Crystalline Mixtures Research Articles

Coamorphous systems of rebamipide: Selection of amino acid coformers based on protein-ligand docking, in vitro assessment and study of interactions by computational and multivariate analysis.

Three coamorphous systems of Rebamipide (REB) with the amino acids namely, Tryptophan (TRP), Phenylalanine (PHE) and Arginine (ARG) are reported. A unique approach for the virtual screening of amino acid coformers is presented by employing molecular docking studies based on interactions of the drug molecule with various amino acid fragments in the drug-receptor cocrystal structure. Successful formation of stable coamorphous systems with ARG, TRP and PHE served as the proof-of-concept along with negative benchmarking standards Histidine and Aspartic acid, wherein coamorphous systems could not be obtained despite multiple trials which resulted in crystalline physical mixtures. The coamorphous systems were characterized by a halo pattern in Powder XRD and a single glass transition temperature (Tg) in modulated DSC. Physical stability assessments of the coamorphous systems showed direct correlation of Tg with the observed stability of the amorphous phase which was found in the order ARGREB > TRPREB ≥ PHEREB. To determine the specific functional groups engaged in the interactions, multivariate analysis was performed on the FTIR spectra. These interactions were further validated by DFT and QTAIM analysis, which revealed key noncovalent interactions in the three coamorphous systems. All three coamorphous systems showed excellent release profiles of the API as demonstrated by the f2 and DE parameters in the order ARGREB ≥ TRPREB > PHEREB ≥ amorphous drug, far exceeding that of the crystalline drug. The interplay of multivariate analysis and QTAIM can be useful in estimating the interactions within the coamorphous systems which can further contribute to stability and physicochemical properties of the systems.

Optimization of Liquid Crystalline Mixtures Enantioseparation on Polysaccharide-Based Chiral Stationary Phases by Reversed-Phase Chiral Liquid Chromatography.

Enantioseparation of nineteen liquid crystalline racemic mixtures obtained based on (R,S)-2-octanol was studied in reversed-phase mode on an amylose tris(3-chloro-5-methylphenylcarbamate) (ReproSil Chiral-MIG) and a cellulose tris(3,5-dichlorophenylcarbamate) (ReproSil Chiral-MIC). These polysaccharide-based chiral stationary phase (CSP) columns for High-Performance Liquid Chromatography (HPLC) were highly effective in recognizing isomers of minor structural differences. The mobile phase (MP), which consists of acetonitrile (ACN)/water (H2O) at different volume ratios, was used. The mobile phases were pumped at a flow rate of 0.3, 0.5, or 1 mL·min-1 with a column temperature of 25 °C, using a UV detector at 254 nm. The order of the elution was also determined. The chromatographic parameters, such as resolution (Rs), selectivity (α), and the number of theoretical plates, i.e., column efficiency (N), were determined. The polysaccharide-based CSP columns have unique advantages in separation technology, and this study has shown the potential usefulness of the CSP columns in separating liquid crystalline racemic mixtures belonging to the same homologous series.

Rapid thermal annealing treatment on WO3 thin films for energy efficient smart windows

Electrochromic devices (ECDs) based on tungsten trioxide (WO3) have garnered significant attention in the areas of smart windows, dynamic display, low-power displays, and in other advanced sectors. The electrochromic property of WO3 is primarily influenced by both electron conduction and ion diffusion processes. This research investigates on the influence of rapid thermal annealing (RTA) on the electrochromic performance of RF sputtered tungsten oxide thin films, which relies on ion diffusion process. RTA treated film showed a mixture of amorphous and crystalline (monoclinic), heterostructure phase. Structural, compositional, electrical, optical, morphological, and electrochromic studies were carried out using various techniques. Based on the electrochromic analysis, WO3 thin films, RTA treated at 300°C showed higher diffusion coefficient with larger optical modulation (ΔT) of 80 % due the formation of heterostructure with more oxygen vacancies. We hope that this research could propose the possibility for developing high-performance electrochromic smart windows.

Dual-frequency-addressable photochromic cholesteric mixture with photo- and electro-switchable optical properties

Cholesteric liquid crystalline mixture with photo-, electro-controllable optical properties was prepared and the features of its switching behavior were demonstrated. The working principle of the obtained switchable cell is based on using dual-frequency-addressable nematic mixture that enables effective control of selectively reflected planar and scattered focal conics texture by applied field frequency modulation. The nematic mixture was doped with the chiral substance in order to induce a cholesteric structure formation with selective light reflection in visible spectral range. Azobenzene-containing photochrome was also introduced into this mixture in order to stimulate photo-optical response. An application of low-frequency electric field as well as UV irradiation induces short-wavelength shift of the selective light reflection. Under action of an electric field, a transition to scattered focal conics texture takes place. Amplitude of the light-induced shift is ca. 50 nm, while the electric field leads to a shift ca. 120 nm. On the contrary, high-frequency electric field induces fast (less than 1 s) restoration of perfect highly reflected planar texture. UV irradiation leads to not only shift of the selective light reflection band, but alters the electrooptic response by increase of frequency necessary for the restoration of the planar state and considerably changes the switching kinetics. The possibility of photopatterning of the obtained electrooptic cells by UV irradiation through a mask is demonstrated. It is shown, that application of electric field of different strength and frequencies enables smart control of the photorecorded image contrast.

Prediction of Phase Composition and Process Resilience in Plasma‐Assisted Hetero‐Aggregate Synthesis using a Machine‐Learning Model with Multivariate Output

AbstractThe synthesis of nanoscale particles and particle aggregates from liquid or gaseous precursors is affected by a variety of trade‐off relations, for example, in terms of product composition, yield, or energy efficiency. Machine‐supported process evaluation and learning (ML) of these relations enables optimization strategies for advanced material processing. Such a workflow is demonstrated on the example of plasma‐assisted aerosol deposition (PAAD) of alumina powders. Depending on processing conditions, these powders comprise of hetero‐aggregate mixtures of crystalline and amorphous polymorphs. Process optimization toward a specific target composition calls for ML approaches. For this, a sufficiently large and consistent dataset of PAAD input (processing) and output (product) parameters is initially generated by real‐world processing, and subsequently extrapolated into a cloud of ≈106 input‐output parameter matrices using Gaussian process regression with multivariate output and input‐output feature analysis. It is subsequently demonstrated how not only the phase composition of the obtained alumina powders, but also product resilience to variations in specific processing parameters, or – as a perspective – the energy efficiency of material processing can be predicted.

Fenton-mediated solar-driven photocatalysis of industrial dye effluent with polyaniline impregnated with activated TiO2-Nps

Various integrated technologies have been investigated for the remediation of heavily polluted industrial dye effluent. Also, more than 70 % of these dyes are known to be solely azo dyes used in the textile industry with 5–30 % presence in the effluent as loose dye molecules which are recalcitrant to treatment. These challenges led to the investigation of energy-efficient processes (solar) and the fabrication of high-performance nano-photocatalysts for proficient photocatalysis of dye effluent while mediating the process with Fenton reagents. The study fabricated nanopolymeric catalyst composites (P-AKT) via novel in situ coupling and impregnation of the polyaniline (PANI) with surface-activated TiO2 NPs. This fabrication is aimed at developing a high-performance catalyst with rapid and proficient photocatalytic activities to photons from sunlight irradiation. The photocatalytic process was mediated using a novel Fenton reagent to enhance the generation of radical species for dye degradation. Various instrumental characterization methods were used to study the structural, molecular, elemental, functional and optoelectronic properties of the fabricated nanocomposite photocatalysts. The result reveals functional groups aiding dye-catalyst bonding and morphological interaction reveal a surface-activated tetragonal crystalline mixture of anatase and rutile from TiO2−Nps embedded in the macromolecular chain of PANI. It also reveals the optimal conditions of 20 mg dosage, 10 mg/L initial concentration with substantial effectiveness at pH of 5 and 7. However, the most efficient photocatalyst recorded was P-AKT-2 % and P-AKT-3 % having 95 % and 94 % efficiencies at 90 min of solar irradiation. The photocatalyst equally demonstrated its capacity for effluent treatability up to 4 cycles of use.

Properties of Antiferroelectric Mixtures Differing in the Amount of Added Racemate

Novel three-component liquid crystalline mixtures composed of chiral and achiral (racemic) liquid crystalline materials were designed and studied by polarizing optical microscopy, differential scanning calorimetry, and UV–VIS spectroscopy. The compositions of liquid crystalline mixtures were developed based on the composition of a two-component (binary) mixture marked as W-1000 with the following phase sequence: Cr ↔ SmCA* ↔ SmC* ↔ SmA* ↔ Iso. This mixture has an antiferroelectric (SmCA*) phase over a wide temperature range and exhibits a helical pitch inversion in this phase. All newly obtained mixtures occur in a wide temperature range of the SmCA* phase, while the ferroelectric (SmC*) phase and the orthogonal (SmA*) phase occur in a narrow temperature range. The new mixtures also have a very long helical pitch in the antiferroelectric phase and a short helical pitch in the ferroelectric phase.

Optical and calorimetric studies near the smectic-A to smectic-C tricritical point

Detailed heat capacity and birefringence measurements have been performed to investigate the transitional behavior near the orthogonal smectic-A to tilted smectic-C (Sm-A–Sm-C) phase transition on several liquid crystalline mixtures comprising of a rod-like mesogen and a hockey stick-shaped compound having substitution of methyl group in the lateral position. Both probing methods were found to be rather successful in assessing the phase transitional behavior with reasonably good accuracy. The data shows a divergent pretransitional excess above and below the transition temperature. Analysis of the data have been performed in detail with the renormalization-group expression with correction-to-scaling terms. The extracted effective critical exponents were observed in between the tricritical and 3D-XY limit. Detailed investigations carried out in this work reveal the dependence of the Sm-A–Sm-C phase transition on the width of the Sm-A phase and the existence of a broad tricritical range.

Frequency response of dielectric relaxation modes in a room temperature antiferroelectric phase liquid crystalline mixture

Thermodynamic, optical, and electrical characterization of a newly formulated mixture of chiral mesogenic molecules has been carried out. The material exhibits different mesophases like paraelectric smectic (SmA*), ferroelectric chiral smectic (SmC*) with synclinic structure, and wide temperature range antiferroelectric chiral smectic (SmCa*) with anticlinic structure. These studies show that at room temperature, the SmCa* phase is present in a wide temperature range of ∼128 °C (from −35.0 °C to 92.6 °C) followed by the SmC* phase (from 92.6 °C to 110.8 °C) as well as SmA* phase (from 110.8 °C to 113.9 °C). Besides the wide temperature range, the SmCa* phase has also been optimized for high helical pitch length, which is useful for helix unwound cells through surface stabilization for application. Frequency-dependent dielectric parameters have been determined for the material in the frequency range of 1 Hz to 40 MHz. The dielectric spectroscopy shows six different relaxation modes in various phases due to the collective and individual molecular behavior. The SmA* phase exhibits soft mode relaxation associated with variations in the amplitude of the tilt angle. The identified soft mode is significantly temperature-dependent. Using the Curie-Weiss law, the transition temperature for the paraelectric SmA* phase to the ferroelectric SmC* phase (Tc) is found to be 111.4 °C. Two relaxation modes in the SmC* phase have been identified Goldstone mode and a domain mode. These modes have extremely high dielectric strength resulting in high permittivity in comparison with other modes. Three modes of relaxation have been detected in the antiferroelectric SmCa* phase. Different characteristic parameters of these modes are strongly temperature-dependent. This study signifies that the present room-temperature antiferroelectric liquid crystals may be a potential candidate for display applications.

Monitoring of Pore Orientation by in Operando Grazing Incidence Small-Angle X-ray Scattering during Templated Electrodeposition of Mesoporous Pt Films.

We have used in operando grazing incidence small-angle X-ray scattering (GISAXS) to monitor structural changes during templated electrodeposition of mesoporous platinum films on gold electrodes from a ternary lyotropic liquid crystalline mixture of aqueous hexachloroplatinic acid and the diblock copolymer surfactant Brij56. While the cylindrical micelles of the lyotropic liquid crystal (LLC) in the hexagonal phase have a center-to-center distance of 7.5 nm with a preferential alignment parallel to the electrode surface, the electrodeposited platinum films contain highly ordered mesopores arranged in a 2D hexagonal structure, with a center-to-center distance of about 8.5 nm and a preferential orientation perpendicular to the electrode surface. The progression of structural changes of the LLC template and the deposited mesoporous Pt could be monitored for the first time in operando by GISAXS: within the first 14 s of deposition, a nucleation burst of Pt coincides with a loss of preferential alignment of the LLC. Initially, the morphology of the 2-dimensionally nucleated Pt replicates the Au substrate. During the following 5 to 7 min, the growth morphology of the Pt film changes, and vertically aligned mesopores form. Our results indicate mutual interaction between the species involved in the electrodeposition and the LLC template, leading to a partial loss of horizontal orientation of the LLC during Pt nucleation before vertical rearrangement of the micelles to the electrode surface. The vertically aligned mesopores in the Pt and the possibility to produce freestanding films make these materials interesting in fields such as electrocatalysis, energy harvesting, and nanofluidics.

Removal of REE and Th from solution by co-precipitation with Pb-phosphates

The supply of technologically important rare earth elements (REE) is a concern in Europe, hence the recovery of REE from alternative sources has recently become widely investigated. One of the problems is the lack of cost-effective technologies for REE recovery from leaching solutions. The present work investigated the potential for recovering REE and Th from leaching solutions by co-precipitation with Pb phosphates. A set of four experiments were conducted using analytical reagent grade chemicals to analyze the effects of Pb and different pH on the efficiency of REE and Th removal from aqueous solutions. After selecting the best conditions, two additional experiments were performed using solutions obtained from leaching REE-rich apatite mine waste.The precipitates resulting from the experiments as well as the solutions before and after precipitation were analyzed. It was found that the formation of a crystalline mixture of REE- and Th- enriched pyromorphite, Pb5(PO4)3Cl, and Pb-phosphates, about which little has been known so far, was responsible for complete (>99%) removal of REE and Th from aqueous solutions at pH 4 and 6. At lower pH, the removal is incomplete except for Sc and Th, which probably form a distinct phases. Besides that, no fractionation of LREE and HREE was observed. The experiments included the study of solutions resulting from the leaching of REE-rich apatite waste, which may contribute to the development of new technologies for REE recovery from wastes.

Time-Dependent Solvent-Driven Solid-State Fluorescence-based Numeric Coding.

Controllable solid-state transformations can provide a basis for novel functional materials. Herein, we report a series of solid-state systems that can be readily transformed between amorphous, co-crystalline, and mixed crystalline states via grinding or exposure to solvent vapors. The present solid materials were constructed using an all-hydrocarbon macrocycle, cyclo[8](1,3-(4,6-dimethyl)benzene) (D4d-CDMB-8) (host), and neutral aggregation-caused quenching dyes (guests), including 9,10-dibromoanthracene (1), 1,8-naphtholactam (2), diisobutyl perylene-3,9-dicarboxylate (3), 4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (4), 4,7-di(2-thienyl)-benzo[2,1,3]thiadiazole (5), and 4-imino-3-(pyridin-2-yl)-4H-quinolizine-1-carbonitrile (6). Seven co-crystals and six amorphous materials were obtained via host-guest complexation. Most of these materials displayed turn-on fluorescence emission (up to 20-fold enhancement relative to the corresponding solid-state guests). The interconversion between amorphous, co-crystalline states, and crystalline mixtures could be induced by exposure to solvent vapors or by subjecting to grinding. The transformations could be monitored readily by means of single-crystal and powder X-ray diffraction analyses, as well as solid-state fluorescent emission spectroscopy. The externally induced structural interconversions resulted in time-dependent fluorescence changes. This allowed sets of privileged number array codes to be generated.

Separation of liquid crystalline racemic mixtures obtained on the basis of (R,S)-2-hexanol on amylose tris(3-chloro-5-methylphenylcarbamate) covalently immobilised on silica in high-performance liquid chromatography

ABSTRACT The separation on the enantiomers of thirteen newly synthesised liquid crystalline racemic mixtures obtained on the basis of (R,S)-2-hexanol was studied in HPLC on a chiral column prepared by covalent immobilisation of the chiral selector, namely amylose tris(3-chloro-5-methylphenylcarbamate) on silica. The mobile phases (MPs) consisting of n-heptane/isopropanol (IPA) or acetonitrile (ACN)/water (H2O) at different volume ratios were used. All measurements were made at room temperature. The order of the elution was also determined. The chromatographic parameters such as: resolution - (R), selectivity - (α) and number of theoretical plates - (N) were determined. On the basis of the obtained results, optimal conditions were indicated for the best separation of the tested racemic mixtures.

Development of Quantitative Structural Analysis for Crystalline/Amorphous Phase Mixtures by Synchrotron X-ray Total Scattering

A technique for the structural analysis of crystalline and amorphous phase mixtures using X-ray total scattering measurement is developed. The technique extracts the pair distribution function of the amorphous phase by subtracting of that of the crystalline phase from the observed scattering. Li2VO2F, a high-capacity cathode material in lithium-ion batteries, partially forms an amorphous phase upon charging. Applying the technique to the Li2VO2F material, the contribution of the hidden amorphous phase is obtained. Analysis of the pair distribution function of the amorphous phase allows the three-dimensional atomic configurations associated with the material function to be visualized. The structural analysis technique is expected to provide an understanding of the material properties from the viewpoint of the microscopic structure in the amorphous phase, not only of the battery materials but also of any mixtures of crystalline and amorphous phases.

Challenges of quantitative phase analysis of iron and steel slags: a look at sample complexity

Quantitative phase analysis (QPA) of slags is complex due to the natural richness of phases and variability in sample composition. The number of phases frequently exceeds 10, with certain slag types (EAF, BOF, blends, stainless) having extreme peak overlap, making identification difficult. Another convolution arises from the variable crystallite sizes of phases found in slag, as well as the mixture of crystalline and amorphous components specific to each slag type. Additionally, polymorphs are common because of the complexity of the steelmaking and slag cooling processes, such as the cation-doped calcium aluminum silicate (Ca3Al2O6, C3A, Z = 24) supercell in LMF slag. References for these doped variants may not exist or in many cases are not known in advance, therefore it is incumbent on the analyzer to be aware of such discrepancies and choose the best available reference. All issues can compound to form a highly intricate QPA and have prevented previous methods of QPA from accurately measuring phase components in slag. QPA was performed via the internal standard method using 8 wt% ZnO as the internal standard and JADE Pro's Whole Pattern Fitting analysis. For each phase, five variables (lattice parameters, preferred orientation, scale factor, temperature factor, and crystallite size) must be accounted for during quantitation, with a specific emphasis on not refining crystallite sizes for iron oxides and trace phases as they are inclined to over-broaden and interact with the background to improve the goodness of fit (R/E value). Preliminary investigations show somewhat reliable results with the use of custom file sets created within PDF-4+ specifically targeted toward slag minerals to further regulate and normalize the analysis process. The objective of this research is to provide a standard protocol for collecting data, as well as to update methodologies and databases for QPA, to the slag community for implementation in a conventional laboratory setting. Currently, Whole Pattern Fitting “Modified” Rietveld block refinement coupled with the addition of a ZnO internal standard gives the most accurate QPA results, though further research is needed to improve upon the complex issues found in this study of the QPA of slags.

Protein Requirements Are Increased in Endurance-Trained Athletes but Similar between Females and Males during Postexercise Recovery.

This study aimed to determine the daily protein requirements of female and male endurance athletes in a home-based setting using noninvasive stable isotope methodology (i.e., indicator amino acid oxidation). Eight males (30 ± 3 yr; 78.6 ± 10.5 kg; 75.6 ± 7.5 mL·kgFFM-1·min-1; mean ± SD) and seven females (30 ± 4 yr; 57.7 ± 5.0 kg; 77.5 ± 7.1 mL·kgFFM-1·min-1) during the midluteal phase were studied. After 2 d of controlled diet (1.4 gprotein·kg-1·d-1) and training (10 and 5 km run·d-1, respectively), participants completed a 20-km run before an at-home indicator amino acid oxidation trial testing a suboptimal, a moderate, and an excess (i.e., 0.2, 1.2, and 2.0 g·kg-1·d-1, respectively) protein intake. Protein was consumed as a crystalline amino acid mixture containing [1-13C]phenylalanine to examine whole-body phenylalanine flux and phenylalanine oxidation (PheOx; the reciprocal of whole-body protein synthesis) through breath and urine sample collection. A modified biphasic linear regression determined the breakpoint in PheOx for each participant to generate an estimated average intake that would maximize whole-body protein synthesis for each sex. PheOx was different (P < 0.01) between all protein intakes with no effect of sex (P = 0.63). Using a modified three-point curve resulted in a breakpoint that was not different (P = 0.94) between males and females (1.60 and 1.61 g·kg-1·d-1, respectively). The recommended intake (i.e., upper 95% confidence interval) was estimated to be 1.81 and 1.89 g·kg-1·d-1 for males and females, respectively. Our findings indicate that endurance athletes consuming a daily protein intake toward the upper end of current consensus recommendations (~1.85 g·kg-1·d-1) will maximize whole-body protein synthesis during postexercise recovery regardless of sex.

Complexities in the structural evolution with pressure of water-ammonia mixtures.

The structural evolution with pressure of icy mixtures of simple molecules is a poorly explored field despite the fundamental role they play in setting the properties of the crustal icy layer of the outer planets and of their satellites. Water and ammonia are the two major components of these mixtures, and the crystal properties of the two pure systems and of their compounds have been studied at high pressures in a certain detail. On the contrary, the study of their heterogeneous crystalline mixtures whose properties, due to the strong N-H⋯O and O-H⋯N hydrogen bonds, can be substantially altered with respect to the individual species has so far been overlooked. In this work, we performed a comparative Raman study with a high spatial resolution of the lattice phonon spectrum of both pure ammonia and water-ammonia mixtures in a pressure range of great interest for modeling the properties of icy planets' interiors. Lattice phonon spectra represent the spectroscopic signature of the molecular crystals' structure. The activation of a phonon mode in plastic NH3-III attests to a progressive reduction in the orientational disorder, which corresponds to a site symmetry reduction. This spectroscopic hallmark allowed us to solve the pressure evolution of H2O-NH3-AHH (ammonia hemihydrate) solid mixtures, which present a remarkably different behavior from the pure crystals likely to be ascribed to the role of the strong H-bonds between water and ammonia molecules characterizing the crystallites' surface.

Sorbitol-coated indomethacin and naproxen particles produced by supercritical CO2-assisted spray drying

Co-spraying active pharmaceutical ingredients (APIs) with excipients is a strategy to create excipient matrices containing API particles to address formulation challenges such as the reconstitution of powders into homogeneous suspensions. In this work, indomethacin and naproxen were co-sprayed with/without sorbitol using supercritical CO2-assisted spray drying (SASD), followed by particle collection in a filter paper, and resuspension in an aqueous excipient solution. SASD yielded particles in the range of 0.4–7.6 µm, naproxen crystalline Form 1 particles in an amorphous sorbitol matrix, and a partially crystalline indomethacin-sorbitol mixture. Most naproxen-sorbitol mixtures successfully constituted homogenous microparticle suspensions where sorbitol matrix dissolved upon contact with water releasing naproxen particles, while indomethacin-sorbitol mixtures were not reconstitutable and not studied further. The API-sorbitol interactions were studied in detail by thermal analysis and COSMO-RS modelling. Overall, the work presented herein provides a better understanding of co-spraying of APIs with excipients for the formulation of reconstitutable dried microparticles.

Antisolvent Crystallization of Telmisartan Using Stainless-Steel Micromixing Membrane Contactors.

Controlled continuous crystallization of the active pharmaceutical ingredient (API) telmisartan (TEL) has been conducted from TEL/DMSO solutions by antisolvent crystallization in deionized water using membrane micromixing contactors. The purpose of this work was to test stainless-steel membranes with ordered 10 μm pores spaced at 200 μm in a stirred-cell (batch, LDC-1) and crossflow (continuous, AXF-1) system for TEL formation. By controlling the feed flow rate of the API and solvent, through the membrane pores as well as the antisolvent flow, it was possible to tightly control the micromixing and with that to control the crystal nucleation and growth. Batch crystallization without the membrane resulted in an inhomogeneous crystallization process, giving a mixture of crystalline and amorphous TEL materials. The rate of crystallization was controlled with a higher DMSO content (4:1 DMSO/DI water), resulting in slower crystallization of the TEL material. Both membrane setups, stirred batch and the crossflow, yielded the amorphous TEL particles when deionized water was used, while a crystalline material was produced when a mixture of DI water and DMSO was used.

An experimental study on the effect of alumina nanocomposites on asphaltene precipitation

This study investigates the inhibition of asphaltene precipitation using alumina–iron nanocomposite (NCP). Al:Fe NCP, successfully synthesized from pure aluminum and iron chloride, is crystalline mixture of hematite and alumina phases with a purity of 99%. Decreasing the content in hematite lowers the particle size from ∼60 to 10 nm. To evaluate the inhibition potential of Al:Fe, a series of experiments consisting of the addition of Al:Fe NCP into a model crude oil followed by a precipitation using n-heptane were conducted. The model oil was a solution consisting of 3 mg of asphaltene extracted from a dead Middle Eastern heavy oil (29.2oAPI) dissolved into 10 g of toluene. 35 vol. % of heptane was required to precipitate asphaltene from the model crude oil. Hereinafter termed as asphaltene onset precipitation (AOP), adding 0.05 wt.% Al:Fe NCP to the model oil requires up to 30 mL of heptane to precipitate the same amount of asphaltenes. The increase in molar ratio in alumina decreases AOV up to 63.5%. The spectral studies revealed that the inhibition of asphaltene precipitation involves both the polar interactions of alumina phase with asphaltene and the decrease of the π–π stacking interaction upon addition of NCPs.