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Beta-lead oxide quantum dot (β-PbO QD)/polystyrene (PS) composite films and their applications in ultrafast photonics
摘要： Polymer composite films, particularly those based on polymers and layered nanomaterials, are attractive materials for exploiting the properties of multiple materials for applications in electronics and photonics. In this work, a beta-lead oxide quantum dot (β-PbO QD)/polystyrene (PS) composite film is successfully fabricated by a solution blending method. The β-PbO QDs are well-distributed within a β-PbO QD/PS composite film and the composite film is transparent and flexible. Owing to the almost complete insolubility of both β-PbO QDs and PS, the as-fabricated β-PbO QD/PS composite film holds the nonlinear photonic response from 540 nm to 1060 nm under complete water immersion, confirming its excellent stability to high humidity. Additionally, the β-PbO QD/PS composite film exhibits a considerable capacity for optical modulation owing to a strong nonlinear absorption coefficient compared with those of other two-dimensional (2D) materials. On the basis of a home-made β-PbO QD/PS composite film saturable absorber, stable mode-locked pulses at 1060 nm are generated under humid conditions. It is anticipated that the β-PbO QD/PS composite films enable the exploitation of new waterproof, flexible photonic devices based on functional 2D materials and polymers.
关键词： composite films,mode-locked pulses,ultrafast photonics,polystyrene,nonlinear absorption,beta-lead oxide quantum dot
更新于2025-11-19 16:56:42
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A Study on the Solvent Vapor Induced Film Formation of PS/AgNPs Composites
摘要： In this study, pyrene (P) tagged polystyrene (PS) latex dispersions and silver nanoparticles (AgNPs) were mixed at various weight fractions in the range between 0 and 50 wt%. The prepared mixtures were dropped on the glass substrates by considering drop casting method and were dried at the room temperature. The resultant powder films were then exposed to solvent vapor to monitor how film formation and morphological behaviors of PS/AgNPs composites are altered. Film formation behavior of composites was assessed via fast transient fluorescence (FTRF) which measures the ?uorescence lifetimes of P from its decay traces during vapor exposure process. It was observed that pyrene lifetimes decreased as vapor exposure time, t increased. A Stern–Volmer kinetic analysis was used for low quenching ef?ciencies to interpret the decrease in pyrene lifetimes. UV-Vis (UVV) technique was employed to monitor optical transparency of the films. In the range of 0-20 wt% of AgNPs content, smooth and transparent films were obtained. However, above this range, the films were seen that they have low transparency and poor film formation since the increment in AgNPs content was lead to aggregations. The Prager–Tirrel model was employed to the FTRF data to obtain back-and-forth frequencies, ν, of the reptating PS chains during vapor induced ?lm formation process. SEM images of the samples were taken after film formation process is completed and were found to be consistent with optical and fluorescence quenching data.
关键词： Polystyrene latex,film formation,reptation frequency,fluorescence lifetime,nanocomposites,crossing-density,Silver nanoparticles,vapor-induced
更新于2025-09-23 15:23:52
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Highly Stable and Ultrafast Hydrogen Gas Sensor Based on 15 nm Nanogaps Switching in a Palladium-Gold Nanoribbons Array
摘要： Palladium (Pd) nanogap hydrogen gas (H2) sensors based on the large volume expansion of β phase palladium hydride (β-PdH) are highly promising, owing to their fast and accurate sensing capability at room temperature in air. However, such sensors do not work well at H2 concentrations below 1%. At such low H2 concentrations, Pd exists as α-PdH, which has a slow and insufficient volume expansion and cannot completely close nanogaps. Furthermore, the lattice strains induced from the phase transition (α-PdH → β-PdH) behavior degrade the stable and repeatable long-term sensing capability. Here, these issues are resolved by fabricating an array of periodically aligned alloyed palladium–gold nanoribbons (PdAu NRB) with uniform 15 nm nanogaps. The PdAu NRB sensor enables highly stable and ultrafast H2 sensing at the full detection range of H2 concentrations from 0.005% to 10% along with the excellent limit of detection (≈0.0027%), which is sufficiently maintained even after seven months of storage in ambient atmosphere. These breakthrough results will pave the way for developing a practical high-performance H2 sensor chip in the future hydrogen era.
关键词： palladium nanogap,nanoribbon,hydrogen gas sensors,polystyrene thermal shrinkage
更新于2025-09-23 15:22:29
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Microfluidic Sensors with Impregnated Fluorophores for Simultaneous Imaging of Spatial Structure and Chemical Oxygen Gradients
摘要： Interior surfaces of polystyrene microfluidic structures were impregnated with the oxygen sensing dye Pt(II) tetra(pentafluorophenyl)porphyrin (PtTFPP) using a solvent-induced fluorophore impregnation (SIFI) method. Using this technique, microfluidic oxygen sensors are obtained that enable simultaneous imaging of both chemical oxygen gradients and the physical structure of the microfluidic interior. A gentle method of fluorophore impregnation using acetonitrile solutions of PtTFPP at 50oC was developed leading to a 10-μm-deep region containing fluorophore. This region is localized at the surface to sense oxygen in the interior fluid during use. Regions of the device that do not contact the interior fluid pathways lack fluorophores and are dark in fluorescent imaging. The technique was demonstrated on straight microchannel and pore network devices, the latter having pillars of 300 μm diameter spaced center to center at 340 μm providing pore throats of 40 μm. Sensing within channels or pores, and imaging across the pore network devices were performed using a Lambert LIFA-P frequency domain fluorescence lifetime imaging system on a Leica microscope platform. Calibrations of different devices prepared by the SIFI method were indistinguishable. Gradient imaging showed fluorescent regions corresponding to the fluid pore network, dark pillars, and fluorescent lifetime varying across the gradient, thus providing both physical and chemical imaging. More generally, the SIFI technique can impregnate the interior surfaces of other polystyrene containers, such as cuvettes or cell and tissue culture containers, to enable sensing of interior conditions.
关键词： Oxygen,sensor,impregnation,fluorophore,chemical imaging,pore network,polystyrene,microfluidic
更新于2025-09-23 15:22:29
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Facile preparation of new polystyrene leucomalachite green thick films and study of their radiochromic behavior for low doses of gamma radiation
摘要： Colourless polystyrene-leucomalachite green (PS-LMG) thick films containing a suitable chloroalkane were prepared by a fast and facile casting method, and were investigated for their radio chromic response behavior under the influence of 1.25 MeV γ-radiation. Their gamma response was studied in the 0.05 kGy to 10 kGy range to evaluate their suitability for potential use as the dosimeter in the radiation processing industries. The films were found to undergo a visibly distinct green coloration in the studied range, with the colour intensity increasing with an increase in the total dose. The radiochromic response of these films when investigated as a function of film thickness showed that the colour development as well as the linearity of the response was markedly affected by the thickness of the films. The effect of dye loading and the chloroalkane concentration on the radiochromic response of these films were also investigated. Depending upon the film thickness and reactant concentrations, the films were found to be capable of visually detecting gamma radiation doses as low as few tens of grays.
关键词： Polystyrene,Thick Films,Leucomalachite Green,Radiochromic,Low Dose
更新于2025-09-23 15:22:29
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Development of Titanium Dioxide (TiO <sub/>2</sub> )-Embedded Buoyant Photocatalyst Balls Using Expanded Polystyrene
摘要： A new immobilization technique of nanoscale TiO2 powders to expanded polystryrene (EPS) balls with temperature-controlled melting method was developed for mass production, and the characterization of TiO2 powder-embedded EPS (TiEPS) balls was evaluated. Based on the scanning electron microscope (SEM) images and associated energy-dispersive X-ray spectroscopy (EDX) analysis, the components of intact EPS balls are carbon and oxygen whereas those of TiEPS balls are carbon, oxygen, and titanium, indicating that TiO2 powders were embedded on the surface of EPS balls. As also evident by the X-ray diffraction (XRD) and FTIR analyses, no significant changes in crystalline structure of TiO2 powders embedded on the EPS balls were found during the preparation and application processes of TiEPS balls. These characterization results indicated that the patches of TiO2 powders were soundly impregnated over the surface of EPS balls without the significant changes in crystalline structure of TiO2 powders and both structural changes and deformation of EPS polymer.
关键词： FTIR,TiO2-Embedded EPS Balls,Photocatalyst,Methylene Blue (MB),Expanded Polystyrene (EPS),X-ray Spectroscopy,TiO2
更新于2025-09-23 15:22:29
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[IEEE 2018 3rd International Conference On Internet of Things: Smart Innovation and Usages (IoT-SIU) - Bhimtal, India (2018.2.23-2018.2.24)] 2018 3rd International Conference On Internet of Things: Smart Innovation and Usages (IoT-SIU) - Organic Thin Film Transistor Based Graphene Drooped Sensors
摘要： Graphene film drooped on a bottom gate bottom contact (BGBC) is adopted for fabricating gas sensing technology. The sensors are competent of identifying toxic gases like CO2, NO2, CO of ultra-low surrounding air by calibrating sensitivity which is the measure of change in maximum drain current in presence of air and in absence of any toxic material on graphene layer whereas, the initial condition of graphene remaining constant except temperature. The main principle of the device is that graphene can act productively to endeavor abounding physio-chemical properties that are beneficial for gas sensing techniques which would keep a check on increasing toxic level at homes, schools, car and would prove to be beneficiary against sick building syndrome (SBS). The sensors provide an advantage of low power, low cost, good sensitivity and stability.
关键词： sensitivity,PEDOT:PSS- Poly(ethylene-dioxythiophene) /polystyrene sulphonate),Sick building syndrome (SBS),Graphene
更新于2025-09-23 15:21:21
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Ultra-sensitive method based on time-resolved fluorescence immunoassay for detection of sulfamethazine in raw milk
摘要： A novel lateral flow assay (LFA) was developed by introducing Eu (III)-doped polystyrene nanoparticles (EuNPs) for rapid and ultra-sensitive detection of sulfamethazine (SM2) in raw milk. The limit of detection and linear range of the proposed method were 0.0045 and 0.05–10 ng/mL, respectively. The recovery of LFA for the detection of SM2 in raw milk was 96.1–108.2%. The proposed LFA provides a rapid and convenient strategy for fast and ultra-sensitive screening of SM2 in raw milk. EuNP-LFA may be a remarkable method for the detection of other targets at low concentrations to ensure food safety.
关键词： Lateral flow assay,sulfamethazine,raw milk,Eu (III)-doped polystyrene nanoparticle
更新于2025-09-23 15:21:21
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Narrowband, infrared absorbing metasurface using polystyrene thin films
摘要： We present the results of an experimental investigation of polystyrene’s suitability as a dielectric material for designing narrowband, infrared metasurface-based absorbers. Our study included characterization of processing parameters of polystyrene films, such as surface roughness and film thickness, which are critical for device fabrication, and the dielectric properties, which we measured, using spectroscopic ellipsometry. Our results confirm that thin film polystyrene is a relatively low-loss dielectric material at long-wave infrared (LWIR) frequencies. Subsequently, this material was used as the dielectric substrate of a thin, narrowband, metasurface-based absorber at LWIR frequencies. The fabricated narrowband absorber demonstrates excellent performance in the LWIR band with absorptivity as high as 96% and a full-width-at-half-maximum bandwidth of 0:502 μm or 4.87%.
关键词： metasurface,infrared,absorber,polystyrene,narrowband,LWIR
更新于2025-09-23 15:21:01
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Near-infrared nanosecond-pulsed laser-activated high efficient intracellular delivery mediated by nano-corrugated mushroom-shaped gold-coated polystyrene nanoparticles
摘要： Here, efficient intracellular delivery of molecules with high cell viability is reported using nanosecond-pulsed laser-activated plasmonic photoporation mediated by high-aspect-ratio nano-corrugated mushroom-shaped gold-coated polystyrene nanoparticles (nm-AuPNPs) at near-infrared wavelength. Upon laser illumination, nm-AuPNPs exhibit greater plasmonic extinction than spherical AuPNPs, which increase their energy efficiency and reduce the necessary illumination of light, effectively controlling cell damage and improving delivery efficiency. Nm-AuPNPs exhibit surface plasmon absorption at near infrared region with peak at 945 nm. Pulsed laser illumination at this plasmon peak triggers explosive nanobubbles, which create transient membrane pores, allowing the delivery of dyes, quantum dots and plasmids into the cells. The results can be tuned by laser fluence, exposure time, molecular size and concentration of nm-AuPNPs. The best results are found for CL1-0 cells, which yielded a 94% intracellular PI dye uptake and ~100% cell viability at 35 mJ/cm2 laser fluence for 945 nm wavelength. Thus, the presented approach has proven to have an inevitable potential for biological cell research and therapeutic applications.
关键词： near-infrared wavelength,intracellular delivery,nanosecond-pulsed laser,gold-coated polystyrene nanoparticles,plasmonic photoporation
更新于2025-09-23 15:21:01