Conventional Slow Evaporation Research Articles

Control of Liquid–Liquid Phase Separation, Nucleation, and Growth of L‐Menthol Single Crystals from Water–Ethanol Solvent Mixtures

AbstractL‐Menthol is a commonly used material in food production for flavor enhancement and fragrances, as well as in pharmaceuticals. However, during the solution crystallization process of L‐menthol, there is a major issue of oiling out or liquid–liquid phase separation (LLPS) in most organic solvents and their mixtures. The objective of the current work is to prevent the LLPS phenomenon and grow high‐quality single crystals of L‐menthol. A water–ethanol mixed solvent with nine different mixing ratios is used, ranging from 0.99W:0.01E to 0.91W:0.09E, through the conventional slow evaporation process. The findings indicate that the mixing composition of the solvent plays a significant role in the variation of solubility, refractive index, LLPS, nucleation, and crystallization. This is clearly demonstrated in the phase diagram. The occurrence of LLPS phenomenon, nucleation, growth behavior, and morphology of L‐menthol single crystals through optical microscopy is identified. Additionally, the internal structure and thermal stability of the grown polymorphs using PXRD, SCXRD, and DSC analyses are confirmed.

Growth, structural, vibrational, characterization and DFT investigations of 2-methylimidazolium hydrogen oxalate dihydrate (2MIO) single crystal-towards third order NLO applications

We report the studies conducted on the single crystal of 2-methyimidazolium hydrogen oxalate dihydrate (2MIO) which was achieved by employing the solution growth technique of conventional slow evaporation wherein the solvent used was deionized water. The confirmation of the grown 2MIO crystal's lattice parameters were accomplished by the analysis of single-crystal X-ray diffraction (SCXRD). The powder sample was utilized for the studies of identifying its crystalline phase, composition, and NLO efficiency. The UV–Vis-NIR studies show that the 2MIO crystal has a better transmittance in the region of entire visible and the lower cut-off wavelength is 280 nm. The decomposition and dissociation points of the 2MIO were studied by employing thermal measurements. The nonlinear optical parameters were computed for 2MIO from the performed Z-scan study. Additionally, quantum chemical studies were carried out on 2MIO molecule which was performed by making use of density functional theory (DFT) at the B3LYP/6–311 G (d.p) method. The optimized geometrical parameters, the bond length and bond angles were compared with the observed experimental XRD data. Hirshfeld surface analysis featuring 2D fingerprint plots were analysed by using Crystal Explorer 3.1 such that it could confirm the intermolecular and weak interactions. Natural bond orbital (NBO) analysis was undertaken to evaluate the donor-accepter interactions and stabilization energies of the molecule. The HOMO-LUMO energy was analysed whereby the energy gap (ΔE) and other related properties of the molecules present in 2MIO were calculated. The first-order hyperpolarizability of 2MIO was measured from the computational studies with which it is established that the obtained value is 4.95 times than that of standard urea.

Investigation on growth, growth kinetics and characterization of L-valine L-valinium perchlorate monohydrate single crystal

The ultimate focus of this paper is on nucleation and growth kinetics, structural and dielectric behavior of l-valine l-valinium perchlorate monohydrate (LVPM) single crystal. LVPM single crystals were grown by conventional slow evaporation technique at room temperature. Salient nucleation parameters, essential for the growth of good quality crystal were estimated with the help of solubility curve and Classical Nucleation Theory (CNT). Single Crystal X-ray Diffraction (SC-XRD) analysis reveals that the synthesized crystal (LVPM) possesses monoclinic structure with lattice parameters as a = 11.227 Å, b = 5.82 Å, c = 13.08 Å, α = γ = 90º and β = 91º. The above results were also confirmed by powder XRD study. The structure of the grown crystal was analyzed by using SHELXT-2014/7 program. It is found that grown crystal belongs to non-centrosymmetric space group P21. All the functional groups and also carboxyl and amino functional groups of LVPM crystal were identified and confirmed by Fourier Transform Infra-red (FTIR) spectroscopy. The molecular structure of the grown crystal and in particular, the presence of amino group was discussed by using 1H and 13C Nuclear Magnetic Resonance (NMR) spectra. The low values of dielectric constant and dielectric loss at higher frequencies indicate that the grown crystal enhances the Second Harmonic Generation (SHG) efficiency. The activation energy of the grown crystal was estimated as 0.1433 eV from AC conductivity study. Kurtz and Perry powder experiment was performed to explore the Nonlinear Optical (NLO) properties of LVPM and its SHG efficiency was found 1.5 times of KDP (1.5’ KDP). The grown material was also found possessing SHG efficiency nearly five times higher than most of the l-arginine compounds. Since the grown material belongs to non-centrosymmetric group and exhibits improved structural, NLO and dielectric behavior, the material will be useful in optoelectronic devices, fiber optic communication, computing, optical switching, image reconstruction, optical storage technology, 3D-images, etc.

Growth, optical, thermal, electrical, mechanical, and antibacterial activity of hexa aqua nickel bis (P-toluene sulfonate) (HNPS) single crystal

The conventional slow evaporation technique is used in the growth of semi-organic single crystals of Hexa aqua nickel bis (P-toluene sulfonate) (HNPS) and the monoclinic system with centrosymmetric space group (P21/n) is corroborated by single-crystal X-ray diffraction analysis. FTIR vibrational analysis inferred the presence of water molecules CH3 and SO3 groups in grown HNPS crystals. Linear optical parameters explored by UV–Visible spectral analyses ensures the high optical activity of HNPS. The green light emission of HNPS was attributed to Photoluminescence analysis. Thermal analysis encapsulates the thermal stability of HNPS crystals up to 590 °C. The dielectric nature of the material was analyzed for various frequencies at room temperature and an increase in DC conductivity of HNPS suggests the semiconducting behavior of the material while heating. The work hardening coefficient is quantified as 3.7 using mechanical analysis. The thermal and mechanical stability suggests the specific application of HPNS in device fabrications. The synthesized HNPS was tested against two gram-positive bacterial strains (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacterial strains (Escherichia coli, Pseudomonas aeruginosa) and showed higher significant antibacterial activity against the pathogen.

Structure, optical, thermal, SHG & photoluminescence studies of L-Serine cadmium chloride single crystals

Novel semi organic nonlinear optical single crystal of l-Serine Cadmium Chloride monohydrate has been synthesized by conventional slow evaporation method. The single crystal XRD have been employed to describe the crystal structure, space group, bond lengths, bond angles and co ordinates of hydrogen bond. The metal organic complexion between l-Serine and Cadmium chloride is taking place through oxygen atom of l-Serine. The lattice parameters obtained from PXRD technique have been found in good agreement with those obtained from SXRD. Williamson-Hall method has been used to determine the lattice strain of the grown crystal. The investigations of intermolecular interactions in LSCC crystal lattice are carried out by Hirshfeld surface analysis. The FTIR spectrum is utilized to determine the possible functional groups present in the crystal. The investigations on optical qualities of the crystal are carried out by incorporating UV–Visible and photoluminescence spectrum. The behaviour of refractive index below energy gap is carried out by Wemple – DiDomenico single oscillator model analysis. The thermal stability along with the decomposition temperature of the synthesized crystal is ascertained by thermogravimetric analysis. The kinetic and thermodynamic parameters of LSCC crystal have been calculated from C-R plot. Photoluminescence spectrum of the synthesized crystal was recorded by using an excitation wavelength of 320 nm. It suggested the suitability of the synthesized material as green laser diode. The SHG efficiency of LSCC crystal is clarified through the Kurtz-Perry technique.

Prospective theoretical investigations of optical, dielectric, mechanical and third-order NLO property in potassium tri-hydrogen di-succinate single crystal

A propitious third-order nonlinear optical crystal potassium tri-hydrogen di-succinate (PTHS) (C8H11O8K) is grown by conventional slow evaporation technique maintained at 303 K. Single crystal XRD analysis (SXRD) evidences the grown crystal pertain to centrosymmetric space group P21/c with monoclinic crystal system and powder X-ray diffraction (PXRD) confirms the purity of the grown crystal. The existence of various functional groups was assessed by Fourier transform infrared (FTIR) spectral analysis and the optical absorption study authenticates to the transparency in the visible region. ICP-OES study substantiates the prevalence of alkali metal potassium. Interestingly, the Urbach energy of the grown crystal is explored to be minimum proving the good crystalline nature of the yielded crystal. The various optical constants were calculated in detail. The optical band gap was used to determine the position of the valence band (Ev) and conduction band (Ec) and the Wemple-Di-Domenico single oscillator method was used to find the different dispersive parameters. In dielectric, the various solid state parameters including electronic polarizability were calculated with different formulas and the value was proved to be higher than that of KDP. To determine the mechanical stability, Vickers microhardness test was carried out and their indentation size effect was elucidated by using different models. The crystal exhibits negative photoconductivity. By using photo acoustic study, the thermal diffusivity value is 1.25 times greater than standard KDP, signifying that the harvested crystal is remarkable material for nonlinear optical applications. In brief, the real and imaginary parts are reviewed by Z-scan technique and the susceptibility was compared with other single crystals.

Second harmonic generation, optical, thermal, piezoelectric and mechanical properties of adipic acid-doped ADP crystals

Single crystals of pure and 2[Formula: see text]mol.% adipic acid (hexanedioic acid) -doped ammonium dihydrogen phosphate (ADP) were grown by conventional slow evaporation of aqueous solution technique. The powder X-ray diffraction and FT-IR analyses indicate that the crystals undergo considerable stress as a result of doping. UV–Vis studies show that the absorption of the adipic acid-doped crystals is less than that of pure ADP. Thermal studies (TG/DTG) disclose that the decomposition temperature of doped ADP is more than that of pure ADP. Vicker’s microhardness study reveals that the addition of adipic acid increases the hardness of the ADP. SHG efficiency and piezoelectric charge coefficient of adipic acid-doped ADP are higher than that of pure ADP.

Growth, characterization and theoretical studies of cadmium (II) thiourea complexes: a comparative study

Single crystals of bis(thiourea)cadmium(II) chloride, bis(ethylene thiourea)-cadmium(II) chloride, tris(allylthiourea)cadmium(II) chloride and tetrakis-(phenylthiourea)cadmium(II)chloride complexes were grown using conventional slow evaporation solution growth technique. The structure and crystallinity of the materials were confirmed by powder XRD analysis. The optical properties of specimens were analyzed by UV-DRS spectroscopy. FT-IR studies recognize the vibrations of functional groups present. SEM examines surface morphology. TGA and DTA expose the specimen's purity, and the decomposition was not identified until the melting point. Microhardness studies also studied the mechanical behavior of the samples. Kurtz and Perry powder technique estimates the second harmonic generation efficiency of the as-grown specimens. It is interesting to observe that the allylthiourea complex exhibits the maximum SHG efficiency. Ethylene and phenylthiourea complexes are SHG inactive since they crystallize in centrosymmetric space groups. The intermolecular interactions and crystal packing make known that close contacts are related with strong interactions.

FTIR spectral analysis of glycine doped ammonium dihydrogen phosphate (ADP) crystal

Ammonium Dihydrogen Phosphate crystals doped with Glycine (GADP) has been grown by slow evaporation method, Rotation method and Sankaranarayanan - Ramasamy (SR) methods with different molar concentration. The Fourier Transform Infra-Red (FTIR) studies have been investigated on the as grown GADP crystals. The FTIR spectrum shows the interaction between ADP and the dopant by the additional peaks which corresponds to the functional groups of Glycine. The standard spectrum statistics of FTIR confirms the presence of all the functional groups. The spectrum for ADP crystals doped with Glycine grown by Rotation and SR methods have similar peaks with slight variation as that of conventional slow evaporation method grown Glycine doped ADP crystals.

Linear–nonlinear optical and quantum chemical studies on Quinolinium 3,5-dinitrobenzoate: A novel third order non-linear optical material for optoelectronic applications

An organic non-linear optical (NLO) crystal of Quinolinium 3,5-dinitrobenzoate (DNBAQ) was synthesized and good quality single crystals of DNBAQ were grown by conventional slow evaporation solution growth technique. Single crystal XRD was utilized to confirm the formation of the charge transfer complex. The crystalline property and the presence of required functional groups was verified employing Powder XRD and FTIR spectral analysis. UV–Vis–NIR and Fluorescence study was performed to determine the optical transmittance and the emission property of the grown crystal. The thermal, mechanical and surface damage threshold stability of the complex was analysed using thermal studies, Vicker’s micro hardness studies and Laser damage threshold measurement. The solid state parameter of electronic polarizability of DNBAQ compound was computed through dielectric studies. The non-linear optical characterizations like Kurtz Perry powder technique and Z-Scan technique ensures the non-linear optical activity of the compound. The frequency conversion efficiency of the grown crystal was estimated to be 70% that of the standard Potassium Dihydrogen Phosphate (KDP). Z-Scan analysis confirms the suitability of the grown crystal for optical limiting and switching applications. Quantum chemical studies were adopted on the optimized geometry of DNBAQ molecule using Density Functional Theory (DFT). Frontier Molecular Orbital (FMO) analysis and Molecular Electrostatic Potential (MEP) analysis were performed. The non-linear optical behaviour of the complex was established by evaluating dipole moment, polarizability and hyperpolarizability features. All the above results confirm the resourceful candidature of DNBAQ material for optoelectronic and photonic applications.

Crystallization of pure adipic acid from methanol solvent and their characterization studies: Intense NLO activity from Centrosymmetric crystal

The influence of methanol solvent in assisting the nucleation of adipic acid crystals has been investigated for the first time. The pH value and nucleation period was determined. The better- quality adipic acid single crystals having crystal size up to 10 × 7 x 6mm3 were grown successfully by conventional slow solvent evaporation experiment at room temperature and their solubility has been experimented with four different solvents namely methanol, ethanol, acetone and water at three different temperature 30°, 40° and 50° respectively. Crystallographic information, crystalline nature and characteristic h k l planes of adipic acid was revealed by single crystal XRD and powder XRD studies. The direct optical band gap energy, characteristic functional groups and other information like thermal decomposition temperature, melting point were studied from UV –Vis-NIR, Spectroscopic FTIR and TG-DTA instrument analysis. The measured powder SHG efficiency of adipic acid is found to be 2.14 times superior to the reference material potassium dihydrogen phosphate (KDP).

Investigation on key properties of solution grown l-Leucine hydrobromide single crystal: A semi-organic NLO material

Good quality single crystals of l-Leucine hydrobromide, a prominent NLO material, have been grown successfully by conventional slow evaporation solution technique to meet the requirement of photonics industry. To confirm the identity of the synthesized material and the % composition of constituent element CHN analysis was carried out. HRXRD rocking curve confirms the better crystalline perfection as it has single sharp peak with FWHM 17.59 arc sec and almost uniform on both sides. Thermal properties were investigated by DSC and photo-acoustic anlaysis. Thermal diffusivity, conductivity and effusivity have been calculated from photo-acoustic analysis. Some electronic parameters of technical importance were also calculated by Clausius- Mossotti relation. Mechanical behavior has been examined by employing nano-indentation technique. Several useful mechanical properties like hardness, stiffness, Young's modulus were studied and found that both hardness and Young's modulus depends upon the peak load.

Influence of l-Lysine-doped Tartaric Acid–Potassium Bromide single crystals: growth and characterization of photonic applications

The effect of l-lysine-doped tartaric acid–potassium bromide (LYTAPB) single crystals has been successfully crystallized by employing conventional slow solvent evaporation method. The lattice unit cell dimensions are valued by single environment crystal X-ray diffraction analysis. The functional groups and spectral properties of the LYTAPB crystal were accredited by FTIR spectral investigation. The linear optical characteristics of the LYTAPB crystal is observed by UV–Vis spectral studied. It has been observed that the load differs linearly through the hardness value. The mechanical stability is measured through the Vickers hardness. Through NLO analysis, the LYTAPB crystal is found to be a phase matchable single crystal and is good transmittance to approve the lower cutoff wavelength district. Second harmonic generation optical susceptibility of the LYTAPB crystal has been verified by Nd:YAG laser technique. Optical limiting achievement of the LYTAPB crystal is established significant wavelength of 1064 nm to possessing SHG efficiency of 1.3 times greater than that of KDP. Hence, it can use the potential material to the frequency–repetition effect of the grown crystals for solid-state photonic materials.

Growth and Z-scan analysis of semi-organic Bis(picolinic acetate) Zinc(II) single crystal for third order NLO applications

Here, we report a new semi-organic single crystal namely Bis(picolinic acetate) Zinc(II) (BPZ) which was grown by a conventional slow evaporation method at room temperature. Structural studies were carried out by single crystal XRD and the results show that Bis(picolinic acetate) Zinc(II) belongs to monoclinic crystal system with space group P21/n. The presence of functional groups in the grown crystal was identified by FTIR spectral analysis. UV-Vis spectral studies reveal that the grown crystals are transparent in the wavelength region of 200-1200 nm. In order to analyze the mechanical strength of the grown crystal, Vickers micro hardness tester was employed. The dielectric properties with respect to different frequency at room temperature were also studied to analyze the dielectric response. The third order nonlinear optical properties were determined by Z-scan studies which shows significant higher values of nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ3). The enhanced third order nonlinear behavior suggests that the title compound is suitable for nonlinear optical applications.

Synthesis, growth, structural, thermal, mechanical and optical properties of barium guanidinium dichloride (BaGuCl2) single crystal for NLO applications

A semi-organic nonlinear optical Barium guanidinium dichloride (BaGuCl2) has been grown by conventional slow evaporation method. Large-sized and optically transparent single crystal of BaGuCl2 was successfully harvested within 90 days. The unit cell parameters were determined using single-crystal X-ray diffraction analysis. FTIR spectral analysis shows the presence of BaGuCl2. Optical absorbance and cut-off wavelength of BaGuCl2 were determined using UV–visible analysis. Second-harmonic generation efficiency of BaGuCl2 was concluded to be 50% better than standard KDP crystal. Thermal stability of the title crystal was explored using thermogravimetric analysis. Microhardness studies were done, and it affirms that the grown crystal is a soft crystal.

Third Order Non Linear Material of L-Threonine Dihydrogen Phosphate Crystals

The L-Threonine dihydrogen phosphate crystals are grown using conventional slow evaporation technique. Single crystal X-ray diffraction studies justify the incorporation of Phosphorus in crystal by variation in unit cell parameters. Field emission scanning electron microscope (FESEM), Energy Dispersive X-ray Analyses (EDAX), and Inductive coupled plasma optical emission spectroscopy provide substantial evidence for the presence of phosphorous and in the crystal. The Second Harmonic Generation (SHG) of the grown crystal is validated using Kurtz-Perry powder technique. The influence of magnesium chloride on nonlinear optical properties (NLO) is investigated using the Third order NLO behaviour by Z-scan method.

Third order non linear material of zinc sulphate doped L-Threonine dihydrogen phosphate single crystal

The Zinc sulphate doped L-Threonine dihydrogen phosphate crystals are grown using conventional slow evaporation technique. Single crystal X-ray diffraction studies justify the incorporation of zinc sulphate in crystal by variation in unit cell parameters. Field emission scanning electron microscope (FESEM), Energy Dispersive X-ray Analyses (EDAX) and Inductive coupled plasma optical emission spectroscopy provide substantial evidence for the presence of phosphorous and zinc in the crystal. The Second Harmonic Generation (SHG) of the grown crystal is validated using Kurtz-Perry powder technique. The influence of zinc sulphate on nonlinear optical properties (NLO) is investigated using the Third order NLO behavior, Z-scan method.

Growth of L-asparagine monohydrate and its structural, optical, mechanical, thermal and electrical studies for nonlinear optical applications

In the recent past, single crystals of organic materials exhibiting nonlinear optical behaviour have garnered much attention in the field of optical data storage and laser technology. In the present article, amino acid crystals of L-asparagine monohydrate (LAM) have been grown successfully by conventional slow evaporation solution growth technique from aqueous solution at room temperature (RT), with double distilled water used as a solvent. Single crystal x-ray diffraction was used to confirm the orthorhombic crystal structure (with P212121 space group) and lattice parameters of the grown crystal were determined. The crystallinity, purity, and phase of L-asparagine monohydrate were also determined from the powder x-ray diffraction data. The optical behaviour of LAM crystals was investigated by UV-Visible-NIR spectroscopy, and no absorption was found in the entire visible region. From the Tauc plot, the optical energy band gap was evaluated to be 5.09 eV. Valence band (EVB) and conduction band (ECB) positions of LAM were calculated from the knowledge of electron affinity (Ea), ionisation energy (Ei) of the elements and optical energy gap. Thermal parameters of the crystal were measured by photoacoustic spectroscopy. In addition, the mechanical stability of L-asparagine monohydrate single crystal was evaluated via shock damage threshold measurement. The dielectric studies as a function of frequency and temperature were carried out to understand the electrical behavior of the grown crystal. From the Z-scan analysis, nonlinear refractive index (n2) and nonlinear absorption coefficient (β) of the LAM crystal were also determined.

Optimizing optical traits of ammonium zinc sulphate hydrate crystal exploiting Nd3+ for photonic device applications

Current investigation explores the impact of Nd3+ ion on linear and nonlinear optical properties of ammonium zinc sulphate hydrate (AZSH) crystal for defining its suitability for photonic device applications. The Nd3+ ion influenced AZSH (Nd-AZSH) crystal has been grown by conventional slow solvent evaporation technique at room temperature. The energy dispersive spectroscopic (EDS) technique has been utilized to uncover the chemical constituents of the Nd-AZSH crystal. The powder X-ray diffraction technique has been employed to evaluate the structural parameters of Nd-AZSH crystal. The influence of Nd3+ on linear optical transmittance of AZSH crystal has been examined within the wavelength range of 200–1100 nm by means of UV–vis spectral analysis. The attributes of Nd3+ in promoting the second harmonic generation (SHG) efficiency of AZSH crystal has been explored by means of Kurtz-Perry powder test. The Nd-AZSH crystal has been tested by the He-Ne laser assisted Z-scan technique to investigate the third order nonlinear optical (TONLO) characteristics at wavelength 632.8 nm. The TONLO refractive index (n2), absorption coefficient (β) and susceptibility (χ3) has been evaluated using the Z-scan data.

Etching and microhardness studies of pure and doped nonlinear optical crystals of Hippuric acid

Abstract Hippuric acid (HA) crystals were grown by conventional slow evaporation method and were doped with urea and thiourea. The solvent used was acetone. The obtained crystals were subjected to single crystal XRD studies using ENRAF NONIUS CAD4-F single crystal X-ray diffractometer with MoKα (λ = 0.7107 A) radiation. The Second harmonic studies reveal that the crystals have appreciable conversion efficiency. The etching studies were carried using Ethanol, methanol and acetone as etchants. The observations indicate that the deformation is minimum. The mechanical hardness were determined and it showed that the crystals are stable for device applications.