Inhibition Of Crystal Growth Research Articles

Supersaturated Antisolvent-Assisted Crystallization for Highly Efficient Inorganic Perovskite Light-Emitting Diodes.

We introduced a strategy to form nanocrystalline CsPbBr3 perovskite films with high luminescence and stability, inhibiting crystal growth using a CsBr supersaturated antisolvent during the antisolvent-assisted crystallization process. We devised this strategy because the supersaturated antisolvent has a higher CsBr concentration over its solubility limit in the saturated antisolvent and consequently will form the smaller perovskite nanocrystalline grains due to the quick precipitation of the CsBr. Here, the CsBr is chosen as a model inorganic antisolvent additive for a crystal growth inhibitor and a passivator. Consequently, we have achieved a nanocrystalline CsPbBr3 film with an average grain size of ∼39 nm by the CsBr supersaturated antisolvent-assisted crystallization process, which is about 41% smaller than the average grain size of the control sample. Hence, the perovskite thin film exhibited a much higher photoluminescence quantum yield than the control film. The maximum current efficiency (CEmax) and the maximum external quantum efficiency (EQEmax) of the corresponding CsPbBr3 perovskite light-emitting diodes (PeLEDs) were approximately twice higher (CEmax of 94.64 cd A-1 and EQEmax of 22.93%) than those of the control device. Simultaneously, the inclusion of CsBr additives played a multifunctional role in diminishing the leakage current of PeLEDs and enhancing their operational lifetime.

AN IN VITRO EVALUATION OF ANTI-UROLITHIASIS POTENTIAL OF SIDDHA FORMULATION SAGALANOI CHOORANAM USING STRUVITE CRYSTAL GROWTH INHIBITION ASSAY

Renal calculus is a rising concern, with a prevalence of 12% across the world and 12% in India, which is around 2 million people affected by Urolithiasis. The rise in the ratio has been correlated to genetic predisposition, working in high temperatures, high caffeine intake, lack of physical activity, and groundwater consumption. Yet the major risk factor is a diet that consists of excess animal proteins, which reduces urinary PH and citrate excretion, leading to the formation of Renal calculi. The main aim of this article is to evaluate the anti-urolithiatic potential of a polyherbal Siddha formulation Sagalanoi chooranam obtained from the classical Siddha text Brahmamuni Karukidai Soothiram 380. From the results, it was concluded that the drug has a high potential as an alternative for the management of renal calculus in Siddha. The ingredients efficiently manage renal calculus due to their potent anti-urolithiasis activity, diuretic and anti-inflammatory activity as cited in modern research articles and by mitigating azhal and Vata humour as mentioned in classical Siddha texts. The effect of Sagalanoi chooranam on struvite crystal growth inhibition assay through a significant reduction in the crystal size further validates the drug's efficiency in managing Renal calculus. In such a scenario, the Siddha drug Sagalanoi chooranam can be used as an individual drug or alongside Biomedicine in the management of Renal calculi.

Attempt to Clarify the Synergistic Effect Mechanism of Clathrate Hydrate Crystal Growth Inhibitors

Attempt to Clarify the Synergistic Effect Mechanism of Clathrate Hydrate Crystal Growth Inhibitors

Higher molecular weight pectin inhibits ice crystal growth and its effect on the microstructural and physical properties of pectin cryogels

Understanding the formation of ice crystals is essential for tailoring the microstructure and physical properties of cryogels. This study investigated the effects and mechanisms of pectin molecular weight (Mw) on impacting ice crystal formation. Pectin fractions various Mw (10.13–212.20 kDa) were prepared by hydrothermal method. The solution of high Mw pectin fractions exhibited higher contact angle, lower water freedom, and stronger adsorption of water molecules. The splat experiment and molecular dynamic (MD) results confirmed that higher Mw pectin have stronger ice crystal growth inhibition activity than lower Mw pectin. Furthermore, the pore size distribution of the cryogel increased from 98–203 μm to 105–267 μm as the molecular weight decreased from 212.2 kDa to 121.0 kDa. Additionally, in the higher Mw pectin cryogel, stronger mechanical strength was observed. These findings suggested that changing the molecular weight of pectin has the potential to regulate the ice crystal growth, microstructure and physical properties of frozen products.

Nanocrystalline sodium mordenite as an efficient low-concentration CO2 adsorbent

Systematic control of the crystal size and morphology of zeolites to enhance their CO2 adsorption performance is of great importance from both environmental and economic perspectives. Here we report the seeded synthesis of sodium mordenite (Na-MOR) with a Si/Al ratio of 4.9 and an average crystal length and width of 70 and 40 nm, respectively, using γ-aminobutyric acid as a crystal growth inhibitor in the absence of any organic structure-directing agent (OSDA). This nanozeolite shows an unprecedented CO2 capacity of 1.58 mmol g−1 under dynamic direct air capture (DAC) conditions at 25 °C, which is approximately 40 % greater than the value (1.15 mmol g−1) of the best zeolite adsorbent (an unidentified OSDA-directed Na-MOR (Si/Al = 5.0) zeolite with Na+ enrichment in 8-ring side pockets), mainly due to its nanocrystalline nature. It has also been characterized by much faster CO2 adsorption kinetics (ca. 5 vs. 50 min equilibration time) compared to a commercial Na-MOR zeolite with Si/Al = 5.0. Our study paves the way for developing a more efficient zeolite-based DAC adsorbent.

Adsorption of DNA and Aptamers to Sodium Urate Crystals and Inhibition of Crystal Growth.

An elevated level of blood uric acid (UA) can cause the formation of kidney stones, gout, and other diseases. We recently isolated a few DNA aptamers that can selectively bind to UA. In this work, we investigated the adsorption of a UA aptamer and random sequence DNA onto sodium urate crystals. Both DNA strands adsorbed similarly to urate crystals. In addition, both the UA aptamer and random DNA can inhibit the growth of urate crystals, suggesting a nonspecific adsorption mechanism rather than specific aptamer binding. In the presence of 500 nM DNA, the growth of needle-like sodium urate crystals was inhibited, and the crystals appeared granular after 6 h. To understand the mechanism of DNA adsorption, a few chemicals were added to desorb DNA. DNA bases contributed more to the adsorption than the phosphate backbone. Surfactants induced significant DNA desorption. Finally, DNA could also be adsorbed onto real UA kidney stones. This study provides essential insights into the interactions between DNA oligonucleotides and urate crystals, including the inhibition of growth and interface effects of DNA on sodium urate crystals.

Improved magnetoelectric coupling of Co–Ti substituted barium hexaferrite at room temperature and related electrical investigations

This paper reports a systematic study of the electrical, multiferroic and magnetoelectric coupling properties of Co–Ti substituted Barium hexaferrites, having the chemical composition BaFe12-2xCoxTixO19 (x = 0–2.0; in steps of 0.5), synthesized using the sol gel auto-combustion method. X-ray Diffraction (XRD) studies and Rietveld refinement confirmed the successful incorporation of Co–Ti ions in the hexaferrite lattice with all the samples displaying Pb63/mmc space group single phase structure. Scanning Electron Microscope (SEM) images revealed the inhibition of crystal growth in a particular direction with Co–Ti substitution. The conduction mechanisms of the samples were analysed from the conductivity measurements and were found to follow Jonschers power law. The complex impedance spectroscopy analysis and the Cole-Cole plot fitted diagrams of the samples indicated the enhancement of bulk resistivity and grain boundary resistivity with substitution. Saturation magnetizations of the substituted samples decreased and were ascribed to the replacement of Fe ions by Co–Ti ions at different crystallographic sites. The observed reduction in anisotropy constant indicated the disturbance in the magnetic axis. The multiferroic nature of the substituted samples at room temperature was confirmed from the soft ferroelectric loops. Room temperature magnetoelectric coupling coefficient was found to be largely enhanced with substitution, achieving an exceptionally high value of 182mV/cmOe for the x = 1.5 sample. This may prove useful for potential use in emerging device applications as a single phase room temperature multiferroic material.

Inhibition of Crystal Nucleation and Growth: A Review

Inhibition of Crystal Nucleation and Growth: A Review

Effective inhibition of crystal growth during wax deposition using CTAB‐grafted faujasite nanoparticles

AbstractIn this work, we developed cetrimonium bromide (CTAB)‐grafted faujasite nanoparticles (C‐g‐F) as wax inhibitors for the deposits that were formed from a model oil system consisting of 5 wt.% paraffin wax in toluene. Our developed nanomaterials were fully characterized, hydrophobically modified, and their deposition inhibition performance compared with virgin CTAB was investigated in a model waxy oil through cold finger setup (CF), differential scanning calorimetry (DSC), cold flow yield strength, and cross‐polarized microscopy (CPM). Applying our nano‐inhibitors at a concentration of 100 ppm led to more than 50 wt.% inhibition and a 30% reduction of deposit cold yield strength. Interestingly, the presence of FAU nanoparticles in the core structure of C‐g‐F contributed to better dispersibility, enhancing surface wettability (reducing interfacial tension with wax crystals), facilitating inhibitions, and preventing co‐crystallization greater than the surfactant alone. The morphological analysis results showed that C‐g‐F, due to their novel surface features, could suppress the unordered wax crystals from networking, resulting in uniform spherical‐like wax aggregates. Hence, the application of tiny concentrations of C‐g‐F (10 to 300 ppm) outperformed stand‐alone surfactants in nucleating the wax crystals.

Osteocalcin: Promoter or Inhibitor of Hydroxyapatite Growth?

Osteocalcin is the most abundant noncollagenous bone protein and the functions in bone remineralization as well as in inhibition of bone growth have remained unclear. In this contribution, we explain the dual role of osteocalcin in the nucleation of new calcium phosphate during bone remodeling and in the inhibition of hydroxyapatite crystal growth at the molecular scale. The mechanism was derived using pH-resolved all-atom models for the protein, phosphate species, and hydroxyapatite, along with molecular dynamics simulations and experimental and clinical observations. Osteocalcin binds to (hkl) hydroxyapatite surfaces through multiple residues, identified in this work, and the fingerprint of binding residues varies as a function of the (hkl) crystal facet and pH value. On balance, the affinity of osteocalcin to hydroxyapatite slows down crystal growth. The unique tricalcium γ-carboxylglutamic acid (Gla) domain hereby rarely adsorbs to hydroxyapatite surfaces and faces instead toward the solution. The Gla domain enables prenucleation of calcium phosphate for new bone formation at a slightly acidic pH of 5. The growth of prenucleation clusters of calcium phosphate continues upon increase in pH value from 5 to 7 and is much less favorable, or not observed, on the native osteocalcin structure at and above neutral pH values of 7. The results provide mechanistic insight into the early stages of bone remodeling from the molecular scale, help inform mutations of osteocalcin to modify binding to apatites, support drug design, and guide toward potential cures for osteoporosis and hyperosteogeny.

Improved industrial induction time-based technique for evaluating kinetic hydrate inhibitors.

Kinetic hydrate inhibitor laboratory testing before field application is one of the key priorities in the oil and gas industry. The common induction-time-based technique is often used to evaluate and screen for kinetic hydrate inhibitors (KHIs). However, the main challenge relates to the stochastic nature of hydrate nucleation observed in fresh systems, which often results in scattered data on hydrate formation with unacceptable uncertainties. A much more precise KHI evaluation method, called crystal growth inhibition (CGI), provides comprehensive insights into the inhibitory behavior of a kinetic hydrate inhibitor, including both hydrate formation and decomposition. Given that industry does not require this much information, it is not feasible to expend either much time or cash on this strategy. This study aims to provide a cost-effective technique that presents maximum data accuracy and precision with relatively little time and cost expenditure. Hence, the impact of water-hydrate memory on improving the accuracy and repeatability of the results of the induction-time-based technique (IT method) was examined. First, the concept of water-hydrate memory, which contains information about how it is created, was reviewed, and then, the factors influencing it were identified and experimentally investigated, like the heating rate of hydrate dissociation and the water-hydrate memory target temperature during heating. Finally, a procedure was developed based on the background information in the earlier sections to compare the consistency of the results, originating from the conjunction of water-hydrate memory with the IT technique. The results of replications at KHI evaluation target temperatures of 12.3-12.4°C and 11.5-11.7°C showed that more repeatable data were obtained by applying water-hydrate memory, and a more conclusive decision was made in evaluating KHI performance than with an IT method. It seems that combining the IT method with water-hydrate memory, introduced as the "HME method", can lead to more definitive evaluations of KHIs. This approach is expected to gain in popularity, even surpassing the accurate but complex and time-consuming CGI method.

The inhibitory effects of epigallocatechin-3-gallate on calcium oxalate monohydrate crystal growth, aggregation and crystal-cell adhesion

Epigallocatechin-3-gallate (EGCG), a predominant phytochemical in tea plant, has been reported to prevent kidney stone formation but with vague mechanism. We investigated modulatory effects of EGCG (at 0.1–100 µM) on calcium oxalate monohydrate (COM) crystals at various stages of kidney stone development. EGCG significantly increased crystal size (at 1–100 µM), but decreased crystal number (at 10–100 µM), resulting in unchanged crystal mass and volume. Interestingly, EGCG at 10–100 µM caused morphological change of the crystals from typical monoclinic prismatic to coffee-bean-like shape, which represented atypical/aberrant form of COM as confirmed by attenuated total reflection - Fourier transform infrared (ATR-FTIR) spectroscopy. EGCG at all concentrations significantly inhibited crystal growth in a concentration-dependent manner. However, only 100 µM and 10–100 µM of EGCG significantly inhibited crystal aggregation and crystal-cell adhesion, respectively. Immunofluorescence staining (without permeabilization) revealed that surface expression of heat shock protein 90 (HSP90) (a COM crystal receptor) on MDCK renal cells was significantly decreased by 10 µM EGCG, whereas other surface COM receptors (annexin A1, annexin A2, enolase 1 and ezrin) remained unchanged. Immunoblotting showed that 10 µM EGCG did not alter total level of HSP90 in MDCK cells, implicating that its decreased surface expression was due to translocation. Our data provide a piece of evidence explaining mechanism underlying the anti-lithiatic property of EGCG by inhibition of COM crystal growth, aggregation and crystal-cell adhesion via reduced surface expression of HSP90, which is an important COM crystal receptor.

Natural self-assembled supramolecules as green inhibitors against methane hydrate formation

Environmentally friendly hydrate inhibitors are the most promising method to solve the environmental pollution of inhibitors, among which Safranine O (SO) with antifreeze protein properties shows excellent application prospects. SO will self-assemble into macromolecules under hydrogen bonding and electrostatic action in an aqueous solution. The assembled macromolecules' hydrophobic and hydrophilic functional groups are regularly arranged with the properties of an antifreeze protein. In the crystal growth inhibition (CGI) test, the supercooling degree of the complete inhibition region (CIR) of 1.0 wt% SO solution for SI hydrate was significantly higher than that of 1.0 wt% PVP solution. Further, the acidic environment did not affect the inhibitory effect of SO on hydrate. The complete inhibition range of 1.0 wt% SO solution on SI hydrate at pH 1.4 and 7.1 was 7.41 °C and 8.35 °C, respectively. These results suggest that SO-based KHIs may provide new ideas for developing highly efficient acid-resistant hydrate inhibitors.

Measurement of Ice-Binding Protein Inhibition of Non-ice Crystal Growth.

The kinetic hydrate inhibitor (KHI) was developed to prevent the formation of undesirable gas hydrate crystals in natural gas pipelines. Studies of antifreeze proteins (AFPs) are gaining attention in the natural gas research field due to their performance in crystal growth inhibition, excellent biodegradation, and low toxicity. Studies of AFPs may provide clues for developing future commercial KHIs used offshore. This chapter presents a simple method of evaluating AFP inhibitory performance as a KHI on tetrahydrofuran (THF) hydrate growth with a unidirectional growth apparatus.

Alkanolamine-based chemically enhanced hydration reaction of ordinary Portland cement

This study aims to elucidate the origin of the improvement of mechanical properties of ordinary Portland cement (OPC) hydrates with the use of alkanolamine grinding agent (GA). It was found that the chemical activation induced by the use of 0.026 wt% GA led to improvements of the early strength as well as later strength. To be specific, GA predominantly enhanced ferrite (C4AF) hydration in both initial and later stages which resulted in more dissolution of calcite. As a result, the promoted ettringite formation at 1 day and monocarboaluminate (Mc) from 2 day were observed. Although the lower content of portlandite (CH) was found over the whole curing period due to the inhibition of CH crystal growth with GA, the amount of amorphous phase was higher from 1 day. More production of amorphous phase was most conspicuous during 7 to 28 days, which was possibly associated with more production of Fe-containing hydrates from the enhanced C4AF hydration.

Effect of seed on synthesis of binder‐free mordenite for dimethyl ether carbonylation

AbstractA series of binder‐free mordenite (MOR) zeolites were successfully prepared by hydrothermal conversion of shaped precursors containing aluminosilicate and MOR seeds. In the synthesis of seed crystals, hexadecyltrimethylammonium bromide (CTAB) was used as a crystal growth inhibitor as well as a pore filler to adjust the morphology and introduce mesoporous pores. As a result, large aggregates, assembled nanosheets, and flowers‐like MOR were successfully synthesized with these MOR seeds. The effect of seed morphology on the performance of the binder‐free MOR was studied by scanning electron microscopy (SEM), N2 adsorption–desorption, and NH3‐TPD characterization techniques. It was found that the mesopore volume of formed MOR was positively correlated with those of the seeds. The synthesized binder‐free MOR showed high activity (0.28 g methyl acetate gcat−1 h−1), 100% selectivity, and high stability in dimethyl ether (DME) carbonylation to methyl acetate, which can be attributed to the larger surface area and more mesopores. The synthesis of MOR nano‐assemblies via this cost‐effective strategy has a wide range of potential applications.

L-lysine-assisted synthesis of gismondine and chabazite nanozeolites for direct air capture of CO2

The search for more efficient and selective solid adsorbents towards carbon capture, particularly in trace CO2 concentration, remains a significant challenge. Here, we present the synthesis of nanocrystalline sodium gismondine (Na-GIS) with Si/Al = 2.5 and potassium chabazite (K-CHA) zeolites with Si/Al = 2.0 using L-lysine as a crystal growth inhibitor. Na-GIS nanozeolites were found to show a CO2 uptake as high as 0.70 mmol g−1 under direct air capture (DAC) conditions (i.e., 298 K and 400 ppm CO2), about 18 times greater than that of microcrystalline Na-GIS, together with high adsorbent stability. Such behavior was also observed for Na-CHA nanozeolites, although the extent of increase (0.47 vs 0.13 mmol g−1) was smaller compared to the microcrystalline counterpart. This study demonstrates that the introduction of nanocrystallinity into small-pore zeolites without losing intrinsic microporosity is a viable route to the development of more efficient zeolite-based DAC adsorbents.

Chemical Modification of Tiopronin for Dual Management of Cystinuria and Associated Bacterial Infections.

Cystinuria is an inherited autosomal recessive disease of the kidneys of recurring nature that contributes to frequent urinary tract infections due to bacterial growth and biofilm formation surrounding the stone microenvironment. In the past, commonly used strategies for managing cystinuria involved the use of (a) cystine crystal growth inhibitors such as l-cystine dimethyl ester and lipoic acid, and (b) thiol-based small molecules such as N-(2-mercaptopropionyl) glycine, commonly known as tiopronin, that reduce the formation of cystine crystals by reacting with excess cystine and generating more soluble disulfide compounds. However, there is a dearth of simplistic chemical approaches that have focused on the dual treatment of cystinuria and the associated microbial infections. This work strategically exploited a single chemical approach to develop a nitric oxide (NO)-releasing therapeutic compound, S-nitroso-2-mercaptopropionyl glycine (tiopronin-NO), for the dual management of cystine stone formation and the related bacterial infections. The results successfully demonstrated that (a) the antibacterial activity of NO rendered tiopronin-NO effective against the stone microenvironment inhabitants, Escherichia coli and Pseudomonas aeruginosa, and (b) tiopronin-NO retained the ability to undergo disulfide exchange with cystine while being reported to be safe against canine kidney and mouse fibroblast cells. Thus, the synthesis of such a facile molecule aimed at the dual management of cystinuria and related infections is unprecedented in the literature.

Nonclassical mechanisms to irreversibly suppress β-hematin crystal growth

Hematin crystallization is an essential element of heme detoxification of malaria parasites and its inhibition by antimalarial drugs is a common treatment avenue. We demonstrate at biomimetic conditions in vitro irreversible inhibition of hematin crystal growth due to distinct cooperative mechanisms that activate at high crystallization driving forces. The evolution of crystal shape after limited-time exposure to both artemisinin metabolites and quinoline-class antimalarials indicates that crystal growth remains suppressed after the artemisinin metabolites and the drugs are purged from the solution. Treating malaria parasites with the same agents reveals that three- and six-hour inhibitor pulses inhibit parasite growth with efficacy comparable to that of inhibitor exposure during the entire parasite lifetime. Time-resolved in situ atomic force microscopy (AFM), complemented by light scattering, reveals two molecular-level mechanisms of inhibitor action that prevent β-hematin growth recovery. Hematin adducts of artemisinins incite copious nucleation of nonextendable nanocrystals, which incorporate into larger growing crystals, whereas pyronaridine, a quinoline-class drug, promotes step bunches, which evolve to engender abundant dislocations. Both incorporated crystals and dislocations are known to induce lattice strain, which persists and permanently impedes crystal growth. Nucleation, step bunching, and other cooperative behaviors can be amplified or curtailed as means to control crystal sizes, size distributions, aspect ratios, and other properties essential for numerous fields that rely on crystalline materials.

Effect of Divalent Cations and Other Ions on the Tetrahydrofuran Crystal Inhibition of Quaternary Ammonium Salts-Relevance to the Efficiency of Gas Hydrate Quaternary Anti-agglomerants.

Gas hydrate anti-agglomerants (AAs) are a class of low-dosage hydrate inhibitor that are used to prevent plugging of gas hydrates in oil and condensate upstream flow lines. Industrial AAs are mostly cationic surfactants which are "hydrate-philic", i.e., they are designed to interact with and modify gas hydrate crystal growth. Tetrahydrofuran (THF) hydrate crystal growth studies have been used for many years to determine useful functional groups to incorporate into AA surfactants. In particular, quaternary ammonium and phosphonium salts with optimized alkyl groups show good THF crystal growth inhibition, which is a key property for AAs. AAs are often screened and tested in model brines containing sodium chloride despite the produced water containing various divalent cations. Recent studies have shown that AAs performed better when tested in brines containing both sodium and calcium ions rather than just sodium ions. Here, we present THF hydrate crystal growth studies on quaternary ammonium and phosphonium salts and other related molecules including guanidinium salts and amine oxides. Tests were carried out with a variety of cations including sodium, calcium, magnesium, and lithium at identical pre-determined subcooling, in order to investigate the effect of the ion size and charge density on the crystal growth inhibition. We also investigate the effect of using the more polarizable iodide ions compared to chloride ions. Our results show that crystal growth inhibition in solutions with calcium ions is somewhat greater than that with sodium ions, in agreement with past studies on the effect of AA performance with mono- and divalent cations. However, the variation does not seem to be primarily related to the charge density and polarizing ability of the cations. This study therefore provides evidence that AAs should be tested in brines containing all the ions present in the produced water and not just sodium chloride brine.