- Koganei, Tokyo, Japan
- Professor at a national university in Japanedit
The present study used optical coherence tomography (OCT) to monitor the dynamics of a highly viscous liquid in a porous tobacco substrate during heating. The OCT technique was integrated with a specially designed heating chamber and an... more
The present study used optical coherence tomography (OCT) to monitor the dynamics of a highly viscous liquid in a porous tobacco substrate during heating. The OCT technique was integrated with a specially designed heating chamber and an air pump for measuring. Two transitional points in the liquid behaviours at different temperatures were estimated using OCT and statistical analysis of the attenuation coefficient. The first point, ‘A’, shows the time approximation at which the penetration-dominant zone transitions into the evaporation-dominant zone. The second point, ‘B’, indicates the time approximation at which rapid evaporation of free liquid transitions into slow evaporation of trapped and bound liquid. This analytical system is an alternative for tracking liquid transport in porous biomass during heating.
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Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf... more
Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf surfaces is challenging due to its low deposition velocities compared to larger particles. In this work, we present a plant-growth chamber that was used to study the effect of submicron black carbon (BC) particles on the growth and photosynthesis of plants. The chamber system simultaneously enables the growth of multiple plants in pots and the deposition of submicron particles onto them. Two spraying methods assisted by ultrasonic and electrostatic forces were employed as aerosol generators to realize the particle deposition. The flow regime inside the chamber was numerically calculated to predict the transportation of aerosol particles, suggesting the optimal operating conditions of the chamber. The gas-phase particle size distribution measurements showed that generated BC particles were suspended in submicron diameter ranges. The aerosol generators were examined in the chamber using three conductor and insulator substrates as a model of plant leaves. Microscope observations and spectroscopic analysis ascertained that submicron BC particles generated from our generators were deposited on all substrate surfaces. Using the developed chamber system, systematic studies can be performed to advance the fundamental understanding of aerosol-vegetation interactions.
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The introduction of exogenous particles into plants has promising applications in agriculture and biotechnology. Nanoparticles can be transported into plants through foliar application or root uptake. However, both methods have... more
The introduction of exogenous particles into plants has promising applications in agriculture and biotechnology. Nanoparticles can be transported into plants through foliar application or root uptake. However, both methods have limitations in terms of the size of the particles (<40 nm) that can be transported due to the barriers of the cell wall and cuticle. In the present study, we proposed a novel method to deliver particles of up to 110 nm into plants by cutting the stem of tomato seedlings. We demonstrated for the first time, using water-insoluble silica colloids, that not only nanoparticles but also submicron particles can be transported toward the leaves when the plant stem is used as the entry point of particles. Thirty-five-day-old tomato seedlings were used as the target plants. When the cut stem seedlings were immersed in the colloidal particle suspension for up to 24 h, significant particle accumulation was observed in the nodes and leaves. The relatively low particle concentrations (10 mg/L) allowed effective transport throughout the plants. Silica particles with average diameters of 10 nm and 110 nm were both well transported and moved through the stem. Even after the particles entered the plant, adventitious roots were formed, resulting in the formation of whole plants with roots, stems, and leaves. This method can be applied not only to tomatoes but also to other food crops for various applications in plant biotechnology.
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Solar distillation, a promising technique for water purification and desalination, requires photothermal materials to efficiently convert solar energy into heat. In this study, a novel method is proposed wherein fresh carbonaceous (soot)... more
Solar distillation, a promising technique for water purification and desalination, requires photothermal materials to efficiently convert solar energy into heat. In this study, a novel method is proposed wherein fresh carbonaceous (soot) particles, as a photothermal material, are embedded into electrospun fibrous membranes by burning candles (to produce soot) and electrospinning of polymer material simultaneously. The proposed method can produce several types of membranes with various particle positions (interior or exterior) in the polymer fiber. The particle positions were adjusted by changing the introduction points of particles using a polymer jet. Polymer fibers with diameters of several hundred nanometers were fabricated. Experiments revealed that the soot particle position did not influence the photothermal conversion performance of the membranes. The fabricated membrane could improve the heat localization up to 194.5% and exhibited water distillation and desalination rates as high as 1.60 and 1.55 kg m À2h À1 , respectively, under 1-sun solar light irradiation. The proposed method opens a new route for the functionalization of polymer membranes.
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Dynamics of water content in a biological tissue is an important information of a biological activity. However, although the conventional measurement method measures the total amount of water contained in the tissue, there is no... more
Dynamics of water content in a biological tissue is an important information of a biological activity. However, although the conventional measurement method measures the total amount of water contained in the tissue, there is no established method for quantitatively measuring the amount of water localized in biological tissue. A spectral-domain optical coherence tomography system (SD-OCT) using two near-infrared wavelengths was developed for applications in cross-sectional imaging and quantitative analysis of evaporation at room temperature. The wavelengths of the light sources were selected as 1060 nm, which is hardly absorbed by water, and 1470 nm, which is absorbed by a factor of 220. In this study, we examined the effect of water absorption and scattering on the attenuation coefficient in a dense medium using a two-wavelengths OCT and showed the possibility of measuring the dynamics of water in the evaporation process through light scattering. Experimental results showed that the attenuation coefficient in a dense medium was more affected by scattering than water absorption. They are highly influenced by scattering caused by the temporal variation of the refractive-index matching effect between the hydrogen-bonded cellulose and free water around it in the process of evaporation. It was concluded that the SD-OCT was a quite practical and useful tool to visualize and quantitatively analyze natural phenomena that have never previously been observed.
The effect of chemical treatment of a metallic substrate on the deposition of aerosols generated by an ultrasonic nebulizer was investigated. A single substrate with areas having different "level" of hydrophilicity (or hydrophobicity) was... more
The effect of chemical treatment of a metallic substrate on the deposition of aerosols generated by an ultrasonic nebulizer was investigated. A single substrate with areas having different "level" of hydrophilicity (or hydrophobicity) was used as a model surface. The treated (more hydrophilic) area became more negatively-charged based on a surface electric potential meter. A low-pressure analysis method (electron-microscope image) and ordinary pressure methods (Raman spectroscopy and X-ray fluorescence) analytical results indicated that in comparison with the untreated area, the treated area trapped more particles in the case of the deposition of "wet" aerosols. In the case of the deposition of more "dry" aerosols, the untreated area trapped more particles rather than that of the treated one. The efficiency of particles deposition not only depended on the degree of hydrophilicity (or hydrophobicity) of the surface but also due to the conditions (wet or dry) of incoming aerosols.
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A protocol for the detachment of solid samples deposited on at substrates and their collection in aqueous samples is proposed based on a suspension-assisted ultrasonic method. As samples, combustion-synthesized magnesium oxide aggregates... more
A protocol for the detachment of solid samples deposited on at substrates and their collection in aqueous samples is proposed based on a suspension-assisted ultrasonic method. As samples, combustion-synthesized magnesium oxide aggregates in the submicron size range were deposited in the gas phase onto three kinds of substrates: a silicon wafer and coarse and ne alumina-coated resin sheets. To enhance the sample particle detachment, a solid-liquid suspension made of candle combustion soot particles was selected as an ultrasound propagation medium, which is di erent from the usual liquid medium, such as water, a surfactant solution, or a solvent. Preliminary detachment experiments were performed using low-power (42 kHz and 35 W) ultrasonication, and the substrates and suspensions were analyzed using scanning electron microscopy (SEM) images and particle size distributions based on dynamic light scattering, respectively. The detachment e ciency, de ned as the fraction of cleaned area on a substrate, was determined from the SEM images and indicates that the detachment using the medium with soot had a higher e ciency compared to that without soot, and there was an optimum soot concentration for particle detachment for all three substrates. The suspension particle size distribution after ultrasonication showed good dispersion of the sample particles in the soot suspension.
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To conserve water in crop production and landscaping, plastic mulch or sheets are commonly used. However, the environmental impact of plastic waste is a concern. Therefore, herein we report that a silane coupling agents-based coating can... more
To conserve water in crop production and landscaping, plastic mulch or sheets are commonly used. However, the environmental impact of plastic waste is a concern. Therefore, herein we report that a silane coupling agents-based coating can be applied to natural clayey soil samples to suppress water evaporation. The hydrophobicity of soils (particle sizes 200-500 µm) can be enhanced. Evaporation flux was investigated using an electronic balance placed inside a chamber by maintaining constant flow, temperature, and relative humidity. The magnitude of evaporation flux was adjusted by placing a hydrophobic-treated soil layer in the system. It is clear that the hydrophobictreated soil particle layer interacts with water capillaries to reduce the evaporation flux, but the effect on water vapor diffusion was small.
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In this study, we report for the first time the use of colloidal fluorescent submicrometer-sized particles as tracers for microliter liquid transport through multilayered biomass. We showed that the in-plane spread and the trans-planar... more
In this study, we report for the first time the use of colloidal fluorescent submicrometer-sized particles as tracers for microliter liquid transport through multilayered biomass. We showed that the in-plane spread and the trans-planar penetration of the liquid can be visualized by mapping the fluorescent particle distribution in each biomass layer using image analysis. The temperature and inter-layer connectivity were found to be vital factors determining the fate of the liquid transport. Inter-layer connectivity is influenced by both the physical connections among the layers and the property of the fluid filling the inter-layer pores. Utilizing this characteristic, we could use our visualization method to detect trace amounts of nano-to sub-micrometer impurities in one of the layers.
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The resistance to deagglomeration of spray-dried agglomerated particles of submicron size was investigated using an ultrasonication system in water. Submicron agglomerates consisting of water-insoluble primary particles with size of 10 or... more
The resistance to deagglomeration of spray-dried agglomerated particles of submicron size was investigated using an ultrasonication system in water. Submicron agglomerates consisting of water-insoluble primary particles with size of 10 or 100 nm were prepared in different shapes by varying the heating profile during spray drying. Deagglomeration experiments were performed using a low-power sonication device. Spherical agglomerates were found to be more resistant to ultrasonic forces, while dent-or doughnut-shaped agglomerates tended to break down. The results show that the shape of the agglomerate plays an important role in the energy balance of the ultrasound operation. The energy produced from the collapse of cavitation bubbles in the ultrasound vessel may be used to promote motion of the agglomerates and deagglomeration.
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To conserve water in crop production and landscaping, plastic mulch or sheets are commonly used. However, the environmental impact of plastic waste is a concern. Therefore, herein we report that a silane coupling agents-based coating can... more
To conserve water in crop production and landscaping, plastic mulch or sheets are commonly used. However, the environmental impact of plastic waste is a concern. Therefore, herein we report that a silane coupling agents-based coating can be applied to natural clayey soil samples to suppress water evaporation. The hydrophobicity of soils (particle sizes 200-500 mm) can be enhanced. Evaporation flux was investigated using an electronic balance placed inside a chamber by maintaining constant flow, temperature, and relative humidity. The magnitude of evaporation flux was adjusted by placing a hydrophobic-treated soil layer in the system. It is clear that the hydrophobic-treated soil particle layer interacts with water capillaries to reduce the evaporation flux, but the effect on water vapor diffusion was small.
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In this study, encapsulation of agarwood oil with non-ionic surfactant, Tween 80 was prepared at critical micelle concentration of 0.0167 % v/v to produce the most stable nano-emulsion in aqueous. The encapsulation has minimized the... more
In this study, encapsulation of agarwood oil with non-ionic surfactant, Tween 80 was prepared at critical micelle concentration of 0.0167 % v/v to produce the most stable nano-emulsion in aqueous. The encapsulation has minimized the bioactive compounds degradation in various pH conditions thus prolong their shelf life and maintained its initial oil grade. The oil grading of the prepared samples were conducted using the gel electrophoresis instead of using common analytical industrial grading such as gas chromatographymass spectrometry (GCMS). The grading method was chosen due to their unique zeta potential value after the encapsulation process. This paper demonstrates the feasibility of applying the electrophoresis principles to separate the encapsulated agarwood oil or grading of the emulsified agarwood oil. The results indicated that the grading process are potential to be further investigate based on their droplet size and zeta potential value at various pH condition when the dro...
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To improve stability of TiO2 nanoparticles in various organic solvents, their surface was modified using a mixture of silane coupling agents having hydrophobic and hydrophilic groups. Decyltrimethoxysilane (DTMS) and... more
To improve stability of TiO2 nanoparticles in various organic solvents, their surface was modified using a mixture of silane coupling agents having hydrophobic and hydrophilic groups. Decyltrimethoxysilane (DTMS) and phenyltrimethoxysilane (PTMS) were used as the former and 3-aminopropyltrimethoxysilane (APTMS), as the latter. First, effects of mixing ratios of silane coupling agents on reactivity with TiO2 nanoparticle surfaces were investigated. The addition of APTMS increased the pH value of TiO2 nanoparticle suspension due to the presence of the amine group and largely affected to the reacted amount of hydrophobic silanes. Next, relationships between the reacted amounts of silanes and their dispersion stability in various organic solvents were then investigated. Surface-modified TiO2 nanoparticles were re-dispersible into low-polar solvents such as hexane, toluene, and THF when the reacted amount of hydrophobic silane was relatively high; however, TiO2 nanoparticles were re-dispersible in highly polar solvents when the reacted amount of hydrophilic silanes increased. By controlling the amount of hydrophilic and hydrophobic silanes added, it is possible to effectively improve the dispersion stability of TiO2 nanoparticles in various organic solvents.
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A detection method based on the surface-enhanced Raman spectroscopy (SERS)-active substrate derived from aerosol nanoparticles and a colloidal suspension for detecting organic molecules of a model analyte (a pesticide) is proposed. This... more
A detection method based on the surface-enhanced Raman spectroscopy (SERS)-active substrate derived from aerosol nanoparticles and a colloidal suspension for detecting organic molecules of a model analyte (a pesticide) is proposed. This approach can detect the molecules of the derived from its solution with the concentration levels of ppb. For substrate fabrication, a gas-phase method is used to directly deposit Ag nanoparticles on to a silicon substrate having pyramidal structures. By mixing the target analyte with a suspension of Ag colloids purchased in advance, clotianidin analyte on Ag colloid can exist in junctions of co-aggregated Ag colloids. Using (i) a nanostructured substrate made from aerosol nanoparticles and (ii) colloidal suspension can increase the number of activity spots.
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Abstract Silica-coated magnetite nanoparticles have been synthesized successfully using a one-step electrochemical method. In this method, pure iron in a dilute aqueous sodium silicate solution that served as a silica precursor was... more
Abstract Silica-coated magnetite nanoparticles have been synthesized successfully using a one-step electrochemical method. In this method, pure iron in a dilute aqueous sodium silicate solution that served as a silica precursor was electrooxidized. We show that the ...
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In order to investigate whether or not airborne nanoparticles with a minimum agglomeration could be used for exposure tests on animals, we developed a nanoparticle generation system and examined the biological effects of the particles in... more
In order to investigate whether or not airborne nanoparticles with a minimum agglomeration could be used for exposure tests on animals, we developed a nanoparticle generation system and examined the biological effects of the particles in an inhalation study. The generation system was composed of an ultrasonic nebulizer and diffusion dryers, and 30 Wistar male rats were exposed to nickel oxide (NiO) nanoparticles for 4 wk (6 h/day). The geometric mean diameter of the particles and the daily average exposure concentration determined by a combination of a differential mobility analyzer and a condensation nucleus counter in the exposure chamber were 139 +/- 12 nm and 1.0 +/- 0.5 x 10(5) particles/cm3, respectively. At 4 days and 1 and 3 mo after the inhalation, each group of 10 rats were sacrificed and NiO nanoparticles deposited in the lung were determined by chemical analysis and the biopersistence (biological half time) was calculated. The deposited amount of NiO nanoparticles in the rat lungs at 4 days after the inhalation was 29 +/- 4 microg. The retained particle amount in the rat lungs after the inhalation exponentially decreased and the calculated biological half time was 62 days. The histopathological change was not severe just after the inhalation nor throughout the observation time. We concluded that nanoparticles with a minimum agglomeration were dispersed stably in the chamber and exposed to rats for 4 wk and that deposited amounts in the rat lungs and the biopersistence of the particles and the biological response in lung were detected.
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Synthesis of europium ion doped yttrium oxide (Y 2 O 3: Eu 3+) phosphor nanoparticles using a relatively high molecular weight polyethylene glycol is reported. Y 2 O 3: Eu 3+ materials could be prepared by simply heating in air provided... more
Synthesis of europium ion doped yttrium oxide (Y 2 O 3: Eu 3+) phosphor nanoparticles using a relatively high molecular weight polyethylene glycol is reported. Y 2 O 3: Eu 3+ materials could be prepared by simply heating in air provided that, water-soluble polymer ...
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Page 1. Journal of The Electrochemical Society, 146 (3) 1227-1230 (1999) 1227 S0013-4651(98)04-012-9 CCC: $7.00 © The Electrochemical Society, Inc. Various types of multicomponent oxide particles have been wide-ly ...
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This study focused on the measurement of the actual charging state of ambient aerosol particles, which is important for understanding the intricate process of adverse health effects caused by particulate matter (PM). The net electrostatic... more
This study focused on the measurement of the actual charging state of ambient aerosol particles, which is important for understanding the intricate process of adverse health effects caused by particulate matter (PM). The net electrostatic charging state of PM2.5 collected on filter media was measured. The Faraday cage method and surface potential
measurements were used in this study. The results showed that the polarities of the net charging state measured using these two methods were in agreement for 42 out of 48 samples (87.5%), and 36 samples (75%) were negatively charged. The filters were not significantly charged by friction between the filters and air not containing PM. Charge
addition to or leakage from the filters was not observed
over a two-month storage period. Net charging
state of PM2.5 collected on the filters was concluded
to be negative in most cases, based on data’s support of the assumption that aerosol charging state is not altered by the process of PM collection using filter.
measurements were used in this study. The results showed that the polarities of the net charging state measured using these two methods were in agreement for 42 out of 48 samples (87.5%), and 36 samples (75%) were negatively charged. The filters were not significantly charged by friction between the filters and air not containing PM. Charge
addition to or leakage from the filters was not observed
over a two-month storage period. Net charging
state of PM2.5 collected on the filters was concluded
to be negative in most cases, based on data’s support of the assumption that aerosol charging state is not altered by the process of PM collection using filter.
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ABSTRACT For standardisation of sampling and measuring methods regarding in-stack measurement of PM2.5 and PM10 mass concentration in flue gas of stationary emission sources, a two stage VIS impactor (virtual impaction surface impactor)... more
ABSTRACT For standardisation of sampling and measuring methods regarding in-stack measurement of PM2.5 and PM10 mass concentration in flue gas of stationary emission sources, a two stage VIS impactor (virtual impaction surface impactor) was developed in which the solid impaction surface of a conventional impactor is replaced by a space of a relatively slow moving air within a cavity of a receiving nozzle. Separation performance of the VIS impactor was examined using a model aerosol-gas stream system with a variety of dust concentrations and then exploited for the flue gas measurement in a coal combustion plant in China. Because a further stack emission is the condensable suspended particle matter (condensable SPM), two types of diluters for this measurement were designed and constructed based on England et al. and W. Lee et al.’s apparatus. Model exhaust gas with heavy metals was prepared in a laboratory scaled experimental arrangement and was mixed with clean air in both dilutor types. The effects of diluter structure, dilution ratio and residence time on the size distribution of condensable SPM are discussed. Keywords: virtual impaction surface impactor, separation efficiency, dilutor, condensable suspended particulate matter.
Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf... more
Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf surfaces is challenging due to its low deposition velocities compared to larger particles. In this work, we present a plant-growth chamber that was used to study the effect of submicron black carbon (BC) particles on the growth and photosynthesis of plants. The chamber system simultaneously enables the growth of multiple plants in pots and the deposition of submicron particles onto them. Two spraying methods assisted by ultrasonic and electrostatic forces were employed as aerosol generators to realize the particle deposition. The flow regime inside the chamber was numerically calculated to predict the transportation of aerosol particles, suggesting the optimal operating conditions of the chamber. The gas-phase particle size distribution measurements showed that generated BC particles were suspended in submicron diameter ranges. The aerosol generators were examined in the chamber using three conductor and insulator substrates as a model of plant leaves. Microscope observations and spectroscopic analysis ascertained that submicron BC particles generated from our generators were deposited on all substrate surfaces. Using the developed chamber system, systematic studies can be performed to advance the fundamental understanding of aerosol-vegetation interactions.
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Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf... more
Understanding aerosol-vegetation interactions is vital in ecosystems. However, the interactions remain elusive partly due to the lack of suitable plant growth chamber systems. Particularly, deposition of submicron particles on leaf surfaces is challenging due to its low deposition velocities compared to larger particles. In this work, we present a plant-growth chamber that was used to study the effect of submicron black carbon (BC) particles on the growth and photosynthesis of plants. The chamber system simultaneously enables the growth of multiple plants in pots and the deposition of submicron particles onto them. Two spraying methods assisted by ultrasonic and electrostatic forces were employed as aerosol generators to realize the particle deposition. The flow regime inside the chamber was numerically calculated to predict the transportation of aerosol particles, suggesting the optimal operating conditions of the chamber. The gas-phase particle size distribution measurements showed that generated BC particles were suspended in submicron diameter ranges. The aerosol generators were examined in the chamber using three conductor and insulator substrates as a model of plant leaves. Microscope observations and spectroscopic analysis ascertained that submicron BC particles generated from our generators were deposited on all substrate surfaces. Using the developed chamber system, systematic studies can be performed to advance the fundamental understanding of aerosol-vegetation interactions.
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The preparation of monodisperse, millimeter-or submillimeter-sized polymeric hydrogel beads by a novel production method combining sedimentation polymerization and electrostatic atomization is presented herein. The beads were prepared by... more
The preparation of monodisperse, millimeter-or submillimeter-sized polymeric hydrogel beads by a novel production method combining sedimentation polymerization and electrostatic atomization is presented herein. The beads were prepared by drop-wise addition or spray of a pre-gel aqueous solution into silicone oil through a nozzle with application of high voltage, and subsequent free-radical polymerization of the pre-gel droplets during their descent. The thermosensitive poly(N-isopropylacrylamide) hydrogel that was used as the model hydrogel has attracted much attention for application in reaction and separation processes. The size of the pre-gel droplets dispensed from the tip of the nozzle corresponded to the size of the resultant hydrogel beads and was controlled by adjusting the applied voltage. The diameter of the pre-gel droplet was estimated from the equilibrium of forces caused by gravity, the electrostatic force, and the liquid–gas surface tension.
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Nanoparticle layers were deposited on a substrate of submillimeter-sized stainless steel wire. The layers were produced from an aqueous TiO2 suspension by pulse direct current (DC) electrophoretic deposition. The electro-sterically... more
Nanoparticle layers were deposited on a substrate of submillimeter-sized stainless steel wire. The layers were produced from an aqueous TiO2 suspension by pulse direct current (DC) electrophoretic deposition. The electro-sterically stabilized suspension was prepared by beads-milling process with TiO2 powders and an anionic surfactant as starting materials. The solid concentration of the prepared suspensions was 7.5 and 30 wt% concentration with average particle sizes of 10 and 50 nm, respectively. To examine the deposited layer structure, a cross-section was spontaneously cleaved perpendicular to the substrate starting from the inner layer towards the outer layer by applying a heat treatment technique. The state of particle inside the layer deposited by pulse DC charging was compared with the one prepared by conventional DC charging from the aspects of morphology and size distributions. More uniform particle layers can be obtained using the pulse DC charging compared to those of the conventional DC. By using pulse DC, a relatively high volume density of the deposited structure (up to 0.35 kg/m3 at 1.3 V/cm) can be obtained.
Research Interests: Engineering, Structure, Nanoparticle, Morphology, Heat Treatment, and 26 moreDensity, Film, DISTRIBUTION, Physical sciences, Titanium dioxide, Stainless Steel, Deposition, Electrophoretic Deposition, CHEMICAL SCIENCES, Suspension, Particle, Electrophoresis, Powder, Particle Size, Layered Structure, Size Distribution, Cross Section, Pulse, Titanium oxide, Anionic Surfactant, Solid, Distribution, Substrate, Electric Field, Electroforesis, and Direct Current(Density, Film, DISTRIBUTION, Physical sciences, Titanium dioxide, Stainless Steel, Deposition, Electrophoretic Deposition, CHEMICAL SCIENCES, Suspension, Particle, Electrophoresis, Powder, Particle Size, Layered Structure, Size Distribution, Cross Section, Pulse, Titanium oxide, Anionic Surfactant, Solid, Distribution, Substrate, Electric Field, Electroforesis, and Direct Current)
(Density, Film, DISTRIBUTION, Physical sciences, Titanium dioxide, Stainless Steel, Deposition, Electrophoretic Deposition, CHEMICAL SCIENCES, Suspension, Particle, Electrophoresis, Powder, Particle Size, Layered Structure, Size Distribution, Cross Section, Pulse, Titanium oxide, Anionic Surfactant, Solid, Distribution, Substrate, Electric Field, Electroforesis, and Direct Current)
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Potable water from several residential areas on the east coast of Malaysia was filtered using a polyether-sulphone (PES) membrane to separate the coarse and fine iron-oxide particles inside the pipelines. The as-received samples consisted... more
Potable water from several residential areas on the east coast of Malaysia was filtered using a polyether-sulphone (PES) membrane to separate the coarse and fine iron-oxide particles inside the pipelines. The as-received samples consisted of a wide distribution of particle sizes, ranging from 5 m to 400 nm. The concentration of fine iron-oxide particles inside a distribution system was extremely low. Hence, a specific method is necessary to concentrate and separate the fine particles from the coarse ones. To study the fine particles from the bulk, excess pressure was applied to the membrane filter so that the clogged particles were released into the permeate. A 100 kDa PES membrane was used to separate the particles , because the samples consisted of a wide molecular-weight cutoff range from 89 g/mol goethite (-FeOOH) to 231 g/mol hematite (Fe 2 O 3). After the filtration process, the size distribution of permeated particles reduced to 550–400 nm. Through X-ray diffraction analysis, numerous polymorphs such as-FeOOH, Fe 3 O 4 , Fe 2 O 3 and maghemite were detected from the samples. The zeta potential value of the permeated particles changed from −18.5 to −13 mV, suggesting that the dispersity of permeated iron-oxide particles became unstable, but remained adequate for electrophoretic deposition (EPD). The fibrous carbon electrode used in the EPD process, could remove up to 87% of the permeated iron-oxide particles compared to solid carbon electrodes (<56%). A high-surface-area, porous electrode and a moderate applied voltage were preferred in order to minimise gas formation, reduce the electro-osmosis effect and increase the deposition efficiency.
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A nanostructure derived from TiO 2 particle deposition onto a biocomposite surface derived from coir dust (CD) was developed to control degradation using a spray dry technique. To stabilise and reduce the size of dispersed particles, the... more
A nanostructure derived from TiO 2 particle deposition onto a biocomposite surface derived from coir dust (CD) was developed to control degradation using a spray dry technique. To stabilise and reduce the size of dispersed particles, the TiO 2 powder was prepared in deionised water at pH 10 and sonicated at 20 kHz and 400 W. The coir dust was obtained from coconut kernel waste and underwent drying treatment before it was mixed with polypropylene (PP) as the substrate. The suspension consisted of particles with an average size and zeta value of 285 nm and À19.2 mV, respectively. The suspension was spray dried onto a hot-pressed substrate (biocomposite) with a surface roughness between 0.23 and 1.57 lm at ambient temperature. Scanning electron microscopy image analysis and Fourier transform infrared spec-troscopy analysis indicated that the TiO 2 particles were successfully deposited onto the substrate, shown by the existence of a carboxylic acid group (ACOOH) in the CD matrix. Moreover, the weight of the deposited substrate increased exponentially with deposition time compared to pure PP substrate. However, the deposition rate of TiO 2 nanoparticles was limited by the ratio of the substrate surface roughness to particle diameter, as predicted by a previous study.
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Highlights • Four Japanese forest tree species were exposed to submicrometer (NH4)2SO4 particles. • No significant effect of the particles on growth was observed after 2 years exposure. • Net photosynthetic rates of 3 species were not... more
Highlights
• Four Japanese forest tree species were exposed to submicrometer (NH4)2SO4 particles.
• No significant effect of the particles on growth was observed after 2 years exposure.
• Net photosynthetic rates of 3 species were not significantly changed by the exposure.
• Net photosynthesis of Cryptomeria japonica was relatively sensitive to (NH4)2SO4.
• Both increase and reduction in net photosynthetic rate were observed in C. japonica.
• Four Japanese forest tree species were exposed to submicrometer (NH4)2SO4 particles.
• No significant effect of the particles on growth was observed after 2 years exposure.
• Net photosynthetic rates of 3 species were not significantly changed by the exposure.
• Net photosynthesis of Cryptomeria japonica was relatively sensitive to (NH4)2SO4.
• Both increase and reduction in net photosynthetic rate were observed in C. japonica.