Search

An investigation is conducted into fast synthesis of electrochromic organomolybdenum oxide (MoO x C y ) thin films onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates via atmospheric pressure plasma jet. A precursor [molybdenum carbonyl, Mo(CO) 6 ] vapor, carried by argon gas, is injected into air plasma torch to synthesize MoO x C y films for offering extraordinary electrochromic performance. Only low driving voltages from − 1 V to 1 V are needed to offer reversible Li + ion intercalation and deintercalation in a 1 M LiClO 4 -propylene carbonate electrolyte. Light modulation with transmittance variation of up to 61%, optical density change of 0.54 and coloration efficiency of 37.5 cm 2 /C at a wavelength of 550 nm after 200 cycles of cyclic voltammetry switching measurements is achieved.

Enhanced lithium electrochromic performances of mixed organo-tungsten oxide (WxOyCz)/organo-molybdenum oxide (MoxOyCz) films by a rapid codeposition onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates at a short exposed duration of 23 s using an atmospheric pressure plasma jet (APPJ) at various mixed concentrations of hexacarbonyl precursors [W(CO)6 and Mo(CO)6] are investigated. The flexible organo-tungsten–molybdenum oxide (WMoxOyCz) films demonstrated noteworthy electrochromic performance for 200 cycles of reversible Li+ ion intercalation and deintercalation in a 1 M LiClO4–propylene carbonate electrolyte by the switching measurements of potential sweep from −1 to 1 V at a scan rate of 50 mV/s and the potential step at −1 and 1 V, even after being bent 360o around a 2.5-cm diameter rod for 1,000 cycles. The optical modulation (ΔT) of 61.3 % for MoOyCz films at a wavelength of 795.6 nm was significantly improved up to 72.5 % for WMoxOyCz films cosynthesized with an APPJ.

The voids at the interface of anisotropic conductive film (ACF) to glass are typically formed during bonding process for Chip-On-Glass (COG) packages. The low temperature (∼23 °C) Ar H 2 plasma pretreatment on glasses are investigated to enhance the void-free bonding of ACF to glass for COG packages. The void fraction of glass with ACF is significantly reduced from 52% of untreated-glass to 0% of Ar H 2 plasma-pretreated glass. The improved void-free ACF bonding is found to be highly dependent on the surface characteristics of glass. The surface energies, surface morphologies and surface compositions of glasses are discussed how to affect the enhanced void-free bonding of ACF to glass by low temperature Ar H 2 plasmas. The surface energies, such as total surface energies, polar surface energies and dispersive surface energies of glasses are obtained by calculating the basis of the measured contact angles of three various surface tensions of liquids. The surface morphologies of glasses are observed by field emitted scanning electron microscopy (FESEM). The surface compositions, such as atomic compositions and chemical bond compositions of glasses are analyzed using X-ray photoelectron spectroscopy (XPS).

This work aims to study the removal of phospholipids from Jatropha oil through a conventional degumming process combined with ultrafiltration membrane separation in a small-scale batch system. The effect of temperature, amount of acid solution added, and speed of centrifugation during the conventional degumming process were analyzed using response surface methodology (RSM). The optimum operating condition was determined to be at 65 °C, with 4 wt% acid solution added and a centrifugation speed of 1600 rpm. After the degumming process, the phospholipid content of Jatropha oil was reduced from 1200 ppm to 60 ppm. This was further reduced to less than 20 ppm by subjecting the oil to ultrafiltration membrane separation. It was found that the entire process not only decreased the phospholipid content of the oil but also improved its fuel properties, especially its kinematic viscosity and carbon residue. The kinematic viscosity was decreased from 30.02 cSt (mm 2 /s) to 27.20 cSt, while the carbon residue was decreased from 7.8% to 4.0%. Aside from the phospholipid content, the other two properties mentioned above were also considered to be important in the use of pure plant oil as a fuel in diesel engines. Future research could investigate the integration and optimization of the conventional degumming process combined with a membrane separation process.

PurposeThe purpose of this paper is to investigate the effects of H2 flow rate on improving the solder wettability of oxidized‐copper with liquid lead‐free solder (96.5Sn‐3Ag‐0.5Cu) by Ar‐H2 plasmas. The aim was to improve the solder wettability of oxidized copper from 0 per cent wetting of copper oxidized in air at 260oC for 1 hour to 100 per cent wetting of oxidized‐copper modified by Ar‐H2 plasmas at certain H2 flow rates and to find correlations between the surface characteristics of copper and the solder wettability with liquid lead‐free solder.Design/methodology/approachTo reduce the copper oxides on the surfaces of oxidized‐copper for improving solder wettability with liquid lead‐free solder, this study attempted to apply Ar‐H2 plasmas to ablate the copper oxides from the surfaces of oxidized‐copper by the physical bombardment of the Ar plasmas and to reduce the surfaces of oxidized‐copper by the chemical reaction of H2 plasmas with the surfaces of oxidized‐copper.FindingsThe solder wettability of oxidized‐copper was found to be highly dependent on the surface characteristics of the copper. The values of polar surface free energy and dispersive surface free energy on the surfaces of oxidized‐copper modified by Ar‐H2 plasmas were close to those values of solid lead‐free solder, which resulted in improved solder wettability with liquid lead‐free solder. Auger spectra indicated that the Ar‐H2 plasma modification was used to remove the copper oxides from the surfaces of oxidized‐copper.Originality/valueThe surface characterization of copper surfaces is typically determined by expensive surface analysis tool such as Auger Electron Spectroscopy (AES). This paper reports the results of a study of a promising technique called the sessile drop test method, for examining the surface free energies such as total surface free energy, polar surface free energy and dispersive surface free energy on the surfaces of copper to clarify how the solder wettability of oxidized‐copper with liquid lead‐free solder was enhanced by Ar‐H2 plasmas.

Reversible lithium intercalation and deintercalation behavior of atmospheric pressure plasma jet (APPJ)-synthesized organonickel oxide (NiO x C y ) thin films under various substrate distances is testified in an electrolyte (1 M LiClO4–propylene carbonate solution) at low driving voltages from −0.5 to 1.5 V. Fast responses of 2 s bleaching at −0.5 V and 6 s coloration at +1.5 V are accomplished for the nano-porous NiO x C y thin films. This study reveals that a rapid synthesis of electrochromic NiO x C y thin films in a single process via APPJ by 21 s is investigated. This study presents a noteworthy electrochromic performance in a light modulation with up to 43% of transmittance variation and a coloration efficiency of 36.3 cm2/C at a wavelength of 830 nm after 200 cycles of cyclic voltammetry measurements.

Silver vanadate (SVO) containing SBA-15 visible-light-driven photocatalyst was synthesized using the incipient wetness impregnation procedure. X-ray diffraction (XRD) results reveal that the SVO/SBA-15 powders consisted of three kinds of phase: pure Ag4V2O7 or pure α-Ag3VO4 or mixed phases of Ag4V2O7 and α-Ag3VO4. The mass spectra indicate that the main oxidation intermediate of toluene is benzaldehyde. The sample loaded with 51 wt% SVO (51SVO/SBA-15) exhibited the best photocatalytic activity. The results of two consecutive cyclic runs and regeneration indicate that the accumulation of benzaldehyde causes an irreversible deactivation of P25, but no deactivation of 51SVO/SBA-15. The enhanced photocatalytic activity of 51SVO/SBA-15 is attributed to mixed crystalline phases of Ag4V2O7 and α-Ag3VO4, where α-Ag3VO4 is the major component. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirms the presence of Bronsted and Lewis acids on the SVO/SBA-15 composites. A favorable crystalline phase combined with high intensities of Bronsted and Lewis acids is considered the main cause of the enhanced adsorption capacity, outstanding photoactivity, and long term stability of the SVO/SBA-15 composites.

An investigation is conducted on the enhanced surface hardness of flexible polycarbonate (PC) substrates using high-rate deposition (~ 19.1–19.9 nm/s) of plasma-polymerized organosilicon oxynitride (SiOxCyNz) films with an atmospheric pressure plasma jet (APPJ) at various substrate distances. It is found that the transparent, hard and flexible SiOxCyNz films can be deposited onto PC substrates at room temperature (23 °C) by injection of precursor tetramethyldisiloxan (TMDSO) into air plasma jet at atmospheric pressure. Pencil hardness measurements (ASTM d -3363) demonstrate that the surface hardness of the PC substrate is greatly enhanced from a soft surface of 3B for un-coated PC substrate to a hard surface of 7H for SiOxCyNz film-coated PC substrate. This study indicates that the performance of surface hardness on PC substrates is highly dependent on the surface characteristics of the PC substrates. The surface morphology of the PC substrate is observed by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The atomic compositions and chemical bonds of APPJ-synthesized SiOxCyNz films are analyzed using X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR).

Electrochromic organomolybdenum oxide (MoO x C y ) films are deposited onto 60 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates by low temperature plasma-enhanced chemical vapor deposition (PECVD) using a precursor of molybdenum carbonyl vapor, which is carried by argon gas, mixed with oxygen gas and synthesized by radio frequency power at room temperature (23 °C). The MoO x C y films with modified surface morphology and compositions of varying oxygen contents are proven to offer noteworthy electrochromic performance. Porous surface of the MoO x C y film (398 nm thick) provides Li + ion diffusion coefficient value of 1.7 × 10 − 10 cm 2 /s for Li + de-intercalation at a potential scan rate of 2 mV/s. High x / y value at high surface composition of oxygen to carbon in the MoO x C y film offers light modulation with transmittance variation of up to 63% and coloration efficiency of 36 cm 2 /C at a wavelength of 800 nm for 200 cycles of Li + intercalation and de-intercalation. PECVD-synthesized MoO x C y thin films show promising electrochromic properties for applications in flexible electrochromic devices.

An investigation was conducted in electrochromic performance of organotungsten oxide WOxCy films deposited onto 40 Ω/square flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates using atmospheric pressure plasma jet (APPJ) at various precursor injection angles. A precursor [tungsten carbonyl, W(CO)6;TC] vapor, carried by argon gas, was injected into air plasma torch. The APPJ-synthesized WOxCy films were proven to offer extraordinary electrochromic performance. Cyclic voltammetry (CV) switching measurements indicated that only low driving voltages from −1 to +1 V are needed to offer reversible Li+ ion intercalation and de-intercalation in a 1 M LiClO4–propylene carbonate (PC) electrolyte. Light modulation with up to 72.5% transmittance variation, optical density change of 0.84 and coloration efficiency of 49.6 cm2/mC at a wavelength of 797.6 nm after 200 cycles of Li+ ion intercalation and deintercalation were obtained.

Electrochromic properties of NiO x (nickel oxide) thin films sputtered on 40 Ω/□ flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates were investigated. Metallic Ni target, sputtered by radio frequency (r.f.) power with argon gases and reacted with oxygen gases at room temperature (23 °C), was proven to provide significant electrochromic properties. Cyclic voltammetry switching measurements found that only low driving voltages from −0.6 V to 1 V were needed to provide reversible Li + ion intercalation and deintercalation. Light modulation with up to 40% of transmittance variation, optical density change of 0.354 and color efficiency of 67 cm 2 /C at a wavelength of 550 nm were obtained for 1100 cycles of Li + intercalation and deintercalation in a 1 M LiClO 4 -PC (propylene carbonate) electrolyte.

In gasohol, the concentration of aqueous ethanol should be further increased from 95.6 % (by mass) to 99.5 % (by mass) by dehydration. In industrial processes. zeolite 3A is usually applied for alcohol-water separation. However, it adsorbs ethanol and water at a similar level (uptake of water/uptake of ethanol = 2.01), resulting in inefficient separation. In this study, potato starch was chosen as an adsorption material because of its very high selectivity and greater capacity for water (uptake of water/uptake of ethanol = 64.18). Conversely, the adsorption capacity of potato starch after regeneration will be substantially reduced, requiring further modification of the material. After regeneration. the unmodified starch decreased its adsorption capacity by 19.70 %. while the immobilized starch had a slight decrease of only 0.56 %. The sol-gel process was used to immobilize the starch, and the equilibrium adsorption isotherm was obtained to describe the immobilized sorbent. The selectivity of the immobilized starch sorbent had a ratio of 4.39 (water to ethanol). Compared to the zeolite 3A in the industrial dehydration process, this selectivity of immobilized starch is almost double that of zeolite 3A. The Langmuir model best describes the experimental isotherm curve of the selected sorbents.

An investigation was conducted on the electrochromic properties of plasma sputtered-nickel–vanadium oxide thin films on 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates. Metallic Ni 0.93 V 0.07 target, sputtered by radio frequency power with argon gases and reacted with oxygen gases at room temperature (23 °C), was proven to provide extraordinary electrochromic performance. Cyclic voltammetry switching measurements found that only low driving voltages from − 1 V to 1 V were needed to provide reversible Li + ion intercalation and deintercalation. The light modulation with up to 52% of transmittance variation, optical density change of 0.446 and color efficiency of 63.8 cm 2 /C at a wavelength of 550 nm was obtained for 200 cycles of Li + intercalation and deintercalation in a 1 M LiClO 4 -propylene carbonate electrolyte.

An investigation was conducted into the electrochromic properties of organotungsten oxide WOxCy films synthesized onto 60 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates using low temperature, plasma-enhanced chemical vapor deposition (PECVD) at varying oxygen concentrations. The PECVD-synthesized WOxCy films were proven to offer remarkable electrochromic performance. Cyclic voltammetry switching measurements revealed that only low driving voltages from −1 to 1 V are needed to provide reversible Li+ ion intercalation and de-intercalation in a 0.1 M LiClO4–PC electrolyte. Light modulation with transmittance variation of up to 72.9% and coloration efficiency of 62.5 cm2/C at a wavelength of 650 nm was obtained.

Electrochromic performance of WOxCy films deposited onto 60 Ω/□ flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates by low temperature plasma-enhanced chemical vapor deposition (PECVD) was investigated. It was proven that extraordinary electrochromic performance was provided when the precursor [tungsten carbonyl, W(CO)6; TC] vapor, carried by argon gas, was mixed with air gas and synthesized by radio frequency (r.f.) power at room temperature (23 °C). Cyclic voltammetry switching measurements found that only low driving voltages from − 1 V to 1 V were needed to provide reversible Li+ ion intercalation and de-intercalation. The light modulation with up to 63.6% of transmittance variation at a wavelength of 650 nm was obtained for 150 cycles of Li+ intercalation and de-intercalation in a 0.1 M LiClO4-PC (propylene carbonate) electrolyte.

A study was conducted into enhancing scratch resistance of flexible polycarbonate (PC) substrates by low temperature plasma-polymerized organosilica (SiO x C y ) with various O 2 flow rates. Low temperature plasma-polymerized SiO x C y by tetramethylsilane (TMS) and O 2 plasmas at room temperature (23 °C) was proven to highly improve scratch resistance of flexible PC substrates. Scratch resistance of PC substrates was greatly enhanced from 75% scratching of un-treated PC substrates to no scratching of plasma-polymerized SiO x C y on PC substrates using steel wool of 300 cycles at 200 g loading. Scratch resistance of PC substrates was strongly dependent on their surface characteristics. Surface hardness of PC substrates was determined by the pencil test. Surface morphology of PC substrate was monitored by atomic force microscopy (AFM) and field emitted scanning electron microscopy (FESEM). The atomic compositions and chemical bondings of TMS-oxygen plasma-polymerized SiO x C y were analyzed by X-ray photoelectron spectroscopy (XPS).

An investigation was conducted on enhanced scratch resistance of polycarbonate (PC) substrates by low temperature plasma-polymerized organo-silicon oxynitride (SiO x C y N z ) with various N 2 flow rates. It was found that the low temperature plasma-polymerized SiO x C y N z with tetramethylsilane (TMS)–O 2 –N 2 plasmas in room temperature (23 °C) can be used for improving the scratch resistance of PC substrates. Scratch test demonstrates this improvement. The scratch resistance of PC substrates was greatly enhanced from the overwhelming presence of scratching (90%) on un-treated PC substrates to a complete lack of scratching (0%) on TMS–O 2 –N 2 plasma-polymerized PC substrates with steel wool for 200 cycles at 300 g loading. The results of this study indicate the performance of scratch resistance on PC substrates was highly dependent on the surface characteristics of PC substrates. The hardness of PC substrates was determined by the pencil test. The surface morphology of PC substrate was monitored by atomic force microscopy (AFM) and field emitted scanning electron microscopy (FESEM). The atomic compositions and chemical bondings of TMS–O 2 –N 2 plasma-polymerized SiO x C y N z were analyzed by X-ray photoelectron spectroscopy (XPS).

An investigation was conducted into plasma polymerization of transparent organosilica (SiOxCy) onto flexible transparent polyethylene terephthalate (PET) substrates for improving wear resistance. The plasma-polymerized SiOxCy with tetramethylsilane (TMS) and oxygen (O2) gases in room temperature (23°C) was proven to highly enhance the wear resistance from the completely worn of untreated PET substrates to no worn of TMS-oxygen plasma-polymerized PET substrates at higher discharge powers, while the wear test of 300 cycles at 300 g loading with a steel wool was applied. The performance of wear resistance on PET substrates was found to be strongly dependent on the surface characteristics of PET substrates. The surface hardness of PET substrates was determined by the pencil test. The surface morphology of PET substrate was observed by atomic force microscopy (AFM). The atomic compositions and chemical bondings of TMS-oxygen plasma-polymerized organosilicas were analyzed by means of X-ray photoelectron spectroscopy (XPS). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The present work applies the regularized boundary integral equations that are newly developed to treat the thermoelastic field in thin anisotropic media. For the anisotropic thermal field, a direct domain mapping technique is applied with a unique interface condition that considers the heat conductance relation. By incorporating the heat conductance effect, the paper investigates how interfacial thermal stresses between generally anisotropic materials vary with the heat conductance coefficient. Accounting for the thermal conductance effect, the paper presents the complete algorithm for computing the thermal as well as the subsequent elastic fields on interfaces between dissimilarly adjoined anisotropic composites.

The reactive sputtering deposition of electrochromic thin films of V2O5 − z onto flexible PET/ITO substrates using argon and oxygen at room temperature (23 °C) was investigated. Cyclic voltammetry measurements showed that only low driving voltages, between − 0.6 V and + 1 V, were needed to provide reversible Li+ ion insertion and extraction. XPS showed that thin film with oxygen deficiency z of 0.13 can offer promising light modulation at a wavelength of 400 nm under visible-UV spectroscopy, with up to 36.5% transmittance variation even after 200 cycles of cyclic voltammetry tests.

The electrochromic properties of VO x C y films deposited onto 40 Ω square flexible PET/ITO substrates by low-temperature plasma polymerization were investigated. The organic precursor was carried by Ar/O 2 and polymerized by r.f. power at room temperature; the plasma-polymerized films were proven to provide extraordinary electrochromic properties of light modulation with up to 35.8% of transmittance variance. Cyclic voltammetry and cyclic potentiostatic switching measurements demonstrated that only low driving voltages from -0.6 to 1 V were needed to provide reversible Li + ion insertion and extraction.

A new type of hydrogen sensor based on a side-polished fiber Bragg grating (FBG) coated with thin palladium film was demonstrated experimentally. The used FBG with the reflectivity of 90% is fabricated in a hydrogen-loaded single-mode fiber (SMF-28) by using the phase mask writing technique of a KrF excimer laser. The experimental results show that proposed sensor can be applied for hydrogen concentration measurements.

The electrochromic properties of V 2 O 5 − z (vanadium oxide) thin films sputtered onto 60 Ω/□ flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates at various oxygen flow rates were investigated. The metallic vanadium (V) target, sputtered by radio frequency (r.f.) power with argon gases, and reacted with oxygen gases in room temperature (23 °C), was proven to provide extraordinary electrochromic properties. Cyclic voltammetry measurement demonstrated that only low driving voltages from − 0.6 V to 1 V were needed to provide reversible Li + ion insertion and extraction to and from a working electrode. The working electrode was part of a PET/ITO/V 2 O 5 − z flexible electrochromic device (FECD) in a 0.1 M LiClO 4 –PC (propylene carbonate) electrolyte with a Pt counter electrode and a saturated calomel reference electrode. Cyclic voltammetric (CV) analyses and ultraviolet (UV)–visible spectroscopy measured the electrochromic thin films of a-V 2 O 5 − z sputtered onto flexible PET/ITO substrate. An oxygen flow rate of 2 sccm with an oxygen deficiency z of 0.169, an insertion coefficient x of 0.097 and x Li + inserted / x Li + extracted ratio of 0.992 can offer excellent light modulation of up to 43.3% of transmittance variance, optical density change of 0.38 and color efficiency of 102.5 cm 2 /C at a wavelength of 400 nm for 200 cycles of Li + insertion and extraction.

Enhanced plasma-sputtered copper film adhesion onto polyimide substrates treated by oxygen glow discharge was investigated. The peel test demonstrates this improvement, with peel strengths of 0.7–1.2 g/mm for copper films prepared on un-modified polyimide substrates and 195.5–262.2 g/mm for copper films on oxygen plasma-modified polyimide substrates at certain plasma conditions. The enhanced adhesive strengths of plasma-sputtered copper films onto polyimide substrates by oxygen plasmas are due mainly to the increased surface energies of the polyimide substrates. Contact angle measurements indicate that the surface energies of polyimide substrates were greatly increased by oxygen plasmas. X-ray photoelectron spectroscopy analysis shows that the increased surface energies of polyimide substrates using oxygen plasmas occur because of the increased oxygen surface concentration and the increased C–O bond proportion.

This study focuses on the effects of particle composition, particle shape, particle size and oxidizing temperature on the electrical properties of copper-filled electrically-conductive adhesives (CFECAs) and the pressure-dependent conduction behavior of compressed copper particles (CCPs). Silver-coated copper particles and un-coated copper particles of both spherical and flake-shaped types were oxidized at 30°C, 175°C and 240°C for two hours. The copper particles were dispersed in an epoxy matrix for CFECAs or compressed in a mold for CCPs. Silver-coated copper particles showed significantly greater oxidation resistance than un-coated copper particles since the silver coating provides good oxidation resistance at temperatures lower than 175°C. Thermogravimetric Analysis (TGA), X-ray diffraction (XRD) and Auger Electron Spectroscopy were used to observe how metal oxides such as AgO and Cu2O affected the electrical properties of CFECAs and the conduction behavior of CCPs. The electrically-conductive adhesiv...

Enhanced solder wettability (SW) of oxidized-Cu (OC) with 96.5Sn-3Ag-0.5Cu lead-free solder (LFS) by Ar-H2 plasmas was investigated. The SW of OC was significantly improved from 0% wetting of Cu oxidized in air at 260°C for 1 h to 100% wetting of OC modified by Ar-H2 plasmas for 10 min. The SW of Cu was found to be highly dependent on the surface characteristics of Cu. By decreasing the total surface energy (TSE), decreasing the polar surface energy (PSE), and increasing the dispersive surface energy (DSE) on the surfaces of OC modified by Ar-H2 plasmas, the SW with LFS improves. X-ray photoelectron spectroscopy (XPS) indicates that Ar-H2 plasma treatment is used to remove the copper oxides CuO and Cu2O from the OC surfaces. The ratio of the total amount of Cu2O to CuO was found to be a good indication of how the copper oxides CuO and Cu2O affect the PSE, DSE, and SW of Cu.

The deposition of electrochromic thin films of a-WO3-z (amorphous tungsten oxide) on flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates by a reactive radio frequency (r.f.) sputtering method was investigated. The method used argon and oxygen at room temperature (23 °C). Cyclic voltammetry measurements showed that only low driving voltages −1 and +1 V were needed to provide reversible Li+ ion insertion and extraction. Cyclic potentiostatic switching and visible–UV spectroscopy showed that thin films with oxygen deficiency z of 0.22 can offer excellent light modulation, with up to 62% transmittance variation and color efficiency of 61.3 cm2 · C−1.

The wear resistance of PET substrates can be enhanced by low-temperature plasma-polymerization of organosilica (SiO x C y ); the effect of varying oxygen flow rates is investigated in this paper. It was found that the low-temperature plasma-polymerization of SiO x C y with tetramethylsilane (TMS) and oxygen (O 2 ) at room temperature (23 °C) can be used for improving the wear resistance of PET substrates, as demonstrated by scratch tests. The wear resistance of PET substrates was greatly enhanced from the completely scratched of the untreated PET substrates to no scratched of TMS/O 2 plasma-polymerized PET substrates, which were obtained at high oxygen flow rates with a steel wool for 300 cycles at 300 g loading. The results of this study indicate that the wear resistance of the treated PET substrates was highly dependent on the surface characteristics of bare PET substrates. The hardness of PET substrates was determined by the pencil test, while the surface morphology was monitored by AFM. The atomic compositions and chemical bonding of the TMS/O 2 plasma-polymerized organosilicas were analyzed by XPS.

This study investigates the enhanced adhesion of paint to cold rolled steel (CRS) in salt bath by Ar–H2 plasmas. It is found that the surface treatment on CRS, prior to painting, by low temperature plasma cleaning with argon–hydrogen plasmas at room temperature (23 °C), can be used for improving the adhesion of paint to CRS in salt bath. The tape test (ASTM 3359 Method) demonstrated this improvement, with a rating of “0” for untreated CRS for aging at a 3.5 wt% NaCl solution for 6 days and “5” for argon–hydrogen plasma-cleaned CRS at certain plasma conditions even for aging at a 3.5 wt% NaCl solution for 6 days. The adhesion performance of paint to CRS in salt bath is highly dependent on the surface characteristics of the CRS and the work of adhesion of paint to CRS.

This study investigates the enhanced corrosion protection of cold rolled steel (CRS) by low-temperature plasma cleaning and plasma polymerization. It is found that the surface treatment on CRS, prior to painting, by a combination of plasma cleaning with argon–hydrogen plasmas and then plasma coating by plasma polymerization with tetraethyl orthosilicate (TEOS)–hydrogen plasmas at room temperature (23 °C), can be used for improving the corrosion protection of painted-CRS. The corrosion test demonstrates this improvement, with the mean corrosion creepage of painted-CRS decreasing from 2 mm for untreated CRS to 0.02 mm for CRS pretreated by a combination of Ar–H 2 plasma cleaning and TEOS–H 2 plasma polymerization at certain plasma conditions after immersion in 3.5% NaCl solution for 10 days. The corrosion protection performance of painted-CRS is highly dependent on the surface characteristics of the CRS and the work of adhesion of paint to CRS.

Surface modification of polyimide films such as Kapton E(N) and Upilex S by air plasmas were investigated for enhanced adhesive strength with sputtered coppers. Peel tests demonstrate this improvement, with the peel strengths of 0.7 g/mm and 1.2 g/mm for unmodified Kapton E(N) and Upilex S and 99.3 g/mm and 91.5 g/mm for air plasma-modified Kapton E(N) and Upilex S at certain plasma conditions. This study reported that the enhanced adhesive strengths of polyimide films with sputtered coppers by air plasmas were strongly affected by the surface characteristics such as surface morphology and surface energy of polyimide films. Atomic force microscopy (AFM) and sessile drop method indicated the surface roughness and the surface energy of polyimide films were much increased by air plasmas that result in much increased peel strengths of polyimide films with sputtered coppers. Electron spectroscopy for chemical analysis (ESCA) observed the increased surface energy on polyimide films by air plasmas were due to the increased surface composition of O and the increased chemical bond of C–O.

Enhanced corrosion protection of painted cold rolled steel (CRS) by low temperature plasma polymerization was investigated. It was found that the surface treatment on CRS prior to painting by plasma cleaning with hydrogen plasmas and then plasma coating by plasma polymerization with tetraethyl orthosilicate (TEOS) plasmas in room temperature (23 °C) can be used for improving the corrosion protection of painted CRS. Tape adhesion tests (ASTM 3359 Method) demonstrated this improvement, with a rating of “0” for untreated CRS for aging at 3.5% NaCl solution for 6 days and “5” for hydrogen plasma-cleaned and TEOS plasma-deposited CRS at certain plasma conditions even for aging at 3.5% NaCl solution for 10 days. The results of this study indicated the performance of corrosion protection on painted CRS was dependent on the surface characteristics of CRS, the wettability of CRS and the work of adhesion of paint to CRS. In this study, the work of adhesion of paint to CRS and the wettability of CRS were calculated from the surface free energy of paint and CRS. The surface free energy of paint and CRS were calculated by the contact angle measurement using sessile drop method, the surface characteristic such as surface morphology of CRS was monitored by atomic force microscopy (AFM) and the surface composition of CRS was characterized by using Electron Spectroscopy for Chemical Analysis (ESCA).

Surface modification of polyimide films such as Kapton E(N) and Upilex S by argon plasma was investigated because of the enhanced adhesive strength with sputtered copper. Peel tests demonstrated this improvement, with a peel strength of 0.7 and 1.2 g/mm for unmodified Kapton E(N) and Upilex S, respectively, and 110.3 and 98 g/mm for argon plasma–modified Kapton E(N) and Upilex S, respectively, in certain plasma conditions. This study showed that the enhanced adhesive strength of polyimide films with sputtered copper by argon plasma was strongly affected by the surface characteristics such as surface morphology and surface energy of polyimide films. Atomic force microscopy and the sessile drop method indicated that the surface roughness and surface energy of the polyimide films were greatly increased by argon plasma, resulting in highly increased peel strength of the polyimide films with sputtered copper. It was observed in electron spectroscopy for chemical analysis (ESCA) that the increased surface energy of the polyimide films from argon plasma was a result of more of the surface being composed of O and N and of the increased number of CO, CO, and CN chemical bonds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 744–755, 2006

Surface modification of polyimide films Kapton E(N) and Upilex S by nitrogen plasmas were investigated for their enhanced adhesion strength with sputtered coppers. Peel tests demonstrate this improvement, with peel strengths of 7 and 12 N/m for unmodified Kapton E(N) and Upilex S, and 1522 and 1401 N/m for nitrogen plasma-modified Kapton E(N) and Upilex S at certain plasma conditions. Atomic force microscopy (AFM) and the sessile drop method indicated the surface roughness, and the surface energy of polyimide films were highly increased by nitrogen plasmas. This study shows the enhanced adhesion strengths of polyimide films with sputtered coppers by nitrogen plasmas, and these nitrogen plasmas were strongly affected by the surface characteristics of polyimide films. Electron spectroscopy for chemical analysis (ESCA) observed the increased surface energy on polyimide films by nitrogen plasmas was due to the increased surface composition of O and the increased chemical bond of CO. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2023–2038, 2005

The effects of oxidation and particle shape on critical volume fractions of silver-coated copper powders in conductive adhesives are investigated. Silver-coated copper powders with spherical and flake-shaped particles were oxidized at temperatures of 30°C, 175°C and 240°C for two hours and dispersed in an epoxy matrix. As silver-coated copper powders are oxidized at 30°C and 175°C, the critical volume fractions of the conductive adhesives are slightly affected by oxidation and particle shape at these temperatures. As the oxidation temperature approaches 240°C, the critical volume fractions of the conductive adhesives are strongly affected by oxidation temperature and particle shape, owing to the formation of oxides such as Cu2O on the surface of silver-coated copper powder—Cu diffuses from the interior to the surface of silver-coated copper powder and reacts with the oxygen in the air. Silver-coated copper powder with flake-shaped particles shows lower critical volume fractions in conductive adhesives than silver-coated copper powder with spherically shaped particles. Polym. Eng. Sci. 44:2075–2082, 2004. © 2004 Society of Plastics Engineers.

The effects of particle compositions, particle shapes, and oxidation temperatures on the electrical properties of conductive adhesives have been investigated. Silver-coated copper powders and uncoated copper powders with spherical and flake-shaped particles are oxidized at temperatures such as 30, 175, 240, 300°C and 350°C for 2 h and dispersed in an epoxy matrix. The results of this study indicate that the electrical properties of the conductive adhesives are strongly affected by the particle compositions and oxidation temperatures and only slightly affected by the particle shapes. Silver-coated copper powders show significantly greater oxidation resistance than uncoated copper powders. To understand how silver-coated copper powders show such oxidation resistance, they are analyzed by the techniques of thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Auger spectroscopy to observe how metal oxides such as AgO, Cu2O, and CuO affect the electrical properties of the conductive adhesives. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2045–2053, 2004

The surface properties of the bond pads of gold pattern-plated (GPP) substrates cleaned by oxygen plasmas dependent on the wire bondability with gold wires are investigated. Optical microscope and scanning electron microscopy are used to interpret the surface morphology of the bond pads. Auger electron spectroscopy and X-ray photoelectron spectroscopy are applied to analyze the surface compositions dependent on the depths and the surface chemical bonds of the bond pads. Oxygen plasmas are found that can reduce the surface impurities such as C, O and Cu for GPP pad and enhance the bonding strength with gold wires. The surface impurities such as Cu, Ni and O are found to cause no gold residue on GPP pad after the wire peel test due to Cu 2 O/CuO and NiO are formed at GPP pad. As the high contents of C and O are observed at the top surface of GPP pad with the contaminants of Cu 2 O/CuO and NiO, the bond pad will be non-bondable with gold wires.

Improvement of primer adhesion to thermoplastic olefins (TPOs) by methane plasma polymerization with a low-temperature cascade arc discharge was investigated. Methane plasma with a low-temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape-adhesion tests (ASTM 3359-92a method) demonstrated this improvement, with a rating of 0 for untreated TPOs and 5 for methane plasma-polymerized TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft, flexible TPOs (ETA-3041c and ETA-3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA-3183) needs to optimize the plasma conditions to pass the dry- and wet-adhesion test with methane plasmas. To relate the surface characteristics of methane plasma-polymerized TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact-angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated with scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis.

Improvement of primer adhesion to thermoplastic olefins (TPOs) by surface modification with a low-temperature cascade arc discharge-air plasmas was investigated. Air plasma with a low-temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape-adhesion tests (ASTM 3359-92a method) demonstrated this improvement with a rating of “0” for untreated TPOs and “5” for air plasma-modified TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft and flexible kind of TPOs (ETA-3041c and ETA-3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA-3183) needs to optimize the plasma conditions to pass the wet-adhesion test using air plasmas. To relate the surface characteristics of air plasma-modified TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact-angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated using scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 623–637, 2002; DOI 10.1002/polb.10122

A GaN/AlGaN-based ultraviolet light-emitting diode (LED) structure with an embedded porous-AlGaN reflector was fabricated by a doping-selective electrochemical (EC) wet-etching process. The n+-AlGaN/undoped-AlGaN (u-AlGaN) stack structures with different Al contents were transformed into porous-AlGaN/u-AlGaN stack structures that acted as the embedded distributed Bragg reflectors (DBRs). The porosity of the EC-treated AlGaN layer was increased by decreasing the Al content in the n+-AlGaN layer. The reflectivity of the porous-AlGaN DBR structure was measured to be 90% at 379.3 nm with a 37.2 nm stopband width. The photoluminescence emission intensity of the DBR-LED was enhanced by forming the embedded porous-AlGaN DBR structure.

The objectives of this research are to develop, for water-blown open cell rigid polyurethane foam, a theoretical model based on Maxwell’s equation (taking into account conduction in the solid and gas phases), and to establish Rosseland’s diffusion equation (taking into account radiation across the cell-gas spaces, but excluding convection) to predict the thermal conductivity of the polyurethane foam. The physical properties performances of the open cell rigid PU foam were experimentally investigated. The mean deviations of thermal conductivities data between the theoretical calculations of this model, compared with experiment data obtained from the ASTM C518 method, are within 3% to 8% within the mean temperatures from 4°C to 32°C, respectively.

An auxiliary sapphire tube serving as a heat capacitor was used in the co-drawing laser-heated pedestal growth system for fabricating small core crystal fibers. A factor of 3 improvement was achieved. Uniform 10-μm-core double-clad Cr4+:YAG crystal fibers were successfully fabricated as a result.

A new type of hydrogen sensor with a side-polished fiber Bragg grating coated with thin palladium film was demonstrated with the Bragg wavelength shift of 0.12 nm in the case of 99 % hydrogen concentrations.

The objective of this study is to investigate how filled core materials with halogen-containing and halogen-free flame retardants affect the flammability behavior. In this study, a thermogravimetric analyzer (TGA) was applied to study the thermal decomposition behavior of filled core materials with increasing temperature. A scanning electron microscope (SEM) was used to investigate the morphology of the filled core materials. Energy disperse spectroscopy (EDS) and dynamic scanning calorimetry (DSC) were used to identify the type of halogen-free flame retardant that was added to the core materials and relate it to the effect on the flammability of the core materials. Electron spectroscopy for chemical analysis (ESCA) was used to identify the content and the chemical bonding of the filled core materials and how this affects the flammability, which was tested by UL-94, for evaluating the propagation of burning and limited oxygen index (LOI), for interpreting the minimum oxygen content required for burning.

The objective of this study is to investigate the adhesive strength and the failure modes of Cu to polyimide for the two and three layers of flex substrates. Peel test was applied to measure the interfacial strength of Cu to polyimide and Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Disperse Spectroscopy (EDS) were used to observe the failure modes. The durability of Cu bonding to polyimide for the two and three layers of flex substrates was also studied by aging at various temperatures from 25/spl deg/C to 400/spl deg/C.

The reliability of oxidized VCSEL has similar result to implanted VCSEL. This paper presents our work on reliability data of oxidized VCSEL device and also the comparison with implanted VCSEL. The MTTF of oxidized VCSEL is 2.73 x 106 hrs at 55°C, 6 mA and failure rate ~ 1 FITs for the first 2 years operation. The reliability data of oxidized VCSEL includes activation energy, MTTF (mean-time-to failure), failure rate prediction, and 85°C / 85% humidity test will be presented below. Commercialization of oxidized VCSEL is demonstrated such as VCSEL structure, manufacturing facility, and packaging. A cost effective approach is key to its success in applications such as Datacomm.

In this paper, we will present the results of the 850nm implanted and oxide-confined vertical cavity surface emitting lasers in multi-Gigabit application. In TrueLight, we have a lot of experience in manufacturing VCSEL with ion-implantation and wet-oxidation technologies for single device Gigabit data transmission application. The ion-implanted VCSEL is reliable with the Mean Time To Failure (MTTF) up to 108 hours at room temperature operation. For the gigabit Ethernet data communication, it provides a very promising solution in short haul application. In transmission experiment we demonstrated the devices could be modulated up to 2.5Gbps and 3.2Gbps data rate. For oxide-confined VCSEL devices, we use wet oxidation technology to approach the device processing and get very good result to achieve the mutli-gigabit data communication application in single device form. The VCSEL device with oxide aperture around 12um could be modulated up to 2.5Gbps and 3.2Gbps. A data of employing VCSEL in high data rate POF transmission is also presented.