The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Mariadriana Creatore - One of the best experts on this subject based on the ideXlab platform.
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On the synergistic effect of inorganic/inorganic barrier layers: An ellipsometric porosimetry investigation
Plasma Processes and Polymers, 2017Co-Authors: Morteza Aghaee, Alberto Perrotta, Sergey A. Starostin, Hindrik Willem De Vries, Mauritius C. M. Van De Sanden, Wilhelmus M. M. Kessels, Mariadriana CreatoreAbstract:In this paper, plasma-enhanced chemical vapor deposited SiO2 layers capped by an ultra-thin plasma-assisted atomic layer deposited Al2O3 over-layer are analyzed by means of ellipsometric porosimetry (EP). In a very recent contribution, we have shown that the combination of the two layers provided excellent intrinsic Moisture Permeation barrier performance down to the 10−5–10−6 g · day−1 · m−2 regime. The present paper therefore addresses the microstructural changes which the SiO2 layers undergo upon Al2O3 deposition, as monitored by ellipsometric porosimetry (EP). It was found that the Al2O3 deposition primarily affects the relative content of open pores with d > 0.3 nm (water as probe) and d > 0.42 nm (ethanol as probe) from 5.35 to 2.81% and from 2.50 to 0.32%, respectively.
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Dynamic Ellipsometric Porosimetry Investigation of Permeation Pathways in Moisture Barrier Layers on Polymers.
ACS applied materials & interfaces, 2016Co-Authors: Alberto Perrotta, Wilhelmus M. M. Kessels, Mariadriana CreatoreAbstract:The quality assessment of Moisture Permeation barrier layers needs to include both water Permeation pathways, namely through bulk nanoporosity and local macroscale defects. Ellipsometric porosimetry (EP) has been already demonstrated a valuable tool for the identification of nanoporosity in inorganic thin film barriers, but the intrinsic lack of sensitivity toward the detection of macroscale defects prevents the overall barrier characterization. In this contribution, dynamic EP measurements are reported and shown to be sensitive to the detection of macroscale defects in SiO2 layers on polyethylene naphthalate substrate. In detail, the infiltration of probe molecules, leading to changes in optical properties of the polymeric substrate, is followed in time and related to Permeation through macroscale defects.
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Low-temperature plasma-assisted atomic layer deposition of silicon nitride Moisture Permeation barrier layers
ACS applied materials & interfaces, 2015Co-Authors: Anne-marije Andringa, Alberto Perrotta, Wilhelmus M. M. Kessels, Koen De Peuter, Harm C. M. Knoops, Mariadriana CreatoreAbstract:Encapsulation of organic (opto-)electronic devices, such as organic light-emitting diodes (OLEDs), photovoltaic cells, and field-effect transistors, is required to minimize device degradation induced by Moisture and oxygen ingress. SiNx Moisture Permeation barriers have been fabricated using a very recently developed low-temperature plasma-assisted atomic layer deposition (ALD) approach, consisting of half-reactions of the substrate with the precursor SiH2(NHtBu)2 and with N2-fed plasma. The deposited films have been characterized in terms of their refractive index and chemical composition by spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). The SiNx thin-film refractive index ranges from 1.80 to 1.90 for films deposited at 80 °C up to 200 °C, respectively, and the C, O, and H impurity levels decrease when the deposition temperature increases. The relative open porosity content of the layers has been studied by means of multisolven...
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Ellipsometric Porosimetry and Electrochemical Impedance Spectroscopy Characterization for Moisture Permeation Barrier Layers
Plasma Processes and Polymers, 2015Co-Authors: Alberto Perrotta, Santiago J. Garcia, Mariadriana CreatoreAbstract:In this work the combination of ellipsometric porosimetry (EP) and electrochemical impedance spectroscopy (EIS) is extensively addressed in order to characterize the nano-porosity and further elucidate its influence on the water Permeation properties of plasma enhanced-CVD SiO2 layers. Pores with diameter in the range of 0.27–0.6 nm are studied by adopting a multi-solvent/multi-ion approach, with EP and EIS, respectively. This combined study has brought to conclude that open pores larger than 0.42 nm are responsible for WVTR values in the range of 10−3-10−5 gm−2 day−1, while pores with diameter between 0.42–0.27 nm were found to drive the transition to excellent Moisture barrier layers (10−6 gm−2 day−1). Moreover, it is shown that EIS is capable of detecting macro-scale defects, next to nano-porosity, being thus a powerful tool for the analysis of Moisture barrier layers.
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Analysis of Nanoporosity in Moisture Permeation Barrier Layers by Electrochemical Impedance Spectroscopy.
ACS applied materials & interfaces, 2015Co-Authors: Alberto Perrotta, Jasper J Michels, Anne-marije Andringa, Santiago J. Garcia, Mariadriana CreatoreAbstract:Water Permeation in inorganic Moisture Permeation barriers occurs through macroscale defects/pinholes and nanopores, the latter with size approaching the water kinetic diameter (0.27 nm). Both Permeation paths can be identified by the calcium test, i.e., a time-consuming and expensive optical method for determining the water vapor transmission rate (WVTR) through barrier layers. Recently, we have shown that ellipsometric porosimetry (i.e., a combination of spectroscopic ellipsometry and isothermal adsorption studies) is a valid method to classify and quantify the nanoporosity and correlate it with the WVTR values. Nevertheless, no information is obtained about the macroscale defects or the kinetics of water Permeation through the barrier, both essential in assessing the quality of the barrier layer. In this study, electrochemical impedance spectroscopy (EIS) is shown as a sensitive and versatile method to obtain information on nanoporosity and macroscale defects, water Permeation, and diffusivity of Moisture barrier layers, complementing the barrier property characterization obtained by means of EP and calcium test. EIS is performed on thin SiO2 barrier layers deposited by plasma enhanced-CVD. It allows the determination of the relative water uptake in the SiO2 layers, found to be in agreement with the nanoporosity content inferred by EP. Furthermore, the kinetics of water Permeation is followed by EIS, and the diffusivity (D) is determined and found to be in accordance with literature values. Moreover, differently from EP, EIS data are shown to be sensitive to the presence of local macrodefects, correlated with the barrier failure during the calcium test.
Li-zhi Zhang - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of a PVA/LiCl blend membrane for air dehumidification
Journal of Membrane Science, 2007Co-Authors: Li-zhi Zhang, Yuan-yuan Wang, Cai-ling Wang, Hui XiangAbstract:A novel vapor-permeable composite membrane for air dehumidification has been fabricated. The membrane used porous polyethersulfone (PES) as the support layer, and dense polyvinylalcohol (PVA) as the active separating layer. To facilitate Moisture Permeation, lithium chloride (LiCl) salts were used as an additive to the PVA solution before it was cast onto the support layer. The effects of the LiCl concentration on the water vapor permeability are investigated. The Permeation tests indicate that the addition of LiCl in PVA cast solution can improve vapor permeability substantially. The observations of the microstructures and the characterization of the synthesized material disclosed that the reason behind increased Moisture rates is that the addition of LiCl increased the hydrophilicity.
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Effects of Membrane Parameters on Performance of Vapor Permeation through a Composite Supported Liquid Membrane
Separation Science and Technology, 2006Co-Authors: Li-zhi ZhangAbstract:Abstract Support liquid membranes have been used in air dehumidification due to their inherent high mass transfer rates. In this study, the effects of membrane structural parameters on vapor Permeation through a LiCl solution based supported liquid membrane are investigated. To aid in the analysis, a mass transfer model has been proposed for Moisture transfer through the membrane, which is composed of a supported liquid layer sandwiched by two hydrophobic protective layers. The model takes into account of the resistance in boundary layers, in the protective hydrophobic layers, and in the supported liquid layer. It is a transient model. It also reflects the distributed nature of Moisture Permeation through the membrane. The results found that the emission rate exhibits a non‐uniform distribution nature on the membrane surface. The structural parameters of the support and the protective layers, such as thickness, pore diameters, and porosity, have great effects on vapor Permeation.
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Fabrication of a lithium chloride solution based composite supported liquid membrane and its Moisture Permeation analysis
Journal of membrane science, 2005Co-Authors: Li-zhi ZhangAbstract:Abstract A novel composite supported liquid membrane has been prepared for ventilation air Moisture recovery. The membrane is composed of three layers: two hydrophobic protective layers and a sandwiched hydrophilic support layer in which LiCl solution is immobilized to facilitate water vapor transfer. A test is conducted to measure the Moisture Permeation rate through the composite membrane. Various resistances in the cell and in the composite membrane are clarified. Linear equilibrium relations between humidity, temperature, and LiCl concentration in the liquid solution layer are obtained to aid in the model set-up. It has been found that the mean Moisture Permeation rate through the composite membrane is around 1.14 × 10 −4 kg m −2 s −1 , almost two times higher than that through a solid hydrophilic cellulose acetate membrane with comparative thickness. Further, the supported liquid layer only accounts for 12% of the total Moisture transfer resistance in the cell, indicating that there is much potential for further performance improvement.
Chieh-ming Tsai - One of the best experts on this subject based on the ideXlab platform.
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Omniphobic Low Moisture Permeation Transparent Polyacrylate/Silica Nanocomposite
ACS applied materials & interfaces, 2013Co-Authors: Sheng-hao Hsu, Yuan-ling Chang, Chieh-ming TsaiAbstract:We report the development of low Moisture Permeation and transparent dense polyacrylate/silica nanocomposite material that can exhibit both superhydrophobic and oleophobic (omniphobic) properties. The material was prepared by a three-step process. The first step involved the preparation of UV polymerizable solventless hybrid resin and the fabrication of nanocomposite. The hybrid resin consisted of a mixture of acrylate monomer, initiator, and acrylate-modified different size silica nanoparticles. The second step was to roughen the surface of the nanocomposite with unique nanotexture by oxygen plasma. In the third step, we applied a low surface tension fluoro monolayer on the treated surface. The nanocomposite exhibits desired superhydrophobicity and oleophobicity with a water contact angle of 158.2° and n-1-octadecene contact angle of 128.5°, respectively; low Moisture Permeation of 1.44 g·mm/m2·day; and good transparency (greater than 82% at 450–800 nm for ∼60 μm film). The material has potential applica...
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omniphobic low Moisture Permeation transparent polyacrylate silica nanocomposite
ACS Applied Materials & Interfaces, 2013Co-Authors: Sheng-hao Hsu, Yuan-ling Chang, Chieh-ming TsaiAbstract:We report the development of low Moisture Permeation and transparent dense polyacrylate/silica nanocomposite material that can exhibit both superhydrophobic and oleophobic (omniphobic) properties. The material was prepared by a three-step process. The first step involved the preparation of UV polymerizable solventless hybrid resin and the fabrication of nanocomposite. The hybrid resin consisted of a mixture of acrylate monomer, initiator, and acrylate-modified different size silica nanoparticles. The second step was to roughen the surface of the nanocomposite with unique nanotexture by oxygen plasma. In the third step, we applied a low surface tension fluoro monolayer on the treated surface. The nanocomposite exhibits desired superhydrophobicity and oleophobicity with a water contact angle of 158.2° and n-1-octadecene contact angle of 128.5°, respectively; low Moisture Permeation of 1.44 g·mm/m2·day; and good transparency (greater than 82% at 450–800 nm for ∼60 μm film). The material has potential applica...
Sheng-hao Hsu - One of the best experts on this subject based on the ideXlab platform.
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Omniphobic Low Moisture Permeation Transparent Polyacrylate/Silica Nanocomposite
ACS applied materials & interfaces, 2013Co-Authors: Sheng-hao Hsu, Yuan-ling Chang, Chieh-ming TsaiAbstract:We report the development of low Moisture Permeation and transparent dense polyacrylate/silica nanocomposite material that can exhibit both superhydrophobic and oleophobic (omniphobic) properties. The material was prepared by a three-step process. The first step involved the preparation of UV polymerizable solventless hybrid resin and the fabrication of nanocomposite. The hybrid resin consisted of a mixture of acrylate monomer, initiator, and acrylate-modified different size silica nanoparticles. The second step was to roughen the surface of the nanocomposite with unique nanotexture by oxygen plasma. In the third step, we applied a low surface tension fluoro monolayer on the treated surface. The nanocomposite exhibits desired superhydrophobicity and oleophobicity with a water contact angle of 158.2° and n-1-octadecene contact angle of 128.5°, respectively; low Moisture Permeation of 1.44 g·mm/m2·day; and good transparency (greater than 82% at 450–800 nm for ∼60 μm film). The material has potential applica...
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omniphobic low Moisture Permeation transparent polyacrylate silica nanocomposite
ACS Applied Materials & Interfaces, 2013Co-Authors: Sheng-hao Hsu, Yuan-ling Chang, Chieh-ming TsaiAbstract:We report the development of low Moisture Permeation and transparent dense polyacrylate/silica nanocomposite material that can exhibit both superhydrophobic and oleophobic (omniphobic) properties. The material was prepared by a three-step process. The first step involved the preparation of UV polymerizable solventless hybrid resin and the fabrication of nanocomposite. The hybrid resin consisted of a mixture of acrylate monomer, initiator, and acrylate-modified different size silica nanoparticles. The second step was to roughen the surface of the nanocomposite with unique nanotexture by oxygen plasma. In the third step, we applied a low surface tension fluoro monolayer on the treated surface. The nanocomposite exhibits desired superhydrophobicity and oleophobicity with a water contact angle of 158.2° and n-1-octadecene contact angle of 128.5°, respectively; low Moisture Permeation of 1.44 g·mm/m2·day; and good transparency (greater than 82% at 450–800 nm for ∼60 μm film). The material has potential applica...
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Transparent hydrophobic durable low Moisture Permeation poly(fluoroimide acrylate)/SiO2 nanocomposite from solventless photocurable resin system
Journal of Materials Chemistry, 2010Co-Authors: Chien-chih Lin, Sheng-hao Hsu, Yuan-ling ChangAbstract:In this article, we report a novel high performance nanocomposite made from environmentally friendly and energy conserving solventless photocurable patternable resin system. The system contains a fluoroimide acrylate oligomer, acrylate monomer, photoinitiator and SiO2 nanoparticles. The fluoroimide acrylate oligomer was synthesized by reacting 2 mole equivalent of 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with 4,4′-(hexafluoroisopropylidene) diamine (6FpDA) first to form fluoroimide dianhydride, and then further reacting with 2 moles of 2-hydroxy ethyl methacrylate (HEMA). The fluoroimide acrylate oligomer was specially designed with carboxylic acid functionality. As compared with bis-phenol A acrylate oligomer, the fluoroimide acrylate oligomer nanocomposite shows an improvement in both physical properties and chemical properties. This new nanocomposite exhibits good cross hatch adhesive strength (>95% on glass) and unusually high hydrophobicity (>140° contact angle). The nanocomposite also shows excellent transparency (>90% transmission at 400–800 nm for 100 μm film), high thermal stability and mechanical durability. The water absorption and the water vapor Permeation of this nanocomposite are reduced to at least one quarter of those of the bis-phenol A acrylate nanocomposite. The chemical characteristics of the fluoroimide acrylate and the formation of nanodomains in the nanocomposite play major roles in providing the outstanding performance.
Alberto Perrotta - One of the best experts on this subject based on the ideXlab platform.
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On the synergistic effect of inorganic/inorganic barrier layers: An ellipsometric porosimetry investigation
Plasma Processes and Polymers, 2017Co-Authors: Morteza Aghaee, Alberto Perrotta, Sergey A. Starostin, Hindrik Willem De Vries, Mauritius C. M. Van De Sanden, Wilhelmus M. M. Kessels, Mariadriana CreatoreAbstract:In this paper, plasma-enhanced chemical vapor deposited SiO2 layers capped by an ultra-thin plasma-assisted atomic layer deposited Al2O3 over-layer are analyzed by means of ellipsometric porosimetry (EP). In a very recent contribution, we have shown that the combination of the two layers provided excellent intrinsic Moisture Permeation barrier performance down to the 10−5–10−6 g · day−1 · m−2 regime. The present paper therefore addresses the microstructural changes which the SiO2 layers undergo upon Al2O3 deposition, as monitored by ellipsometric porosimetry (EP). It was found that the Al2O3 deposition primarily affects the relative content of open pores with d > 0.3 nm (water as probe) and d > 0.42 nm (ethanol as probe) from 5.35 to 2.81% and from 2.50 to 0.32%, respectively.
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Dynamic Ellipsometric Porosimetry Investigation of Permeation Pathways in Moisture Barrier Layers on Polymers.
ACS applied materials & interfaces, 2016Co-Authors: Alberto Perrotta, Wilhelmus M. M. Kessels, Mariadriana CreatoreAbstract:The quality assessment of Moisture Permeation barrier layers needs to include both water Permeation pathways, namely through bulk nanoporosity and local macroscale defects. Ellipsometric porosimetry (EP) has been already demonstrated a valuable tool for the identification of nanoporosity in inorganic thin film barriers, but the intrinsic lack of sensitivity toward the detection of macroscale defects prevents the overall barrier characterization. In this contribution, dynamic EP measurements are reported and shown to be sensitive to the detection of macroscale defects in SiO2 layers on polyethylene naphthalate substrate. In detail, the infiltration of probe molecules, leading to changes in optical properties of the polymeric substrate, is followed in time and related to Permeation through macroscale defects.
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Low-temperature plasma-assisted atomic layer deposition of silicon nitride Moisture Permeation barrier layers
ACS applied materials & interfaces, 2015Co-Authors: Anne-marije Andringa, Alberto Perrotta, Wilhelmus M. M. Kessels, Koen De Peuter, Harm C. M. Knoops, Mariadriana CreatoreAbstract:Encapsulation of organic (opto-)electronic devices, such as organic light-emitting diodes (OLEDs), photovoltaic cells, and field-effect transistors, is required to minimize device degradation induced by Moisture and oxygen ingress. SiNx Moisture Permeation barriers have been fabricated using a very recently developed low-temperature plasma-assisted atomic layer deposition (ALD) approach, consisting of half-reactions of the substrate with the precursor SiH2(NHtBu)2 and with N2-fed plasma. The deposited films have been characterized in terms of their refractive index and chemical composition by spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). The SiNx thin-film refractive index ranges from 1.80 to 1.90 for films deposited at 80 °C up to 200 °C, respectively, and the C, O, and H impurity levels decrease when the deposition temperature increases. The relative open porosity content of the layers has been studied by means of multisolven...
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Ellipsometric Porosimetry and Electrochemical Impedance Spectroscopy Characterization for Moisture Permeation Barrier Layers
Plasma Processes and Polymers, 2015Co-Authors: Alberto Perrotta, Santiago J. Garcia, Mariadriana CreatoreAbstract:In this work the combination of ellipsometric porosimetry (EP) and electrochemical impedance spectroscopy (EIS) is extensively addressed in order to characterize the nano-porosity and further elucidate its influence on the water Permeation properties of plasma enhanced-CVD SiO2 layers. Pores with diameter in the range of 0.27–0.6 nm are studied by adopting a multi-solvent/multi-ion approach, with EP and EIS, respectively. This combined study has brought to conclude that open pores larger than 0.42 nm are responsible for WVTR values in the range of 10−3-10−5 gm−2 day−1, while pores with diameter between 0.42–0.27 nm were found to drive the transition to excellent Moisture barrier layers (10−6 gm−2 day−1). Moreover, it is shown that EIS is capable of detecting macro-scale defects, next to nano-porosity, being thus a powerful tool for the analysis of Moisture barrier layers.
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Analysis of Nanoporosity in Moisture Permeation Barrier Layers by Electrochemical Impedance Spectroscopy.
ACS applied materials & interfaces, 2015Co-Authors: Alberto Perrotta, Jasper J Michels, Anne-marije Andringa, Santiago J. Garcia, Mariadriana CreatoreAbstract:Water Permeation in inorganic Moisture Permeation barriers occurs through macroscale defects/pinholes and nanopores, the latter with size approaching the water kinetic diameter (0.27 nm). Both Permeation paths can be identified by the calcium test, i.e., a time-consuming and expensive optical method for determining the water vapor transmission rate (WVTR) through barrier layers. Recently, we have shown that ellipsometric porosimetry (i.e., a combination of spectroscopic ellipsometry and isothermal adsorption studies) is a valid method to classify and quantify the nanoporosity and correlate it with the WVTR values. Nevertheless, no information is obtained about the macroscale defects or the kinetics of water Permeation through the barrier, both essential in assessing the quality of the barrier layer. In this study, electrochemical impedance spectroscopy (EIS) is shown as a sensitive and versatile method to obtain information on nanoporosity and macroscale defects, water Permeation, and diffusivity of Moisture barrier layers, complementing the barrier property characterization obtained by means of EP and calcium test. EIS is performed on thin SiO2 barrier layers deposited by plasma enhanced-CVD. It allows the determination of the relative water uptake in the SiO2 layers, found to be in agreement with the nanoporosity content inferred by EP. Furthermore, the kinetics of water Permeation is followed by EIS, and the diffusivity (D) is determined and found to be in accordance with literature values. Moreover, differently from EP, EIS data are shown to be sensitive to the presence of local macrodefects, correlated with the barrier failure during the calcium test.