring the resistance through the thickness of the composite. The crack initiation toughness value of the composites containing carbon fibers showed improvement over control composites. Composites containing 350 µm length carbon fibers and 2000 fiber/mm2 not only showed the best crack initiation toughness but also provided sensitive network for detecting crack growth.

Polyaniline-based multifunctional glass fiber reinforced conductive composite for strain monitoring

In this study, polyaniline (PANI) was introduced for improving the self-sensing capability of glass fiber reinforced polymer composites. A PANI-based conductive polymer matrix was employed to develop high conductive glass fiber reinforced conductive composite (GFRCP). Piezoresistive characterization studies were conducted on the GFRCP specimens by subjecting to monotonic and cyclic loading. Further thermal study was performed to ratify the thermal stability of the composite. During all tests, the DC resistance was measured to correlate the strain. The gauge factor of the sensor was estimated as 1.5. Moreover, stability, reversibility and repeatability of the self-sensing GFRCP composites are estimated. The responses of the GFRCP composite established the material has outstanding self-sensing abilities to monitor the strain. This new GFRCP composite not only acts as a self-sensing structural strain sensor but also its high electrical conductivity can open up new opportunities to explore its’ other functionality, like damage detection, lightning strike protection (LSP), mechanical vibration sensing, and self-protection from an electromagnetic wave (EMI shielding).

Hierarchical Reinforcing Fibers for Energy Harvesting Applications - A Strength Study

This work is concerned with the study of the strength of nanocoated reinforcing fibers. In more detail, glass fibers were coated with an efficient thermoelectric (TE) ink in order to create multifunctional reinforcing fibers for advanced composite structural applications. The main scope is to evaluate the fracture properties of the TE-enabled hierarchical glass fibers. The hybrid nanocrystal TE ink was synthesized via a solvothermal reaction and further fully characterized in coating form. The morphology and wetting properties of the TE ink deposition onto glass fibers were evaluated via SEM and contact angle measurements. Enhanced values by 19.4% in tensile strength for the coated glass fibers compared to the reference are being reported, measured at single fiber level. The evaluated multifunctional glass fiber strength will be utilised during ongoing research for the interfacial shear strength determination.

Silica-templated hierarchically porous carbon modified separators for lithium–sulfur batteries with superior cycling stabilities

Lithium–sulfur batteries (LSBs) have attracted considerable attention for use in next-generation rechargeable storage devices owing to their high theoretical capacities (1675 mA h g−1) and natural abundance of sulfur. However, the commercialization of LSBs is hindered by the polysulfide shuttle effect and unstable cycling performances of the conventional cell configurations. As the separator is a crucial component of the cell assembly, separator modification is considered an effective approach to the fabrication of a high-performance LSB without the use of a sophisticated cathode. In this study, hierarchically porous carbons are used for the fabrication of multi-functional glass fiber (GF) separators as upper current collectors and polysulfide trapping materials. An optimized porous carbon (denoted as MC-SM) is fabricated by tuning the porosity properties such as the Brunauer–Emmett–Teller surface area and pore distribution. The MC-SM-coated GF separator provides excellent discharge capacity of 1019 mA h g−1 and Columbic efficiency (~100%) at a current density of 0.2C after 150 cycles. Even at high current rates, the cell with the fabricated porous carbon can deliver considerable reversible capacities of 700 mA h g−1 at 1C and 591 mA h g−1 at 2C after 500 cycles.