By means of breaking tests on PtIr contact materials via a JF04C contact material testing machine, it was attempted to elucidate the characteristics of the various surface morphology and material transfer after the ar...By means of breaking tests on PtIr contact materials via a JF04C contact material testing machine, it was attempted to elucidate the characteristics of the various surface morphology and material transfer after the arc erosion process caused by break arc. The material transfer characteristics appeared in the experiments were concluded and analyzed. Meanwhile, the morphology of the anode and cathode surface were observed and analyzed by SEM.展开更多
The increasing demand on high quality optical systems with complex geometries, low tolerances and a low installation space necessitates new replicative production systems for complex optical glass elements. The techno...The increasing demand on high quality optical systems with complex geometries, low tolerances and a low installation space necessitates new replicative production systems for complex optical glass elements. The technology precision blank moulding shows promising properties to comply with these demands on an industrial bulk production. Due to the required high surface quality and low surface roughness of produced optical elements, moulding dies must have comparable low roughness and defect-free surfaces. To reduce wear and chemical interaction with the hot glass, moulding dies are often coated with a thin sputtered physical vapour deposition (PVD) coating. The objective of this research work was to analyze the diffusion behaviour inside different industrially used low-Tg (transformation point) glasses and their interaction with three different noble metal coating systems during an application oriented heating test. Therefore, three different PtIr coating systems with different interlayers (50 nm nickel as reference, 20 nm chromium, without interlayer) were deposited and tested in combination with six different industrially used low-Tg glasses. Using energy-dispersive X-ray spectroscopy (EDS) a diffusion of the light alkali and alkaline earth metals (sodium, potassium, calcium) was detected. The interaction between glass and coating was analyzed by EDS, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The different chemical compositions of the glasses have a significant influence on the interaction between glass and coating system. Several correlations between the chemical composition of the glasses and the amount of glass adhesion on the three coating systems were identified. The percentage of ions allocated to network modifiers lithium oxide, sodium oxide and potassium oxide correlates with the intensity of the interaction between coating and glass. The intensity of glass adhesion on the reference coating system PtIr/Ni is related with the zinc content in the glasses. Due to a diffusion process of the nickel interlayer, a direct correlation between the zinc content in the glasses and glass adhesion exists. The coating system with chromium interlayer showed comparable results to the system without interlayer.展开更多
Dosage of chemotherapeutic drugs is a tradeoff between efficacy and side-effects.Liposomes are nanocarriers that increase therapy efficacy and minimize side-effects by delivering otherwise difficult to administer ther...Dosage of chemotherapeutic drugs is a tradeoff between efficacy and side-effects.Liposomes are nanocarriers that increase therapy efficacy and minimize side-effects by delivering otherwise difficult to administer therapeutics with improved efficiency and selectivity.Still,variabilities in liposome preparation require assessing drug encapsulation efficiency at the single liposome level,an information that,for non-fluorescent therapeutic cargos,is inaccessible due to the minute drug load per liposome.Photothermal induced resonance (PTIR) provides nanoscale compositional specificity,up to now,by leveraging an atomic force microscope (AFM) tip contacting the sample to transduce the sample's photothermal expansion.However,on soft samples (e.g.,liposomes) PTIR effectiveness is reduced due to the likelihood of tip-induced sample damage and inefficient AFM transduction.Here,individual liposomes loaded with the chemotherapeutic drug cytarabine are deposited intact from suspension via nano-electrospray gas-phase electrophoretic mobility molecular analysis (nES-GEMMA) collection and characterized at the nanoscale with the chemically-sensitive PTIR method.A new tapping-mode PTIR imaging paradigm based on heterodyne detection is shown to be better adapted to measure soft samples,yielding cytarabine distribution in individual liposomes and enabling classification of empty and drug-loaded liposomes.The measurements highlight PTIR capability to detect ~ 103 cytarabine molecules (~ 1.7 zmol) label-free and non-destructively.展开更多
The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneiti...The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneities in the phase,structure and composition of these functional materials makes it difficult to directly monitor and identify the influence of local physicochemical parameters on their global functionality.In this review we will discuss recent developments in the field of IR nanospectroscopy that enables the extraction of detailed chemical information at the nanoscale and the identification of nanoscale properties that influence the global performances of functional materials.Specifically,we will discuss the ways by which infrared (IR) nanospectroscopy techniques,namely photo thermal induced resonance (PTIR) and scattering scanning near-field optical microscopy (s-SNOM),are utilized in order to identify nanoscale properties and their influence on the functionality of halide-perovskite solar cells and catalytic nanoparticles.In the last part of this review we will address the technical challenges and opportunities in expanding the scope of IR nanospectroscopy measurements into the field of electrochemistry-based functional materials.展开更多
基金The National Nature Science Foundation of China(No.u0837601)
文摘By means of breaking tests on PtIr contact materials via a JF04C contact material testing machine, it was attempted to elucidate the characteristics of the various surface morphology and material transfer after the arc erosion process caused by break arc. The material transfer characteristics appeared in the experiments were concluded and analyzed. Meanwhile, the morphology of the anode and cathode surface were observed and analyzed by SEM.
基金The author gratefully acknowledge the financial support of the Federal Ministry of Economics and Technology(BMWi)within the project“Coat4Glass―Wissensbasierte Schichtoptimierung für das Prazisionsblankpressen von Glasoptiken”at RWTH Aachen University.
文摘The increasing demand on high quality optical systems with complex geometries, low tolerances and a low installation space necessitates new replicative production systems for complex optical glass elements. The technology precision blank moulding shows promising properties to comply with these demands on an industrial bulk production. Due to the required high surface quality and low surface roughness of produced optical elements, moulding dies must have comparable low roughness and defect-free surfaces. To reduce wear and chemical interaction with the hot glass, moulding dies are often coated with a thin sputtered physical vapour deposition (PVD) coating. The objective of this research work was to analyze the diffusion behaviour inside different industrially used low-Tg (transformation point) glasses and their interaction with three different noble metal coating systems during an application oriented heating test. Therefore, three different PtIr coating systems with different interlayers (50 nm nickel as reference, 20 nm chromium, without interlayer) were deposited and tested in combination with six different industrially used low-Tg glasses. Using energy-dispersive X-ray spectroscopy (EDS) a diffusion of the light alkali and alkaline earth metals (sodium, potassium, calcium) was detected. The interaction between glass and coating was analyzed by EDS, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The different chemical compositions of the glasses have a significant influence on the interaction between glass and coating system. Several correlations between the chemical composition of the glasses and the amount of glass adhesion on the three coating systems were identified. The percentage of ions allocated to network modifiers lithium oxide, sodium oxide and potassium oxide correlates with the intensity of the interaction between coating and glass. The intensity of glass adhesion on the reference coating system PtIr/Ni is related with the zinc content in the glasses. Due to a diffusion process of the nickel interlayer, a direct correlation between the zinc content in the glasses and glass adhesion exists. The coating system with chromium interlayer showed comparable results to the system without interlayer.
文摘Dosage of chemotherapeutic drugs is a tradeoff between efficacy and side-effects.Liposomes are nanocarriers that increase therapy efficacy and minimize side-effects by delivering otherwise difficult to administer therapeutics with improved efficiency and selectivity.Still,variabilities in liposome preparation require assessing drug encapsulation efficiency at the single liposome level,an information that,for non-fluorescent therapeutic cargos,is inaccessible due to the minute drug load per liposome.Photothermal induced resonance (PTIR) provides nanoscale compositional specificity,up to now,by leveraging an atomic force microscope (AFM) tip contacting the sample to transduce the sample's photothermal expansion.However,on soft samples (e.g.,liposomes) PTIR effectiveness is reduced due to the likelihood of tip-induced sample damage and inefficient AFM transduction.Here,individual liposomes loaded with the chemotherapeutic drug cytarabine are deposited intact from suspension via nano-electrospray gas-phase electrophoretic mobility molecular analysis (nES-GEMMA) collection and characterized at the nanoscale with the chemically-sensitive PTIR method.A new tapping-mode PTIR imaging paradigm based on heterodyne detection is shown to be better adapted to measure soft samples,yielding cytarabine distribution in individual liposomes and enabling classification of empty and drug-loaded liposomes.The measurements highlight PTIR capability to detect ~ 103 cytarabine molecules (~ 1.7 zmol) label-free and non-destructively.
文摘The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneities in the phase,structure and composition of these functional materials makes it difficult to directly monitor and identify the influence of local physicochemical parameters on their global functionality.In this review we will discuss recent developments in the field of IR nanospectroscopy that enables the extraction of detailed chemical information at the nanoscale and the identification of nanoscale properties that influence the global performances of functional materials.Specifically,we will discuss the ways by which infrared (IR) nanospectroscopy techniques,namely photo thermal induced resonance (PTIR) and scattering scanning near-field optical microscopy (s-SNOM),are utilized in order to identify nanoscale properties and their influence on the functionality of halide-perovskite solar cells and catalytic nanoparticles.In the last part of this review we will address the technical challenges and opportunities in expanding the scope of IR nanospectroscopy measurements into the field of electrochemistry-based functional materials.
