Increasing Aluminum Content Research Articles

Effect of aluminum content on the structural, morphology, and electrical properties of Al1-x Sbx thin films

Bulk AlxSb1-x samples were prepared with different x ratios (0.1, 0.3, 0.5, 0.7 and 0.9) by quenching technique. This was done throughout mixing the aluminum and antimony elements according to the proper atomic weight and put them in an evacuated quartz ampoule which then sealed and heated at 1273 K for five hours and left to cool in air. Thin films of AlxSb1-xwere prepared by using thermal evaporation under vacuum of 10-5 mbar on glass substrates at room temperature with deposition rate (10-15nm/min) at thickness of ∼ 500nm. The structures of AlxSb1-x bulk and thin films have been studied by X–ray diffraction technique. The results showed that all alloys have polycrystalline structures and the peaks at composition ratio x = 0.3, 0.5 and 0.7 were identical with the AlSb standard peaks while at x = 0.1 and 0.9 the peaks are identical with Sb and Al respectively. The x-ray pattern of the prepared thin films are polycrystalline and the peaks identical with cubic structure also the peaks intensity decrease with the increase of aluminum ratio in the prepared thin films. AFM measurements showed the non-regular variation (increasing and decreasing) of both the average grain size and average surface roughness with the increasing of composition ratio. AlxSb1-x thin films showed high charge carrier concentration nH especially at x = 0.1 and 0.3 on the other side charge carrier concentration showed reduction with the increase of aluminum content whereas nH reach minimum value at x = 0.7 and then increases with further increase of aluminum content. The electrical conductivity of AlxSb1-x declare similar behavior where it reach minimum value at x = 0.5. From another side AlxSb1-x thin films show high conductivity resemble that of metallic material especially also at x = 0.1 and 0.3.

Tailorable nano MgO.xAl2O3 spinel compositions along line of homogeneity via gel combustion route: Influence on phase evolution

Very fine sized (∼5–15 nm) magnesium aluminate spinel (MgO.xAl2O3) powder of different degree of solid solubility (x = 1, 1.25, 1.50, 1.75, and 2) have been attempted for synthesis following a gel combustion method to meet its high demand in the fields of refractory, photo catalysis, sensor and strategic applications, etc. Nitrates of magnesium and aluminum were used as oxidants for exothermic reactions fuelled by urea added with formaldehyde solution acting as reductant. Thermal decomposition reactions of polymer gels resulting in phases containing varied cationic ratio (Mg2+:Al3+) were investigated through DTA-TGA studies. Phase identification of synthesized powders derived from varying mole ratio of metal nitrates was performed by X-ray diffractometry (XRD) through Rietveld refinement using HighScore Plus software and was reconfirmed by Fourier Transform Infrared Spectroscopy (FTIR). Particle morphology was examined under Field Emission Scanning Electron Microscope (FESEM) & Transmission Electron Microscope (TEM). XRD pattern revealed the as-synthesized stoichiometric magnesium aluminate spinel (MgAl2O4) powder to be in amorphous state. In contrast, increasing trends in the extent of crystallinity in the as-synthesized form was obvious for alumina richer compositions. Dependence of development of crystallinity was explained in the light of thermal stability of polymer containing varied valent cations. Unlike crystallinity, a reverse trend is observed in case of cell parameter of the as-synthesized different non-stoichiometric spinel varieties where lattice parameter decreased with increasing alumina concentrations following Vegard's law. Variation in cell dimension against alumina concentration is caused by the insertion of smaller substituting Al3+ ions (0.054 nm) for Mg2+ ions (0.072 nm) in the unit cell. TEM observation reveals that the synthesized powder is aggregate of fine nano crystals. Crystallites were larger with increasing alumina concentration. An initial sintering behavior of the powder synthesized at 1400 °C has also been reported. Initial sintering trials were attempted under spark plasma sintering process.

Liquid-Phase Synthesis and Properties of Constant Lattice Parameter AlGaInAsP Solid Solutions on Indium Phosphide Substrates

Heterophase equilibria in the AlxGayIn1– x– yAszP1 –z/InP heterosystem have been analyzed in terms of a simple solution model in the temperature range 813–1023 K. We have assessed the stability limits of AlGaInAsP solid solutions synthesized on indium phosphide substrates and investigated kinetic features of the crystallization of constant lattice parameter AlGaInAsP solid solutions on InP substrates. The crystallization rate of AlGaInAsP solid solutions on InP substrates has been shown to depend on the synthesis temperature, the molten zone composition and length, and the temperature gradient. In addition, it has been shown to decrease with increasing aluminum concentration, independent of the molten zone length, owing to the decrease in the diffusion coefficient in the liquid phase. We have obtained composition dependences of component distribution coefficients in the AlxGayIn1– x– yAszP1 –z /InP heterosystem and shown that raising the synthesis temperature leads to a reduction in KAl and KP. The effect of synthesis conditions on the structural and luminescence properties of AlGaInAsP solid solutions on InP has been examined.

Increase of metallic silver nanoparticles in Chitosan:AgNt based polymer electrolytes incorporated with alumina filler

Abstract In the present work, the possibility of increasing the amount of metallic silver particles in chitosan (CS)-based polymer nano-composites was discussed. To prepare the electrolyte, a fixed amount of silver nitrate (AgNO3) inorganic salt was added to the natural CS biopolymer. Various techniques, such as UV–vis, SEM, EDX and impedance spectroscopy, were used to characterise the samples. Remarkable enhanced surface plasmonic resonance (SPR) peaks were observed at 420 nm in the UV–vis spectra of the samples incorporated with various amounts of alumina (Al2O3) nano-particles. The intensity of SPR peaks increased with increasing alumina concentration. The SEM image of pure CS showed a smooth surface and little white specks were observed in the SEM image of CS: AgNO3 system. The number of white specks were increased on the surface of the samples incorporated with 1 and 3 wt% of alumina. The sharp intense peaks due to metallic silver particles appeared in the EDX spectra at 3–3.6 keV. The second loop did not manifest for the CS: AgNO3 system because the amount of Ago nanoparticles were low. The distinguishable second loops were observed in impedance plots of CS: AgNO3 systems containing 1 and 3 wt% of alumina filler. The second loop in impedance plots was ascribed to metallic silver particles and its diameter increased with increasing alumina concentrations. The experimental data was fitted with electrical equivalent circuits (EEC). The EEC model reveals that the samples filled with Al2O3 filler needs two circuits for exhibiting best fitting. The dielectric constant increased at 1 wt% of alumina and then it decreased as alumina was increased to 3 wt%. The AC conductivity spectra were presented for all of the samples. The maximum DC conductivity of about 2.3 × 10−6 S/cm was obtained for the CS: AgNO3 system doped with 1 wt% alumina. The DC conductivity decreased at 3 wt% alumina due to the reduction of more silver ions to metallic silver particles.

Increased Aluminum Content in Certain Brain Structures is Correlated with Higher Silicon Concentration in Alcoholic Use Disorder.

Introduction: Alcohol overuse may be related to increased aluminum (Al) exposure, the brain accumulation of which contributes to dementia. However, some reports indicate that silicon (Si) may have a protective role over Al-induced toxicity. Still, no study has ever explored the brain content of Al and Si in alcoholic use disorder (AUD). Materials and methods: To fill this gap, the present study employed inductively coupled plasma optical emission spectrometry to investigate levels of Al and Si in 10 brain regions and in the liver of AUD patients (n = 31) and control (n = 32) post-mortem. Results: Al content was detected only in AUD patients at mean ± SD total brain content of 1.59 ± 1.19 mg/kg, with the highest levels in the thalamus (4.05 ± 12.7 mg/kg, FTH), inferior longitudinal fasciculus (3.48 ± 9.67 mg/kg, ILF), insula (2.41 ± 4.10 mg/kg) and superior longitudinal fasciculus (1.08 ± 2.30 mg/kg). Si content displayed no difference between AUD and control, except for FTH. Positive inter-region correlations between the content of both elements were identified in the cingulate cortex, hippocampus, and ILF. Conclusions: The findings of this study suggest that AUD patients may potentially be prone to Al-induced neurodegeneration in their brain—although this hypothesis requires further exploration.

Augmented antibacterial efficacies of the aluminium doped ZnO nanoparticles against four pathogenic bacteria

An ingenious study aimed to understand the influence of crystallite size, surface defects and morphology of the aluminium doped ZnO nanoparticles on their enhancement of antibacterial activities are reported herein. A cost effective wet chemical synthesis route was adopted for the synthesis of aluminium doped ZnO nanoparticles. X-ray diffraction analysis substantiates the hexagonal phase of the aluminium doped ZnO nanoparticles. The original contributions of the respective crystallite sizes and lattice strains of the synthesized nanoparticles are realized by size-strain plot (SSP) analysis. The UV-vis spectroscopic analysis revealed that the band gaps of the synthesized samples are widened on aluminium doping. The surface defects and vacancies present in the synthesized samples are revealed by the room temperature photoluminescence analysis. FESEM micrographs of the samples reveals that the crystallite sizes of ZnO decreases with the increase in aluminium content and a change in platelet to narrow sized spherical morphology. An investigation on the antibacterial activities of the aluminium doped ZnO nanoparticles was performed on Escherichia coli, Proteus mirabilis, Enterococcus faecalis and Staphylococcus aureus bacteria. The aluminium doping in ZnO leads to an enhanced antibacterial activity. The 5%Al:ZnO nanoparticle sample shows the highest antibacterial efficiency of 117% for the Proteus mirabilis bacterium. These results clearly demonstrate that the aluminium doped ZnO nanoparticles are promising candidates for antibacterial applications.

Effect of Ti/Al ratio on the performance of Ni/TiO2-Al2O3 catalyst for methane reforming with CO2

A series of mesoporous nanocrystalline TiO2-Al2O3 supports containing 0 to 100% alumina were synthesized via improved evaporation-induced self-assembly (EISA) strategy. The surface of the mixed oxide supports was decorated with nickel nanoparticles (10 wt%) via urea deposition-precipitation method. The catalysts containing different Ti/Al ratio were examined for methane reforming with CO2 regarding their activity and stability. Catalysts in both calcined, as well as in spent stages, were comprehensively characterized by various techniques like N2-physisorption analysis (BET), XRD, H2-TPR, NH3-TPD, TGA/DTG, SEM, ICP-MS, and TEM. The results show that a synergy between TiO2 and Al2O3 exist, and the doping of alumina with titania enhanced the catalytic activity and stability for an optimum doping ratio. The deactivation of pure titania supported catalyst was probably due to the sintering of Ni crystallites, partial coverage of Ni active sites by the TiOx species and the shrinkage of titania structure, however, it presents a high coke resistive catalyst. Doping up to 25% of alumina with titania was shown to retard the crystal growth of titania and redox characteristics of titania suppressed the deposition of coke over the catalyst surface. Different characterization techniques confirm the increase in coke deposition in TAL catalysts with an increase in alumina content.

Densification behaviour and the effect of heat treatment on microstructure, and mechanical properties of sintered nickel-based alloys

The present work focused on the densification behaviour and heat treatment effect on the mechanical properties of spark plasma sintered Ni–Fe–Al–Cr alloys. Five initial alloys were prepared by mixing of elemental compositions of each alloy followed by sintering. The five alloys, Ni–30Fe–20Cr, Ni–30Fe–15Cr–5Al, Ni–30Fe–10Cr–10Al, Ni–30Fe–5Cr–15Al, and Ni–30Fe–20Al, were sintered at sintering temperature of 950 °C, pressure of 50 MPa, heating rate of 150 °C/min, and at a holding time of 10 min and heat-treated. Microstructure and mechanical properties of the sintered alloys were investigated prior to and after heat treatment by scanning electron microscopy (SEM) and a Future-tech Vickers microhardness tester respectively. Results showed that the relative density of the alloys increases as the aluminium content increases. The microhardness increases at 800 °C for 2 h ageing time and decreases after prolonged ageing. Therefore, optimum strengthening of sintered nickel alloys can be obtainable within short duration of ageing as prolonged results in adverse hardness values.

Corrosion behavior of Ni-Al alloys beneath chlorides melt salt at 700 °C

Corrosion behavior of the binary Ni-xAl alloys (x = 6, 10, and 15 at.%) is comparatively studied in pure oxygen with and without a ZnCl2-KCl melt deposit at 700 °C. The oxidation of all alloys in oxygen atmosphere is strongly accelerated by ZnCl2-KCl deposits, with the formation of porous oxide scales and internal attack of the matrix induced by chlorine. The corrosion resistance of Ni-Al alloys under these present corrosion conditions is improved with increasing aluminum content of alloys, which is ascribed to the formation of alumina in the inner layer of corrosion products. The effect of aluminum is attributed to the increasing of the Al2O3 content in the oxide scales, which may act as barrier to prevent the rapid migration of the reactants through the oxides film layer. A mechanism accounting for the accelerated corrosion of Ni-Al alloys beneath ZnCl2-KCl deposits is regarded as a result of the combination of electrochemical reactions and active oxidation under mixed chlorides deposits.

Preparation of Fly Ash-Based Porous Ceramic with Alumina as the Pore-Forming Agent

Low-cost porous ceramic from fly ash with alumina as the pore-forming agent was produced. The effect of the alumina content on line shrink, bulk density, mechanical strength, porosity, and phase composition of porous ceramic were investigated in detail. The results showed that the addition of alumina can help to improve the porosity and then it can change the pore structure of porous ceramic. Meanwhile, the addition of alumina can react with SiO2 in fly ash which can form the mullite. With the increase of alumina content, the content of quartz decreased gradually, while the alumina and mullite increased. Furthermore, the pore size becomes uniform and the permeability increased gradually. After sintering at 1250 ℃ for 0.5 h, the porous ceramic has been obtained the bending strength of ≥ 35MPa and the porosity of ≥ 28% with the addition content of alumina (25 wt%).

The effect of aluminum additives on the content and parameters of the fine structure of titanium carbosilicide in SHS powders

The dependence of the phase composition and parameters of the fine structure of titanium carbosilicide in powders obtained by the self-propagating high-temperature synthesis on the concentration of aluminum in the 5Ti/2SiC/1C reaction mixture was investigated. The aluminum concentration was varied in the range of 0.1–0.4 mole fraction while maintaining the total carbon content. It has been established that aluminum additives not only affect the yield of titanium carbosilicide, but also contribute to the predominant formation of Ti5Si3 instead of TiSi2 in synthesis products, which is identified in non-aluminum powders. The introduction of a small amount of aluminum (0.1 mole fraction) leads to the formation of a solid solution of Ti3Si1–xAlxC2 and reduces the content of impurity phases in SHS powders by 6 %. With a higher aluminum content in the reaction mixture, the concentration of carbosilicide in SHS powders decreases, and that of binary compounds (TiC, Ti5Si3, TiAl) increases accordingly. Within the concentration range of 0.1–0.25 mole fraction, no noticeable effect was observed from the introduction of aluminum on the crystal lattice parameters of titanium carbosilicide in SHS powders. A significant increase in the parameters a and c of Ti3Si1–xAlxC2 (from a = 3.067 Å, c = 17.67 Å to a = 3.07 Å, c = 17.73 Å) while maintaining the ratio with с/a within known values (с/a = 5.78) is observed only when the aluminum concentration is 0.4 mole fraction. The crystallite size of titanium carbosilicide depends primarily on the burning parameters. At the same time, the deformation of the Ti3Si1–xAlxC2 crystal lattice in SHS powders monotonically grows with increasing aluminum content in the reaction mixture in the investigated concentration range.

Structure and reactivity of synthetic CaO-Al2O3-SiO2 glasses

Reactivity of glasses is predominantly linked to the degree of depolymerization of the glass structure. In this work, eight calcium aluminosilicate glasses were synthesized with compositions reflecting the glassy phases of industrial fly ashes and slags. The chosen composition ranges allow for isolation and identification of the roles of Ca and Al. The reactivity of the glasses is found to be mainly dependent on the CaO content as calcium depolymerizes the glass structure and increases the rate of reaction of the glasses. The effect of Al2O3 on glass reactivity is less pronounced and relies on chemical weakening of the glass structure. However, an increasing alumina content has a pronounced effect on the hydrate phase assemblage, bound water content, portlandite consumption and the heat of reaction. The resulting compressive strength of composite cement mortars incorporating the synthesized CaO-Al2O3-SiO2 glasses is found to be a function of both the degree of glass reaction and the actual phase assemblage.

Comparison of temperature dependence of internal damping of selected magnesium alloys

Abstract The research is focused on the study of the temperature dependence of the internal damping of selected magnesium alloys with different contents of aluminium - AZ31 and AZ61. These alloys are currently widely used in various types of industry, mainly in the automotive industry. It belongs to a group of materials called HIDAMETS because they have excellent damping properties. The internal damping of the samples was measured on a unique ultrasonic device constructed at Žilina University in Žilina. Specimens were measured at baseline in the temperature range from 25 °C to 400 °C. Changes in internal damping caused by varying aluminium contents in investigated alloys were noted. As the aluminium content increases, maximum internal damping is achieved due to the formation, growth and subsequent dissolution of the continuous precipitate in the microstructure.

Effect of Alumina Contents on the Physicomechanical Properties of Alumina (Al2O3) Reinforced Polyester Composites

Polyester-based composites filled with various contents of alumina (Al2O3) (i.e., 0, 1, 5, and 10 vol%) have been fabricated in this study. Physical and mechanical properties of the composites have also been analysed. The analysis results showed that the experimental density of the polyester/alumina composites was smaller than the theoretical density, which could be attributed to the formation of voids during preparation of the composites. Meanwhile, the tensile strength, stiffness, and hardness of the composites increased with increasing alumina content, while the strain-at-break of the composites decreased. It was observed that the composites containing 5 vol% of alumina had the best tensile strength, stiffness, and hardness. The uniform distribution and dispersion of alumina particles were likely responsible for the improvement of the mechanical properties. In other hand, small decrease in tensile strength, stiffness, and hardness of composite was found in the composites with 10 vol% of alumina. The formation of agglomerates and voids was believed to be the main factor for the decrease of the both properties.

Aluminium release by coated and uncoated fluid-warming devices.

The use of fluid-warming systems is recommended for infusion rates >500ml.h-1 to avoid peri-operative hypothermia. Some fluid-warming devices use disposable aluminium-heated plates for heat transfer, but there is no protective coating to separate the fluid from the heated aluminium surface. It is unknown if this could promote release of aluminium into infusion fluids. We investigated a coated (Fluido compact) and an uncoated (enFlow) fluid-warming device using normal saline or balanced electrolyte solution as infusion fluids, pumped through the heated disposables at flow rates of 2, 4 and 8ml.min-1 for 60min each. Aluminium concentrations in the fluid samples were analysed using graphite furnace atomic absorption spectrometry. With saline the coated and uncoated devices yielded aluminium concentrations below the level of quantification (<128μg.l-1 ). Similarly, balanced electrolyte solution in the coated device yielded aluminium concentrations <128μg.l-1 . However, balanced electrolyte solution in the uncoated device yielded aluminium concentrations of up to 6794 (3465-8002 [1868-7421]) μg.l-1 . Repeating this last study at a flow rate of 2ml.min-1 resulted in quite high aluminium concentrations when the uncoated device was not heated (~1000μg.l-1 ) and higher concentrations after the device was heated. We conclude that using uncoated aluminium plates in fluid-warming systems can lead to a risk of administering potentially harmful concentrations of aluminium when balanced crystalloid solutions are used. The mechanism is unclear, but heat is in part involved. Coating for aluminium within medical devices in direct contact with infusion fluids should be recommended.

Evolution Mechanism of Inclusions in Medium-Manganese Steel by Mg Treatment with Different Aluminum Contents

To investigate the effect of magnesium addition on the evolution of inclusions in medium-manganese steel with different aluminum contents, both thermodynamic calculation and high-temperature simulation experiments were carried out in the present work. The in situ observation experiments were used to clarify the related evolution process of inclusions. The samples taken from the melts were analyzed by scanning electron microscopy and energy dispersive spectroscopy. The compositions of steel were determined by inductively coupled plasma-optical emission spectrometer. The results show that the aluminum content in steel has a certain influence on the magnesium content, under the same conditions, magnesium content increases with increasing aluminum content. The inclusions transformed from MnO·Al2O3 to Al2O3 when the aluminum content was higher than 0.0076 mass pct. After magnesium treatment, the inclusions gradually transformed into MgO·Al2O3, and the MgO/Al2O3 mole ratio in inclusions decreased with the increase of aluminum content. The diameter of the inclusions decreased, and number density of inclusions increased in steel after magnesium addition. The phenomenon that large-sized cluster-like Al2O3 inclusions transform into finely dispersed Mg-containing inclusions was firstly observed in situ by confocal laser scanning microscope.

Effect of Quenching Process on Microstructure and performance of High-Boron High-Speed Steel

The effects of quenching process on microstructure and hardness of High-Boron High-Speed Steel (HB-HSS) containing 0.4%C-6.0%Cr-4.0%Mo-1.0%V-1.0%Si-0.5Mn-x%B-y%Al (x=1.0, 1.5, 2.0, y=1.0, 2.0, 3.0) were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Rockwell hardness tester. The experimental results indicate that the quenching microstructure of HB-HSS consists of α-Fe, M2(B, C), M7(B, C)3 and a few of M23(C, B)6。With the increase of quenching temperature, the net structure of borocarbides is damaged and the borocarbides are evenly distributed in the matrix. When the quenching temperature is 1050 °C, the Rockwell hardness of HB-HSS increases with the increase of boron content. The Rockwell hardness of HB-HSS decreases with the increase of aluminum content. When the quenching temperature is 1050 °C, the aluminum content is 1.0% and boron content is 1.0%-2.0%, the combination of the microstructure and the hardness of HB-HSS is the best. Keywords: High-boron high-speed steel; Quenching microstructure; Borocarbide; Hardness.

Influence of aluminum content on the microstructure and properties of the in-situ TiC reinforced AlxFeCoNiCu high entropy alloy matrix composites

TiC particles reinforced AlxFeCoNiCu multi-principal elements alloys matrix metallic composites AlxFeCoNiCu/TiC with different content aluminum were fabricated in-situ from Al-Fe-Co-Ni-Cu-Ti-C system through vacuum inductive melting method. The microstructure and properties of AlxFeCoNiCu/TiC composite has been analyzed. In-situ TiC reinforcements particles were uniformly distributed in the matrix and their interfaces with the matrix are very clean and no reaction layer at the interfaces. With the increase of aluminum content, the structure of matrix changed from FCC structure to BCC and FCC bi-phase structure, the ultensile fracture strength increases to a maxmium and then decreases. When the content of aluminum mole rate (x) increases from 0.2 to 0.6, the ultensile fracture strength of the composites increases from 502 MPa to a maxmium of 675 MPa. And then with the further increase of x to 1.0, the ultensile fracture strength decreases to 595 MPa.

Structure and thermophysical properties of polytetrafluoroethylene-aluminum composite materials produced by explosive pressing

Metal filled composite materials on the basis of polytetrafluoroethylene (PTFE) are widely used in tribotechnical units of different equipment. Amongst the metal fillers for PTFE, aluminum is the most perspective, it has high thermal conductivity and low density, which is relevant for the aircraft industry. Due to low adhesion of PTFE to metals, the thermal conductivity and strength properties of these CM are low, so it is perspective to use explosive pressing (EP) which provides the conditions for an increase in physical-chemical interaction between CM components. The work researches the influence of EP on the structure, thermal expansion and thermal conductivity of composite materials on the basis of PTFE containing 10 and 30% vol. of aluminum. It has been established that EP, as well as sintering in a closed volume, contributes to a decrease in thermal expansion and an increase in the thermal conductivity of composite materials, which is connected to structural changes accompanied by an intensification of adhesive interfacial interaction. At the same time, with an increase in aluminum concentration, the efficiency of EP increases due to the increase in the number of contacts between metal particles, as well as the occurrence of an interphase zone, with peculiar properties.

The hydrophobic surface state of talc as influenced by aluminum substitution in the tetrahedral layer

Talc is both an important industrial mineral product recovered by flotation, and also in other cases, a gangue mineral of concern in the flotation of certain sulfide ores, such as the PGM ores from South Africa and from the United States. The talc face surface is naturally hydrophobic with a water sessile drop contact angle of nearly 80°, which accounts for its flotation recovery in one case, and its contamination of sulfide mineral concentrates in other instances. Due to the presence of impurities in the talc structure the surface properties change. One such effect is the presence of aluminum, which can replace silicon in the silica tetrahedral layer of the talc structure. This results in a charge imbalance on the face surface because Si+4 is replaced by Al+3. Sessile drop contact angle and bubble attachment time measurements were made, and these results were compared to the results from molecular dynamics simulations (MDS). The extent of aluminum substitution in the silica tetrahedral layer was considered, and the sessile drop contact angle was found to decrease with increased aluminum content, decreasing from about 80° for no substitution (talc) to 0° for extensive substitution (phlogopite). The water film was found to be stable at the surface of highly aluminum substituted crystals due to the interaction between water molecules and the increased polarity of the surface state. This stable water film restricts the air bubble from attaching to such face surfaces. However, in the absence of aluminum substitution, no interactions between the water molecules and the face surface were observed and the air bubble readily attached to the face surface. This study provides additional understanding of how aluminum substitution in the tetrahedral layer affects the fundamental surface properties of talc, paving the way for the design of improved reagents for talc flotation as an industrial mineral product, and for talc depression in the recovery of sulfide mineral concentrates.