Article
Environmental Sciences
Hongwei Luo, Chaolin Tu, Dongqin He, Anping Zhang, Jianqiang Sun, Jun Li, Juan Xu, Xiangliang Pan
Summary: This comprehensive review summarizes the aging process of microplastics (MPs) and the factors that impact their aging, and discusses the effects of aging on the interaction of MPs with contaminants. The review also outlines a range of characterization methods that elucidate the mechanistic processes of these interactions. The rate and extent of MPs aging are influenced by their physicochemical properties and other environmental factors, which ultimately affect the adsorption and aggregation of aged MPs with environmental contaminants.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Physical
Sara Gomez, Elizabeth Florez, Nancy Acelas, Cacier Hadad, Albeiro Restrepo
Summary: This passage describes a cage-like structure (H2O)(20) consisting of 30 hydrogen bonds, which successfully encapsulates Astatide with minimal geometrical distortion. While the stability of the cage is slightly destabilized, the non-covalent interactions are actually strengthened. In the [At@(H2O)(20)](-) cluster, the host center dot center dot center dot cage interactions are anti-electrostatic, bringing both negatively charged atoms in direct contact as in At delta-center dot center dot center dot O delta--H delta+. An analysis of orbital interactions reveals that the explicit host center dot center dot center dot cage contacts are inverted hydrogen bonds, involving the same type of donor -> acceptor charge transfer as in hydrogen bonding, without a proton bridging the two negative charges.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Robin Kueng, Tobias Pausch, Dustin Rasch, Robert Goestl, Bernd M. Schmidt
Summary: The supramolecular coordination cage within a star-shaped water-soluble polymer can respond to ultrasonication-induced shear force and release pharmaceutically active cargo encapsulated within its hydrophobic nanocavity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Liwei Cheng, Zhi Li, Jinlong Cui, Ran Zhu, Jia Li, Huibo Qin, Bei Liu, Guangjin Chen, Fulong Ning
Summary: As an important hydrate control method, kinetic hydrate inhibitors (KHIs) have gained extensive attention in the oil and gas industry. The addition of synergistic reagents with high efficiency to improve the inhibition performance of KHIs is of great significance for the prevention and treatment of hydrates.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Multidisciplinary
Qingqing Sun, Luis Escobar, Jorn de Jong, Pablo Ballester
Summary: This study reports the self-assembly of a tetra-cationic super aryl-extended calix[4]pyrrole tetra-pyridyl ligand into a water-soluble Pd(ii)-cage featuring two endohedral polar binding sites, which requires specific types of guests for efficient assembly. High conformational selectivity is observed in the inclusion of isomers of alpha, omega-bis-formamides, and the uptake and release mechanism/kinetics of selected polar guests are briefly investigated using pair-wise competition experiments.
Article
Energy & Fuels
Zhiyuan Wang, Pengfei Li, Shikun Tong, Jianbo Zhang, Chenru Zhou, Jihao Pei, Hemin Yang, Chenwei Liu
Summary: In this study, a high-pressure visualization microscopic force testing system was used to investigate the adhesion force between methane hydrate particles and wall droplets. The results showed that the adhesion force reached the lowest value at a QAs1 solution concentration of 0.2 wt% (CMC), with values of 589.81 mN/m and 1123.63 mN/m under 1 and 10 subcooling conditions, respectively. The mechanism of QAs1 in reducing adhesion force was found to be mainly through the reduction of gas-water interfacial tension under lower subcooling conditions and the steric hindrance effect of QAs1 molecules under higher subcooling conditions.
Article
Chemistry, Physical
Dilare Kainai, Jie Zhang, Dongsheng Bai
Summary: This study investigates the melting behavior of gas hydrates with empty cages under overheating driving force using molecular dynamics simulations. The melting point of methane hydrates with different motifs is determined, and the effects of overheating driving force, cage occupancy, and empty cage distribution on the melting rate and mechanism are explored. The results show that the induction time of melting is influenced by the overheating, and the activation energy is related to the distortion of the hydrate skeleton. The melting process can be divided into linear and final stages, and the melting rate is affected by overheating and occupancy. Different empty cage distributions result in different melting behaviors. The proposed phenomenological equation describes the influence of real-time changes in occupancy and empty cage distribution on the melting rate and mechanism. The study also discusses the transition of hydrate cages from filled-like to empty-like with decreasing guest molecule size.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Mechanical
Dingtang Zhao, Jun Hong, Ke Yan, Qiangqiang Zhao, Bin Fang
Summary: The study analyzes the dynamic interaction between the rolling element and cage, proposes a dynamic model, and evaluates and discusses the impacts under different circumstances.
MECHANISM AND MACHINE THEORY
(2022)
Article
Chemistry, Physical
Jinxiang Liu, Yujie Yan, Gang Chen, Jun Zhang, Shengli Liu
Summary: In this study, the inhibition performance of poly(N-alkyl-N-vinyl acetamide)s with varying alkyl side chain lengths as kinetic hydrate inhibitors was investigated through calculations and simulations. Results show that increasing the alkyl side chain length enhances adsorption strength and chemical reactivity, improving inhibition performance.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Electrochemistry
Jesus Alberto Perez-Garcia, Francisco Javier Bacame-Valenzuela, Fabricio Espejel-Ayala, Luis Ortiz-Frade, Yolanda Reyes-Vidal
Summary: Redox mediators (RM) are used to improve the performance of microbial electrochemical systems (MES) by facilitating indirect electron transfer. Pyocyanin, which is considered an RM, can adsorb to glassy carbon electrodes and its adsorption and concentration have an effect on electron transfer rate. The study provides insights into the redox cycle of pyocyanin and its application in electrochemical-microbial systems.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
Yuqi Miao, Huashan Yan, Bengen Hong, Xiaowen Zhou, Lichao Tong, Yanfei Xiao, Sen Qiu, Bin Yang, Qibang Long, Yong Li, Yi Xia, Tingsheng Qiu
Summary: This study used DFT to investigate the adsorption mechanism of impurity Al3+ dihydroxy hydrate on the kaolinite surface and the influence of impurity Mg, Ca, and Fe on surface properties. The results showed that doping affected the adsorption ability and surface activity.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Multidisciplinary
Shihang Rao, Yajun Deng, Zhenchao Li, Hailong Lu, Qian Zhang
Summary: CO2 hydrate formation in a restricted space was studied using in situ visual observation. The results showed that the hydrate film first appeared at the gas-liquid interface and then spread on the surface of the silicon wafer. The effect of solid surface on CO2 hydrate formation was also investigated, and it was found that no hydrate spreading was observed on the hydrophobic surface, whereas the hydrate film spread on the hydrophilic surface. Quantitative analysis indicated that the interfacial tension between the hydrate and silicon wafer played a more significant role in hydrate spreading rate and film thickness compared to pressure and temperature.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Polymer Science
Ziqiao Zhong, Zhiwei Chen, Yuke Xie, Wenhao Wang, Zhengwei Huang, Ying Huang, Chuanbin Wu, Xin Pan
Summary: The study found that LLPNs coated with a high concentration of sulfobetaine can block their interaction with BSA, but not at lower concentrations. In contrast to other coating materials, sulfobetaine interacts with LLPNs and is partially inserted into their hydrophobic region. This study suggests that coating-modified nanoparticles do not necessarily avoid interacting with proteins.
Article
Chemistry, Physical
Stephan Mohr, Remi Petuya, Juan Sarria, Nirupam Purkayastha, Scot Bodnar, Jonathan Wylde, Ioannis N. Tsimpanogiannis
Summary: Molecular dynamics simulations were used to study the adsorption of ten hydrate anti-agglomerants on a mixed methane-propane sII hydrate surface covered with layers of liquid water. It was found that the presence and thickness of the liquid water layer are crucial parameters for anti-agglomerant adsorption studies. Additionally, an optimal thickness of the liquid water layer favoring hydrate growth was identified. The results showed good agreement with theoretical predictions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Zhi Li, Yue Zhang, Yimao Shen, Xiaodeng Yang, Tianduo Li, Guangjin Chen
Summary: This study synthesized chitosan derivatives with different hydrophilic/hydrophobic properties and compared them with carboxymethyl chitosan derivatives to investigate their relationship with methane hydrate. The experimental results showed that the inhibitory effects of chitosan derivatives were significantly better than carboxymethyl chitosan derivatives. The length and properties of the chitosan derivatives' branched chains played a vital role in hydrate inhibition. Gas-induced agitation provided insights into the hydrate inhibition mechanism of chitosan derivatives.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Energy & Fuels
Kai Gao, Guang-Jun Guo, Mingmin Zhang, Zhengcai Zhang, Bo Peng
Summary: The study found that the methane adsorption on rough graphite surfaces with different tilt angles has irregular density profiles and varying adsorption strength. The average adsorption density of methane initially increases and then decreases with increasing tilt angle, reaching a maximum at 5 degrees. The findings suggest that surface roughness and layer-accumulated adsorption potential play key roles in determining methane adsorption behavior.
Article
Energy & Fuels
Jie Chen, Chanjuan Liu, Zhengcai Zhang, Nengyou Wu, Changling Liu, Fulong Ning, Bin Fang, Yizhao Wan, Qingtao Bu, Gaowei Hu
Summary: Strong static electric fields can induce the migration of Na+ and Cl- ions, leading to the decomposition of methane hydrate. Increasing electric field strength enhances the destructive ability of ions to hydrate, resulting in faster decomposition. This study provides insights into a new method for natural gas hydrate extraction and inhibition of hydrate formation in pipelines, as well as the potential of using hydrate as a new ion exchange membrane material in the future.
Article
Thermodynamics
Zhengcai Zhang, Peter G. Kusalik, Nengyou Wu, Changling Liu, Yongchao Zhang
Summary: This study investigates the stability of natural gas hydrates in confined space through molecular simulations, focusing on the effects of pore size and pore surface properties. The results show that the melting points of methane hydrate are controlled by the slit size, while the mineral surface has a minor effect. Additionally, the specific surface area of hydrate particles determines their stability in silica slits. Methane hydrate dissociates faster in confined space, especially in hydrophilic systems.
Article
Chemistry, Physical
Mingmin Zhang, Zhengcai Zhang, Dongdong Ni
Summary: This study investigates the growth mechanism of sH hydrate through large-scale molecular dynamics simulations and finds that the improper trapping of MPD molecules at the hydrate surface is the main cause of slow crystal growth. Increasing pressure promotes hydrate growth, but excessive pressure leads to cross-growth of different types of hydrates. Furthermore, the proper concentration of MPD is also crucial for the growth of sH hydrate.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Lei Wang, Kyle Hall, Zhengcai Zhang, Peter G. Kusalik
Summary: This study utilizes molecular simulations to investigate the behavior of CH4/H2S mixed hydrate nucleation. It is found that CH4 is enriched in the hydrate phase while the aqueous phase is enriched in H2S. Nonstandard cages and cages with heptagonal faces play a significant role in the early-stage gas hydrate structural transitions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Zhengcai Zhang, Peter G. Kusalik, Nengyou Wu, Changling Liu, Fulong Ning
Summary: This study investigated the impacts of calcite nanoparticles on methane hydrate formation through molecular dynamics simulations. The results revealed that the nanoparticles inhibit methane hydrate nucleation and do not have clear connections with nucleated hydrates. Furthermore, the nanoparticles only affect hydrate growth when the growth front approaches the bound water around the nanoparticles.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Energy & Fuels
Lei Wang, Zhengcai Zhang, Peter G. Kusalik
Summary: This study uses molecular dynamics simulations to investigate the nucleation behavior of gas hydrates in water nanodroplets immersed in a non-aqueous liquid. The study examines key factors influencing nucleation and finds that H2S tends to initiate hydrate formation. The results provide important insights into the molecular mechanism of clathrate hydrate nucleation in water-in-oil emulsions.
Article
Energy & Fuels
Chao Zheng, Guang-Jun Guo, Xuwen Qin, Yanhui Dong, Cheng Lu, Bo Peng, Wei Tang, Hang Bian
Summary: Water/methane two-phase flow in a hydrophilic cylindrical nanopore was studied using molecular simulations, and a water lock model and its formation mechanism were proposed. These findings are valuable for understanding two-phase percolation and optimizing gas production and water removal schemes during hydrate exploitation.
Article
Chemistry, Multidisciplinary
Cuiping Tang, Abdolreza Farhadian, Avni Berisha, Mohamed A. Deyab, Jie Chen, Danial Iravani, Alireza Rahimi, Zhengcai Zhang, Deqing Liang
Summary: Gas hydrate and corrosion inhibitors are commonly used in oil and gas pipelines to ensure smooth flow, but compatibility issues arise when they are co-injected. Using anti-agglomerant hydrate inhibitors is an effective method to control gas hydrate plugging in deep-water hydrocarbon flow lines or drilling operations.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Yue Zhao, Fansen Zeng, Dachuan Zhao, Lei Lin, Zhengcai Zhang
Summary: This study investigates the growth process of carbon dioxide hydrate in the presence of salt through systematic molecular dynamics simulations. The results show that the growth rate of hydrate decreases with increasing solution salinity, and the number of ions bound in the hydrate structure is related to the growth rate and salinity. The replacement of water molecules by ions at the vertex of the cages is energetically unfavorable. The temperature has a maximum effect on the growth rate, while pressure has a negligible impact. The ion concentration in the hydrate phase decreases with temperature and is hardly affected by pressure. The trapping of ions in the hydrate phase is kinetically controlled by ion diffusion properties.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Energy & Fuels
Jie Chen, Zhengcai Zhang, Yongchao Hao, Daniel Porfirio Luis Jimenez, Jiafang Xu, Nengyou Wu, Fulong Ning, Bin Fang, Jun Zhang, Jianye Sun, Xiluo Hao, Qingguo Meng, YanLong Li, Yizhao Wan, Chanjuan Liu, Gaowei Hu
Summary: The formation and dissociation of gas hydrate can be influenced by electrostatic fields, making it a potential technology with great application value in hydrate exploitation, prevention, and related technologies. The molecular dynamics simulation revealed that the migration and destruction of ions in the hydrate are influenced by the strength of the electrostatic field. The insights gained from this study are beneficial for the application of electrostatic field in hydrate mining and safety of oil and gas pipeline transportation.
Article
Thermodynamics
Zhengcai Zhang, Peter G. Kusalik, Changling Liu, Nengyou Wu
Summary: In this study, molecular simulations were used to investigate the formation of methane hydrates in surface-modified silica pores, and the impact of pore surface characteristics was emphasized. The results showed that methane hydrate formation had no preference towards hydrophobic or hydrophilic pore surfaces. It was also found that pre-filling the pores with methane could accelerate hydrate formation. This study enhances understanding of the hydrate formation process in pores and has implications for the design of gas hydrate promoters or inhibitors.
Review
Geosciences, Multidisciplinary
Yong-chao Zhang, Le-le Liu, Gao-wei Hu, Qing-tao Bu, Cheng-feng Li, Zheng-cai Zhang, Jian-ye Sun, Chang-ling Liu
Summary: This study reviews the formation mechanisms of grain-displacing hydrate from the perspective of geological accumulation and microscale sedimentary property, and proposes shortcomings in current theories and suggestions for future study.
Review
Geosciences, Multidisciplinary
Zheng-cai Zhang, Neng-you Wu, Chang-ling Liu, Xi-luo Hao, Yong-chao Zhang, Kai Gao, Bo Peng, Chao Zheng, Wei Tang, Guang-jun Guo
Summary: This article provides a systematic evaluation of recent advances in molecular dynamics simulation of hydrate nucleation and growth. It explores the enlightening significance of these studies for hydrate applications. Additionally, potential directions for molecular simulation in the research of hydrate nucleation and growth are proposed, and the future of molecular simulation research in this field is discussed.
