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arXiv 2022年

作者： Mishra, Prakash Yamamoto, Yoh Johnson, J. Karl Jackson, Koblar A. Zope, Rajendra R. Baruah, Tunna Computational Science Program University of Texas at El Paso El PasoTX79968 United States Department of Physics University of Texas El PasoTX79968 United States Department of Chemical & Petroleum Engineering University of Pittsburgh PittsburghPA15261 United States Physics Department Science of Advanced Materials Program Central Michigan University Mt. PleasantMI48859 United States

We study the effect of self-interaction errors on the barrier heights of chemical reactions. For this purpose we use the well-known Perdew-Zunger [J. P. Perdew and A. Zunger, Phys. Rev. B, 23, 5048 (1981)] self-interaction-correction (PZSIC), as well as two variations of the recently developed, locally scaled self-interaction correction (LSIC) [R. R. Zope et al., J. Chem. Phys. 151, 214108 (2019)] to study the barrier heights of the BH76 benchmark dataset. Our results show that both PZSIC and especially the LSIC methods improve the barrier heights relative to the local density approximation (LDA). The version of LSIC that uses the iso-orbital indicator z as a scaling factor gives a more consistent improvement than an alternative version that uses an orbital-dependent factor w based on the ratio of orbital densities to the total electron density. We show that LDA energies evaluated using the self-consistent and self-interaction-free PZSIC densities can be used to assess density-driven errors. The LDA reaction barrier errors for the BH76 set are found to contain significant density-driven errors for all types of reactions contained in the set, but the corrections due to adding SIC to the functional are much larger than those stemming from the density for the hydrogen transfer reactions and of roughly equal size for the non-hydrogen transfer reactions. Copyright © 2022, The Authors. All rights reserved.

关键词： Local density approximation

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Microporous Polymer Membranes: Molecular Stents Enhanced Solvent-Accessibility for Organic Solvent Transport

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Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2025年 e16748页

作者： Shuang Guo Chuanjie Fang Jiaqi Li Xiaohe Wang Weilin Feng Hukang Guo Ming Xie Yongbing Zhuang Young Moo Lee Liping Zhu MOE Key Laboratory of Macromolecular Synthesis and Functionalization MOE Engineering Research Center of Membrane and Water Treatment Technology Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China. Department of Polymer Science and Engineering Department of Chemical Engineering University of Bath Bath BA2 7AY UK. State Key Laboratory of Biochemical Engineering Institute of Process Engineering University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing 100190 China. Department of Energy Engineering College of Engineering Hanyang University Seoul 04763 South Korea.

Microporous polymer membranes with high solvent permeability are pivotal for upgrading molecular separations in organic solvents, but this remains challenging due to numerous sub-0.4 nm ultra-micropores resulting from local tight packing, which limit solvent-accessibility. Herein, a microporous polyimide with high intrinsic free volume [PI-TB-NDI, naphthalenediimide (NDI) and Tröger's base (TB)] is synthesized for organic solvent nanofiltration. The resulting polymer showed high free volume because of fused aromatic rings and a twisted structure. Aromatic rings enhanced solvent resistance due to strong molecular interaction, but increased detrimental local tight packing as well. To suppress local tight packing without compromising the molecular interactions vital for stability, an ortho-methyl group is deliberately introduced onto the TB unit to increase both intra- and inter-molecular steric hindrance, imparting an H-shaped TB-NDI-TB molecular stent. On the introduction of ortho-methyl groups, the sub-0.4 nm ultra-micropores are enlarged to ultra-micropores (0.6-0.7 nm) to give the membrane with rich solvent-accessible sub-nanochannels. This resulted in an unprecedented enhancement of solvent permeability, with ethanol permeability 2-8 times greater than that of state-of-the-art polymer membranes with similar selectivity. These findings advance the design strategy of microporous membranes with well-tailored free volume without post-treatments, enabling upscaling and efficient separation of precious species in organic solvents.

关键词： free volume microporous polymer membranes molecular stents organic solvent transport

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Highly stable, active and recyclable solid acid catalyst based on polymer-coated magnetic composite particles

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Chinese chemical Letters 2019年第12期30卷 2043-2046页

作者： Jianxin Luo Xucheng Zhang Chunyan Zhang Tao Wang Xue Chen Hongyu Chen Steve King Changchun Wang Department of Materials and Chemical Engineering Hunan Institute of TechnologyHengyang 421002China State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular ScienceFudan UniversityShanghai 200433China Dow Chemical China Holding Company Shanghai 201203China Dow Chemical Company Lake Jackson 77566United States

A facile approach has been adopted for coating cross-linked polystyrene(PS) shells on the surface of Fe304 magnetic clusters using reflux-precipitation polymerization(RPP).Treating the PS shell with chlorosulfonic acid yields magnetic composite particles with acid *** adjusting the amount and proportion of monomers(styrene and divinylbenzene),the obtained magnetic composite particle solid acid(MPM-5 S) exhibits a saturation magnetization value of 18 emu/g,a specific surface area of 243 m^2/g and an acid density of 2.113 mmol/*** MPM-5 S magnetic solid acid catalyst was evaluated for esterification of oleic acid with methanol to prepare *** mild conditions,the conversion of oleic acid reached 91%,which was much higher than the catalytic activity of Amberlyst-15 and close to the catalytic activity of concentrated H2 *** solid acid catalyst can be recovered by magnetic separation and reused three times maintaining over 95% of its initial catalytic ***,the solid acid can be used to catalyze the dehydration of fructose to 5-hydroxymethylfurfural.

关键词： Reflux precipitation polymerization Solid acid Magnetic separation Biodiesel Recyclability

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3D-printing methacrylate/chitin nanowhiskers composites via stereolithography: Mechanical and thermal properties

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Materials Today: Proceedings 2020年 33卷 1819-1824页

作者： Reymark D. Maalihan Bryan B. Pajarito Rigoberto C. Advincula Polymer Research Laboratory Department of Chemical Engineering University of the Philippines Diliman Quezon City 1101 Philippines Chemical and Food Engineering Department Batangas State University Batangas City 4200 Philippines Department of Macromolecular Science and Engineering Case Western Reserve University OH 44106 USA

We report on the mechanical and thermal properties of stereolithography (SLA) 3D-printed methacrylate (MA) resin reinforced by chitin nanowhiskers (CNWs). CNWs were synthesized by acid hydrolysis of crab shell chitin and nanocomposites with 0 wt%, 0.5 wt%, 1.0 wt%, and 1.5 wt% CNWs loading were prepared by slurry compounding method. The obtained CNWs (diameter = 23 ± 5 nm, length = 253 ± 100 nm, and aspect ratio = 11 ± 3) are well dispersed within the bulk of MA at 1.0 wt% loading, implying good interfacial adhesion between the nanofiller and the resin matrix possibly due to hydrogen bonding interactions. The addition of up to 1.0 wt% CNWs to neat MA enhances the tensile strength, strain at break, modulus, and maximum thermal degradation temperatures of the nanocomposites. Moreover, the incorporation of CNWs not only improves the mechanical and thermal properties, but also preserves the excellent resolution and accuracy of 3D-printed MA/CNWs nanocomposites.

关键词： 3D-printing Stereolithography Chitin nanowhisker Methacrylate Slurry compounding Nanocomposites

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Enhancing the Electron Pair Approximation with Measurements on Trapped Ion Quantum Computers

arXiv

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arXiv 2023年

作者： Zhao, Luning Goings, Joshua Wang, Qingfeng Shin, Kyujin Kyoung, Woomin Noh, Seunghyo Rhee, Young Min Kim, Kyungmin IonQ Inc College ParkMD20740 United States Chemical Physics Program Institute for Physical Science and Technology University of Maryland College ParkMD20742 United States Materials Research & Engineering Center CTO Division Hyundai Motor Company Uiwang16082 Korea Republic of Department of Chemistry KAIST Daejeon34141 Korea Republic of

The electron pair approximation offers a resource efficient variational quantum eigensolver (VQE) approach for quantum chemistry simulations on quantum computers. With the number of entangling gates scaling quadratically with system size and a constant energy measurement overhead, the orbital optimized unitary pair coupled cluster double (oo-upCCD) ansatz strikes a balance between accuracy and efficiency on today’s quantum computers. However, the electron pair approximation makes the method incapable of producing quantitatively accurate energy predictions. In order to improve the accuracy without increasing the circuit depth, we explore the idea of reduced density matrix (RDM) based second order perturbation theory (PT2) as an energetic correction to electron pair approximation. The new approach takes into account of the broken-pair energy contribution that is missing in pair-correlated electron simulations, while maintaining the computational advantages of oo-upCCD ansatz. In dissociations of N2, Li2O, and chemical reactions such as the unimolecular decomposition of CH2OH+ and the SN2 reaction of CH3I + Br−, the method significantly improves the accuracy of energy prediction. On two generations of the IonQ’s trapped ion quantum computers, Aria and Forte, we find that unlike the VQE energy, the PT2 energy correction is highly noise-resilient. By applying a simple error mitigation approach based on post-selection solely on the VQE energies, the predicted VQE-PT2 energy differences between reactants, transition state, and products are in excellent agreement with noise-free simulators. © 2023, CC BY.

关键词： Trapped ions

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A Review of Carbon dots (CDs) Application in Sensing and Removing Medical Waste 5

A Review of Carbon dots (CDs) Application in Sensing and Rem...

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5th International Conference on Energy, Environmental and Information System, ICENIS 2020

作者： Alkian, Ilham Sutanto, Heri Aprimanti Utami, Bella Rafika Duri, Inten A'Yuni, Dewi Qurrota Hadiyanto, H Master Program of Environmental Science School of Postgraduate Studies Diponegoro University Semarang Indonesia Department of Physics Faculty of Science and Mathematics Diponegoro University Semarang Indonesia Department of Chemical Engineering Faculty of Engineering Diponegoro University Semarang Indonesia Smart Materials Research Center Diponegoro University Semarang Indonesia

Carbon dots materials (CDs) have the capability in the management of medical waste problem because of its advantage in the detection and degradation of pollutants. The synthesized CDs through various processes and raw materials have been applied to medical wastes, especially antibiotics such as tetracycline (TC), amoxicillin (AMX), para-Nitrophenol (p-NP), doxycycline (DC), ciprofloxacin (CIP), and oxytetracycline (OTC). These antibiotics are detected by utilizing changes in the luminescence property of CDs from the turn-off and turn-on mechanisms. Afterward, the degradation process is conducted using CDs as support materials agent semiconductors in the photosynthesis scheme. In general, CDs can be referred to as multifunction smart materials with the ability to detecting the presence of the antibiotics in simple, sensitive, and selective ways, and potency of medical pollutant removal clearly and effectively. © The Authors, published by EDP sciences, 2020.

关键词： Antibiotics

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Electrochemical detection of antimalarial drug (Amodiaquine) using Dy-MOF@MWCNTs composites to prevent erythrocytic stages of plasmodium species in human bodies

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Microchemical Journal 2024年 202卷

作者： Peter, X. Thatheyus Kuo, Chih-Yu Malar, P. Govindasamy, Mani Rajaji, Umamaheswari Yusuf, Kareem Thinfilm Photovoltaics Laboratory Department of Physics and Nanotechnology SRM Institute of Science and Technology Tamil Nadu Kattankulathur 603203 India Department of Chemical Engineering and Biotechnology National Taipei University of Technology Taipei Taiwan International Ph.D. Program in Innovative Technology of Biomedical Engineering and Medical Devices Ming Chi University of Technology New Taipei City 243303 Taiwan Research Center for Intelligence Medical Devices Ming Chi University of Technology New Taipei City 243303 Taiwan Centre for Applied Research Saveetha School of Engineering Saveetha Institute of Medical and Technical Sciences (SIMATS) Tamil Nadu Chennai 602105 India Department of Chemistry College of Science King Saud University Riyadh 11451 Saudi Arabia

Herein, we report on fabrication of dysprosium-based metal–organic framework (Dy-MOF)@multiwalled carbon nanotubes (MWCNT) composites modified with glassy carbon electrode (Dy-MOF@MWCNT/GC) as a working electrode for Antimalarial drug detection. Dy-MOF@MWCNT composites was prepared by sonochemical process along with ultrasonication. The composite structure, phase purity, morphology and composition of the composites were confirmed by X-ray diffraction, Scanning electron microscope, and X-ray photoelectron spectroscopy. Further, Dy@MWCNT composites were deposited on a glassy carbon electrode by drop casting method, and used as an electrode material to efficiently detect Amodiaquine (ADD) by electrochemical techniques such as CV and DPV. The as-prepared Dy@MWCNT composite material showed the oxidation peak current of ADD to be ∼ 60 % higher than other unmodified GC electrodes and showed a low charge transfer resistance (R_ct) of 24 Ω. The Dy@MWCNT provided a broad linear range of 0.4 to 20 µM with a limit of detection of 0.377 μM and sensitivity of 1.817 μA.μM⁻¹ for the detection of ADD. According to the pH study, the amount of electrons and protons involved in the electrochemical processes of ADD was calculated and a plausible mechanism for ADD electro-oxidation was proposed. Thus, the prepared sensor exhibited practical usefulness by determining the ADD drug in human urine samples. Hence, the results shows that the Dy@MWCNT- modified sensor has good electrocatalytic activity for the redox of ADD. © 2024 Elsevier B.V.

关键词： Amodiaquine Antimalarial drug Carbon nanomaterials Electrochemical sensor Metal organic framework

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Probabilistic Genotype-Phenotype Maps Reveal Mutational Robustness of RNA Folding, Spin Glasses, and Quantum Circuits

arXiv

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arXiv 2023年

作者： Sappington, Anna Mohanty, Vaibhav Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Program for Health Sciences and Technology Harvard Medical School BostonMA02115 United States Massachusetts Institute of Technology CambridgeMA02139 United States Harvard/MIT MD-PhD Program Harvard Medical School BostonMA02115 United States Department of Chemistry and Chemical Biology Harvard University CambridgeMA02138 United States

Recent studies of genotype-phenotype (GP) maps have reported universally enhanced phenotypic robustness to genotype mutations, a feature essential to evolution. Virtually all of these studies make a simplifying assumption that each genotype—represented as a sequence—maps deterministically to a single phenotype, such as a discrete structure. Here, we introduce probabilistic genotype-phenotype (PrGP) maps, where each genotype maps to a vector of phenotype probabilities, as a more realistic and universal language for investigating robustness in a variety of physical, biological, and computational systems. We study three model systems to show that PrGP maps offer a generalized framework which can handle uncertainty emerging from various physical sources: (1) thermal fluctuation in RNA folding, (2) external field disorder in spin glass ground state finding, and (3) superposition and entanglement in quantum circuits, which are realized experimentally on IBM quantum computers. In all three cases, we observe a novel biphasic robustness scaling which is enhanced relative to random expectation for more frequent phenotypes and approaches random expectation for less frequent phenotypes. We derive an analytical theory for the behavior of PrGP robustness, and we demonstrate that the theory is highly predictive of empirical robustness. © 2023, CC BY.

关键词： Quantum computers

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Deterministic synthesis of phase pure 2D perovskites via progressive transformation of layer thickness

arXiv

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arXiv 2022年

作者： Hou, Jin Li, Wenbin Zhang, Hao Sidhik, Siraj Blancon, Jean-Christophe Even, Jacky Kanatzidis, Mercouri G. Mohite, Aditya D. Department of Materials Science and NanoEngineering Rice University HoustonTX77005 United States Department of Chemical and Biomolecular Engineering Rice University HoustonTX77005 United States Applied Physics Graduate Program Smalley‐Curl Institute Rice University HoustonTX77005 United States INSA de Rennes CNRS UMR 6082 Rennes35708 France Department of Chemistry Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States

Two-dimensional (2D) halide perovskites have emerged as semiconductor platforms for realizing efficient and durable optoelectronic devices. However, the reproducible synthesis of 2D perovskite crystals with desired layer thickness (or n value) greater than 2, has been an enduring challenge due to the lack of kinetic control (temperature, time, stoichiometry) for each layer thickness. Here, we demonstrate a novel method term as the kinetically controlled space confinement (KCSC) for the deterministic growth of phase pure Ruddlesden-Popper (RP) and Dion-Jacobson (DJ) 2D perovskites. The phase-pure growth was achieved by progressively increasing the temperature (fixed time) or the crystallization time (fixed temperature), which allowed for an acute control of the crystallization kinetics. We also observe a systematic transformation from a lower n-value to n=3, 4, 5, 6 in 2D perovskites. In-situ photoluminescence spectroscopy and imaging suggest that the progressive transformation from lower to higher n-value occurs via intercalation of excess precursor ions. These experiments enabled the development of a machine learning assisted multi-parameter phase diagram, which predicts the growth of 2D phase with a specific n-value. © 2022, CC BY.

关键词： Perovskite

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Rapid and non-destructive determination of vitamin C and antioxidant activity of intact red chilies using visible near-infrared spectroscopy and machine learning tools

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Case Studies in chemical and Environmental engineering 2023年 8卷

作者： Devianti Sufardi Hafsah, Siti Sariadi Ahmad, Fachraniah Arianti, Nunik Destria Saputra, Edo Hartuti, Sri Department of Agricultural Engineering Faculty of Agriculture Syiah Kuala University Banda Aceh 23111 Indonesia Department of Soil Science Faculty of Agriculture Universitas Syiah Kuala Banda Aceh 23111 Indonesia Department of Agrotechnology Faculty of Agriculture Universitas Syiah Kuala Banda Aceh 23111 Indonesia Department of Chemical Engineering Politeknik Negeri Lhokseumawe Lhokseumawe 24301 Indonesia Department of Information System Nusa Putra University Sukabumi 43155 Indonesia Department of Agricultural Technology Faculty of Agriculture Universitas Riau Pekanbaru 28293 Indonesia Agricultural Engineering Study Program IPB University Bogor 16680 Indonesia

Red chili peppers are extensively used in the culinary industry due to their high vitamin C, antioxidant content, spice, and natural colorant properties. Traditional methods for determining these parameters are time-consuming and unstable. This study investigates the viability of visible near-infrared spectroscopy as a rapid and nondestructive method for determining vitamin C content and antioxidant activity in intact red chilies. Visible near-infrared spectroscopy measures the sample's light absorption, proportional to its chemical composition. Collecting intact red chili samples from various sources and determining their vitamin C content and antioxidant activity using conventional methods were required for the study. The visible near-infrared spectra of the pieces were collected using a spectrometer, and chemometric models were devised to correlate the spectra with the vitamin C content and antioxidant activity. Traditional methods were compared to visible near-infrared spectroscopy regarding their performance of prediction. In conjunction with chemometric models and machine learning algorithms, visible near-infrared spectroscopy could accurately predict red chilies' vitamin C content and antioxidant activity. The developed models exhibited high calibration and prediction coefficients, low root mean square errors, and high prediction-to-deviation ratios. The identified absorption peaks in the visible near-infrared spectra were related to the samples' color pigments and water content. This study demonstrates the feasibility of visible near-infrared spectroscopy as a rapid and nondestructive method for determining the vitamin C content and antioxidant activity of intact red chilies. The findings may have significant ramifications for the food industry, providing a more efficient and secure quality control and nutritional labeling method. It is recommended that additional research and validation be conducted to ensure the applicability of the developed models to var

关键词： Chemometrics tools Machine learning Red chilies Spectroscopy

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