Chemistry Proceedings

Research

Jump to: Other

2 pages, 237 KiB

Open AccessAbstract

Interactions Energy, Energy Frameworks, Hirshfeld Surface and Topological Analyses of a Mononuclear Co(II) Coordination Framework

by Amani Direm, Brahim El Bali, Koray Sayin, Mohammed S. M. Abdelbaky and Santiago García-Granda

Chem. Proc. 2022, 9(1), 1; https://doi.org/10.3390/IOCC_2022-12167 - 17 Jan 2022

Viewed by 788

Abstract

Heterocyclic ligands and their metallic complexes are biologically active materials [...] Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

2 pages, 163 KiB

Open AccessAbstract

Coal Fly Ash Zeolites—From Synthesis to Application in Acetone Optical Detection

by Katerina Lazarova, Silviya Boycheva, Marina Vasileva, Denitza Zgureva-Filipova and Tsvetanka Babeva

Chem. Proc. 2022, 9(1), 10; https://doi.org/10.3390/IOCC_2022-12159 - 14 Jan 2022

Viewed by 660

Abstract

Recently, a widely used method for recycling fly ash waste of coal collected from the electrostatic precipitators has been the synthesis of zeolites from this waste material [...] Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

1 pages, 176 KiB

Open AccessAbstract

The Effect of Controlled Mixing on ROY Polymorphism

by Margot Van Nerom, Dominique Maes, James F. Lutsko and Quentin Galand

Chem. Proc. 2022, 9(1), 17; https://doi.org/10.3390/IOCC_2022-12152 - 13 Jan 2022

Viewed by 641

Abstract

In this work, we report the investigation of various experimental conditions and their influence on the polymorphism of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophen carbonitrile, commonly known as ROY. These conditions include an in-house-developed microfluidic chip with controlled mixing of parallel flows. ROY is known for its ability [...] Read more.

In this work, we report the investigation of various experimental conditions and their influence on the polymorphism of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophen carbonitrile, commonly known as ROY. These conditions include an in-house-developed microfluidic chip with controlled mixing of parallel flows. ROY is known for its ability to form a large variety of polymorphs, including at least ten forming under standard conditions. Nucleation is triggered by adding water as an antisolvent to ROY dissolved in acetone. We observe that different ROY concentrations and different solvent-to-antisolvent ratios naturally favor different polymorphs. Nevertheless, identical samples prepared with different mixing methods, such as shaking and magnetic stirring, consistently lead to the formation of different polymorphs. In addition, different mixing rates that can be linked to shear stress strongly influence the crystallization. A fourth parameter, namely confinement of the sample, is also found to be critical. Untangling all of these parameters and their influences on polymorphism calls for an experimental setup allowing all four to be controlled accurately. To that end, we developed a novel customized microfluidic setup allowing reproducible and controlled mixing conditions. Two parallel flows of antisolvent and ROY dissolved in solvent are injected into a transparent microchannel. Next, slow and progressive mixing can be achieved through molecular diffusion. Additionally, the microfluidic chip is equipped with a piezoceramic element, allowing the implementation of various mixing rates through acoustic mixing. With this device, we demonstrate the importance of parameters other than concentration that are involved in the polymorphism of ROY. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

Other

Jump to: Research

9 pages, 1647 KiB

Open AccessProceeding Paper

Comparative Investigation of Membrane Systems for Crystallization and Spherical Agglomeration

by Izabela Lackowska, Marijana Dragosavac and Brahim Benyahia

Chem. Proc. 2022, 9(1), 2; https://doi.org/10.3390/IOCC_2022-12162 - 15 Jan 2022

Viewed by 1428

Abstract

In this study, two novel spherical agglomeration processes based on membrane systems were successfully implemented to produce spherical agglomerates of benzoic acid crystals obtained via antisolvent crystallization. Two membrane configurations were considered: a flat disc mounted in a dispersion cell equipped with a [...] Read more.

In this study, two novel spherical agglomeration processes based on membrane systems were successfully implemented to produce spherical agglomerates of benzoic acid crystals obtained via antisolvent crystallization. Two membrane configurations were considered: a flat disc mounted in a dispersion cell equipped with a mixing impeller, and a second configuration which uses a cylindrical membrane equipped with a vibrating module which created shear with upward–downward vibration. To optimize the performance of the spherical agglomeration process, the impact of the bridging liquid flowrate, membrane pore size and pore arrangement, as well as agitation rate were investigated. Both systems were successfully used to generate spherical agglomerates with enhanced quality and size distribution at comparable flux conditions. This work opened new opportunities to investigate the scalability of the proposed spherical agglomeration system under the optimized operating conditions identified from the current study. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

8 pages, 1630 KiB

Open AccessProceeding Paper

X-ray Diffraction Study of Fluorine-Functionalized Thiosemicarbazones and Cyclometallated Compounds

by Marcos Rúa-Sueiro, Paula Munín-Cruz, Juan M. Ortigueira and José M. Vila

Chem. Proc. 2022, 9(1), 3; https://doi.org/10.3390/IOCC_2022-12140 - 12 Jan 2022

Viewed by 1103

Abstract

In this work, an X-ray diffraction study of fluorine-functionalized thiosemicarbazone ligands and their corresponding cyclometallated compounds is discussed. The results are in agreement with previous characterization by IR spectroscopy, ¹H and ¹⁹F NMR spectroscopy. Suitable crystals were obtained for a thiosemicarbazone [...] Read more.

In this work, an X-ray diffraction study of fluorine-functionalized thiosemicarbazone ligands and their corresponding cyclometallated compounds is discussed. The results are in agreement with previous characterization by IR spectroscopy, ¹H and ¹⁹F NMR spectroscopy. Suitable crystals were obtained for a thiosemicarbazone ligand and a cyclometallated compound. The crystal structure analyses are in accordance with the proposed structures: a fluorine-functionalized thiosemicarbazone ligand and a cyclometallated compound in which the thiosemicarbazone is a tridentate [C, N, S] ligand. A comparative study of bond distances and angles is shown, providing information about the coordination of the ligand to the metal center. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

7 pages, 1481 KiB

Open AccessProceeding Paper

Physico-Chemical Interaction in the Ag₂Se–Zn(Cd, Hg, Pb)Se–SnSe₂ Systems

by Lyudmyla Piskach, Olga Velychko, Anatolii Fedorchuk, Yuri Kogut, Ivan Olekseyuk and Oleg Parasyuk

Chem. Proc. 2022, 9(1), 4; https://doi.org/10.3390/IOCC_2022-12155 - 13 Jan 2022

Cited by 1 | Viewed by 1085

Abstract

The quaternary compounds A^I₂B^IIC^IVX₄, where A^I–Cu, Ag; B^II–Zn, Cd, Hg; C^IV–Si, Ge, Sn; and X–S, Se, Te, crystallize in non-centrosymmetric structures and may be of interest for nonlinear [...] Read more.

The quaternary compounds A^I₂B^IIC^IVX₄, where A^I–Cu, Ag; B^II–Zn, Cd, Hg; C^IV–Si, Ge, Sn; and X–S, Se, Te, crystallize in non-centrosymmetric structures and may be of interest for nonlinear optics. Here, we present in detail isothermal sections and physico-chemical equilibria in the Ag₂Se–Zn(Cd, Hg, Pb)Se–SnSe₂ systems where some of these compounds were found. The crystal structure of Ag₂ZnSnSe₄ was determined for the first time as the tetragonal symmetry, S.G. I

\bar{4}

2m, lattice parameters a = 0.60434(2), c = 1.13252(5) nm. No quaternary compounds were found in the Ag₂Se–PbSe–SnSe₂ system. Ag₈SnSe₆–PbSe is the triangulating section in this system. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

9 pages, 2534 KiB

Open AccessProceeding Paper

Structural Study of a Pd–Fe Hetero-Trinuclear Compound

by Paula Munín-Cruz, Marcos Rúa-Sueiro, Juan M. Ortigueira, María Teresa Pereira and José M. Vila

Chem. Proc. 2022, 9(1), 5; https://doi.org/10.3390/IOCC_2022-12145 - 12 Jan 2022

Viewed by 872

Abstract

Cyclometallated compounds, specifically cyclopalladates, have been synthesized for years. In this work, we describe a new family of compounds in which an iron core has been introduced in addition to Pd. This novel characteristic provides interesting properties to these compounds, such as the [...] Read more.

Cyclometallated compounds, specifically cyclopalladates, have been synthesized for years. In this work, we describe a new family of compounds in which an iron core has been introduced in addition to Pd. This novel characteristic provides interesting properties to these compounds, such as the possibility of undergoing reduction–oxidation processes due to the versatility of the iron nucleus. An XRD study of the resulting crystalline structure allows explaining the compound behavior. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

5 pages, 551 KiB

Open AccessProceeding Paper

Techno-Economic Evaluation and Optimization of Batch, Fed-Batch and Multistage Continuous Crystallization Processes

by Jiaxu Liu and Brahim Benyahia

Chem. Proc. 2022, 9(1), 6; https://doi.org/10.3390/IOCC_2022-12144 - 12 Jan 2022

Cited by 1 | Viewed by 1874

Abstract

Over the last decade, continuous manufacturing techniques have been increasingly used in the pharmaceutical manufacturing industry. However, despite the outstanding performance associated with the steady-state operation, continuous processes face common and important challenges of low efficiency and high material wastes during the start-up [...] Read more.

Over the last decade, continuous manufacturing techniques have been increasingly used in the pharmaceutical manufacturing industry. However, despite the outstanding performance associated with the steady-state operation, continuous processes face common and important challenges of low efficiency and high material wastes during the start-up and shutdown. Considering that most pharmaceutical manufacturing campaigns are accomplished in a short operation window, an optimal start-up and shut down strategy will have a significant impact on the economic and environmental performance of the continuous pharmaceutical process. In this study, a combined start-up, steady-state, and shutdown optimization of a three-stage mixed suspension mixed product removal (MSMPR) crystallizer was compared against optimized batch and fed-batch crystallizers. The crystallization of Aspirin (acetylsalicylic acid, ASA) in ethanol (solvent) and water (antisolvent) was used as a case study. The optimization problems were solved using a hybrid method, which combines a genetic algorithm and a sequential quadratic programming (SQP) method. The multistage continuous crystallizer was designed and optimized to maximize on-spec production over a total operating window of 800 min. It was shown that a maximum on-spec production of 5510 g can be achieved with the continuous process. A batch and a fed-batch crystallizer were designed and optimized to achieve the same production rate to help establish a reliable basis for rigorous techno-economic analysis and comparison. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

6 pages, 567 KiB

Open AccessProceeding Paper

Fabrication and Characterization of Perovskite Solar Cells Using Copper Phthalocyanine Complex with Tetracyanoquinodimethane

by Atsushi Suzuki, Ryota Hasegawa, Takeo Oku, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 8; https://doi.org/10.3390/IOCC_2022-12154 - 13 Jan 2022

Viewed by 1259

Abstract

In this paper, the fabrication and characterization of CH₃NH₃PbI₃ perovskite solar cells using decaphenylpentacyclosilane, copper phthalocyanine complex (CuPc) doped with tetracyanoquinodimethane (TCNQ), was performed. The effects of a carboxylic acid, amino, or sulfonic acid sodium salt group, substituted [...] Read more.

In this paper, the fabrication and characterization of CH₃NH₃PbI₃ perovskite solar cells using decaphenylpentacyclosilane, copper phthalocyanine complex (CuPc) doped with tetracyanoquinodimethane (TCNQ), was performed. The effects of a carboxylic acid, amino, or sulfonic acid sodium salt group, substituted with CuPc doped with TCNQ, on photovoltaic properties was investigated to improve carrier generation and diffusion related to short-circuit current density. The incorporation of carboxylic acid or amino, substituted with CuPc doped with TCNQ, would optimize the tuning energy levels of the valence band, promoting charge transfer and diffusion with a suppressing trap near the interface in the hole-transporting layer. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

6 pages, 908 KiB

Open AccessProceeding Paper

Effects of Co-Addition of Copper, Sodium and Ethylammonium to CH₃NH₃PbI₃ Perovskite Compound

by Riku Okumura, Takeo Oku, Atsushi Suzuki, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 11; https://doi.org/10.3390/IOCC_2022-12142 - 12 Jan 2022

Viewed by 958

Abstract

From the band calculation, the copper d-orbital band formed slightly above the valence band maximum would function as an acceptor level promoting the generation of carriers. In addition, the excitation processes from the p-orbital of iodine and the d-orbital of copper to the [...] Read more.

From the band calculation, the copper d-orbital band formed slightly above the valence band maximum would function as an acceptor level promoting the generation of carriers. In addition, the excitation processes from the p-orbital of iodine and the d-orbital of copper to the s-orbital of sodium could suppress carrier recombination. Total energy calculations showed that, the stability of the crystal structure decreases with the addition of copper and sodium, but increases with the addition of ethylammonium. Therefore, it is expected that the combination of these compounds can compensate for the disadvantage of unstable crystal structure. The calculated results could be obtained by optimizing the composition of the perovskite and the annealing conditions. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

7 pages, 837 KiB

Open AccessProceeding Paper

Electronic Structures of Eu-Doped FAPbI₃ Perovskite Crystals Studied by First-Principles Calculation

by Atsushi Suzuki and Takeo Oku

Chem. Proc. 2022, 9(1), 12; https://doi.org/10.3390/IOCC_2022-12178 - 9 Feb 2022

Viewed by 1446

Abstract

The effects of maxed-valence states on electronic structures of europium (Eu)-incorporated CH(NH₂)₂PbI₃ (FAPbI₃) and CH₃NH₃PbI₃ (MAPbI₃) perovskite crystals were investigated by first-principles calculation. Partial replacements of europium ions into [...] Read more.

The effects of maxed-valence states on electronic structures of europium (Eu)-incorporated CH(NH₂)₂PbI₃ (FAPbI₃) and CH₃NH₃PbI₃ (MAPbI₃) perovskite crystals were investigated by first-principles calculation. Partial replacements of europium ions into the perovskite crystals influenced the electronic structures. In the case of the FAPb(Eu⁺³)I₃ crystal, there was wide distribution of the 5p orbital of iodine near the valence band, and of the 3d orbital of the Eu³⁺ ion near the conductive band. Incorporation of Eu²⁺ ions into the perovskite crystal provided low energy levels at the VB, with an increase in the bandgap and a decrease in m_h*/m_e. This behaviour suggests improvement of carrier mobility related to short-circuit current and conversion efficiency, as compared with the incorporation of Eu³⁺ ions into the perovskite crystal. The partial substitution of europium ions at the position of lead ions as the B-site in the perovskite crystal caused the electron correlation based on the charge transfer between the 5p orbital of iodine and the 3d orbital of Eu ions, and narrowed the band dispersion with a decrease in the effective mass ratio, which was expected to improve the carrier mobility related to the short-circuit current density and the conversion efficiency. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

9 pages, 2395 KiB

Open AccessProceeding Paper

Effects of Guanidinium Addition to CH₃NH₃PbI₃ Perovskite Solar Cells Inserted with Decaphenylpentasilane

by Iori Ono, Takeo Oku, Atsushi Suzuki, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 13; https://doi.org/10.3390/IOCC_2022-12158 - 14 Jan 2022

Cited by 1 | Viewed by 1244

Abstract

Effects of addition of guanidinium [C(NH₂)₃; GA] on MAPbI₃ perovskite solar cells fabricated at a high temperature of 190 °C in atmospheric air were investigated on the photovoltaic properties and first principles calculations. The addition of guanidinium iodide [...] Read more.

Effects of addition of guanidinium [C(NH₂)₃; GA] on MAPbI₃ perovskite solar cells fabricated at a high temperature of 190 °C in atmospheric air were investigated on the photovoltaic properties and first principles calculations. The addition of guanidinium iodide and the insertion of decaphenylpentasilane between the perovskite and hole transport layer improved the external quantum efficiency and short-circuit current density, and the conversion efficiencies were stable after 1 month. First principles calculations on the density of states and band structures showed reduction of the total energy by the GA addition and the effectiveness of the nitrogen atoms in GA. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

9 pages, 3643 KiB

Open AccessProceeding Paper

Fabrication and Characterization of Ethylammonium- and Rubidium-Added Perovskite Solar Cells

by Keinoshin Takada, Takeo Oku, Atsushi Suzuki, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 14; https://doi.org/10.3390/IOCC_2022-12153 - 13 Jan 2022

Cited by 2 | Viewed by 1288

Abstract

Conversion efficiencies and stability of the perovskite solar cells were improved by adding a small amount of ethylammonium (EA) and rubidium (Rb) to the CH₃NH₃PbI₃ compounds. Addition of ethylamine hydrobromide and rubidium iodide provided an increase in carrier [...] Read more.

Conversion efficiencies and stability of the perovskite solar cells were improved by adding a small amount of ethylammonium (EA) and rubidium (Rb) to the CH₃NH₃PbI₃ compounds. Addition of ethylamine hydrobromide and rubidium iodide provided an increase in carrier concentration and promotion of crystal growth, resulting in an improvement in conversion efficiencies and stability. First-principles calculations showed that the addition of Rb lowered the total energy and made the crystal stable. The band calculation also shows that the EA addition reduce the effective mass and improves the carrier mobility. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

7 pages, 1269 KiB

Open AccessProceeding Paper

Steady-State and Transient Electrical Properties of Liquid Crystal Cells

by David Webb and Yuriy Garbovskiy

Chem. Proc. 2022, 9(1), 15; https://doi.org/10.3390/IOCC_2022-12147 - 12 Jan 2022

Cited by 1 | Viewed by 1506

Abstract

Rapidly expanding and new applications of liquid crystal materials cover a wide range of technology products. A very incomplete list includes conventional and miniature high-resolution displays, AR/VR glasses, smart windows, dynamic lenses, tunable filters and retarders, electrically controlled sensors, reconfigurable antennas for wireless [...] Read more.

Rapidly expanding and new applications of liquid crystal materials cover a wide range of technology products. A very incomplete list includes conventional and miniature high-resolution displays, AR/VR glasses, smart windows, dynamic lenses, tunable filters and retarders, electrically controlled sensors, reconfigurable antennas for wireless and space communications, and many other commercially available devices. The aforementioned devices are enabled by the collective reorientation of thermotropic molecular liquid crystals under the action of applied electric fields. The reorientation effects in liquid crystals can be altered by ionic contaminants typically present in mesogenic materials in small quantities. Therefore, information about ions in liquid crystals is very important because it allows for a proper selection of liquid crystal materials and uncompromised performance of liquid crystal devices. This information can be obtained by performing electrical measurements of liquid crystal materials. Measurements of basic electrical parameters (DC conductivity, charge mobility, and ion density) are carried out using sandwich-like liquid crystal cells of finite thickness. Once a cell is filled with liquid crystal materials, interactions between ions and the cell substrates will result in the time dependence of the ion density and DC electrical conductivity until a steady state is reached. In this paper, we show how complementary information about ionic processes in liquid crystal cells can be obtained by analyzing their transient and steady-state electrical properties. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

5 pages, 833 KiB

Open AccessProceeding Paper

Effects of Cu, K, and Guanidinium Addition to CH₃NH₃PbI₃ Perovskite Solar Cells

by Ayu Enomoto, Atsushi Suzuki, Takeo Oku, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 16; https://doi.org/10.3390/IOCC_2022-12168 - 17 Jan 2022

Cited by 2 | Viewed by 956

Abstract

Fabrication and characterization of CH₃NH₃PbI₃ perovskite solar cell with the addition of copper (Cu²⁺), and potassium (K) or guanidinium (GA) was performed. The additive effects on the photovoltaic properties, morphologies, and crystalline structures were investigated by [...] Read more.

Fabrication and characterization of CH₃NH₃PbI₃ perovskite solar cell with the addition of copper (Cu²⁺), and potassium (K) or guanidinium (GA) was performed. The additive effects on the photovoltaic properties, morphologies, and crystalline structures were investigated by the experimental results, electronic structures, and thermodynamic stabilities. The stability and conversion efficiency of the perovskite solar cells was improved by incorporating Cu²⁺ at the lead site, and K or GA at the organic cation, CH₃NH₃, at A-site in cubic crystal. The simultaneous addition of Cu²⁺ and K to the perovskite crystal suppressed the crystal decomposition while inhibiting desorption of MA, improving the stability of the performance. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

5 pages, 1750 KiB

Open AccessProceeding Paper

Fabrication and Characterization of New Er-Doped Yttrium–Scandium–Aluminum–Garnet Ceramics

by Elena Dobretsova, Vadim Zhmykhov, Sergey Kuznetsov, Marina Nikova, Irina Chikulina, Vitaly Tarala, Dmitry Vakalov, Roman Khmelnitsky, Lubov Badyanova, Alexandr Pynenkov, Konstantin Nishchev, Yurii Pyrkov, Vladimir Seregin and Vladimir Tsvetkov

Chem. Proc. 2022, 9(1), 18; https://doi.org/10.3390/IOCC_2022-12163 - 15 Jan 2022

Cited by 1 | Viewed by 1107

Abstract

We report the fabrication and characterization of yttrium–aluminum–garnet (Er:YAG) and yttrium–scandium–aluminum–garnet (Er:YSAG) ceramics for the implementation of analysis as an active medium for 1500 nm lasing. High erbium content Er:YAG and Er:YSAG ceramics are fabricated from Er:YAG and Er:YSAG powders, respectively. All ceramic [...] Read more.

We report the fabrication and characterization of yttrium–aluminum–garnet (Er:YAG) and yttrium–scandium–aluminum–garnet (Er:YSAG) ceramics for the implementation of analysis as an active medium for 1500 nm lasing. High erbium content Er:YAG and Er:YSAG ceramics are fabricated from Er:YAG and Er:YSAG powders, respectively. All ceramic samples belong to the garnet-type cubic structure (space group Ia3d) without any traceable impure phases. Including Sc³⁺ in the Er:YAG crystal structure leads to improved mechanical characteristics and elastic–plastic properties of the materials. The optical transmittance of ceramics is affected strongly by including Sc³⁺ and increases up to 60% at about 1500 nm. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

5 pages, 1133 KiB

Open AccessProceeding Paper

Study of the Critical Behaviour in the Vicinity of Various Phase Transitions Associated with Two Antiferroelectric Enantiomers R-Mhpobc, S-Mhpobc and Their Racemic Mixture

by Barnali Barman

Chem. Proc. 2022, 9(1), 19; https://doi.org/10.3390/IOCC_2022-12148 - 12 Jan 2022

Viewed by 708

Abstract

High-resolution birefringence measurements and modulated differential scanning calorimetry have been carried out in order to investigate the critical behaviour near the isotropic to smectic-A, smectic-A to smectic-C* phase transitions associated with two well known antiferroelectric liquid crystalline materials R- and S-enantiomers of MHPOBC [...] Read more.

High-resolution birefringence measurements and modulated differential scanning calorimetry have been carried out in order to investigate the critical behaviour near the isotropic to smectic-A, smectic-A to smectic-C* phase transitions associated with two well known antiferroelectric liquid crystalline materials R- and S-enantiomers of MHPOBC [4-(1-methylheptyloxycarbonyl) phenyl 4-octyloxybiphenyl-4-carboxylate] and their racemic mixture. The heat capacity anomaly and the birefringence data serve as order parameters, and the critical exponents extracted from these order parameters corresponding to the various transitions associated with the investigated materials indicates the nature of the transition, whether it is first-order or second-order. The data have been analyzed in detail with the renormalization-group expression with correction-to-scaling terms. A comparison of the specific heat-capacity critical exponent found from the mean-square fluctuations of the tilt angle <δθ2(T)> and the critical exponent (α′) explored from the birefringence differential quotient Q(T) for the SmA-SmC* phase transition has also been undertaken for pure R-MHPOBC. The nature of phase transition associated with the racemic mixture of MHPOBC has also been discussed in the light of precise birefringence and specific heat capacity measurements. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

7 pages, 1132 KiB

Open AccessProceeding Paper

Photovoltaic Properties and Microstructures of Polysilane-Added Perovskite Solar Cells

by Shinichiro Mizuno, Takeo Oku, Atsushi Suzuki, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa and Tomoya Hasegawa

Chem. Proc. 2022, 9(1), 20; https://doi.org/10.3390/IOCC_2022-12169 - 17 Jan 2022

Cited by 2 | Viewed by 1099

Abstract

CH₃NH₃PbI₃ perovskite photovoltaic devices inserted with a polysilane layer were fabricated and characterized. A Decaphenylcyclopentasilane (DPPS) in chlorobenzene solution was spin-coated between the perovskite layer and the hole transport layer of spiro-OMeTAD, and the resulting device was annealed [...] Read more.

CH₃NH₃PbI₃ perovskite photovoltaic devices inserted with a polysilane layer were fabricated and characterized. A Decaphenylcyclopentasilane (DPPS) in chlorobenzene solution was spin-coated between the perovskite layer and the hole transport layer of spiro-OMeTAD, and the resulting device was annealed at 190 °C. The DPPS-treated devices had higher conversion efficiencies than the standard ones, and they were stable in ambient air. Microstructural observations suggested that DPPS would work effectively as a bulk-hetero structure with perovskite layers. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

9 pages, 7025 KiB

Open AccessProceeding Paper

Targeting Desired Particle Size for Improved Dissolution and Manufacturability of Mefenamic Acid

by Wei Li, Chris D. Rielly and Brahim Benyahia

Chem. Proc. 2022, 9(1), 21; https://doi.org/10.3390/IOCC_2022-12165 - 15 Jan 2022

Cited by 2 | Viewed by 1005

Abstract

This work aims at the production of uniformly sized, equant shaped crystals using a direct nucleation control (DNC) strategy to help achieve enhanced manufacturability and bioavailability of the active pharmaceutical ingredients (API). A crystallization system equipped with in situ and external wet-milling devices [...] Read more.

This work aims at the production of uniformly sized, equant shaped crystals using a direct nucleation control (DNC) strategy to help achieve enhanced manufacturability and bioavailability of the active pharmaceutical ingredients (API). A crystallization system equipped with in situ and external wet-milling devices was used. The experiments were conducted using mefenamic acid (MFA) mixed into solvents of 2-butanol and heptane with a mass ratio of 90:10. Firstly, a linear cooling crystallization was conducted as a reference case and also to identify suitable DNC set-points, which were then implemented using closed-loop feedback control based on the measurement of the FBRM counts. The in situ and external wet-milling based DNC approaches were compared in terms of temperature cycling efficiency and final crystal size and shape. This integrated wet-milling crystallization system demonstrated enhanced control over the crystal size distribution (CSD) and morphology compared to conventional cooling crystallization processes. In addition, the expansion of the design space was achieved by integrating wet-mill to DNC crystallization compared to the cooling crystallization-only process. In addition, enhanced control of the rate of nucleation and attrition is accomplished through combining wet-milling and DNC. Full article

(This article belongs to the Proceedings of The 3rd International Online Conference on Crystals)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Chem. Proc., 2022, IOCC 2022

The 3rd International Online Conference on Crystals

Research

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI