Two novel Zn(II) coordination polymers based on trigonal ligand: 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine

Two novel Zn(II) coordination polymers, [Zn₅(pytpy)₈(fum)₄(H₂O)₄(OH)₂]_n · n(CH₃OH) · 2n(H₂O) (1) and [Zn₃(pytpy)₄ (btc)₂]_n · 2n(H₂O) (2) (pytpy = 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine, H₂fum = fumaric acid, H₃btc = 1,3,5-benzenetricarboxylic acid) have been hydrothermally synthesized and structurally characterized. Complex 1 is a 2D layer structure, which is constructed from linear pentanuclear Zn(II) subunits interconnected via bidentate-bridging pytpy ligands and tridentate-bridging fum²⁻ anions. Complex 2 is a 3D network structure, μ₂-pytpy ligands link the layers based on the heart-like hexanuclear subunits to form the 3D network. Both complexes show strong fluorescence emission upon excitation at 310 nm in solid state. Additionally, these two complexes possess great thermal stabilities, especially for 2, the framework is stable up to 350 °C.     

Preparation of templated mesoporous silica membranes on macroporous α-alumina supports via direct coating of thixotropic polymeric sols

A simple method for depositing mesoporous silica films directly on macroporous α-alumina supports is reported. A polymeric silica sol was prepared by hydrolysis of tetraethylorthosilicate in acid propanol in presence of hexadecyltrimethylammonium bromide as template. The rheology of the sol was changed by a modified urea-based thixotropic agent, which was used in a concentration range between 2% and 10% on volume. The dynamic viscosity of the sol was measured as a function of shear rate. The rheology modifier was found to increase the viscosity of the sol and confer at the same time a thixotropic behavior to it. Long range order in the unmodified and modified materials was analyzed by XRD on powders after calcination at 500 °C. It was found that the pore size increased with increasing concentration of additive, while the degree of order decreased until eventually, at high concentrations, the ordered porous structure collapsed completely. The gradual pore size increase at lower concentration is thought to be caused by swelling of the surfactant micelles by the rheology modifier.The modified sols were deposited via dip-coating on α-alumina disks. The morphology of the silica top layers was characterized by SEM. Pore size distributions and permeances of the prepared membranes were assessed by permporometry and single gas permeation measurements, respectively. The membranes had narrow pore size distributions, with an average diameter of about 2 nm. Permeabilities of H₂, He, CH₄ and O₂ were compared. Hydrogen permeances up to 6 × 10⁻⁷ mol s⁻¹ m⁻² Pa⁻¹ were measured at 473 K. The gas flux across the membrane follows a Knudsen-type mechanism, as shown by the permselectivities.     

Relationship between surface acidity and activity of solid-acid catalysts in vapour phase dehydration of methanol

A series of solid-acid catalysts comprised of γ-alumina and modified γ-alumina with different of silica were prepared by co-precipitation method. The catalysts were characterized using XRD, TGA, NH₃-TPD and BET techniques. Dehydration of methanol to dimethyl ether (DME) on solid-acid catalysts was studied in a fixed-bed reactor at the same operating conditions (T = 300 °C, P = 16 bar, WHSV = 26.07 h^− 1). According to the experimental results, silica-modified catalysts have shown better performance compared to the pure γ-alumina. It was found that surface areas increase with increasing silica loading. The results of NH₃-TPD analysis showed that the surface acidity of aluminosilicate catalysts increases with increase in SiO₂/Al₂O₃ molar ratio. Also, it was found that the catalysts with highest portion of weak and/or moderate acid sites exhibit the best catalytic performance and stability. The sample with 3 wt.% silica loading has exhibited the best activity for methanol conversion.     

Solvent-free infiltration method for mesoporous SnO2 using mesoporous silica templates

Mesoporous tin oxide (SnO₂) materials, exhibiting high surface areas, crystalline frameworks and various mesostructures, were successfully obtained by a facile solvent-free infiltration method from mesoporous silica templates. Various kinds of mesoporous silica materials, such as KIT-6 (bicontinuous 3-D cubic, Ia3d), SBA-15 (2-D hexagonal, p6mm), SBA-16 (3-D cubic with cage-like pores, Im3m) and spherical mesoporous silica (disordered), were utilized as the hard templates. Tin precursor (SnCl₂ · 2H₂O, m.p. 310–311 K) was infiltrated spontaneously within the mesopores of silica templates by melting the precursor at 353 K without using any solvent. The heat-treatment of SnCl₂-infiltrated composite materials at 973 K under static air conditions and subsequent removal of silica templates by using HF result in the successful preparation of mesoporous SnO₂ materials. The mesostructures as well as the morphologies of mesoporous SnO₂ materials thus obtained were very similar with those of the mesoporous silica templates. The mesoporous SnO₂ materials exhibit high surface areas of 84–121 m²/g as well as high pore volumes in the range of 0.22–0.35 cm³/g. The present solvent-free infiltration method is believed to be a simple and facile way for the preparation of mesoporous materials via nano-replication from mesoporous silica templates.     

Textural and Structural Properties of Mesoporous Silica Synthesized Under Refluxing Conditions

Mesoporous silica with pore sizes of 3–6 nm has been synthesized under refluxing and autogenous pressure conditions of hydrothermal synthesis from precursor gels having different alkaline pH. The mesoporous silica prepared is characterized by powder X-ray diffraction, nitrogen adsorption-desorption measurement and scanning electron microscopy. Thermal stability has been tested by XRD analysis of mesoporous silica after thermal treatment at 823 K, 6 h; 1023 K, 1 h and 1223 K, 1 h. The results indicate that the mesoporous silica prepared under refluxing condition from precursor gel of pH 11 has large surface area (ca.1103 m² g^{− 1}) and pore volume (ca. 0.868 cm³ g^{− 1}) and is thermally stable at 1223 K. The surface area, pore volumes and pore wall thickness increase as the pH of the precursor gel is increased for refluxing condition of synthesis. The comparison of textural properties revealed that the refluxing condition is advantageous over autogenous pressure condition for obtaining mesoporous silica with higher surface area (852 m² g^{− 1}), pore volume (0.894 cm³ g^{− 1}) and pore diameter > 4 nm with wall thickness of 1.59 nm, when synthesized from precursor gel of pH 9.2. The ²⁹Si NMR spectra showed that a great part of the Si atoms exists as silanol groups. The mesoporous silica made at the lower pH (9.2) under refluxing conditions have more condensed framework. In calcined mesoporous silica, the proportion of partly condensed silica (Q³) is higher than fully condensed silica (Q⁴).     

Phase separation temperatures in the polystyrene—poly(α-methyl styrene)—methylcyclohexane system

The phase separation temperatures (PST) in the ternary system polystyrene (PS) (M_w = 1.75 × 10⁴ g mol⁻¹ — poly(α-methyl styrene) (PαMS) (M_w = 6.0 × 10⁴) — methylcyclohexane (MCH) and the binary systems PS-MCH and PαMS-MCH have been determined by using a He---Ne laser light-scattering apparatus over the total polymer weight fraction (W_{PS + PαMS}) range of 0.018 to 0.80 and various polymer blend ratios. The PST determined at a scattering angle of 0° agreed with those at 90° for the binary systems over polymer concentrations of 0.1 to 0.7 and for the ternary over W_{PS + PαMS} of higher than 0.3. Deviations of the PST determined at an angle of 90° from those at 0° were observed in the ternary system when W_{PS + PαMS} was lower than 0.3. Two phase separation temperatures, at which the intensity scattered from zero angle changed discontinuously, are observed at concentrations lower than W_{PS + PαMS} = 0.042 in the ternary system. The PST in the ternary system decreases monotonically with increasing W_{PS + PαMS} over 0.3 to 0.7. The phase diagram for the PS-PαMS-MCH system at W_{PS + PαMS} = 0.8 is characterized by a maximum PST around − 14°C.     

Polymer-polymer interaction parameters in the ternary system polystyrene/poly(α-methyl styrene)/n-butyl chloride

The polymer-polymer interaction parameter χ′12, for the polystyrene/poly(α-methyl styrene)/n-butyl chloride ternary system, has been determined from activity coefficients of the solution measured using piezoelectric vapour sorption methods in the temperature range 30°–60°C. (These measurements where carried out in the concentration range 0.06 < ψ₀ < 0.26, where ψ is the segment fraction of the solvent). The values of χ¹⁰₁₂ extrapolated to zero solvent concentration over the range 30°–60°C, are large and negative (−0.2 to −0.9) χ¹₁₂ was found to increase with ψ₀. The negative values of χ¹₁₂ in this work are in agreement with the T_g in the polystyrene

Full-size image (1K)

M_w = 9.09 × 10⁴) blends on the point of blend compatibility. The polymer-polymer interaction parameters obtained in this work are discussed by taking into account the high susceptibility of polymers in the glassy state to solution of organic solvents.     

Efficient catalysis of mesoporous Al-MCM-41 for Mukaiyama aldol reactions

Mesoporous aluminosilicates, Al-MCM-41 (Si/Al = 20 and 50), efficiently catalyzed Mukaiyama aldol reaction of benzaldehyde with 1-(trimethylsiloxy)cyclohexene in CH₂Cl₂ at 0 °C to afford the corresponding β-trimethylsiloxy ketone in quantitative yield. On the other hand, mesoporous silica (MCM-41), amorphous SiO₂–Al₂O₃, and H–Y and H-ZSM-5 zeolites barely catalyzed the reaction. Additionally, the less ordered Al-MCM-41 prepared by mechanical compression exhibited much lower catalytic activity compared with Al-MCM-41, indicating that the presence of the ordered mesoporous structure in aluminosilicates is crucial for the catalysis. The Al-MCM-41 catalyzed Mukaiyama aldol reaction was applicable to a wide range of aldehydes and silyl enol ethers. Furthermore, the Al-MCM-41 catalyst could be recycled at least three times without any loss in the yield. Thus, mesoporous aluminosilicates are promising heterogeneous catalysts for fine chemicals synthesis.     

One-step synthesis of fine SrTiO3 particles using SrSO4 ore under alkaline hydrothermal conditions

The employment of mineral SrSO₄ crystals and powders for preparing SrTiO₃ compound was investigated, with coexistence of Ti(OH)₄·4.5H₂O gel under hydrothermal conditions, at various temperatures (150–250 °C) for different reaction intervals (0.08–96 h) in KOH solutions with different concentrations. The complete dissolution of the SrSO₄ crystal occurred at 250 °C for 96 h in a 5 M KOH solution, resulting in the synthesis of SrTiO₃ particles with two different shapes (peanut-like and cubic). In contrast, very fine SrTiO₃ pseudospherical particles were crystallized when SrSO₄ powders were employed as precursor. Variations on the SrTiO₃ particle shape and size were found to be caused by the differences in the dissolution rate of the SrSO₄ phase in the alkaline KOH solution. The crystallization of SrTiO₃ particles was achieved by a bulk dissolution–precipitation mechanism of the raw precursors, and this mechanism was further accelerated by increasing the reaction temperature and concentration of the alkaline media. Kinetic data depicted that the activation energy required for the formation of SrTiO₃ powders from the complete consumption of a SrSO₄ single crystal plate under hydrothermal conditions, is 27.9 kJ mol⁻¹. In contrast, when SrSO₄ powders were employed (28–38 μm), the formation of SrTiO₃ powder proceeded very fast even for a short reaction interval of 3 h at 250 °C in a 5 M KOH solution.     

Adsorption and binding of the transgenic plant proteins, human serum albumin, β-glucuronidase, and Cry3Bb1, on montmorillonite and kaolinite: Microbial utilization and enzymatic activity of free and clay-bound proteins

Human serum albumin (HSA), β-glucuronidase (GUS), and the Cry3Bb1 protein from Bacillus thuringiensis subsp. kumamotoensis are expressed by genetically-modified plants. Commercial samples of these proteins adsorbed and bound rapidly on the clay minerals, kaolinite (K) and montmorillonite (M). Adsorption increased as the concentration of protein increased and then reached a plateau. The greatest amount of adsorption and binding occurred with the Cry3Bb1 protein, of which there was no desorption: 6.7 ±0.21 μg adsorbed and bound μg^− 1 of M; 2.1 ± 0.39 μg adsorbed and bound μg^− 1 of K. With GUS, 2.2 ± 0.29 μg adsorbed and 1.7 ±0.21 μg bound μg^− 1 of M; 1.5 ± 0.28 μg adsorbed and 1.0 ± 0.03 μg bound μg^− 1 of K. HSA was adsorbed and bound the least: 1.2 ±0.04 μg adsorbed and 0.8 ± 0.05 μg bound μg^− 1 of M; 0.4 ± 0.05 μg adsorbed and 0.4 ± 0.03 μg bound μg^− 1 of K. However, X-ray diffraction analyses indicated that only HSA intercalated M, and none of the proteins intercalated K, a nonswelling clay. When bound, the proteins were not utilized for growth by mixed cultures of soil microorganisms, whereas the cultures readily utilized the free (i.e., not adsorbed or bound) proteins as sources of carbon and energy. The enzymatic activity of GUS was significantly enhanced when bound on the clay minerals. These results indicated that recombinant proteins expressed by transgenic plants could persist and function in soil after release in root exudates and from decaying plant residues as the result of the protection provided against biodegradation by binding on clay minerals.     

Ferromagnetic mixed tribridged dinuclear copper(II) complex [Cu2(OAc)2(OH)(dpa)2]PF6 · H2O (dpa = 2,2′-dipyridylamine): 3D superstructure based on hydrogen bond and π…π interaction

A new dinuclear complex [Cu₂(OAc)₂(OH)(dpa)₂] PF₆ · H₂O (1) is prepared and structurally and magneto-structurally characterized. The monocationic core contains one acetate in familiar bidentate η¹:η¹:μ₂-bridge and another in the rare monoatomic bridge along with one hydroxo intermediary. 1 packs through N–H…O and O–H…O hydrogen bonds and π…π interaction resulting a 3D supramolecular continuum and displays high-energy intraligand ¹(π − π^*) fluorescence and intraligand ³(π − π^*) phosphorescence in glassy solution.     

Synthesis of doped ceria with mesoporous flowerlike morphology and its catalytic performance for CO oxidation

Mesporous flowerlike ceria Ce_0.9M_0.1O_2−δ (M = Y, La, Zr, Pr and Sn) have been synthesized successfully by a hydrothermal method. The impacts of doping on their physical properties are investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption, Raman and X-ray photoelectron spectroscopy (XPS). The doped materials show relatively high stability against the grain growth at 800 °C under reducing and oxidizing atmosphere. The catalytic activities of all flowerlike ceria materials for CO conversion are quite high (200 < T₅₀ < 320 °C) due to their high specific surface area (>100 m²/g), open mesoporous structure (pore size  3.9 nm) and nano-crystalline nature (grain size < 10 nm). Among flowerlike materials, Pr and Sn doped ceria show enhanced activity while La, Y, Zr doped ceria show decreased activity compared to undoped ceria.     

Effect of sintering temperature on varistor properties and aging characteristics of ZnO–V2O5–MnO2 ceramics

The microstructure, electrical properties, dielectric characteristics, and DC accelerated aging behavior of the ZVM-based varistors were investigated for different sintering temperatures of 800–950 °C. The microstructure of the ZVM-based ceramics consisted of mainly ZnO grain and secondary phase Zn₃(VO₄)₂, which acts as liquid-phase sintering aid. The Zn₃(VO₄)₂ has a significant effect on the sintered density, in the light of an experimental fact, which the decreases of the Zn₃(VO₄)₂ distribution with increasing sintering temperature resulted in the low sintered density. The breakdown field exhibited the highest value (17,640 V/cm) at 800 °C in the sintering temperature and the lowest value (992 V/cm) at 900 °C in the sintering temperature. The nonlinear coefficient exhibited the highest value, reaching 38 at 800 °C and the lowest value, reaching 17 at 850 °C. The varistor sintered at 900 °C exhibited not only high nonlinearity with 27.2 in nonlinear coefficient, but also the highest stability, in which %ΔE_1 mA = −0.6%, %Δα = −26.1%, and %Δ tan δ = +21.8% for DC accelerated aging stress of 0.85 E_1 mA/85 °C/24 h.     

Nanostructured α- and β-cobalt hydroxide thin films

A new perspective in the use of electrochemical methods to deposit cobalt hydroxide thin films is presented. Ordered arrays of α-Co(OH)₂ (hydrotalcite-like (Co-HT)) and β-Co(OH)₂ nanoparticles were synthesized on transparent conductive oxide (TCO) substrates by localized cathodic electrogeneration of hydroxyl via the reduction of NO₂⁻ (or NO₃⁻) ion precursors in solution containing Co²⁺ in very low concentration. The thin films, analyzed by X-ray diffraction and scanning electron microscopy were found to be composed of vertically oriented platelets with the crystallographic c-axis parallel to the substrate surface. Turbostratic disorder was not observed in the films. UV/Vis spectra and thermal gravimetric analyses (TGA) indicated distinct variation between the Co-HT structures. Films deposited at 60 °C using a nitrite precursor generated uniform, vibrant-green mixed-valence Co-HT (Co²⁺/Co³⁺). Nitrate precursors yielded a “hydroxyl-deficient” Co-HT (Co²⁺ only). Films deposited at 95 °C in nitrate solution yielded β-Co(OH)₂. The films obtained in presence of nitrite were thicker than those obtained in nitrate. They were formed of β-Co(OH)₂ and contained traces of Co-HT.     

On the effect of La–Cr–O– phase composition on diesel soot catalytic combustion

A series of samples of La–Cr–O– perovskites were designed as catalysts for diesel soot combustion. They were prepared by using co-precipitation method, at ambient temperature using ammonia followed by a hydrothermal treatment (T = 200 °C, P = 20 atm, t = 24 h). All the chromium-containing precursors were then calcined at high temperature to develop the oxide catalyst. Two phase composition 86%LaCrO₃–(14%) La₂CrO₆ or 94%LaCrO₃–6%La₂O₃ were formed depending on the atmosphere of calcination (oxygen or hydrogen respectively) used. Their respective BET surface areas were 1.1 and 6.5 m² g⁻¹. Highly crystalline, pure phase of LaCrO₃ and La₂CrO₆ powders were also prepared, with BET area of 4 and 3 m² g⁻¹, respectively. The crystalline structure and properties of all samples were characterised by X-ray diffraction (XRD), using Rietveld refinement, and temperature-programmed reduction (TPR) techniques. O₂-TPD measurements performed on all samples showed the presence of suprafacial, weakly chemisorbed oxygen only for LaCrO₃, which contributes actively to soot combustion. TPR study performed on all catalysts showed that while pure LaCrO₃ and La₂O₃ samples did not reduce, the biphasic catalysts showed the presence of oxygen depletion peaks characteristic of lattice oxygen mobility in the samples at ca. 665 °C. Catalytic combustion of diesel soot was studied over all catalysts. The results showed that pure LaCrO₃ exhibited significant catalytic activity which was sensitively affected by the modifier La₂CrO₆ or La₂O₃.     

Intrinsic kinetics of Fischer–Tropsch reactions over an industrial Co–Ru/γ-Al2O3 catalyst in slurry phase reactor

The rate of Fischer–Tropsch synthesis over an industrial well-characterized Co–Ru/γ-Al₂O₃ catalyst was studied in a laboratory well mixed, continuous flow, slurry reactor under the conditions relevant to industrial operations as follows: temperature of 200–240 °C, pressure of 20–35 bar, H₂/CO feed ratio of 1.0–2.5, gas hourly space velocity of 500–1500 N cm³ g_cat^− 1 h^− 1 and conversions of 10–84% of carbon monoxide and 13–89% of hydrogen. The ranges of partial pressures of CO and H₂ have been chosen as 5–15 and 10–25 bar respectively. Five kinetic models are considered: one empirical power law model and four variations of the Langmuir–Hinshelwood–Hougen–Watson representation. All models considered incorporate a strong inhibition due to CO adsorption. The data of this study are fitted fairly well by a simple LHHW form − R_H2 + CO = ap_H2^0.988p_CO^0.508 / (1 + bp_CO^0.508)² in comparison to fits of the same data by several other representative LHHW rate forms proposed in other works. The apparent activation energy was 94–103 kJ/mol. Kinetic parameters are determined using the genetic algorithm approach (GA), followed by the Levenberg–Marquardt (LM) method to make refined optimization, and are validated by means of statistical analysis. Also, the performance of the catalyst for Fischer–Tropsch synthesis and the hydrocarbon product distributions were investigated under different reaction conditions.     

Thermal properties of the nitrogen-rich Ca-α-Sialons

Nitrogen-rich Ca-α-Sialon (Ca_xSi_12−2xAl_2xN₁₆ with x = 0.2, 0.4, and 0.8, 1.2 and 1.6) ceramics were prepared from the mixtures of Si₃N₄, AlN and CaH₂ powders in a hot press at 1800 °C using a pressure of 35 MPa and a holding time of 4 h, and then were investigated with respect to reaction mechanism, phase stability and oxidation resistance. In addition the sample with x = 1.6 was prepared in the temperature range 600–1800 °C using a pressure of 35 MPa and a holding time of 2 h. The α-Sialon phase was first observed at 1400 °C but the α-Si₃N₄ and AlN phases were still present at 1700 °C. Phase pure Ca-α-Sialon ceramics could not be obtained until the sintering temperature reached 1800 °C. The phase pure nitrogen-rich Ca-α-Sialon exhibited no phase transformation in the temperature range 1400–1600 °C. In general, mixed α/β-Sialon showed better oxidation resistance than pure α-Sialon in the low temperature range (1250–1325 °C), while α-Sialons with compositions located at α/β-Sialon border-line showed significant weight gains over the entire temperature range tested (1250–1400 °C). The phases formed upon oxidation were characterized by X-ray, SEM and TEM studies.     

The role of particle size on the electrochemical properties at 25 and at 55 °C of the LiCr0.2Ni0.4Mn1.4O4 spinel as 5 V-cathode materials for lithium-ion batteries

The role of the particle size on the electrochemical properties at 25 and at 55 °C of the LiCr_0.2Ni_0.4Mn_1.4O₄ spinel synthesized by combustion method has been determined. Samples with different particle size were obtained by heating the raw spinel from 700 to 1100 °C, for 1 h in air. X-ray diffraction patterns revealed that all the prepared materials are single-phase spinels. The main effect of the thermal treatment is the remarkable increase of the particles size from 60 to 3000 nm as determined by transmission electron microscopy. The electrochemical properties were determined at high discharge currents (1C rate) in two-electrode Li-cells. At 25 and at 55 °C, in spite of the great differences in particle size, the discharge capacity drained by all samples is similar (Q_dch ≈ 135 mAh g⁻¹). Instead, the cycling performances strongly change with the particle size. The spinels with Φ > 500 nm show better cycling stability at 25 and at 55 °C than those with Φ < 500 nm. The samples heated at 1000 and 1100 °C, with high potential (E ≈ 4.7 V), elevate capacity (Q ≈ 135 mAh g⁻¹), and remarkable cycling performances (capacity retention after 250 cycles >96%) are very attractive materials as 5V-cathodes for high-energy Li-ion batteries.     

Catalytic reduction of NH4NO3 by NO: Effects of solid acids and implications for low temperature DeNOx processes

Ammonium nitrate is thermally stable below 250 °C and could potentially deactivate low temperature NO_x reduction catalysts by blocking active sites. It is shown that NO reduces neat NH₄NO₃ above its 170 °C melting point, while acidic solids catalyze this reaction even at temperatures below 100 °C. NO₂, a product of the reduction, can dimerize and then dissociate in molten NH₄NO₃ to NO⁺ + NO₃⁻, and may be stabilized within the melt as either an adduct or as HNO₂ formed from the hydrolysis of NO⁺ or N₂O₄. The other product of reduction, NH₄NO₂, readily decomposes at ≤100 °C to N₂ and H₂O, the desired end products of DeNO_x catalysis. A mechanism for the acid catalyzed reduction of NH₄NO₃ by NO is proposed, with HNO₃ as an intermediate. These findings indicate that the use of acidic catalysts or promoters in DeNO_x systems could help mitigate catalyst deactivation at low operating temperatures (<150 °C).     

气溶胶溶剂萃取技术制备β-谷甾醇亚微粒

The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system (ASES) and characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) analysis. The effects of operational parameters including pressure, temperature, solution concentration, and ratio of flow rate (CO2/solution, r) on particle size (PS), yield, and morphology were investigated. The results showed that microparticles of β-sitosterol (less than 1000 nm size and larger than 70% yield) could be obtained at 10-15 MPa, 35-50°C, 15 mg&#8226;ml－1, 10/1(r); β-sitosterol particles were found to occur as three mophologies: flakes, rods, and spheres by varying ratio of flow rate or solution concentration. In contrast, the crystallinity of β-sitosterol decreased, whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore, ASES was an effective method to produce submicroparticles of β-sitosterol.