Comparative Study Of Surfaces Research Articles

Fabrication and structure analysis of freestanding BaTiO3–CeO2 epitaxial nanocomposite membranes

Vertically aligned nanocomposite films hold the promise of making a significant contribution to the performance enhancement and multifunctional integration of flexible thin-film devices but are hindered by the difficulty of direct epitaxial growth on flexible substrates. In this work, freestanding BaTiO3–CeO2 epitaxial nanocomposite membranes were prepared by using water-soluble Sr3Al2O6 as the sacrificial buffer during film deposition. The membrane's lattice parameters as well as their epitaxial relationship, before and after its removal from the single-crystal substrates, were quantitatively measured and analyzed by combining x-ray diffraction and TEM. In addition, synchrotron soft x-ray absorption spectroscopy reveals the discrepancy in the surface and internal electron states of Ce and Ti via comparative studies in total electron yield mode and transmission mode, respectively. This work exemplified that freestanding membranes provide a convenient platform for (1) the study of in-plane lattice information of epitaxial oxide films via TEM and for (2) the comparative study of surface and internal electron band information of epitaxial oxide films.

A comparative study of surface modified nanohydroxyapatite using PVA polymer extracted from Seashells, Coral Skeletons and Eggshells for biomedical applications

The necessity and usage of hydroxyapatite in the form of bone and dental substitutes are increasing day by day. Hydroxyapatite derived from natural biomaterials promotes better osteointegration and biocompatibility with host bone. The present investigation aims to compare the properties of three distinct naturally occurring calcium precursors (seashells, coral skeletons, and eggshells) derived from nHAp/PVA composites (Polymeric composites). All the prepared samples were examined through characteristic instruments such as XRD (X-ray diffraction), FT-IR (Fourier Transform Infrared) Spectroscopy, TG-DTA (Thermogravimetric-Differential Thermal Analysis), SEM/EDAX (Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy), and XPS (X-Ray Photoelectron Spectroscopy). Furthermore, the samples were subjected to the Simulated Body Fluid (SBF), Hemocompatibility and Antimicrobial assay to find the Bioactivity, Hemocompatible and Antibacterial efficiency of the samples. The surface morphology of seashell nHAp/PVA shows a spherical shape while coral and eggshell-derived nHAp/PVA exhibits rod-shaped morphology. However, the achieved particle is found to be in the range of 32 to 41 nm. Also, coral-derived nHAp/PVA composites show a maximum crystallinity of 83.7% with a minimum weight loss of about 49.96%. This study demonstrates that among the prepared samples, coral nHAp/PVA performs better, but in terms of availability, seashell/PVA takes the lead with good results in all aspects. Though the eggshell nHAp/PVA satisfies several characteristic studies, it shows less stableness on TG-DTA. This study suggests that both Seashells and Corals can be utilized as calcium precursors in the making of quality hydroxyapatite that can be further processed in the making of hard tissue replacements/substitutes.

Comparative Surface Study of Ru/Cu- and Ag/Cu-Doped RHS Catalysts from Waste Biomass for Biofuel Application.

The present study compares the surface, textural, and catalytic properties of porous silica doped with bimetallic metal ions that was made from rice husk (RH) biomass. Due to the use of a surfactant during the synthesis process, porous RH-silica (RHS) was derived. In situ doping of silver/copper and ruthenium/copper has been achieved via the xerogel and hydrogel formation methods. The prepared catalysts have been analyzed by various methods, such as surface area and narrow pore size distribution, to confirm their porosity. Powder X-ray diffraction, Fourier transform infrared, and electron microscopy examination were further performed for physicochemical characterization of the synthesized materials. Transmission electron microscopy images showed that ruthenium and copper ions were incorporated perfectly, forming a hexagonal mesoporous (MCM-41) texture due to hydrogel formation and the method of preparation. Copper oxide nanoparticles with silver incorporation in RHS form cube-shaped particles for CuO formation on the surface of the silica matrix instead due to the method of preparation. In this case, ruthenium/copper-doped porous silica forms hexagon-shaped particles of RuO formation in the mesoporous matrix. Finally, the acetylation of glycerol using acetic acid on as-prepared catalysts has been studied. The catalytic activity increases with an increase in temperature and optimization of the molar ratio of glycerol and acetic acid. Increases in temperature result in higher selectivity toward triacetin formation instead of the conventional formation of monoacetin. Hence, we compared the surface physicochemical properties, catalytic conversion, and selectivity nature of bimetallic metal (Ru/Cu and Ag/Cu) ions incorporated in RHS prepared by different synthetic routes.

Comparative study of surface, elemental, structural and optical morphologies of titanium dioxide-zinc oxide (TiO2-ZnO) and titanium dioxide-zinc oxide/graphene (TiO2-ZnO/Gn)

The aim of this study is to synthesize a highly dense nanosized TiO2-ZnO sample with graphene (TiO2-ZnO/Gn) thin film via solution immersion method and compare its properties with TiO2-ZnO thin film without graphene. To prepare the titanium dioxide solution, the titanium butoxide precursor was added to ethanol, glacial acetic acid and triton-x-100 with a drop of deionized water. Next, to prepare for the ZnO/Gn solution, the zinc nitrate hexahydrate was added to hexamethylenetetramine (HMTA). Then, a specific weight of graphene was added into the solution before left for ageing. The thin films will be characterized in order to consider and enhance the potential of TiO2-ZnO/Gn thin film in treating wastewater. Ultra-Violet Visible spectroscopy (UV–vis), X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM) were used to determine the optical, structural and morphological properties of the samples. From the UV–vis absorption spectra, the TiO2-ZnO/Gn shows the better UV–vis performance compared to the TiO2-ZnO sample. While the FESEM images for TiO2-ZnO/Gn confirmed the presence of the Gn deposited on the thin film with specific grain-like structures of TiO2, hexagonal nanorod ZnO and wrinkles shape of Gn. Finally, the XRD analysis confirmed the crystallinity of the samples, and the elements present on the glass substrate. It has shown that there are TiO2, ZnO and Gn peaks present in the XRD patterns. Thus, TiO2-ZnO/Gn is the best candidate to be used as the photocatalyst in treating the wastewater.

Photoaging phenomena of biodegradable polybutylene succinate and conventional low density polyethylene by artificial weathering – A comparative surface study

Polybutylene succinate (PBS) is a promising eco-friendly alternative to many conventional plastics. It is not intended for outdoor use when a longer shelf life is desired. Research about the weatherability of PBS is important to expand its applicability. In the present study, the degree of aging on injection-molded sheets of biobased PBS and additive-free LDPE was investigated. These were subjected to accelerated photo-aging by 14-, 28-, and 56-days daylight exposure and 7-days UV irradiation. The comparison with LDPE confirmed that photo-initiated degradation processes occurred. The aging phenomena were monitored by atomic force microscopy, contact angle goniometry, Fourier-transform infrared spectroscopy, and synchrotron-assisted X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure. The results demonstrated effects in early stages of aging for PBS on surface morphology, roughness and wetting behavior. No significant chemical changes were detected on the surface of exposed PBS samples. For LDPE chemical changes in sp2/sp3 ratio, atomic oxidation state, and wetting behavior were observed for UV- and daylight weathered LDPE. However, no effects were apparent on the LDPE surface morphology. The biobased PBS is thus chemically more stable, but more surface-sensitive to accelerated photoaging than the LDPE used here.

Comparative Study of Surface Contaminated Layer on Titanium Aluminum Alloy and Titanium Alloy Investment Castings

A comparative study of the surface contaminated layer formed by chemical reaction between ceramic-mold and titanium aluminum alloy castings or titanium alloy castings were carried out. The morphology, thickness and hardness of the surface contaminated layer were characterized by means of metalloscopy and microhardness measurement. The results show that surface contaminated layers formed between Ti-Al alloy castings and ceramic-mold, also formed between Ti alloy castings and ceramic-mold. The surface contaminated layers of Ti-Al alloy castings were continuous and compact, their thickness was about 0~90 μm. The surface contaminated layers of titanium alloy castings were not even, their thickness was 0~900 μm. Titanium alloy is more liable to react with the ceramic -mold than the Ti-Al alloy.

Counterion-Induced Tailoring of Energy Transfer in Hydrothermally Grown Nanostructured ZnO for Photocatalysis

Morphological tailoring of zinc oxide (ZnO) nanostructures, viz., nanogranules, hexagonal pillars, and nanorods, has been demonstrated using the hydrothermal method by varying the precursor salts of zinc. Counterions of precursor salts, such as zinc chloride, zinc acetate, and zinc nitrate, are found to influence nucleation and growth of the nanostructures. Determination of crystalline and morphological properties of different nanostructures has been carried out by using X-ray diffraction and field emission scanning electron microscopy. The X-ray photoelectron spectroscopy technique is used for the investigation in a comparative surface study of ZnO nanostructures, and possible growth mechanisms of different nanostructures have been described. Bandgap and Urbach energies of the materials are also affected by the counterions of the precursor salts. Fourier transform infrared spectra of ZnO nanostructures show shifting of band positions of the functional group caused by variation of the precursor salt. Features of photoluminescence emission spectra of the ZnO nanostructures are ascribed to the association of different defect states due to the change of counterions. Moreover, the variation of precursor salts also influences the efficiency of Förster resonance energy transfer between the donor (ZnO) and acceptor (MB dye). ZnO with different nanostructures exhibits commendable photocatalysis degradation efficiency toward methylene blue dye (MB dye). Thus, the emission property and photocatalytic property of the ZnO nanostructures can be tuned by the variation of precursor salts. In this work, the role of counterions is established as a tool to control the ZnO nanostructures along with achieving control over the defect state emissions. This work not only establishes a relation between defects and photocatalysis, but also it deals with the variation of oxygen defects induced by the counterions of the zinc precursor salts.

Comparative study of lead zirconate titanate ceramic and carbon fiber reinforced polymer composite surfaces machined by abrasive water jet

This article describes a comparative study of surfaces of lead zirconate titanate ceramic and carbon fiber reinforced polymer composite materials. In the present study, abrasive water jet machining technique is used to machine ceramic and composite materials. Major process parameters namely stand-off distance, water pressure and traverse speed are considered. The experiments are designed by using response surface methodology. After machining, surface roughness of the machined samples is measured by surface roughness tester. The significance and influence of process parameters are studied by performing analysis of variance. It is observed that water pressure, stand-off distance and traverse speed are significant parameters in machining of lead zirconate titanate ceramic and water pressure and traverse speed are significant parameters in machining of carbon fiber reinforced polymer composite material. It is observed that increase in water pressure and decrease in stand-off distance decreases surface roughness in machining of ceramic material. The surface roughness is reduced from 3.189 to 2.010 µm. Increase in water pressure and decrease in traverse speed results in decrease in surface roughness in machining of composite material. The surface roughness varies between 2.392 and 3.998 µm. Further, the machined surfaces of ceramic and composite materials are examined by using scanning electron microscope to study the microscopic features of the machined surfaces. It is observed that machined surfaces of ceramic and composite material reveal three distinct regions of surface roughness.

Investigations of the characteristics and chemical bonds of Al and F co-doped ZnO films as a function of F2 flow rate

In this study, we investigate the effect of fluorine (F[Formula: see text] flow rate on the crystal characteristics and chemical bonds of Al-Doped ZnO (AFZO) Films. At first, 1 wt% Al2O3 was mixed with 99 wt% ZnO to form the Al-doped ZnO ceramic target, the radio frequency (RF) magnetron sputtering method was used to deposit the AFZO films by introducing different flow rates of F2 gas using F2/(Ar + F2) mixing atmosphere during the deposition process. F2 flow rates (F2/(Ar + F2)) were changed in the range of [Formula: see text]%, and F2 ratio was controlled using the mixing gases of (F2(5%) + 95% Ar) and pure Ar. AFZO films were deposited on the EagleXG glass and the films’ thickness was about 330 nm by controlling the deposition time. After AFZO films were deposited, their crystalline structure and electrical characteristics were well investigated. Finally, a comparative study of surfaces of AFZO films was investigated using X-ray photoelectron spectroscopy (XPS) to find the variations of the chemical bonds as the deposition temperature and F2 flow rate were changed.

Effects of different annealing temperatures on the physical, optical, and electrical characteristics and chemical bonds of Ga and F Co-doped ZnO films

In this study, we would investigate the effect of annealing temperature on the physical, optical, and electrical characteristics and chemical bonds of F- and Ga-co-doped ZnO (FGZO) Films. At first, 3 wt% Ga2O3 was mixed with 97 wt% ZnO to form the Ga-doped ZnO ceramic target, and the radio frequency (RF) magnetron sputtering method was used to deposit FGZO films. 0.2% CF4 flow rate (CF4/Ar) was controlled using the mixing gas of CF4 and pure Ar, and the mixing gas was introduced during the deposition process, which acted as the source of F− ions. FGZO films were deposited on the EagleXG glass and the films’ thickness was about 300 nm by controlling the deposition time. After FGZO films were deposited, they were annealed at 200, 300, and 400 °C. A comparative study of composition of FGZO films was investigated using secondary-ion mass spectrometry (SIMS) to analyze the distributions of F, Zn, Ga, and C elements, respectively, as the annealing temperature was changed. Another comparative study of FGZO films was that we proposed a modified Burstein-Moss (BM) equation to investigate the relationship between the carrier concentration and the shift of optical energy bandgap. Third comparative study of surfaces of FGZO films were investigated using X-ray photoelectron spectroscopy (XPS) to find the variations of the chemical bonds.

Analysis, fabrication and detailed comparative study of surface and interior rotor PMSM prototypes of identical nominal ratings and stators

This paper presents an in-depth analysis, performance evaluation and comparative study of two 5-kW, 8-pole, 750-rpm laboratory prototypes of a permanent magnet synchronous motor (PMSM) of identical nominal ratings with surface and interior permanent magnet (PM) rotor structures having same stator and armature winding (fractional slot distributed winding). The key electrical (such as rated voltage, current, power, speed, number of poles, etc.) and mechanical variables (such as overall volume, air-gap length, rotor diameter, shaft dimensions and magnetic material) of the fabricated prototypes have also been kept same to pin-point the direct influence of the two different rotor configurations (surface and interior PMSM) on the parameters, performance and operation of these PMSMs. For the two machines, a detailed comparison of air-gap flux density distribution, THD in induced voltage, torque ripple, losses, efficiency, torque–speed characteristics, field weakening capability, steady-state parameters at different operating conditions, etc. has been conducted. The salient observations from this comparative study have been duly highlighted. This paper also includes an in-depth comparison of volume and cost of PM used in the two types of PMSMs. The short-time performance figures of the said motors have also been presented. The possibility of demagnetisation of PMs, during a sudden fault, has also been investigated for both PMSMs. Challenges of making of both rotors have been discussed. The theoretically determined parameters and analytically evaluated performance figures have been verified through standard FEM packages and then validated experimentally on the prototypes.

Synthesis, characterization and photovoltaic applications of noble metal—doped ZnS quantum dots

Un-doped zinc sulphide (ZnS) and noble metal-doped ZnS quantum dots were synthesized by chemical method. The synthesized nanomaterial was characterized by UV-Visible, Fourier Transformed Infra-red Spectrometer (FTIR), Fluorescence, High Resolution Transmission Electron Microscope (HRTEM) and X-ray Diffraction (XRD). Scanning electron microscope complemented with energy dispersive X-ray was used to study particle size and chemical composition of un-doped and metal-doped ZnS QDs. A significant red shift in absorption band was observed in metal doped ZnS sample having concentration of impurity 0.05 M with respect to the un-doped ZnS with increasing the size of nanocrystals. Such red shift of the absorption bands are attributed due to quantum confinement effect. As un-doped and noble metal-doped ZnS QDs are direct band gap materials. The band gap energy of ZnS, Ag-doped, and Au-doped ZnS quantum dots is found to 2.5 eV, 2.4 eV and 2.2 eV, respectively. PL spectrum of the un-doped zinc sulphide nanocrytals witnessed two bands, first at 418 nm and second at 468 nm. However, PL spectrum of Ag-doped ZnS nanocrystals shows no green light emission band while a broad emission ranging up to 700 nm in Au-doped ZnS sample. XRD spectra of synthesized QDs exhibited that the material was in cubic phase. X-ray Photoelectron Spectroscopy (XPS) was used for comparative study of surfaces of zinc sulphide and noble metal zinc sulphide nanocrystals. The effects of inserting ZnS and noble metal doped ZnS nanocrystals in the active layer on the performance of organic solar cells were studied. The active layer mainly comprises of electron acceptor [6,6] phenyl-C61-butyric acid methyl ester (PCBM) and organic electron donor poly (3-hexylthiophene (P3HT) with quantum dots dissolved in dichlorobenzene. The cell conversion efficiency improved by embedding the doped QDs in the active layer blend. The cells fabricated with ZnS QDs exhibited cell conversion efficiency of 1.46%. By doping with silver and gold, the cell conversion efficiency was increased about 1.85% and 2.01%, respectively. The morphology of blend of nanocrystals with P3HT:PCBM were studied using atomic force microscopy.

Structural, optical and photovoltaic properties of P3HT and Mn-doped CdS quantum dots based bulk hetrojunction hybrid layers

Cadmium sulphide (CdS) and Mn-doped CdS nanocrystals were synthesized by co-precipitation method. The nanocrystals were characterized by Fluorescence, Fourier Transformed Infra-red Spectrometer (FTIR), UV–Visible, X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), Field Emission Scanning Electron Microscope (FESEM), and High Resolution Transmission Electron Microscope (HRTEM). A considerable blue shift of absorption band with respect to the cadmium sulphide was observed by the Mn concentration (0.5 M) in the doped sample with decreasing the size of nanocrystals. Other reason for this may be Mn doping. Subsequently the band gap was altered from 2.11 to 2.21 eV due to quantum confinement effect. Scanning electron microscope supplemented with EDAX was operated to find grain size and chemical composition of the synthesized nanomaterials. The PL spectrum of Mn-doped CdS nanocrystals displays three PL bands the first one, within the range of 500 nm and the second band at 537 nm, and the third one around 713 nm is labelled red band emission due to attributed to a 4T1→6A1 transition within the 3d shell of divalent manganese. XRD analysis showed that the material was in cubic crystalline state. A comparative study of surfaces of un-doped and metal doped CdS nanocrystals were investigated using X-ray Photoelectron Spectroscopy (XPS). The synthesized nanomaterial in combination with polymer, poly (3-hexyl thiophene) was operated in the construction of photovoltaic cells. The photovoltaic devices with CdS nanocrystals exhibited power conversion efficiency of 0.34% without annealing and 0.38% with annealing. However, the power conversion efficiency was enhanced by a factor of 0.35 without annealing and 0.42 with annealing with corporation of Mn impurity in CdS lattice. Atomic Force Microscopy was employed for morphology and packing behavior of blend of nanocrystals with organic polymer.

Influence of the dopant concentration on structural, optical and photovoltaic properties of Cu-doped ZnS nanocrystals based bulk heterojunction hybrid solar cells

Zinc sulphide (ZnS) and Cu-doped ZnS nanoparticles were synthesized by the wet chemical method. The nanoparticles were characterized by UV-visible, fluorescence, fourier transform infra-red (FTIR) spectrometry, X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). Scanning electron microscopy supplemented with EDAX was employed to observe the morphology and chemical composition of the un-doped and doped samples. A significant blue shift of the absorption band with respect to the un-doped zinc sulphide was sighted by increasing the Cu concentration in the doped sample with decreasing the size of nanoparticles. Consequently, the band gap was tuned from 3.13 to 3.49 eV due to quantum confinement. The green emission arises from the recombination between the shallow donor level (sulfur vacancy) and the t2 level of Cu2+ . However, the fluorescence emission spectrum of the undoped ZnS nanoparticles was deconvoluted into two bands, which are centered at 419 and 468 nm. XRD analysis showed that the nanomaterials were in cubic crystalline state. XRD peaks show that there were no massive crystalline distortions in the crystal lattice when the Cu concentration (0.05–0.1 M) was increased in the ZnS lattice. However, in the case of Cu-doped samples (0.15–0.2 M), the XRD pattern showed an additional peak at 37° due to incomplete substitution occurring during the experimental reaction step. A comparative study of surfaces of undoped and Cu-doped ZnS nanoparticles were investigated using X-ray photoelectron spectroscopy (XPS). The synthesized nanomaterial in combination with poly(3-hexylthiophene) (P3HT) was used in the fabrication of solar cells. The devices with ZnS nanoparticles showed an efficiency of 0.31%. The overall power conversion efficiency of the solar cells at 0.1 M Cu content in doped ZnS nanoparticles was found to be 1.6 times higher than the reference device (P3HT:ZnS). Furthermore, atomic force microscopy and X-ray diffraction techniques were employed to study morphology and packing behavior of blends of nanocrystals and polymer respectively.

Comparative study of surface and body absorptions for axisymmetric modeling of long pulsed laser heating material: theoretical model and mathematical solutions of temperature

In this article, we presented the comparative study of surface and body absorptions for axisymmetric modeling of long pulsed laser heating material. First, theoretical models of surface absorption is established based on the representation of heat source term through the surface boundary of material, and mathematical solutions of its homogeneous equation are obtained using separation of variables and Laplace transform method. Next, theoretical models of body absorption is established based on the representation of heat source term in the heat conduction equation, and mathematical solutions of its non-homogeneous equation are obtained using integral transform method. The presented methods are validated through modeling results of the surface absorption and body absorption model, respectively.

Comparative Study of Surface Hardened Automobile Gears

Comparative Study of Surface Hardened Automobile Gears

Comparative Study of Surface and Core Microflora of Chronic Tonsillitis

The main objective of this study is to find the correlation and differences between the microflora isolated and characterized from the surface and core regions of the tonsils, where the subjects were initially defined as tonsillitis. The maximum age incidence was from 6 to 12 years where the sex incidence was more in females than males. In majority of the patients, jugulodigastric nodes are palpable where the squeeze test was positive to 22% of cases. Sore throat and odynophagia are the symptoms predominantly found and these were presented with 2 to 3 years of duration among maximum cases, where in the average duration was 1 year and 7 months. Majority of the patients had chronic parenchymatous tonsillitis but enlarged adenoids were the most commonly associated ENT condition. Among the bacterial isolates, 87% was possible to aerobic isolation whereas 13% possibility was for both aerobic and anaerobic bacterial members. In the surface region, β haemolytic streptococci and Staphylococcus aureus are predominant isolates whereas in core region, β haemolytic streptococci and Streptococcus pneumoniae are possible. The variations in the bacterial isolates were possible maximum in core region compared to surface. Bacteriodes was the common anerobe found in both core and surface but dominance of Fusobacterium was identified in surface area only. The raised ASO titre was found in majority of the patients. Norfloxacin and ciprofloxacin are the common and routine antibiotic classically found effective against the isolates that re-establishing the superiority of the newer generation antibiotics to traditional penicillin.

Comparative Study of Surface Modified Carbonized Eichhornia crassipes for Adsorption of Dye Safranin

Eichhornia charcoal and surfactant modified eichhornia charcoal are prepared and characterized by FTIR, XRD, SEM, BET, pHPZC, and Boehm titrations. Effect of pH, contact time, adsorbent dose, and temperature are investigated to optimize conditions for adsorption of dye safranin. Experimental data were speculated for various kinetic and thermodynamics models and alluded that adsorption follows second order kinetic model. The Langmuir model deduced the maximum adsorption capacity as 84.8 mg g−1 for modified adsorbent. Thermodynamics and activation parameters corroborated that present adsorption system is spontaneous, feasible, endothermic, particle diffusion controlled, and physical in nature.

Comparative Surface Study on Hydrogen Terminated Si Surface Covered with Alcohols

We investigated the relative coverage of an alcohol adsorbed on a hydrogen terminated Si (H-terminated Si) surface by angle resolved X-ray photoelectron spectroscopy (ARXPS). We found that both Si2p (103.3 eV; Si-O) and O1s (532.5 eV; Si-O) spectra increased in the order of IPA < ethanol < methanol through all takeoff angles, and both spectra increased as the takeoff angle decreased in these alcohol treatments. The H-terminated Si surface was oxidized by coating these alcohols. In addition, the C1s (284.6 eV; C-H or C-C/H) spectrum slightly increased in order of IPA < ethanol < methanol through all takeoff angles, and increased as the takeoff angle decreased. The relative coverage of alcohols adsorbed on the H-terminated Si and their water contact angles are discussed in greater detail.

Comparative Surface Study on Silicon Dioxide Film Covered with Alcohols

We investigated the relative coverage of an alcohol adsorbed on silicon dioxide (SiO2) film by angle resolved X-ray photoelectron spectroscopy (ARXPS). We found that both Si 2p (103.3 eV; Si-O) and O 1s (532.5 eV; Si-O) spectra decreased in order of IPA > ethanol > methanol through all takeoff angles. In addition, both spectra decreased as the takeoff angle decreased in these alcohol treatments. The C 1s (284.6 eV; C-H) spectrum increased in order of IPA < ethanol < methanol through all takeoff angles, and increased as the takeoff angle decreased. Both Si 2p and O 1s signal intensities could be affected by the amount of carbon on the surface during takeoff of the X-ray. We hypothesize that alcohols are adsorbed on the outermost surface of SiO2 film and that the surface may be sufficiently covered with methyl groups or methanol. However, the surface is not completely covered with ethyl groups or propyl groups. The relative coverage of alcohols adsorbed on the SiO2 film in addition to their water contact angles are discussed in greater detail.