Melt Crystallization Research Articles

Rotomolded polypropylene‐ignimbrite composites: Giving a second life to mineral dust wastes

AbstractThe possibility of rotomolding polypropylene (PP) composites with high loadings of a silica‐based dust of ignimbrite, a byproduct of volcanic stone extraction is demonstrated. This study aims to establish the properties of composites with various ratios of mineral dust as a filler in PP matrices at loadings from 5 to 30 wt%, ultimately transforming mining residues into a valuable resource for composite production and creating a value chain around the traditional mining industry. Once the composites were obtained, they were subjected to several characterization techniques to comprehensively assess their mechanical and thermal properties. In general, a high percentage of ignimbrite powder has resulted in a reduction in the mechanical properties of neat PP, although no significant changes were observed for composites at lower loadings. Furthermore, the incorporation of this mineral material modified the thermal properties of the PP, enhancing its thermal stability. The blending of the matrix and filler resulted in a reduction in both the melting crystallization temperatures for highly‐filled composites. Rotomolded items with good aesthetics, with stone‐like appearance, were obtained without any modification on the mineral dust or even without any melt compounding, therefore not increasing the energy consumption during the composites production.Highlights Composites production is a suitable strategy for valorization of mineral residues. Welded ignimbrite residual dust has been used for the first time in composites. Mineral dust has been successfully used in composites obtained by rotomolding. Polypropylene with up to 30% of the stone dust can be processed. Good aesthetics and mechanical features can be obtained with mineral wastes.

Role of BPO4 flux in BaBPO5 crystal growth characterized through high-temperature Raman spectroscopy

In this study, we explored the growth of incongruently melting crystals in a starting solution with flux to better understand the role of flux in crystal growth mechanisms. We recorded the spectrum of BaBPO5 crystals across a 200-1400 cm−1 range for detailed Raman spectroscopic analysis. The observed Raman bands corresponded to the vibrations of PO4 and BO4 units. These units link with B-O-P bonds via common corners to form PBO7 groups that serve as basic structural units of the crystal. Notably, these PBO7 structures remain stable at high temperatures up to the crystal melting point, at which the isolated PO4 groups predominantly exist in the melt, as revealed by high-temperature Raman spectroscopy. Further investigations into the Raman spectra of the starting solution enriched with BPO4 self-flux indicate that PBO7 groups are crucial for crystal growth. The addition of PBO4 flux aids in the formation of these PBO7 units. This research paves the way for expanding our understanding to other systems, which will help elucidate the mechanisms behind crystal growth.

Enhanced Crystallinity Through Melt Annealing of Thermoplastic Polyurethanes

ABSTRACTThis study evaluated the influence of melt annealing on thermoplastic polyurethane (TPU) synthesized via reactive extrusion, aiming to enhance TPU melt crystallization behavior. The melt annealing process involved reprocessing the polymer in a twin‐screw extruder, leveraging a novel approach to manipulating crystallization behavior by optimizing melt annealing conditions to activate microphase separation. Differential scanning calorimetry analysis indicated increased nucleation density and a shift in peak crystallization temperature to higher values during cooling. Phase morphology was examined using scanning electron microscopy, while gel permeation chromatography was utilized to assess molecular weight changes. X‐ray diffraction provided insights into TPU microstructural modifications, and mechanical properties were evaluated via tensile tests. Fourier‐transform infrared spectroscopy was employed to analyze annealing‐induced changes in the hard segment structure and interpolymer bonding. The findings demonstrated that annealing enhances mechanical properties, promotes microphase separation, and increases the energy available for movement and realignment of hard segments, thereby improving TPU's thermal stability. Precise control of annealing temperature was critical to prevent adverse effects on polymer morphology or molecular weight reduction. Annealing at 210°C yielded the highest degree of crystallinity, optimizing mechanical properties and thermal stability.

High drug-loaded amorphous solid dispersions of a poor glass forming drug: The impact of polymer type and cooling rate on amorphous drug behaviour.

Enhancing the aqueous solubility via amorphization of crystalline poor glass-forming drugs represents a challenge, particularly when drug dosing is high. In such scenarios, there is often a need for high polymer loadings leading to an increase in the dosage form mass and less patient acceptability. This work investigated the role that polymer type and after-melt cooling rate had upon the amorphicity of solid dispersions (SDs) containing high levels of naproxen and three commonly used polymeric excipients: Eudragit® EPO, Kollidon® VA64, and Soluplus®. Using a combination of thermogravimetry, conventional and fast-scan DSC, oscillatory rheology, in silico Hansen solubility parameter computation, FTIR, and PXRD, we have shown that amorphicity could be affected by the cooling rate with the specific polymer type and amount playing a significant role in the degree of this impact. The amorphous drug content, evident at higher cooling rates, was found to be dependent on drug-polymer interaction and polymer melt viscosity. Higher polymer concentration and faster cooling produced less melt crystallization upon cooling, which was attributed to a shift in nucleation to lower temperatures where it could be inhibited by polymer matrix viscosity. Amorphous drug content, which contained drug nuclei, was evidenced by cold crystallization upon reheating. After 4 weeks of 'gentle' storage, cold crystallization increased if nucleation was the dominant process, whereas cold crystallization decreased if crystal growth prevailed. Storage at elevated temperature and humidity resulted in the absence of cold crystallization, and increased melt crystallisation. Thus, faster cooling could serve as an additional tool to improve amorphous yield and stability of high drug-loaded SDs, however, intermolecular polymer-drug interaction, melt viscosity of the drug-polymer matrix, and storage conditions are of critical importance to achieve this goal.

Energy amplification in plasma crystals due to multiple torsions

Interacting torsions are examined within a two-dimensional monolayer crystal suspended in an argon complex plasma for 1–10 W discharge powers and pressures of 135–155 mTorr. Two torsions embedded in a lattice are shown to amplify the kinetic energy and range of motion of particles located between the torsions to nearly three times that observed in single torsion systems. It is also shown that multiple torsions can interact via amplified particle energy when separated by up to 14 interparticle distances (Δ). The torsion separation distance also showed a positive linear trend with power and a slightly positive correlation with the pressure. This amplification of energy is possible due to the fact that multiple torsions in a lattice increase the interparticle distance of the lattice by 16% more than single torsion systems, leading to additional freedom of motion in the lattice plane. These combined findings show that multiple torsions heat the lattice differently depending on their separation from the other torsion. The midpoint particles between torsions absorb the majority of energy from the two torsions, and energy addition at the midpoint is nonlinear. The addition of more torsions to the lattice may lead to melting of the plasma crystal.

Crystallization of CoWB ternary boride in nickel-based metallic glass

The crystallization kinetics of CoWB ternary boride were investigated through non-isothermal differential scanning calorimetry experiments, using a Ni-based metallic glass precursor as the starting material. The effects of isothermal heat treatment temperature on the phase evolutions were also systematically studied. The results showed that the melt crystallization and glass crystallization behaviors of the alloy differ from each other. The continuous heating transformation diagram plotted from non-isothermal analyses is consistent with the results of isothermal heat treatments. A broad ternary boride precipitation zone was demonstrated, involving the gradual precipitation of CoWB crystals. Avrami exponent values for the early crystallization stage showed that the crystallization mechanism of CoWB is governed by the interface-controlled three-dimensional growth mechanism, and nucleation rate is high. As the crystallization progresses, a diffusion-controlled growth occurs and the nucleation rate decreases. This study offers insights into the heat treatment of CoWB-reinforced nickel matrix nanocomposites, benefiting future research and industrial production processes.

GEOCHEMICAL CHARACTERIZATION OF ORTHO-DERIVED GNEISS AND GRANITOIDS OF THE PAN-AFRICAN PROVINCE OF DAMAGARAM (SOUTH-EAST NIGER)

The Pan-African province of Damagaram, object of this study, corresponds to the north-eastern extension of the Benin-Nigerian Shield. The main geological formations that outcrop in this region consist of migmatitic gneiss, banded gneiss, mylonitic gneiss, porphyritic granites, two-mica granites, biotite granites and alkaline granites. The petrogenesis of ortho-derived gneisses and granitoids of Damagaram province was studied using the methods of geochemistry on total rock (major elements, trace elements and rare earth elements). The chemical composition (major elements and trace elements) shows that the precursor magmas come from the subalkaline series. The analyzed samples are characterized by a high SiO2 content (≥ 65%) and show a calc-alkaline potassium to shoshonitic affinity typical of the subduction zone. The high alkaline content (Na2O + K2O) and the A/CNK and A/NK parameters indicate that these rocks are aluminous to hyperalumino. Enrichment in certain large lithophilic elements (LILEs) (Rb, Ba, Th and Sr) and depletion in certain high field intensity elements (HFS) such as Nb, P and Ti are favorable criteria for the involvement of the crust in the genesis of these rocks. The light rare earth enrichment (LREE) and heavy rare earth depletion (HREE), as well as the negative europium (Eu) anomaly, suggest that these rocks as a whole would come from either fractional crystallization or partial melting of a pre-existing continental crust. The geochemical characteristics indicate that the geodynamic domain of these formations corresponds to the syn-collisional and intraplate volcanic arc geotectonic environments.

Development and characterization of PLA food packaging composite

AbstractThis study focuses on the development of bioactive packaging materials by incorporating grape pomace and copper particles into polylactic acid (PLA) composites. The goal is to increase the shelf life of packaged foods while benefiting the health of consumers through the use of these active materials. 6 recipes of composite materials based on polylactic acid and Proviplast 2624 plasticizer were obtained. The additives added were: grape pomace, added at 0.5%, 1% and 1.5%, and copper particles, formed using PEG 600 + CuSO₄, added at 2%, 5% and 8%. Material characterization techniques: FTIR Spectroscopy, used to study the chemical structure. Differential scanning calorimetry (DSC): examined thermal transitions such as glass transition and melting temperatures. Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG): evaluated thermal stability and degradation temperatures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM): analyzed the surface morphology and structure. Mechanical tests: evaluated tensile strength, elongation at break and flexibility.Thermal property analyzes revealed that the additives acted as plasticizers, reducing the intermolecular forces between PLA chains, which decreased the glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tm). The addition of grape pomace and copper particles decreased the degradation temperature of PLA composites, indicating a slight reduction in thermal stability. The transformation temperatures changed and the nature of the thermal transitions (exothermic or endothermic) varied with additive concentrations. Mechanical properties indicated a reduction in tensile strength with increasing additive concentration. Elongation at break and longitudinal modulus of elasticity increased significantly, especially with grape pomace, improving the flexibility of PLA. These changes indicate that the material can absorb more energy before breaking, making it more ductile and more suitable for flexible packaging applications. Increased flexibility and improved thermal resistance ensure that these materials can withstand the demands of packaging, handling and shipping. The combination of improved flexibility, thermal resistance and moderate tensile strength makes these PLA-based composites incorporated with grape pomace or copper particles, enhance the aspect of sustainability by recycling agricultural waste, making the material both ecological and functional, making it a viable option for active food packaging.

Exciton crystal melting and destruction by disorder in a bilayer quantum Hall system with a total filling factor of one

Exciton crystal melting and destruction by disorder in a bilayer quantum Hall system with a total filling factor of one

In-line detection of salt formation during vitrification using millimeter wave radiometry and interferometry

Vitrification is an internationally significant industrial process used for the treatment and immobilization of hazardous and radioactive waste. For successful silicate melt vitrification, molten salt formation during melter operation must be avoided. As such, proper process controls and continuous monitoring are critical to minimizing melting problems. Several in-situ process technologies for glass melters are well-developed; however, the lack of in-situ surface salt formation detection methods presents a risk to vitrification at the Waste Treatment & Immobilization Plant (WTP) on the US Hanford Site. While proposed previously, millimeter wave (MMW) radiometry and interferometry are demonstrated for the first time for in-line detection of salt formation in simulated nuclear waste glass melts. The experimental radiometer and interferometer setup uses the optical properties of the melt and a dual receiver operating at ∼ 137 GHz to elucidate melting behavior. A series of previously characterized glasses supersaturated with sulfate (Na2SO4), chloride (NaCl), or fluoride (NaF) salts are analyzed using the MMW system. This provides insight into volatile losses, fining, salt formation, salt identity, crystallization, and optical properties of a heterogeneous melt. Relevant terahertz (MMW/THz) optical properties are also compiled. Millimeter wave measurements are evaluated here for the ability to detect phase changes in salt-forming glass melt compositions without opaque body radiometry assumptions. This contribution demonstrates MMW radiometry with interferometry as a useful method for in-situ salt detection, enabling risk reduction in nuclear waste vitrification melters.

Thermal Treatment Induced Crystal Development and Crystal Orientation Change in Electrospun Coaxial Fibers Comprising Dual Crystalline Polymers.

This study investigates the crystallization behavior of electrospun coaxial fibers composed of crystalline poly(ethylene oxide) (PEO) in the core and crystalline poly(L-lactide) (PLLA) in the sheath. The influence of cold crystallization temperature and premelting temperature on the crystallization of PEO and PLLA is investigated. At a cold crystallization temperature of ≤60°C, PLLA remained immobile. PEO crystallization is hard-confined, leading to a low degree of crystallinity. At a cold crystallization temperature of >60°C, PEO melted, whereas PLLA crystallized. An increase in cold crystallization temperature results in an increase in the crystallite size and crystallinity of PLLA. Furthermore, the melt crystallization behavior of PEO in the coaxial fibers is strongly influenced by its premelting temperature and crystallization temperature. A higher premelting temperature leads to enhanced interdiffusion between PEO and PLLA. This increased confinement results in a decrease in PEO's crystallizability. Additionally, premelting relaxes the PEO chains, causing a shift in crystal orientation from parallel to the fiber axis (observed in as-electrospun fibers) to perpendicular to the fiber axis (observed in melt-crystallized fibers). Moreover, at a low melt crystallization temperature, demixing between PEO and PLLA is observed. This, coupled with a higher degree of supercooling, leads to an increase in PEO's crystallizability.

Impact of statistical poly(propylene co-ethylene) on the thermo-mechanical properties of high-density polyethylene

A series of high-density polyethylene and a statistical copolymer of poly(propylene-co-ethylene) blends in a wide range, namely (0, 10, 20, 30, 40, 50, 60,70, 80, 90, 100) abbreviated as HDPE/VM were systematically investigated by using a rheometer, differential scanning calorimetry (DSC) measurements, polarized optical microscopy (POM) and tensile tests. Rheometer results show that adding VM decreases dynamic viscosity, storage, and loss modulus. Han plot shows that HDPE and VM are compatible and miscible in the range from 20 to 60 VM % in the molten state. DSC results show little nucleation effect of VM on HDPE (HDPE’s melt crystallization temperature shifts 2 °C higher). Moreover, a linear composition dependence of ∆cp ∆Hc, ∆Hm shows that PE and VM are most probably compatible in the molten state in composition range from 20 to 60%. However, upon crystallization, the VM and PE domains occur distinctively. The results of the tensile tests demonstrated a decrease in elastic modulus, yield stress, and ultimate tensile strength as VM content increased. At low VM content (less than 20%), high elongation at break was detected for the blends, and very fine spherulites of HDPE were found across the sample by POM.

Insights on Arc Magmatic Systems Drawn from Natural Melt Inclusions and Crystallization Experiments at PH2O =800 MPa under Oxidizing Conditions

Abstract Whole rock compositions at Buldir Volcano, western Aleutian arc, record a strong, continuous trend of iron depletion with decreasing MgO, classically interpreted as a calc-alkaline liquid line of descent. In contrast, olivine-hosted melt inclusions have higher total iron (FeO*) than whole rocks and show little change in FeO* with decreasing MgO. To investigate this discrepancy and determine the conditions required for strong iron depletion, we conducted oxygen fugacity (ƒO2) buffered, water-saturated crystallization experiments at 800 MPa and ƒO2 = QFM+1.6 ± 0.4 (1$\sigma$) (where QFM refers to the quartz-fayalite-magnetite buffer) on a high-Al, basaltic starting material modeled after a Buldir lava. Experimental conditions were informed by olivine-hosted melt inclusions that record minimum entrapment pressures as high as 570 MPa, >6 wt.% H2O, and ƒO2 of QFM+1.4 (±0.2), making Buldir one of the most oxidized and wettest arc volcanoes documented globally. The experiments produce melts with Si-enrichment and Fe-depletion signatures characteristic of evolved, calc-alkaline magmas at the lowest MgO, although FeO* remains roughly constant over most of the experimental temperature range. Experiments saturate CrAl-spinel and olivine at 1160oC, followed by clinopyroxene and Al-spinel at 1085oC, hornblende at 1060oC, and, finally, plagioclase and magnetite between 1040oC and 960oC. Hornblende crystallization, not magnetite, generates the largest increase in SiO2 and largest decrease in FeO* in coexisting melts. Compositions of melt inclusions are consistent with experimental melts and reflect crystallization of a basaltic parent magma at high PH2O. In contrast, the whole rock compositional trends are influenced by magma mixing and phenocryst redistribution and accumulation. The crystallization experiments and natural liquids (melt inclusions and groundmass glass) from Buldir suggest that for an oxidized, hydrous primary basalt starting composition, significant Fe-depletion from the melt will not occur until intermediate to late stages of magma crystallization (< ~4.5 wt.% MgO). We conclude that the Buldir whole rock trend cannot be reproduced by crystallization at arc-relevant oxygen fugacities and is not a true liquid line of descent, warranting caution when interpreting volcanic trends globally.

Effect of Soret diffusion on the growth of spherical crystals in supercooled alloy melts under oscillatory flow.

The growth of spherical crystals in binary alloy melts with thermal diffusion effects under oscillatory flow is investigated analytically. Using the multiple scale method, we derive approximate analytical solutions for both the crystal interface growth rate and the solute concentration. Our results demonstrate that the Soret effect significantly influences both the solute concentration near the crystal interface and the crystal growth rate. Specifically, with a positive Soret coefficient, the growth rate of spherical crystals in a binary dilute alloy melt decreases as the coefficient increases, while the solute concentration near the interface increases. In contrast, with a negative Soret coefficient, the growth rate of the spherical crystals increases as the coefficient decreases, and the solute concentration near the interface decreases. Additionally, the presence of oscillatory flow markedly promotes the grain refinement induced by the Soret effect.

Preparation and melt-spun applications of PA6-based Poly(Amide-Ether) copolymers phase change fibers with passive temperature management

Phase change fiber, as an intelligent fiber material used in passive thermal management, can balance the temperature of the microenvironment near human skin. However, the traditional blending method makes phase change material prone to leakage during the processing and applications. Herein, this work introduces the phase change material PTMEG into the polyamide 6 (PA6) chain through melt polymerization to prepare a series of PA6-based poly(amide-ether) copolymers. Copolymers exhibit an obvious microphase separation structure, with the PA6 segments and the PTMEG segments can form independent crystalline and amorphous regions. PTMEG in copolymers through polymerization method exhibits better thermal stability compared with the blended way, which effectively solves the leakage problem of phase change materials. The copolymers can be directly melt-spun (1500 m/min) to prepare PA6-based phase change fibers. The fiber can maintain excellent mechanical properties (breaking strength of 2.12 cN/dtex). Meanwhile, the crystallization enthalpy and melting enthalpy of the PTMEG in the fiber are 10.59 J/g and 12.44 J/g, respectively. The thermal management time of the fiber in the hot environment is 349 s, and the maximum temperature difference is lower 5.6 ℃ from the PA6 fiber. In addition, the exothermic duration in a cold environment is 536 s, and the maximum temperature difference is higher 1.1 °C from the PA6 fiber. Meanwhile, the thermal enthalpy of the fiber remained stable (fluctuation within 2 %) after 20th thermal cycles, and the loss rate is less than 2 % after washing at 25 ℃, 50 ℃ and 90 ℃. The fiber exhibits good thermal stability, water washability and cyclic stability. Preparation of high enthalpy polymers directly by copolymerization will provide new ideas for phase change fibers for apparel.

Preparation and scintillation properties of Eu3+-doped high crystallinity tellurite glass ceramics

In this study, a high-crystallinity glass-ceramic scintillator doped with Eu³⁺ containing Bi₂Te₄O₁₁ nanocrystals was prepared using a traditional melt crystallization method. The optimal heat treatment conditions, phase structure, and luminescent properties of the glass-ceramics were systematically investigated using various characterization techniques, including DSC, XRD, SEM, and spectrophotometry. To achieve glass-ceramic samples with high transmittance and excellent luminescent performance, the optimal heat treatment process was determined to be 500 °C for 10 min. The final sample was found to have a density of 5.9 g/cm³ and a crystallinity of 70 %. Strong orange-red light emission was exhibited by the glass-ceramic under both 465 nm light and X-ray excitation. The maximum integral X-ray excited luminescence (XEL) intensity was found to reach 20.2 % of that of the commercial Bi4Ge3O12 (BGO) scintillation crystal. It is indicated by the research that Eu³⁺-doped high-crystallinity tellurate glass-ceramics are promising candidate materials for scintillators in the field of X-ray detection.

Evaluation of critical process parameter on the production of sustainable bead foams based on polylactic acid

A commercial grade of polylactic acid (PLA) was foamed without using modifiers to obtain expanded polylactic acid bead foams (EPLA). Typically, the foaming process is influenced by both melt properties and crystallization behavior. While factors like water temperature, die structure, and die temperature are known to have effects on bead foam processing, these aspects have not been thoroughly explored in the context of PLA bead foam production. To address this gap, a comprehensive investigation was undertaken, varying water temperature, die structure, and die temperature to discern their impact on PLA processing behavior. Results revealed that water temperature significantly influenced foaming behavior, particularly at elevated temperatures near the glass transition of PLA. Additionally, the study demonstrated that die size wielded a notable influence on all foam properties, dictating process limits. With the selection of an appropriate die size, the die temperature could be manipulated within the range of 190°C to 160°C, revealing a substantial impact on the overall process. Remarkably, the lowest densities achieved were 63 kg/m3 with an average cell size of 36 µm and a cell density of 1.1*107 cells per cm3.

Preparation of a trans-free fat blend to substitute partially hydrogenated oil

Partially hydrogenated oil (PHO) possesses a mild flavor and exceptional processing characteristics, making it historically the primary choice for creamer. The discovery of health problems of trans fatty acids has accelerated the development of alternative fats. This study aimed to develop an optimal PHO alternative fat by physical blending. Based on the correlation between physicochemical properties and sensory attributes, soybean oil, fully hydrogenated palm kernel oil, and fully hydrogenated soybean oil (45/45/10, w/w/w) were selected to make the alternative fat. The fat blend exhibited a solid fat content (SFC) curve identical to PHO, along with similar melting crystallization behavior, crystal nucleation pattern and growth mode, viscosity (705 mPa s), and taste profile. Pearson correlation analysis was used to further clarify the correlation between properties and tastes. The result showed that the SFCs and fatty acid compositions have strong correlations with tastes. It provides a reference scheme for preparing fats with ideal tastes.

Influence of low voltage programmed thawing on the quality of frozen pork and its myofibrillar protein

This study explored the effects of low voltage programmed thawing (LVPT) on thawing period, water status, current density as well as physicochemical properties of pork muscle, considering air thawing (AT), water immersion thawing (WT) and cold storage thawing (CST) for the comparison, additionally making fresh meat (FM) as the control. The thawing process used current limiting to gradually reduce the maximum output current to 500, 200 and 100 mA, respectively, by applying a safe voltage of 35 V in a home defrosting apparatus. Using two pairs of foil plate, the thawing (LVPT-2) with dual current loop accelerated the melting of ice crystals than the process with one pair of polar plate (LVPT-1) and one current loop. From −18 °C to −1 °C, the thawing period of LVPT-2 was reduced by 14.54 %, 11.72 %, and 15.95 % compared with that of LVPT-1 for samples within the thickness of 2, 3 and 4 cm, respectively. During the process, the intensity and density of the current loaded on the frozen meat gradually increased. LVPT-1 retained water and reduced its migration inside the meat, and protein solubility was better maintained. As the thickness increased, the effect of LVPT-2 on the moisture distribution and protein solubility of the sample decreased. LVPT-1 treatment resulted in less fat oxidation as well as stable secondary and tertiary structures of myofibrillar proteins compared to other treatments. At low voltage, the ability of LVPT −2 to maintain meat quality was reduced due to the increase in current density. In addition, LVPT-1 reduced muscle damage because of rapid melting of ice crystals. In contrast, LVPT-2 was conductive the formation of potential hot spots due to dual current loop passed through the pork in final phase of thawing, which would adversely influence the quality of thawed meat. Finally, LVPT could improve the rate of thawing, water binding capacity and meat quality, especially, there was no overheating effect on the meat because of current limiting.

Advancing the development of supersonic natural gas liquefaction through understanding heavy hydrocarbon crystallization mechanism

During supersonic natural gas liquefaction, the solidification of heavy hydrocarbon molecules can be used to improve the efficiency of the liquefaction. This study investigates the supersonic crystallization of n-hexane using an experimental system designed by ourself for precise measurement of liquid heavy hydrocarbon vaporization. The results demonstrate that n-hexane gas condenses rapidly 1.5 cm downstream of the nozzle throat, releasing significant latent heat. The subsequent crystallization of these droplets transitions the substance fully from liquid to solid, and the latent heat released during crystallization is much lower than that during condensation. Under different conditions, we found that higher partial pressures intensify n-hexane crystallization, accelerating liquid phase growth despite slower solid phase mass increase. Furthermore, larger nozzle expansion ratios shorten the time and space distribution of the liquid phase mass fraction. Molecular dynamics simulations reveal n-hexane’s melting and surface crystallization temperatures to be approximately 160 ± 1 K and 158 ± 1 K, respectively, with a supercooling degree of 2 K, explaining the observed crystallization behavior in supercooled droplets.