Article
Chemistry, Multidisciplinary
Hope Nelson, William Richard, Hailee Brown, Abigail Medlin, Christina Light, Stephen T. Heller
Summary: The use of N-carbonylimidazoles enables catalytic chemodivergent aniline or alcohol acylation with high chemoselectivity and practicality. These acylation reactions show unprecedented levels of chemoselectivity for multiple functional groups and can be operated on a multigram scale.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Multidisciplinary Sciences
Dorin Stanica-Ezeanu, Danuta Matei
Summary: PET, widely used in food packaging and fishing nets, can be efficiently depolymerized by hydrolysis in marine waters. Metal ions in seawater act as catalysts for this process. Mathematical modeling shows that global ocean can convert PET within years.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Boyong Ye, Ruru Zhou, Zixin Zhong, Songlin Wang, Han Wang, Zhaoyin Hou
Summary: Abandoned plastics, especially waste polyethylene terephthalate (PET), pose a significant threat to the environment and ecology. Scientists have focused on the recycling of these hazardous materials. In this study, an efficient method of catalytic upcycling of waste PET to dimethyl terephthalate (DMT) was developed using environmentally friendly TixSi1-xO2 solid acids. The Ti0.5Si0.5O2 catalyst showed high activity and could be recycled multiple times without losing its effectiveness, providing a green pathway for PET recycling.
Article
Polymer Science
Allen C. Chang, Akanksha Patel, Sarah Perry, Yahue Soong, Christian Ayafor, Hsi-Wu Wong, Dongming Xie, Margaret J. Sobkowicz
Summary: This study explores the efficiency of melt extrusion pretreatment of poly(ethylene terephthalate) (PET) prior to enzymatic depolymerization. It finds that specific surface area (SSA) is a key factor in reducing depolymerization time, with higher SSA substrates showing higher depolymerization rates and no induction phase. The mechanism of enzymatic depolymerization is characterized by the appearance of anisotropic pitting. Longer incubation time allows for nearly full recovery of monomeric products in low SSA substrates.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Wataru Muramatsu, Hisashi Yamamoto
Summary: We describe the development of a reliable catalytic protocol for peptide bond formation that is generally applicable to natural and unnatural alpha-amino acids, beta-amino acids, and peptides bearing various functional groups. A 10 mol % loading of HSi[OCH(CF3)(2)](3) as a catalyst was sufficient to guarantee a consistently high yield of the resulting peptide. This method facilitates the sustainable utilization of natural resources by using a catalyst and an auxiliary based on earth-abundant silicon.
Article
Chemistry, Multidisciplinary
Pengyu Wu, Guoping Lu, Chun Cai
Summary: A novel bimetallic catalyst CoMo@NC derived from Mo@ZIF-CoZn has been prepared, showing enhanced catalytic performance in hydrogenolysis for recycling terephthalate-based polyesters. The synergistic catalysis between Mo-sites and Co-sites inside the catalyst contributes to its high efficiency. This work highlights new possibilities for bimetallic catalysts in sustainable chemistry.
Article
Polymer Science
Kazuki Fukushima, Yuya Watanabe, Tetsuya Ueda, So Nakai, Takashi Kato
Summary: This study investigates the efficacy of organocatalysts for the depolymerization of poly(trimethylene carbonate) (PTMC), an aliphatic polycarbonate, and finds that organic acids and bases show high activity in the degradation process. The findings provide a promising standard for the chemical recycling of aliphatic polycarbonates, contributing to the development of sustainable materials.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Multidisciplinary Sciences
Yuantao Peng, Jie Yang, Chenqiang Deng, Jin Deng, Li Shen, Yao Fu
Summary: This article introduces an efficient method to recycle waste polyethylene terephthalate using acetolysis, which allows for the separation of terephthalic acid and ethylene glycol diacetate in high purity, as well as closed-loop recycling. Life cycle assessment shows that this method offers a low-carbon pathway for the full upcycling of waste polyethylene terephthalate.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Chemical
Lars Biermann, David Quast, Esther Brepohl, Carsten Eichert, Stephan Scholl
Summary: The study investigated the alkaline depolymerization reaction of PET under quasi-solvent-free conditions, providing a new approach for recycling PET waste. Adjustment of base particle size, reaction temperature, and mixing speed can influence the yield of terephthalic acid. PET can be depolymerized almost quantitatively at moderate reaction temperatures, with the quality of the terephthalic acid monomer primarily influenced by the reaction temperature.
CHEMICAL ENGINEERING & TECHNOLOGY
(2021)
Article
Environmental Sciences
Lei Tian, Ewa Skoczynska, Robert-Jan Van Putten, Heather A. Leslie, Gert-Jan M. Gruter
Summary: Concerns about the environmental and health impacts of microplastics and nanoplastics, collectively referred to as MNP, have increased in recent years. This study focuses on the quantification of small polyethylene terephthalate microplastics (PETMNP) in influents and effluents from wastewater treatment plants using a three-step method of drying, PET depolymerization, and LC-MS analysis. PETMNP was detected in all influents (ranging from 24.9 μg/L to 680 μg/L) and most effluents.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Biotechnology & Applied Microbiology
Rodrigo Brackmann, Claudia de Oliveira Veloso, Aline Machado de Castro, Marta Antunes Pereira Langone
Summary: This study investigated the degradation of post-consumer PET using five commercial hydrolase enzymes. Humicola insolens cutinase (HiC) was found to be the most active enzyme. The concentration and ratio of hydrolysis products varied significantly with reaction temperature. The enzymatic PET hydrolysis by HiC was sensitive to enzyme concentration, with a maximum achieved at 40-50 vol% of HiC. These findings contribute to optimizing enzyme-based PET recycling technologies.
Article
Engineering, Environmental
Peng Huang, Joe Pitcher, Alan Mushing, Fernando Lourenco, Michael P. Shaver
Summary: The adoption of glycol-modified poly(ethylene terephthalate) (PET-G) as an alternative thermoplastic enables a transition from the current linear economy to a sustainable circular economy for non-recyclable multi-materials. Chemical recycling of PET-G is demonstrated for the first time, showcasing its effective depolymerization capabilities. The system exhibits high selectivity and tolerance, enabling kilogram-scale depolymerization and recovery of metal components from complex multi-layered credit cards.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Chemistry, Multidisciplinary
Anup S. Joshi, Niloofar Alipourasiabi, Keerthi Vinnakota, Maria R. Coleman, Joseph G. Lawrence
Summary: The research demonstrates that copolymerization of PET with FDCA can improve the efficiency of esterification and alkaline hydrolysis, potentially reducing the carbon footprint of PET production.
Article
Engineering, Environmental
Mi Yan, Yayong Yang, Tianchi Shen, Nurak Grisdanurak, Agamuthu Pariatamby, Mohammad Khalid, Dwi Hantoko, Haryo Wibowo
Summary: In this study, supercritical ethanol depolymerization (SCED) was used to recover monomer from waste PET. The effects of reaction temperature, reaction time, and liquid/solid mass ratio on depolymerization efficiency were investigated. The optimal conditions for depolymerization were found to be 310℃, 60 min, and a liquid/solid ratio of 10:1. SCED showed potential for monomer recovery from waste PET.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Chemistry, Organic
Meixia Liu, Huimin Hu, Runbo Sun, Haoyuan Li, Anjun Ding, Xiaoyong Liu, Zhengjiang Fu, Shengmei Guo, Hu Cai
Summary: We present a nickel-catalyzed reductive cross-coupling method to synthesize phosphinic amides from readily available nitroarenes and phosphine oxides. The reaction employs NiCl2/Xantphos as catalyst, zinc as reductant, and TMSCl as additive, delivering various phosphinic amides in moderate to good yields. Notably, a gram-scale synthesis was successfully achieved, making this method practical for the synthesis of phosphinic amides. Mechanistic insights were also obtained from control experiments.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Materials Science, Biomaterials
Valentina Montagna, Junko Takahashi, Meng-Yu Tsai, Takayuki Ota, Nicolas Zivic, Seigou Kawaguchi, Takashi Kato, Masaru Tanaka, Haritz Sardon, Kazuki Fukushima
Summary: The newly developed glycerol-based aliphatic polycarbonate polymer PMDO demonstrated good biocompatibility, inhibited platelet adhesion and protein denaturation, and showed higher hydrolytic property compared to PTMC. The presence of specific hydrated water in the polymer contributed to the improved blood compatibility and hydrolytic biodegradability of PMDO.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2021)
Article
Chemistry, Physical
Qi Gao, Hajime Nakamura, Tanvi P. Gujarati, Gavin O. Jones, Julia E. Rice, Stephen P. Wood, Marco Pistoia, Jeannette M. Garcia, Naoki Yamamoto
Summary: The study utilizes VQE to investigate biradical systems on quantum simulators and devices, providing guidelines for selecting active spaces in chemical systems. Results show that VQE on a quantum simulator reproduces results from Full CI, while calculations on a quantum device exhibit deviations from exact values.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Physical
Julia E. Rice, Tanvi P. Gujarati, Mario Motta, Tyler Y. Takeshita, Eunseok Lee, Joseph A. Latone, Jeannette M. Garcia
Summary: Quantum chemistry simulations of industrially relevant molecules are conducted using variational quantum algorithms for near-term quantum devices. Calculations of energies and dipole moments are focused on the dissociation curves of lithium hydride, hydrogen sulfide, lithium hydrogen sulfide, and lithium sulfide, with a novel approach to dipole moment calculations on quantum hardware.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Qi Gao, Gavin O. Jones, Mario Motta, Michihiko Sugawara, Hiroshi C. Watanabe, Takao Kobayashi, Eriko Watanabe, Yu-ya Ohnishi, Hajime Nakamura, Naoki Yamamoto
Summary: A quantum chemistry study was conducted on the first singlet and triplet excited states of phenylsulfonyl-carbazole compounds, with quantum simulations on devices showing excellent agreement with experimental data. By utilizing state tomography to purify quantum states and correct energy values, large errors in unmitigated results could be improved to minimal differences with exact values, leading to excellent agreement between predicted values by quantum simulations and those found in experiments.
NPJ COMPUTATIONAL MATERIALS
(2021)
Article
Polymer Science
Kazuki Fukushima, Kodai Matsuzaki, Masashi Oji, Yuji Higuchi, Go Watanabe, Yuki Suzuki, Moriya Kikuchi, Nozomi Fujimura, Naofumi Shimokawa, Hiroaki Ito, Takashi Kato, Seigou Kawaguchi, Masaru Tanaka
Summary: A novel polymer conjugate has been developed to form anisotropic nanoassemblies independent of the crystalline nature of the hydrophobic block. Molecular dynamics simulations show that rigid hydrogen-bonding motifs contribute to the anisotropic alignment of block copolymers, and amorphous hydrophobic blocks containing these motifs can form nonspherical assemblies. Enhanced cell proliferation is observed in cell cultures containing anisotropic polymer assemblies with specific aspect ratios or lengths.
Review
Chemistry, Multidisciplinary
Mario Motta, Julia E. Rice
Summary: Digital quantum computers provide a computational framework for solving the Schrodinger equation for many-particle systems, with recent remarkable growth in quantum computing algorithms for quantum simulation. This review introduces emerging algorithms for the simulation of Hamiltonian dynamics and eigenstates, focusing on their applications to electronic structure in molecular systems. Theoretical foundations, implementation details, strengths, limitations, and recent advances of the method are discussed.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Caleb N. Jadrich, Vince E. Pane, Binhong Lin, Gavin O. Jones, James L. Hedrick, Nathaniel H. Park, Robert M. Waymouth
Summary: A new organocatalyst has been discovered for the ring-opening polymerization of lactones, which exhibits fast and living polymerization reactions. The anions of 2,2'-bisindole activate the monomer via the counterion, enabling modulation of the polymerization rate by changing the counterion.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Kazuki Fukushima, Yuki Ota, Takashi Kato
Summary: A methoxy-bearing aliphatic poly(ester-ether) with increased hydration properties has been developed for potential applications in blood-contacting medical devices, showing promise as a biodegradable and biocompatible polymer derived from renewable feedstocks.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2022)
Article
Polymer Science
Yuya Watanabe, Riki Kato, Kazuki Fukushima, Takashi Kato
Summary: Aromatic ester triad mesogens are incorporated into biodegradable aliphatic polycarbonate sequences to enhance their physical properties while maintaining degradability.
Article
Polymer Science
Kazuki Fukushima, Yuya Watanabe, Tetsuya Ueda, So Nakai, Takashi Kato
Summary: This study investigates the efficacy of organocatalysts for the depolymerization of poly(trimethylene carbonate) (PTMC), an aliphatic polycarbonate, and finds that organic acids and bases show high activity in the degradation process. The findings provide a promising standard for the chemical recycling of aliphatic polycarbonates, contributing to the development of sustainable materials.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Shota Yamazaki, Mahoko Harada, Yuya Watanabe, Rongjian Lang, Takashi Kato, Osamu Haba, Kazuki Fukushima, Jiro Kumaki
Summary: Polylactide (PLA) forms extended-chain crystals in a Langmuir monolayer due to the acceleration of crystallization on the water surface. Star-shaped poly(L-lactide)s (PLLAs) with 2-12 arms were synthesized and their crystallization behavior in a monolayer was studied. PLLAs with 2-4 arms showed alignment in the same direction and folding at the central polyol unit, while PLLAs with 6 and 12 arms showed extension in opposite directions, likely due to steric hindrance. Star-shaped PLLAs have a reduced crystallization rate compared to linear PLA, possibly because of their unique crystallization behavior with aligned arms.
Article
Quantum Science & Technology
Tanvi P. Gujarati, Mario Motta, Triet Nguyen Friedhoff, Julia E. Rice, Nam Nguyen, Panagiotis Kl. Barkoutsos, Richard J. Thompson, Tyler Smith, Marna Kagele, Mark Brei, Barbara A. Jones, Kristen Williams
Summary: Modeling electronic systems is an important application for quantum computers. In this work, the authors propose a workflow to model chemical reactions on surfaces using quantum computing algorithms. They develop and compare two local embedding methods to determine active spaces and introduce a technique for circuit simplification to reduce the quantum resources required.
NPJ QUANTUM INFORMATION
(2023)
Article
Chemistry, Multidisciplinary
Takayuki Ota, Valentina Montagna, Yuji Higuchi, Takashi Kato, Masaru Tanaka, Haritz Sardon, Kazuki Fukushima
Summary: This study investigates the ring-opening reactions of γ-carbonyl-substituted ε-caprolactones and finds that chain propagation hardly occurs, as the propagating species preferentially transform to α-substituted five-membered lactones. This study contributes to understanding the chemistry of ring-opening reactions of substituted lactones for designing functional degradable polymers.
Article
Polymer Science
Yuya Watanabe, Shunya Takaoka, Yuta Haga, Kohei Kishi, Shunta Hakozaki, Atsushi Narumi, Takashi Kato, Masaru Tanaka, Kazuki Fukushima
Summary: Simple and efficient synthetic routes for functionalized cyclic carbonates are crucial for the practical application of biodegradable functional biomaterials. In this study, a six-membered cyclic carbonate with a triethylammonium carboxylate was successfully prepared from 2,2-bis(methylol)propionic acid. The esterification of the organic carboxylate salt with alkyl bromides enabled the synthesis of functionalized cyclic carbonate monomers, which could be polymerized effectively. The resulting aliphatic polycarbonates demonstrated good antiplatelet properties.
Article
Polymer Science
Kazuki Fukushima, Gavin O. Jones, Hans W. Horn, Julia E. Rice, Takashi Kato, James L. Hedrick
