Surface Free Energy Parameters Research Articles

Correlations of Surface Free Energy and Solubility Parameters with Dielectric Constant, Refractive Index, and Density for Liquids.

There should be some intrinsic correlations between the surface free energy (γ) and solubility (δ) parameters, called characteristic parameters here, of substances with their fundamental physical properties such as the refractive index (nD), relative dielectric constant (εr), and density (ρ) because they are all related to intermolecular interactions. Understanding the correlations between characteristic parameters and fundamental physical quantities is of great fundamental and practical importance. In the current work, possible relationships between the characteristic parameters (γ and δ) and the physical quantities (nD, εr, and ρ) were explored by a trial-and-error fitting method based on the data of 92 liquids (including 14 nonpolar, 37 polar, and 41 hydrogen-bonded liquids). The γ parameters include total (γt), dispersive (γd), and polar (γp) ones, and the δ parameters include the Hildebrand parameter (δt) and the Hansen-dispersive (δd), polar (δp), and hydrogen-bonded (δh) ones. For each characteristic parameter, its relationship with the physical quantities was established. The applicability of the so-obtained relationships was confirmed using the data of another 66 liquids as an external data set. The empirical relationships can be used to estimate the characteristic parameters of liquids from their easily measurable physical quantities.

Properties and interaction of layers in board-biodegradable primer-printing ink screen-printed system

Surface interactions of the materials during and after the printing process are extremely important for understanding and optimizing the process of graphic reproduction. In screen printing on porous and absorbent substrates, mesh type and ink composition significantly influence the properties of the printed product. To protect the absorbent printing substrates such as board from moisture penetration and to ensure the optimal interaction of the printed ink layer and the substrate, board substrates can be coated with protective primers before printing. In this research, biodegradable primers made of poly(ɛ‐caprolactone) and poly(lactic acid) were applied on the board substrate which was then screen‐printed using two screen rulings of the mesh and two different types of water‐based printing inks on unprimed and primed board substrates. Printed ink layer thickness, surface roughness, water vapor transmission rate, surface free energy and adhesion parameters were measured/calculated on all produced samples. Microscopy of the printed elements was performed to visualize the influence of the primers on the printed line edge. Results of the research have shown that the primers influence the roughness reduction of the printed ink layer. Furthermore, thickness of the printed ink layers increased when the primers were applied on the substrate, pointing to the decreased permeability of the board, which was confirmed by the reduced water vapor transmission rate of the primed and printed substrates. The surface free energies of the tested surfaces and the adhesion parameters between biodegradable primers and prepared printing inks differed depending on the type of the ink and primer, pointing to the optimal combination of the primer and ink for the favorable acceptance of printing ink on the substrate. Results of this research have enabled the optimization of the quality of screen‐printed board product.

Effect of Industrial Solid Waste as Fillers on the Rheology and Surface Free Energy of Asphalt Mastic.

The continuous growth of industrial solid waste production has generated many environmental problems. We evaluated the potential of industrial solid waste as a substitute filler in asphalt mastic, with the aim of increasing the use of sustainable road construction materials. In this study, X-ray fluorescence spectroscopy (XRF) and scanning electron microscopy (SEM) were used to characterize the oxide composition and micromorphology of limestone (LS), red mud (RM), steel slag (SS), and ground granulated blast-furnace slag (GGBFS). Four asphalt mastics containing LS, RM, SS, and GGBFS with a filler-to-binder weight ratio of one were prepared. An evaluation of the rheology and wetting of the solid-waste-filler asphalt mastic was conducted using a frequency sweep, temperature sweep, linear amplitude sweep (LAS), multiple stress creep and recovery (MSCR), and surface free energy (SFE) methods. The results showed that SS increased the complex modulus, elastic component of the asphalt mastic and decreased the nonrecoverable creep compliance at stress levels of 0.1 and 3.2 kPa, which improved the rutting resistance of the asphalt mastic and reduced deformation under high-temperature conditions. The RM and GGBFS increased the fatigue performance of the asphalt mastic under strain loading, enhanced its fatigue life, and maintained good performance under long-term loading. The dispersive component of the SFE parameter of the solid-waste-filler asphalt mastic was larger than the polar component for the largest share of the surface energy composition. The SFE of the asphalt mastic prepared from the industrial solid-waste filler was reduced; however, the difference was insignificant compared to the limestone asphalt mastic. Solid-waste-filler asphalt mastic has performance characteristics, and its actual application can be based on different performance characteristics to select an appropriate solid-waste filler. The results of this study provide new technological solutions for solving the utilization rate of solid waste materials and sustainable road construction in the future.

The Influence of Alkaline Pretreatment of Waste Nutshell for Use in Particulate Biocomposites

The aim of this work was to determine how different types of alkaline pretreatment influence the properties of waste almond and hazelnut nutshell, as well as their compatibility with model inorganic geopolymer matrixes for the formation of biocomposites with potential use in civil engineering. For alkaline pretreatment, 3, 6 and 9% NaOH water solutions and milk of lime were used under different temperature and time conditions. The rise in the crystallinity index was confirmed by X-ray powder diffraction analysis, while the corroboration of the removal of amorphous and undesirable components was demonstrated through Fourier-transform infrared spectroscopy. Furthermore, the effectiveness of the pretreatments was confirmed via simultaneous differential thermal and thermogravimetric analysis, and the positive change in the morphology of the surface of the waste nutshell (WN) and the deposition of the desired phases was established using scanning electron microscopy. Surface free energy and adhesion parameters were calculated using the Owens, Wendt, Rabel and Kaelble method for WN as fillers and geopolymers as model novel inorganic binders. This research indicates that the 6% NaOH treatment is the optimal pretreatment process for preparing WN as the filler in combination with potassium and metakaolin geopolymer that has been cured at room temperature.

Investigating the effect of fundamental properties of materials on the mechanisms of thermal cracking of asphalt mixtures

In most of tests and models to evaluate the thermal cracking of asphalt mixture, the consideration of different elements within the asphalt mixture has been neglected to provide a corrective solution. Accordingly, in this research, the evaluation of the mechanisms of thermal cracking involved assessing the impact of surface free energy (SFE) parameters and other fundamental properties of bitumen and aggregate. These parameters included the adhesion and cohesion free energy, the ratio of the base element to the acid element of the aggregate SFE (RBA), the creep stiffness of bitumen, the rate of changes in creep stiffness (m-value), and specific surface area (SSA) of aggregate. To this end, Wilhelmy plate (WP) test, universal sorption device (USD) test, the bending beam rheometer (BBR) test and the pull-off test were performed. In the following, models were presented to evaluate the effect of mentioned parameters as independent variables on the mechanisms of thermal cracking using an artificial neural network (ANN). The sensitivity analysis of the Artificial Neural Network (ANN) model revealed that in the status of adhesive failure, the cohesion free energy and m-value did not affect the Pull-off adhesion strength. On the other hand, the adhesion free energy, RBA, and the SSA were directly proportional and the creep stiffness was inversely proportional to the Pull-off adhesion strength. Also, in the status of cohesive failure, the adhesion free energy, the RBA, and the SSA did not affect the Pull-off cohesion strength. On the other hand, the cohesion free energy and m-value were directly proportional and the creep stiffness was inversely proportional to the Pull-off cohesion strength.

Correlations of Surface Free Energy and Solubility Parameter with Dielectric Constant and Density for Inorganic Solids.

There should be some intrinsic correlations between the surface free energy (γ) and solubility (δ) parameters, called characteristic parameters here, of substances with their basic physical properties such as the relative dielectric constant (εr) and density (ρ), because they are all related to intermolecular interactions. Several correlations have been proposed empirically (or semiempirically) for liquids, but not for solids. It is essential to establish such correlations for solids because the estimation of γ and δ for solids is difficult and/or time-consuming. In the current work, the γ, δ, εr, and ρ data of 34 inorganic solids were chosen, and possible relationships between the characteristic parameters (γ and δ) and the physical quantities (εr and ρ) were explored by a trial-and-error fitting method based on the data of the solids. Six equations relating γ and δ to εr and δ were established. The γ parameters include total (γt), dispersive (γd), and polar (γp) ones, and the δ parameters include the Hildebrand parameter (δt) and the Hansen-dispersive (δd), polar (δp), and hydrogen-bonding (δh) ones. The empirical equations can be used to estimate the characteristic parameters of inorganic solids from their easily measurable physical quantities.

Bitumen binders modified with chemically-crosslinked chitosan

Nowadays, the observed trend in road materials technology covers the study of environmentally-friendly modifiers. Therefore, the possibility of modifying bitumen with chitosan and its mixtures with epichlorohydrin was evaluated. The studies were carried out for four different percentages of biopolymer (1.0%, 2.5%, 4.0% and 5.5%) and two percentages (1% and 2%) of crosslinking agents and included the assessment of their influence on the basic binder properties, surface free energy parameters and chemical structure. The results indicate that the appropriately selected quantitative chitosan/epichlorohydrin ratio leads to their crosslinking inside the bitumen causing a softening effect. The study also shows the possible benefits of using biopolymer-modified binders in the production of asphalt mixtures by the enhancement of surface-free energy parameters and reduction of the dynamic viscosity. Chitosan is an environmentally-friendly biodegradable biopolymer, and its chemical crosslinking has a positive effect on the properties of modified bitumen.

Surface Modification and Properties of Thin Ink Films with Added TiO2 and ZnO Nanoparticles Applied on Paperboard Substrates.

In this study, the surface modification of thin ink films with added nanoparticles was used to improve the functional properties of ink applied on paperboard substrates. The surface modification was performed by additional exposure of the samples to xenon radiation. Anatase TiO2, rutile TiO2 and ZnO were added to the base ink. The effect of surface modification on the surface, structural, and mechanical properties of the printed ink films was determined by FTIR-ATR spectroscopy, calculating the surface free energy and adhesion parameters, performing the rub resistance test of the printed samples, and by measuring the resistance to bending. Color measurements on the ink films were performed in order to observe the optical properties of unmodified and modified samples. The results showed that surface modification significantly improved the adhesion properties of the thin ink films and the mechanical properties of the samples. The results obtained on uncoated and coated paperboard showed that the addition of rutile TiO2 and ZnO nanoparticles had the greatest effect on the rub resistance of the ink films. The results of the color analysis showed that the addition of nanoparticles did not change the optical properties of the modified ink films and that rutile TiO2 and ZnO nanoparticles improved the lightfastness of the applied ink films.

Investigations on Adhesion Characteristics between High-Content Rubberized Asphalt and Aggregates.

The use of waste tires to prepare rubberized asphalt has been a hot trend in recent years, and the characteristics of adhesion between rubberized asphalt and aggregates are important factors affecting the performance of asphalt pavement. However, there is a lack of uniform results on the adhesion characteristics of rubberized asphalt. Therefore, crumb-rubber-modified asphalt (CRMA) with 15%, 20%, and 25% rubber contents was prepared in this work, and the basic rheological parameters and cohesive energy of the rubberized asphalt were characterized by DSR. The adhesion properties between rubberized asphalt and aggregates were characterized based on macroscopic binder bond strength (BBS), surface free energy (SFE) theory, and nanoscale atomic force microscopy (AFM) tests. The results show that crumb rubber (CR) can improve the high-temperature elastic properties of asphalt; secondly, CR can have a negative impact on the maximum tensile strength of asphalt and aggregates. CR can improve the SFE parameter of asphalt. The work of adhesion of rubberized asphalt and limestone is the highest, followed by basalt and, finally, granite. Finally, CR can cause the catanaphase in asphalt to gradually break down and become smaller, and the adhesion of rubberized asphalt can be reduced. Overall, CR can reduce the adhesion performance of asphalt, and this work provides a reference for the application of rubberized asphalt.

Optimization of surface free energy parameters for asphalt binder-aggregate system based on RBF neural network model

Asphalt pavement is subject to water damage frequently, which reduces the level of service that it provides and contributes to many road diseases. The surface free energy (SFE) theory has proven to be a trustworthy approach to assess water damage in asphalt mixtures. The goal of this investigation was to optimize the SFE parameters of asphalt binder-aggregate systems using an RBF neural network model. In this research, the SFE parameters of asphalt binder-aggregate systems were calculated firstly. Then, the modified boiling water test and the immersion Marshall test, as well as the freeze–thaw splitting test were then used to assess the asphalt mixtures’ adhesive properties and water stability. Thereafter, the comprehensive analysis method of entropy weight was used to conduct a thorough evaluation of the asphalt mixtures’ resistance to water damage. Next, the comprehensive evaluation index, Wi, of the asphalt mixtures’ resistance to water damage was used as the output layer of the RBF neural network model to optimize the SFE parameters. Finally, the feasibility of the optimized the SFE parameters using RBF neural network model was verified by establishing the connection between the optimized SFE parameters and the asphalt mixtures’ resistance to water damage by the entropy weight comprehensive analysis method. The results showed that among the SFE parameters of asphalt binder-aggregate systems optimized using the RBF neural network model, the Lewis base component and the Lifshitz nonpolar component of the aggregate played a dominant role in the ability to resist water damage, followed by the VDW adhesion work and the VDW de-bonding work formed by van der Waals forces. Furthermore, the asphalt binder-aggregate system composed of limestone had the best adhesion properties among all aggregates.

Rejuvenation effect of waste cooking oil on the adhesion characteristics of aged asphalt to aggregates

There are many studies on the rejuvenation of waste cooking oil (WCO) on reclaimed asphalt pavement (RAP), focusing mostly on mechanical properties of asphalt mixture while rarely on the adhesion of asphalt to aggregates. In this study, the surface free energy (SFE) method and molecular dynamics (MD) simulation were used to study the effect of WCO on the adhesion of asphalt and aggregate from the macroscopic and nanoscopic levels, respectively. Four types of aggregates (basalt, limestone, granite, and sandstone) and minerals (SiO2, MgO, CaCO3, and CaO) representing aggregates were selected. The SFE of asphalt and aggregate was obtained, then the adhesion work, debonding work, and the energy ratio (ER) were calculated to evaluate moisture susceptibility. Then the asphalt-mineral interface model was built and the adhesion work under dry and wet conditions and interaction energy were analyzed. The results show that from the SFE perspective, WCO can improve the SFE parameters of aged asphalt and its adhesion work with aggregates, whereas the rejuvenation effect decreases with the increase of WCO content. The aging process will increase the debonding work of the interface, resulting in aged asphalt easier stripping from the aggregate. The resistance to moisture damage ranks as basalt > limestone > granite > sandstone. From the SFE perspective, the van der Waals interaction contributes the main component of adhesion work of asphalt with SiO2, MgO, and CaO, while the electrostatic interaction is the main component with CaCO3. Under the wet condition, the adhesion work of the asphalt-SiO2 interface is affected to the smallest extent due to the minimal interaction between SiO2 and water molecules. Combining with the results of the SFE method and MD simulation, WCO plays a rejuvenation effect, improving the resistance to moisture damage. This study can guide the selection of aggregates to make WCO recycled asphalt mixture with sound moisture resistance.

Evaluation of the adhesion property and moisture stability of rubber modified asphalt mixture incorporating waste steel slag

The present study was conducted to recycle waste tire rubber and steel slag (SS) in asphalt pavement and investigates the moisture stability of asphalt mixtures incorporating these solid wastes. To this end, two types of aggregates (SS and diabase), three kinds of SS content and multiple freeze–thaw cycles were considered and three kinds of adhesion assessment methods: pull-out test and surface free energy (SFE) method, and freeze–thaw splitting test were performed. Three corresponding adhesion evaluation indicators like adhesion strength, SFE characteristics, and tensile strength ratio were obtained and six energy parameters were introduced to characterize moisture susceptibility of asphalt mixture. To explore the relations between the SFE parameters and the adhesion evaluation indicators, a grey correlation analysis method was adopted. Asphalt mixtures with high consumption of SS obtained a better moisture resistance because SS has a superior adhesion strength and higher SFE components than diabase aggregate. Stripping energy increase was found to be the main failure mode of the asphalt rubber-SS aggregate system. SFE method provides a comprehensive and accurate evaluation of adhesion property of loose asphalt rubber–SS aggregate system and moisture stability of compacted asphalt mixtures.

Evaluation of polyphenylene sulfide by surface thermodynamics approaches: Comparison with common polymers

AbstractPoly(phenylene sulfide) (PPS) is an advanced thermoplastic and widely used in industrial applications requiring high performance. Research on improving the surface properties of PPS is still ongoing and a detailed surface free energy (SFE) knowledge of this polymer is necessary for its applications related to surface wettability. In this study, wettability characteristics of PPS were evaluated by SFE calculations. For this purpose, the apparent contact angles of nine different test liquids having various surface tensions were measured on the PPS surface by the sessile drop method. After that, the dispersive and polar components of SFE were calculated using geometric (Owens and Wendt's method) and harmonic (Wu's method) mean approaches. The Lifshitz‐van der Waals, acidic and basic components of SFE were calculated using van Oss‐Chaudhury‐Good method. Additionally, the surface tension values of PPS were also determined by equation of state, Zisman's critical surface tension and Fowkes' approaches. In the present study, the effects of calculation methods and selected liquid pairs on SFE parameters were systematically investigated. It was found that selected liquid pairs and calculation methods affected the SFE considerably. The reasons for this were examined and the SFE components of PPS was compared with some common polymers for better evaluation.

Correlation between bond strength and surface free energy parameters of asphalt binder-aggregate system

The bonding potential is one of the imperative parameters of the asphalt binder-aggregate compositions and significantly affects the resistance of the asphalt mixtures against moisture damages. The properties of asphalt binder and aggregate have considerable effects on the moisture sensitivity and bond strength of the asphalt binder-aggregate composition. In the present study, the effects of the aging and stiffness of the asphalt binder, aggregate type, and their interactions on the bond strength and moisture susceptibility of the asphalt binder-aggregate systems were evaluated. The binder bond strength (BBS) test with a new approach of analyzing the failure pattern and the surface free energy (SFE) method were carried out to characterize the bond strength and bond energy parameters. The relationship between the bond strength, failure pattern in the BBS test, and SFE properties were presented. The results indicated strong and meaningful correlations between the SFE properties, failure patterns, and bond strength under dry and wet conditions. The meaningful and good correlations between the failure patterns and bond energies under dry and wet conditions demonstrate that the changes in the adhesive and cohesive failures in the asphalt binder-aggregate compositions highly depend on the SFE properties. Besides, according to SFE results and the failure patterns under dry and wet conditions, new energy parameters were introduced to evaluate the bond strength and moisture sensitivity.

Impacts of surface wettability and roughness of styrene-acrylic resin films on adhesion behavior of microalgae Chlorella sp

Biofilm attached cultivation is a promising method for efficient production of microalgae. Determining the surface property index to select an appropriate substrate benefiting the algae adhesion and biofilm formation is very important for the cultivation method. This work focused on elucidating and quantifying the influence of surface wettability and roughness of substrate on Chlorella vulgaris adhesion. Firstly, surface modified styrene-acrylic (SA) resin films by adding different dosage of perfluoroalkyl ethyl acrylate (FM) were prepared. Property characterization shows that the surface contact angle in water, formamide and diiodomethane of FM modified SA films is significantly associated with the FM dosage, while the other surface properties including zeta potential, surface potential and surface roughness have insignificant difference. The calculated surface free energy parameters show that the SA films belong to the non-polar substrata. A well quantitative correlation that the adhesion capacity of C. vulgaris linearly declines with the increase of water contact angle was obtained. And a near linear relationship between the adhesion capacity and the surface free energy (γ), or the cohesion free energy (ΔGcoh) was also observed. Secondly, the surface roughness solely changed SA films were prepared by replicating the morphology of stainless steel sieves through the PDMS template method. The patterned SA films have alternately arranged rectangular “valleys” and “ridges”. A well linear correlation between the microalgae adhesion capacity and the surface roughness was also obtained.

Laboratory evaluation of the effect of rejuvenators on the interface performance of rejuvenated SBS modified bitumen mixture by surface free energy method

The surface free energy and related parameters of asphalt binder affect the wettability of asphalt binder to aggregate and its moisture sensitivity. In this research, the surface free energy and related parameters of SBS modified bitumen (SMB) after aging/rejuvenating were tested and analyzed. And then based on this data, the effect of common rejuvenator cashew shell oil and active isocyanate rejuvenators on the water damage resistance and moisture sensitivity were evaluated and predicted. The results indicated that the surface free energy of SMB decreased after aging, while rejuvenators all can enhance the surface free energy. The cohesion work of aged SMB increased after rejuvenating, and the adhesion work between aged SMB and granite were enhanced by 12.4% at least with the addition of rejuvenators, namely, rejuvenators can improve its cracking resistance and interface stability, and active rejuvenator hexamethylene diisocyanate showed the best performance. Water boiling test showed that the adhesion grade of SBS modified bitumen on granite decreased from adhesion grade 5 to adhesion grade 3 after aging, while active rejuvenators can bring the adhesion grade of aged SMB on granite to the original level. This paper would be helpful to understand the moisture resistance mechanism of rejuvenated SBS modified asphalt mixture with active regeneration technology.

Solvothermal synthesis of carbonate-type layered double hydroxide monolayer nanosheets: Solvent selection based on characteristic parameter matching criterion

Monolayer nanosheets of CO32−-type layered double hydroxides (LDHs) have many special applications, but their fabrication is challenging. Herein, Co2Al-CO3 and Co2Fe-CO3 LDH nanosheets were synthesized via a solvothermal method. 31 solvents with different characteristic parameters, including the surface free energy (γ) and solubility (δ) parameters were chosen, to explore the correlation between the formation of monolayer LDHs (ML-LDHs) and the characteristic parameters of solvents. The results reveal that when the solvents used have the characteristic parameters matching to those of the LDHs, CO32−-type ML-LDHs with a thickness of ca. 1 nm can be obtained. The mixed-solvent strategy can provide the effective solvents for the synthesis of ML-LDHs. The dispersions of CO32−-type ML-LDHs can be stable for at least six months without obvious precipitation. In addition, it is demonstrated that the δ parameters of LDHs can be calculated from the γ parameters via the molar volume-free γ–δ equations developed previously. Furthermore, a new parameter called “surface free energy distance” is introduced, which can be used for screening effective solvents for the synthesis of ML-LDHs. To the best of our knowledge, this is the first time to investigate the applicable of the characteristic parameter matching principle for the bottom-up synthesis of ML-LDHs. This work deepens the understanding on the feature of CO32−-type LDHs and provides a solvent selection strategy for the synthesis of CO32−-type ML-LDHs.

Investigating the effectiveness of carbon nanomaterials on asphalt binders from hot storage stability, thermodynamics, and mechanism perspectives

The utilization of carbon nanomaterials such as graphene oxide (GO) and carbon nanotube (CNT) to modify asphalt binders is an innovative process. The feasibility of modifying asphalt binder with carbon nanomaterials was evaluated from the perspectives of storage stability, thermodynamic property, thermal stability and chemical structure. Accordingly, a combination of the segregation tests, dynamic mechanical rheological analyses and micro-morphology observation methods were adopted to verify whether the carbon-based nanoparticles could possibly segregate in the asphalt binders. The sessile drop method based on the surface free energy (SFE) theory was utilized to calculate the thermodynamic parameters of carbon nanomaterials-modified binders and the aggregates, and the effect of aging on the thermodynamic characteristics of the modified binders was evaluated. Moreover, the thermal gravimetric analysis (TGA) was performed to assess the effect of GO and CNT on the thermal characteristics of the binders. Finally, changes in the chemical structure were detected via Fourier transform infrared (FTIR) spectroscopy. The physical tests of the softening point differences, the rheological responses and the microscopic morphologies showed that the carbon nanomaterial-modified binders could achieve storage stability characteristics. The results of the SFE and related parameters suggested that the carbon-based nanoparticles can promote the thermodynamic characteristics of the asphalt binder. The rolling thin film oven (RTFO) process promoted the thermodynamic properties of the modified binders while the 12-day ultraviolet aging had an adverse effectiveness on the thermodynamic properties of the modified binders. For TGA tests, three indicators such as the residues at 600 °C revealed that CNT enhanced the thermal stability of the binders while GO weakened the thermal characteristics of the binders. The FTIR data demonstrated that no chemical reactions occurred in the process of preparing carbon nanomaterial-modified binders.

Surface free energy analysis of ITO/Au/ITO multilayer thin films on polycarbonate substrate by apparent contact angle measurements

A detailed surface free energy (SFE) knowledge of transparent conducting oxide (TCO)/metal/TCO electrodes is necessary for their applications related to surface wettability. However, SFE analysis of these surfaces has not been performed systematically previously. In this study, ITO and ITO/Au/ITO multilayer thin films were coated onto O2 plasma treated polycarbonate (PC) substrates by magnetron sputtering. The wettability characteristics of untreated PC, O2 plasma treated PC, ITO, Au interlayer, and ITO/Au/ITO multilayer thin films were evaluated by apparent contact angle measurements of nine different test liquids having various surface tensions. Following this, Lifshitz-van der Waals, acidic, basic, dispersive, and polar components of SFE were calculated using acid-base, geometric and harmonic mean approaches. In the present study, in which the significance of calculation methods and selected liquid pairs on SFE parameters were investigated, the effect of Au interlayer presence on SFE parameters were also evaluated simultaneously. The results showed that the total SFE values of ITO/Au/ITO multilayer thin films were found to be higher than that of ITO surface. The reasons behind this difference were discussed in terms of SFE components obtained using various liquid pairs by different methods. The results were also supported with XRD, XPS, AFM, and TEM analysis.

The influences of powder surface energy on the dispersibility technology of polyvinyl alcohol fiber

AbstractIn order to quantitatively analyze the effect of powder on fiber dispersion, the surface free energy theory was applied to test the surface free energy parameters of each powder based on the “capillary rise method”. Then, the surface free energy of each powder was further calculated. Finally, based on a certain ratio, the fiber reinforced cement was formed. In terms of the test piece, the profile of the cement slurry was imaged through the method of scanning electron microscopy. Through the image, the distribution of the fiber in the profile was quantified, and the relationship between the free energy of the powder surface and the distribution of the fiber in the cement slurry was clarified. It indicates that there is a strong correlation between the dispersibility and the surface energy of the powder. The greater the surface energy of the powder, the higher the distribution coefficient of the fiber in the cement paste.