Crystallization System Research Articles

Exploring the affluent potential of glyceryl mono oleate – myristol liquid crystal nanoparticles mediated localized topical delivery of Tofacitinib: Study of systematic QbD, skin deposition and dermal pharmacokinetics assessment

This study aimed to design and characterize Tofacitinib (TF)-loaded lyotropic liquid crystalline nanoparticles (TF-LCNP) gel using quality by design-driven approach to enhance the skin delivery of TF. The present work investigated the impact of two different liquid lipids on different critical quality attributes of LCNP. The optimized lyotropic liquid crystals system was constructed with the glyceryl monooleate,myristol, Lutrol® and water system. The optimized TF - LCNP showed particle size of 74.82 ± 4.26 nm, polydispersity index of 0.124 ± 0.024, and entrapment efficiency of 68.29 ± 5.24 %. The TF-LCNP showed sustained release for 24 h and followed quasi-Fickian diffusion from non-swellable matrix diffusion with n value of 0.197. The ex vivo permeation studies exhibited that amount of TF permeated through LCNP gel and cream after 24 h were found to be 61.11 ± 1.5 µg/cm2 and 37.7 ± 3.5 µg/cm2, respectively. The penetration mechanism of TF-LCNP gel through skin layers followed the Korsmeyer- Peppas model (n-value of 1.687), indicated Case-II relaxational release of TF. The tape stripping studies showed that TF loaded LCNPs retained 3 fold and 2.81 fold greater TF in stratum corneum and viable skin layers than conventional cream. The coumarin – 6 loaded LCNP study using Fluorescence microscopy confirmed the penetration of TF-LCNP into the deeper layers of skin. The dermal pharmacokinetic studies revealed that the LCNP showed a steady equilibrium state in 5–8 h in epidermis and dermis layers. The total amount of TF permeated with developed LCNP formulation was 3.42 times and 2.19 times higher in epidermis and dermis compared to the TF-cream. The developed formulation exhibited good spreadability and rheology and has not shown any significant changes in stability and scale-up studies. In a nutshell, the developed TF-LCNP strategy poses excellent potential in targeting the viable skin layer.

Microfluidic strategy for coating and modification of polymer-bonded nano-HNS explosives

Polymer bonded explosives (PBXs) have the characteristics of high energy density, and excellent safety and mechanical performances. In this work, a microfluidic crystallization system (MCS) based on microscale chaotic advection is proposed to control and optimize the crystallization environment of PBXs. Comparison with the macroscale method not only verifies the feasibility of the MSC in the preparation of PBXs, but it also boasts a narrower particle size distribution, regular morphology, and high crystal quality. Furthermore, based on the advantages of the rapid and simple preparation of the MCS, the suitable polymer-coated explosive composite system can be quickly screened out. Four typical binders were selected by the MCS to coat the nano-hexanitrostilbene (nano- HNS), and their properties were analyzed. On this basis, the surface modification and coating mechanism of the binder on HNS crystals and the effect of micro mixing conditions on PBXs crystal growth were studied. Finally, the anti-overload performance of four different PBXs was evaluated through air gun experiments. The results show that all four PBXs can maintain the stability of the charge under strong external dynamic load conditions. This study provides an efficient route to prepare PBXs with narrow particle size distribution, high crystal quality and resistant high overload. This work serves those studying the composite system of crystals and polymers, as well as polymer-coated crystals.

Matrix-based reduction approach for one-sided fuzzy three-way concept lattices

Three-way concept analysis is a mathematical model of the combination of formal concept analysis and three-way decision, and knowledge discovery plays a significant impact on formal fuzzy contexts since such datasets are frequently encountered in real life. In this paper, a novel type of one-sided fuzzy three-way concept lattices is presented in a given formal fuzzy context with its complement, in which a ternary classification is available. In such case, we comprehensively explore the connections between the proposed models and classical fuzzy concept lattices among elements, sets, and orders. Furthermore, approaches to granular matrix-based reductions are investigated, by which granular consistent sets, and granular reducts via discernibility Boolean matrices are tectonically put forward. At last, the demonstrated results are performed by several experiments which enrich the research of three-way concept analysis.

Classical nucleation theory of ice nucleation: Second-order corrections to thermodynamic parameters.

Accurately estimating the nucleation rate is crucial in studying ice nucleation and ice-promoting and anti-freeze strategies. In classical nucleation theory, estimates of the ice nucleation rate are very sensitive to thermodynamic parameters, such as the chemical potential difference between water and ice Δμ and the ice-water interfacial free energy γ. However, even today, there are still many contradictions and approximations when estimating these thermodynamic parameters, introducing a large uncertainty in any estimate of the ice nucleation rate. Starting from basic concepts for a general solid-liquid crystallization system, we expand the Gibbs-Thomson equation to second order and derive second-order analytical formulas for Δμ, γ, and the nucleation barrier ΔG*, which are used in molecular dynamics simulations. These formulas describe well the temperature dependence of these thermodynamic parameters. This may be a new method of estimating Δμ, γ, and ΔG*.

Photophysics of the electronic states S0 and S1 for the coplanar molecular structures of the α,ω‐diphenylpolyenes DPH and DPO

AbstractSpectroscopy of the monoclinic and orthorhombic crystalline forms of all‐trans‐diphenylhexatriene (DPH) and all‐trans‐diphenyloctatetraene (DPO) show absorption and emission bands that do not generate the widely known Stokes shift of the polyene compounds, discovered by Hausser et al. in 1953 and repeatedly studied over the last 60 years. It can be concluded from our study that the crystallization system, whether in a monoclinic or orthorhombic system, does not significantly influence the photophysics of DPH and DPO in the crystal phase.

Methyl Hexadecyl Viologen Inclusion in Cucurbit[8]uril: Coexistence of Three Host–Guest Complexes with Different Stoichiometry in a Highly Hydrated Crystal

The host–guest inclusion complexes of cucurbiturils with alkyl viologen have interesting architectures, chemical properties, and potential applications in sensors and nanotechnology. A highly hydrated triclinic crystal of cucurbit[8]uril (CB[8]) complexed by methyl hexadecyl viologen (MVC16) is characterized by the unprecedented coexistence in the crystal of three host–guest complexes with 3:2, 2:2, and 1:1 stoichiometries. In all these complexes, the hook-shaped alkyl chain of the MVC16 is hosted in the CB[8] macrocycles, while the methyl viologen moieties have various environments. In the Z-shaped 3:2 complex, a central CB[8] unit hosts two viologen heads in the cavity, while the 2:2 complex is held together by π-stacking interactions between two viologen units. In the square 2D tiling crystal packing of CB[8] macrocycles, the same site which favors the dimerization observed in the 2:2 complex is also statistically occupied by a single methyl viologen moiety of the 1:1 complex. The rational interpretation of the crystal structure represented an intriguing challenge, due to the complicated statistical disorder in the alkyl chains hosted in CB[8] units and in the methyl viologen moieties of 2:2 and 1:1 complexes. In contrast with the solution behavior dominated by the 2:1 complex, the coexistence of three host–guest complexes with 3:2, 2:2, and 1:1 ratios highlights the fundamental importance of packing effects in the crystallized supramolecular complexes. Therefore, the crystallization process has permitted us to capture different host–guest systems in a single crystal, revealing a supramolecular landscape in a single photo.

Experimental Investigation of an Integrated Crystallization and Wet-Milling System with Temperature Cycling to Control the Size and Aspect Ratio of Needle-Shaped Pharmaceutical Crystals

Experimental Investigation of an Integrated Crystallization and Wet-Milling System with Temperature Cycling to Control the Size and Aspect Ratio of Needle-Shaped Pharmaceutical Crystals

Simultaneous optimisation of heat and power integration of evaporation–crystallisation systems: a case study of distiller waste from Solvay process

Simultaneous optimisation of heat and power integration of evaporation–crystallisation systems: a case study of distiller waste from Solvay process

Waste heat utilization from boiler exhaust gases for zero liquid discharge of desulphurization wastewater in coal-fired power plants: Thermodynamic and economic analysis

Zero liquid discharge (ZLD) of wet flue gas desulphurization (WFGD) wastewater in coal-fired power plants (CFPPs) would contribute to sustainable development of fossil electricity generation. In the present work, improved flue gas-driven forced-circulation multi-effect distillation and crystallization (FCMEDC) systems were proposed for achieving low-cost ZLD of WFGD wastewater. Different types of integration scenarios were investigated, including FCMEDC systems driven by waste heat recovered from boiler and economizer exhaust gases, and incorporated with low-pressure economizer and flue gas bypass high-pressure economizer systems. Thermodynamic and techno-economic analysis models were developed for comprehensive evaluation of the technical and economic feasibility of the integrated ZLD schemes. The levelized cost of wastewater (LCOW) and operating expenditure (OPEX) were found to be significantly reduced by 41.5% and 53.6%, respectively, when plant auxiliary steam was substituted by boiler exhaust gas as the heat source in a 600 MW unit. A parametric study was further conducted to investigate the impact of wastewater salinity and flow ratio on the process design. The flue gas-driven FCMEDC system demonstrated favorable adaptability to variations in wastewater quality. Moreover, sensitivity analysis suggested that the LCOWs of the proposed ZLD systems were explicitly subject to the expected lifetime, brine disposal options, and brine pre-concentration. The methodology and results could provide insights into the process development of WFGD wastewater ZLD systems based on the FCMEDC technology.

Boron recovery from montmorillonite clay waste using sequential leaching followed by cooling crystallization techniques

A four-stage sequential leaching (SL) and subsequently cooling crystallization (CC) techniques have been implemented for the recovery of boron from the clay waste (CW) induced by the borax derivatives production facility located in Kirka district of Eskisehir province, NW of Turkey. Optimum experimental solid-liquid ratio and agitation time for SL tests were determined by preliminary experiments. In the first leaching stage, approximately 85% of boron in the CW was transited to the leachate. A logarithmic decrease in the boron transition efficiency was obtained as a function of stages. After four-stage SL procedure, CC procedure was carried out with the last leachate at 4.0 °C ±0.3 stabilized refrigerator. Approximately 77% of dissolved boron in the last leachate was crystallized by CC as high purity borax crystals. Mineralogical, chemical, and physical definitions of the crystals were determined by X-ray diffraction (XRD), instrumental element analysis following microwave digestion, and scanning electron microscopy (SEM) procedures, respectively. As a result, sequential leaching followed by cooling crystallization system was determined as an effective methodology for the recovery of boron from the CW as high purity borax form.

Integration of seeding- and heating-induced crystallization with membrane distillation for membrane gypsum scaling and wetting control

Although membrane distillation (MD) has great potential in treating high-salinity wastewater, continuous accumulation of inorganic salt due to increasing concentration inevitably causes supersaturation and subsequent membrane scaling. Crystallizer is an effective tool used for removal of salts; however, it has been hardly applied for sparingly soluble salts. In this study, a simultaneous membrane distillation–crystallization (SMDC) system was developed for gypsum scaling control. Induced crystallization was adopted to retard the membrane scaling. The transmittance and ion concentration of the concentrate were measured to investigate the performance of the induced crystallization. The membrane scaling was characterized by both vapor flux measurements and scanning electron microscopy. Besides, the permeate conductivity was monitored to assess the membrane wetting during MD, and the energy evaluation was performed for the SMDC system during the reverse osmosis brine treatment. Results showed that the seeding of gypsum at dosage of 1 g L−1 effectively restricted the membrane scaling and wetting. Although the combination of seeding and heating showed better membrane scaling control performance, the energy consumption of the SMDC system increased by 4 times without considering heat recovery. Therefore, feed seeding alone is an efficient and economical measure to restrict gypsum scaling and wetting during the high-salinity wastewater treatment using MD.

Superhydrophobic PVDF/micro fibrillated cellulose membrane for membrane distillation crystallization of struvite

Phosphate recovery is essential due to the depletion of phosphate resources and the phosphate loss by surface run-off. Membrane distillation crystallization (MDC) system with macroporous membrane provides a large interfacial surface for water removal at low temperature and phosphate concentration for crystal growth in the phosphate recovery strategy. However, the water vapour removal rate is limited by the membrane porosity and pore size. Membrane wetting and fouling on the hydrophobic membrane surface further reduce phosphate recovery in the long operation. In this work, polyvinylidene fluoride (PVDF) membrane was enhanced by adding micro fibrillated cellulose (MFC) filler to enhance phosphate recovery through struvite precipitation in MDC. The membrane was further modified by non-fluorinated silane (hexadecyltrimethoxysilane or octadecyltrichlorosilane) after phase inversion to attain superhydrophobicity. MFC promoted pore growth and porosity creation in PVDF/MFC membrane as the solvent-non-solvent exchange rate was boosted during phase inversion. In silane modification, abundant moieties of MFC further promoted vertical polymerization for creating superhydrophobic surface. The PVDF/MFC membrane modified with octadecyltrichlorosilane obtained the highest water contact angle of 154.4°, liquid entry pressure of 1.51 bar, relatively large pore size of 0.40 μm and satisfactory porosity of 45.1%, resulting in the stable permeate flux in MDC. The needle-like struvite crystals formed after pH adjustment and the modified membrane surface was not fouled even after 24 h of operation.

Mathematical modeling and experimental validation of continuous slug-flow tubular crystallization with ultrasonication-induced nucleation and spatially varying temperature

Continuous slug-flow tubular crystallization has been explored by several research groups in academia and industry as a way to produce crystals while having low capital equipment costs. In this crystallization type, slugs of slurry and gas consecutively travel through a tube, with a high degree of mixing and temperature uniformity within each slug. This article presents an experimental system for slug-flow tubular crystallization that employs a spatial temperature profile and directed non-contact ultrasonication to induce primary nucleation to enable the generation of a wide variety of crystal size distributions. The crystal size distributions are compared for data collected from a full-factorial experimental design (27 experiments in total) to predictions from a population balance model that includes the effects of ultrasonication on primary nucleation. This population balance model for tubular crystallization is the first that incorporates the effects of ultrasonication and dissolution on the crystal size distribution. The crystal size distributions are reasonably consistent with the model, within 20% prediction error, for all experiments in which the spatial temperature profile is monotonically decreasing and at low to moderate supersaturation. Potential causes for weaker agreement for other experiments are discussed.

Observation of New Dynamics of Transitions among Intermediate Species in Crystal Evolution and Its Role in a Generic Model of Crystallization

The mass and phase transitions among intermediate species are unique dynamics in nonclassical crystallization that are under investigation. In this research, we used a pulsed laser to initiate crystallization in its early stages and observed the crystal evolution through transitions and interactions among the intermediate species. The crystal evolution was induced and observed in situ simultaneously by the same electron beam in a transmission electron microscope without a liquid cell environment, thereby eliminating the complexity introduced by the additional nucleation in the precursor solution. The observed mass diffusion among species in an anti-Ostwald ripening way indicated that crystallization systems were composed of intermediate species in various phases. We found that these intermediate species were not like rigid building blocks but kept changing in size and phase and evolving in multistage transitions. Considering the observations, we propose a generic model by extending the classical nucleation theories to describe the dynamics of intermediate transitions and all possible crystal evolution pathways, discovered or not.

Recovery of iron by jarosite crystallization and separation of vanadium by solvent extraction with extractant 7101 from titanium white waste liquid (TWWL).

The jarosite crystallization and new extractant system for extractant 7101 was used to separate iron and extract vanadium from titanium white waste liquid (TWWL). The influence factors and mechanisms of crystallization and solvent extraction were investigated and analyzed using SEM-EDS, XRD, FT-IR, solution thermodynamic theory and extraction isothermal curve. More than 97% of iron was precipitated with the following conditions: potassium chlorate 15 g/L, pH value of 1.6, temperature of 95 °C and time of 90 min, in which the crystallization product was jarosite with a purity of 99.5%; the pH value of the solution decreased after precipitation. The extraction efficiency of vanadium reached 88.6% with 10% Fe, 5% Al(III) but less for Mg(II), K(I) and Na(I) under the conditions X7101 of 0.5, pH value of 2.0, time of 4 min and stirring speed of 40 r/min. The extraction of metal ions occurred in the order V(V) > Fe(III) > Al(III) > Mg(II) > K(I). Vanadium minimally existed as H2V10O284- at pH 2.0, and the functional groups NH and C-N contributed to vanadium extraction using the extractant 7101. Four stages extraction and three stages of re-extraction were predicated by McCable-Thiele plots.

Multi‐objective optimization of cane sugar continuous crystallization system design based on computational fluid dynamics

This work focused on improving circulation and mixing of the massecuite and reducing the energy loss in the cane sugar continuous crystallization system. The developed Computational Fluid Dynamics (CFD) model is based on the continuous crystallization system of a sugarcane mill in Guangxi, China and verified with the actual operation data. The calculated entropy production and pressure drop of the system are used as indices for assessing the performance of the system. Next, 350 CFD simulations are conducted in the parametric experiment platform with 9 parameters and produces a collection of data. Then based on the CFD data set, the data-driven model is employed for regression of the relations between key parameters and indices. The implemented data-driven model is used for Non-dominated Sorting Genetic Algorithm (NSGA-II) to obtain the optimal result of Pareto frontier. CFD simulation with the optimized parameters reduces entropy by 9.76% and reduces pressure drop by 11.52%. Novelty impact statement Multi-objective optimization of cane sugar continuous crystallization system is performed. The entropy is reduced by 9.76% and the pressure drop is reduced up to 11.52%. The proposed method show the good applicability.

Energy efficient supercritical water desalination using a high-temperature heat pump: A zero liquid discharge desalination

Supercritical water desalination (SCWD) is zero liquid discharge technology that can potentially control the solubility of different electrolytes. However, SCWD is an energy-intensive process and requires high-quality thermal heat (> 450 °C). This study proposes the integration of a high-temperature heat pump to reduce the SCWD energy requirement. The integrated system energy consumption improves by 36% for 3.5% feed concentration and 14% for 20% feed, and the distillate cost reduces by 15% and 10%. Another benefit of the proposed integration is the system can be operated using only electricity as a heat source, as is the case with commonly used high-recovery thermal desalination technology. The integrated SCWD-heat pump system shows superior performance compared to the commercially used brine concentrator and crystallizer system. It is approximately 20% more energy-efficient for 25% feed concentration and 8% cheaper. Hence, the integrated SCWD-heat pump has the potential to outperform the pre-existing high-recovery desalination technology.

Thermo‐Kinetic Investigation of the Preparation of Micronized Ammonium Perchlorate Particles by Using Rapid Cooling Crystallization Method

AbstractProduction of micronized ammonium perchlorate particles (AP) (<25 μm) has a great importance in the composite solid propellant industry. In the present study, an attempt was made to consider thermo‐kinetic preparation of AP particles by using simple McCabe model in a cooling crystallization system. For this reason, an experimental design based on temperature, pressure, time, and concentration was used. Temperature in the range of 323–343 K, pressure in the range of 3 –18 Pa, and concentration in the range of 0.4–0.5 g/mL were set for the experiments. The time parameter was variable regarding to the temperature and concentration of each experiment and it was measured to evaluate the rate of process. The crystal size as an experiment response was estimated using image analysis of produced samples by MIP software in micrometer scale. Finally, a growth rate equation was established considering the results obtained from temperature variations, pressure, concentration, and time. Decrease in temperature variations caused to increase in crystallization rate and crystal size. The pressure above 7.5 Pa resulted in producing crystals smaller than 40 μm. The lowest crystal size was observed in the concentration of 0.45–0.5 g/mL and the crystallization time below 8 s. In addition, the results obtained from presented equation and experiment were matched with McCabe model.

Synthesis of the AgBr – AgI system optical crystals

Abstract The presented work is devoted to the study and development of the technology for obtaining the AgBr – AgI crystals system. Studies have been carried out to study the phase diagram in order to clarify the region of stable solid solutions' existence. Based on the data obtained, the modes were selected and single crystals of various compositions were synthesized. Their main optical properties, such as the spectral transmission range, were investigated and the refractive indices were determined at the wavelength of the short-wave absorption edge and the CO2 laser (10.6 μm). The work’ results are necessary for the manufacture of various structures IR fibers, windows, lenses, and other optical products, which are widely used in different fields of science and technology, including laser, endoscopic, and diagnostic medicine.

Polytetrafluoroethylene-like Nanoparticles as a Promising Contrast Agent for Dual Modal Ultrasound and X-ray Bioimaging.

Various noninvasive imaging techniques are used to produce deep-tissue and high-resolution images for biomedical research and clinical purposes. Organic and inorganic bioimaging agents have been developed to enhance the resolution and contrast intensity. This paper describes the synthesis of polytetrafluoroethylene-like nanoparticles (PTFE≈ NPs), their characterization, biological activity, and bioimaging properties. Transmission electron microscopy (TEM) images showed the shape and the size of the as-obtained small and ultrasmall PTFE≈ NPs. Fourier transform infrared spectroscopy (FTIR) confirmed the PTFE-like character of the samples. X-ray diffraction (XRD) enabled the determination of the crystallization system, cell lattice, and index of crystallinity of the material in addition to the presence of titania (TiO2) as the contamination. These findings were corroborated by X-ray photoelectron spectroscopy (XPS) that identifies the chemical states of the elements present in the samples along with their atomic percentages allowing the determination of both the purity index of the sample and the nature of the impurities. Additionally, diffuse reflectance ultraviolet-visible spectroscopy (UV-vis) was used to further assess the optical properties of the materials. Importantly, PTFE≈ NPs showed significant in vitro and in vivo biocompatibility. Lastly, PTFE≈ NPs were tested for their ultrasound and X-ray contrast properties. Our encouraging preliminary results open new avenues for PTFE-like nanomaterials as a suitable multifunctional contrast agent for biomedical imaging applications. Combined with suitable surface chemistry and morphology design, these findings shed light to new opportunities offered by PTFE nanoparticles in the ever-booming biomedical field.