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- 摘要
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- 实验方案
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Synthesis of surface-replicated ultra-thin silica hollow nanofibers using structurally different carbon nanofibers as templates
摘要： Ultra-thin silica hollow nano?bers were successfully synthesized using three kinds of well-de?ned carbon nano?bers (CNFs) with di?erent surface structures as e?ective templates via pyrolysis of polycarbomethylsilane-coated CNFs. The prepared silica hollow nano?bers replicated the characteristic surface morphologies of the CNFs, such as herringbone, platelet, and tubular types with edge or basal planes. Especially, the unique HCNF template, with tiny ?bril aggregates on the surface, was the most e?ective template material for synthesizing ultra-thin silica hollow nano?bers with uniform and hierarchical meso-pores and high surface areas (over than 680 m2/g). The chemical and physical properties of the silica nano?bers were evaluated with various analytical techniques, such as TGA, HR-TEM, FE-SEM, XRD, XPS, and N2 adsorption/desorption, and discussed in detail.
关键词： Carbon nano?ber,Template synthesis,Mesoporous ultra-thin silica hollow nano?ber
更新于2025-09-19 17:15:36
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Synthesis and Luminescence Properties of Core-Shell-Shell Composites: SiO2@PMDA-Si-Tb@SiO2 and SiO2@PMDA-Si-Tb-phen@SiO2
摘要： Two novel core-shell composites SiO2@PMDA-Si-Tb, SiO2@PMDA-Si-Tb-phen with SiO2 as the core and terbium organic complex as the shell, were successfully synthesized. The terbium ion was coordinated with organic ligand forming terbium organic complex in the shell layer. The bi-functional organosilane ((HOOC)2C6H2(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as PMDA-Si) was used as the first ligand and phen as the second ligand. Furthermore, the silica-modified SiO2@PMDA-Si-Tb@SiO2 and SiO2@PMDA-Si-Tb-phen@SiO2 core-shell-shell composites were also synthesized by sol-gel chemical route. An amorphous silica shell was coated around the SiO2@PMDA-Si-Tb and SiO2@PMDA-Si-Tb-phen core-shell composites. The core-shell and core-shell-shell composites both exhibited excellent luminescence in solid state. The luminescence of core-shell-shell composites was stronger than that of core-shell composites. Meanwhile, an improved luminescence stability property for the core-shell-shell composites was found in the aqueous solution. The core-shell-shell composites exhibited bright luminescence, high stability, long lifetime, and good solubility, which may present potential applications in the bio-medical field.
关键词： silica shell,2,5-bis((3-(triethoxysilyl)propyl)carbamoyl)terephthalic acid (PMDA-Si),lifetime,photoluminescence,core-shell composite,core-shell-shell composite
更新于2025-09-19 17:15:36
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A SERS aptasensor for sensitive and selective detection of bis(2-ethylhexyl)phthalate
摘要： Bis(2-ethylhexyl)phthalate (DEHP) is an endocrine disruptor commonly present in plastic products, such as PVC tubes and water bottles. In this work, a surface enhanced Raman spectroscopy (SERS) based aptasensor was developed and utilized for rapid, easy, sensitive, and specific detection of trace DEHP. A DEHP aptamer was immobilized on magnetic particles. Raman reporter molecule conjugated silver nanoparticles were clustered and coated with silica to provide a stable SERS signal. The SERS silica particle was then functionalized with 1,2,4-benzenetricarboxylic acid 1,2-bis(2-ethylhexyl) ester to increase its affinity to the DEHP aptamer. In the presence of a sample with DEHP, the high-affinity SERS silica particle competes with the DEHP molecule to bind with the aptamer on the magnetic particle. By measuring the signal of free SERS silica particles in the supernatant after magnetic separation, the concentration of DEHP in the sample was quantitatively determined. The developed DEHP aptasensor had a detection range from 0.008 to 182 nM and a limit of detection (LOD) of 8 pM. The aptasensor also showed high selectivity when exposed to interferents with analogous structures. The aptasensor was successfully tested for the detection of DEHP spiked in tap water, bottled water, and a carbonate beverage. The developed SERS-based aptasensor provides a rapid, sensitive, and easy-to-use method for the quantitative detection of DEHP in environmental and food analysis.
关键词： silica particles,SERS,competitive binding,detection,DEHP,aptasensor
更新于2025-09-19 17:15:36
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Fluorescein- and EGFR-Antibody Conjugated Silica Nanoparticles for Enhancement of Real-time Tumor Border Definition Using Confocal Laser Endomicroscopy in Squamous Cell Carcinoma of the Head and Neck
摘要： Intraoperative de?nition of tumor free resection margins in head and neck cancer is challenging. In the current proof-of-principle study we evaluated a novel silica nanoparticle-based agent for its potential use as contrast enhancer. We synthesized silica nanoparticles with an average size of 45 nm and modi?ed these particles with the ?uorescence stain ?uorescein isocyanate (FITC) for particle detection and with epidermal growth factor receptor (EGFR)-targeting antibodies for enhanced tumor speci?city. The nanoparticles exhibited good biocompatibility and could be detected in vitro and in vivo by confocal laser scanning microscopy. Additionally, we show in an ex vivo setting that these modi?ed nanoparticles speci?cally bind to tumor samples and could be detected using a handheld confocal ?uorescence endomicroscope. From a clinical point of view, we believe that this method could be used for tumor border contrast enhancement and for better intraoperative de?nition of R-0 tumor resection.
关键词： silica nanoparticles,EGFR,contrast agent
更新于2025-09-19 17:13:59
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Highly Stabilized Gradient Alloy Quantum Dots and Silica Hybrid Nanospheres by Core Double Shells for Photoluminescence Devices
摘要： This Letter reports the synthesis approach and application of colloidal suspensions containing gradient alloy quantum dots (QDs) and silica hybrid spheres with improved thermal and photostability, invisible QD aggregation, and high material compatibility. These hybrid nanospheres are characterized by using silica spheres as cores, adsorbing QDs as one shell, and then coating a silica layer as another shell (termed SiO2?QD?SiO2). They were synthesized by using Sto?ber and adsorption methods. The experimental conditions affecting the optical properties were fully investigated. A light-guiding microstructure array (LGMA) was fabricated and tested for photoluminescence demonstration. After accelerated aging tests for 240 h under 85 °C, 40% relative humidity, and 450 nm blue light excitation, the luminance of the SiO2?QD?SiO2 LGMA remained stable, which was 1.6 times greater than that of untreated QD samples. This structure with long-term photothermal stability could pave the way for displays or lighting applications.
关键词： photostability,photoluminescence,thermal stability,quantum dots,silica hybrid nanospheres
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Epitaxial Lifted-Off Thin Film GaInP/GaAs/GaInNAsSb Lattice-Matched Triple Junction Solar Cells
摘要： The increasing number of computational servers in data centers is imposing tighter constraints on the networking infrastructure. Scalable power efficient optical interconnect network becomes necessary to leverage the bandwidth capacity of current electronic switches or opto-electronic components. Hence, novel optical interconnect technology can enhance the network capacity by harnessing the feasibility of simultaneous processing of optical signal in the wavelength and time domains. In this paper, we present a four channel optical passive wavelength-striped mapping (PWSM) device, which passively time compresses/expands serial packets through optical wavelength multiplexing/demultiplexing. The PWSM device, which has a 1 × 4 channel optical wavelength demultiplexer with integrated optical delay lines, is designed in a low-loss Si3N4 (propagation loss ～3.1 dB/m) waveguide platform. The PWSM device multiplexes/demultiplexes four WDM channels and offsets in time the adjacent channels to optically serialize/de-serialize data packets. In this demonstration, a 64 ns long data packet is formed at the output of the device by combining four 16 ns data segments of the packet in time domain. Incremental optical insertion loss between adjacent channels is ～9.7 dB due to the integrated passive optical delay waveguides. The data rate of the four segmented packets and the combined packet is 25 Gb/sec. We have measured a bit error rate performance below 1 ×10?9 for the 64 ns serial data packet regenerated by the PWSM device for a received optical power of –6.7 dBm.
关键词： silica and silicon nitride photonics,wavelength filtering devices,Photonic integrated circuits
更新于2025-09-19 17:13:59
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[Laser Institute of America ICALEO? 2016: 35th International Congress on Applications of Lasers & Electro-Optics - San Diego, California, USA (October 16–20, 2016)] International Congress on Applications of Lasers & Electro-Optics - Experimental and numerical study on laser welding of glass using a CO2 laser and glass fiber as filler material
摘要： Automated laser welding with filler wires for bridging gaps and for connecting complex devices has been established for different metal materials. In spite of that, it is still a challenge to transfer this welding process to the brittle material glass. Therefore, glass welding is often realized through a manual process by heating the glass with a gas flame. In addition, welding of non-rotational components requires filler material for gap bridging between the joining partners, which is applied manually today. This work presents an experimental and numerical study on laser welding of fused silica using glass fiber as a filler material to bridge gaps. The goal was to achieve a defined weld penetration depth and heat affected zone which is important for the production of optical elements. Therefore, a CO2 laser heats up the glass components as well as the glass fiber within a temperature controlled welding process. The numerical investigations were used to identify the general process window for welding fused silica. Within the experimental study, the process parameters, such as the defined welding temperature, laser focal spot size, and feed rate were varied to investigate their impact on the welding outcome. In addition, the impact of the filler wire coating on the material composition of the welded component in the joint zone was investigated. Compared to the manual process, laser welding with glass fiber as a filling material leads to a highly reproducible process enabling a high automation level.
关键词： fused silica,temperature controlled welding,heat affected zone,laser welding,glass fiber,filler material,glass,CO2 laser,weld penetration depth
更新于2025-09-19 17:13:59
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Femtosecond Laser-inscribed Non-volatile Integrated Optical Switch in Fused Silica based on Microfluidics-controlled Total Internal Reflection
摘要： We demonstrate a non-volatile optical power switch, fabricated by femtosecond laser inscription in a fused silica substrate, with switching operation based on microfluidics-controlled total internal reflection. The switch consists of crossed waveguides and a rectangular, high aspect ratio microfluidic channel, located at the waveguide crossing. The switching between total internal reflection and transmission at the channel wall is determined by the refractive index of the medium inside the channel. Femtosecond laser inscription allows for co-integration of low-loss optical waveguides and channels with smooth sidewalls and thus the fabrication of low insertion loss switches that are broadband and show low polarization dependent losses. The measured total internal reflection loss of the fabricated switch is about 1.5 dB at the wavelength 1550 nm. The loss due to transmission through the channel filled with refractive index matching liquid is about 0.5 dB. Detailed finite time domain and beam propagation method difference simulations of the switch’s performance indicate that the losses can be further reduced by optimizing its geometry, together with further adjusting the inscription parameters.
关键词： Fused silica,Non-volatile,Single mode waveguides,Total internal reflection,Microfluidics,Femtosecond laser inscription,integrated optical switch
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Tunable 360 Degrees Phase Shifter Based on Spoof Surface Plasmon Polaritons Waveguide
摘要： The increasing number of computational servers in data centers is imposing tighter constraints on the networking infrastructure. Scalable power efficient optical interconnect network becomes necessary to leverage the bandwidth capacity of current electronic switches or opto-electronic components. Hence, novel optical interconnect technology can enhance the network capacity by harnessing the feasibility of simultaneous processing of optical signal in the wavelength and time domains. In this paper, we present a four channel optical passive wavelength-striped mapping (PWSM) device, which passively time compresses/expands serial packets through optical wavelength multiplexing/demultiplexing. The PWSM device, which has a 1 × 4 channel optical wavelength demultiplexer with integrated optical delay lines, is designed in a low-loss Si3N4 (propagation loss ～3.1 dB/m) waveguide platform. The PWSM device multiplexes/demultiplexes four WDM channels and offsets in time the adjacent channels to optically serialize/de-serialize data packets. In this demonstration, a 64 ns long data packet is formed at the output of the device by combining four 16 ns data segments of the packet in time domain. Incremental optical insertion loss between adjacent channels is ～9.7 dB due to the integrated passive optical delay waveguides. The data rate of the four segmented packets and the combined packet is 25 Gb/sec. We have measured a bit error rate performance below 1 ×10?9 for the 64 ns serial data packet regenerated by the PWSM device for a received optical power of –6.7 dBm.
关键词： wavelength filtering devices,Photonic integrated circuits,silica and silicon nitride photonics
更新于2025-09-19 17:13:59
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Position Dependence of Emission Wavelength of a SiO2 Colloidal Photonic-Crystal Laser
摘要： In this paper, a wavelength tunable colloidal-crystal laser with monodispersed silica particles was demonstrated. Silica particles were synthesized through the modified St?ber process and self-assembled into the colloidal photonic-crystal structure, which was then used to form the optic cavity of a wavelength tunable laser device. Due to Bragg’s diffraction of the colloidal photonic-crystal and the coffee ring effect, the forbidden energy gap of light varied with different lattice sizes at different positions of the colloidal photonic-crystal. When the pumping pulsed laser irradiated on the gain medium of the sample, the fluorescence was restricted and enhanced by the colloidal photonic-crystal. Lasing emission with a single peak occurred when the energy of the pumping laser exceeded the threshold energy. The threshold energy and the full-width at half-maximum (FWHM) of the proposed laser were 7.63 μJ/pulse and 2.88 nm, respectively. Moreover, the lasing wavelength of the colloidal photonic-crystal laser could be tuned from 604 nm to 594 nm, corresponding to the various positions in the sample due to the coffee ring effect.
关键词： St?ber process,colloidal-crystal laser,wavelength tunable,self-assemble,silica particles
更新于2025-09-19 17:13:59