Article
Polymer Science
Christian Aponte-Rivera, Michael Rubinstein
Summary: This study presents a scaling theory to predict the dynamics of symmetric and asymmetric unentangled liquid coacervates formed by solutions of oppositely charged polyelectrolytes. Symmetric coacervates consist of polycations and polyanions with equal charge densities and a single correlation length, while asymmetric coacervates have unequal charge densities and a double semidilute structure with two correlation lengths. The dynamic coupling in asymmetric coacervates increases the friction and contribution to zero-shear viscosity of high-charge-density polyelectrolytes, with a non-monotonic salt concentration dependence of the zero-shear viscosity predicted.
Article
Polymer Science
Quhui Chang, Jian Jiang
Summary: The study found that the alteration of charge distribution due to different PE chain structures directly affects the adsorption behavior of PEs on an oppositely charged surface. In a salt-free system, PE chain structure and sequence variables have a significant impact on adsorption behaviors, showing complex behaviors in adsorption amounts. Additionally, overcharging only occurs when the bare surface charge density is low enough.
Article
Polymer Science
Shensheng Chen, Pengfei Zhang, Zhen-Gang Wang
Summary: In this study, dissipative particle dynamics was used to investigate the behavior of polyelectrolyte complexes in dilute solutions. The results show that net-charged macromolecular clusters are formed in the systems, which depends on the overall charge asymmetry. When the charge ratio reaches a threshold value, the polyions condense into a single large coacervate cluster. The addition of salt leads to salting-out and salting-in phenomena, and the length and concentration asymmetry play significant roles in polyelectrolyte complex coacervation.
Article
Chemistry, Physical
Soumik Mitra, Arindam Kundagrami
Summary: The interplay between Coulomb interaction energy, free ion entropy, and conformational elasticity is an intriguing aspect in polyelectrolytes. A theory is developed to explore the thermodynamics of complex formation in polyelectrolyte solutions, specifically the complexation of two oppositely charged polyelectrolytes. The theory takes into account the solvent polarity, dielectricity, and Coulomb strength, and reveals the role of entropy and enthalpy in driving complexation.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Polymer Science
Taichi Ikeda
Summary: Glycidyl triazolyl polymer (GTP)-based anionic poly-(ionic liquid)-s were synthesized and characterized. These anionic GTPs exhibited phase separation behavior and lower Tg compared to cationic GTPs. The presence of water improved the ionic conductivity. The electrostatic interaction between the TFSI pendant and the EMIM cation influenced the polymer-polymer interaction.
Article
Polymer Science
Anna A. Glagoleva, Alexander A. Yaroslavov, Valentina V. Vasilevskaya
Summary: In this study, computer simulation was used to study the adsorption and diffusion of polyelectrolyte macromolecules on oppositely charged surfaces. The relationship between the ionization degree of the macromolecules, surface charge, and the coverage and charge of the adsorbed layer was investigated. The polymer diffusion within the adsorbed layers was also examined, taking into account its dependency on the surface coverage and macromolecular ionization degree. The findings provide valuable insights for the development of functional coatings.
Article
Chemistry, Applied
Kaitao Zhang, Mostafa Y. Ismail, Henrikki Liimatainen
Summary: This study proposes a method for designing water resistant assembled nanopaper through controlled aqueous complexation of oppositely charged cellulose nanoconstituents. The mechanical properties and water barrier properties of the nanopaper can be enhanced through electrostatic interaction between charged nano-entities, providing a new pathway for the fabrication of functionalized films and sheets.
FOOD HYDROCOLLOIDS
(2021)
Article
Polymer Science
Christos Gioldasis, Leonidas N. Gergidis, Costas Vlahos
Summary: This study investigates the internal stratification of a polyelectrolyte complex formed by mixing charged polyelectrolyte brush with cationic-neutral diblock copolymers. The researchers find that the fraction of neutralized polyelectrolyte brush units increases with the increase in charged units for high grafting densities. By adjusting the choice of cationic-neutral copolymer, different grafting densities of neutral brush can be obtained. Furthermore, the addition of salt leads to a reduction in complexed copolymer chains, with higher salt concentrations resulting in greater reduction. The findings are in agreement with experimental predictions and provide new insights into the structure and shape of the coacervate.
MACROMOLECULAR THEORY AND SIMULATIONS
(2022)
Article
Polymer Science
Artem M. Rumyantsev, Nicholas E. Jackson, Albert Johner, Juan J. de Pablo
Summary: The primary sequence of charged monomers in a polyampholyte significantly affects its conformational properties. The study uses theory and simulations to predict the influence of sequence on the behavior of globally neutral polyampholytes under salt-free conditions. The results show that the charge blockiness along the chain plays a crucial role in determining the internal structure and coil-globule transition of polyampholytes.
Article
Polymer Science
Christos Gioldasis, Leonidas N. Gergidis, Costas Vlahos
Summary: The structural and electrical characteristics of polyelectrolyte complex micelles (PCMs) formed by mixing of oppositely charged double hydrophilic copolymers are studied using molecular dynamics simulations. The addition of divalent salt ions induces secondary micellization, leading to changes in micelle morphology. Mixtures of different types of copolymers also affect the morphology and aggregation number of PCMs.
JOURNAL OF POLYMER SCIENCE
(2021)
Article
Physics, Multidisciplinary
Yao Li, Hai-Long Dong, Jin-Si Zhang, Cheng Lin, Zhi-Jie Tan
Summary: Salt ions play a critical role in regulating interactions between charged particles. The effective interactions between oppositely charged particles can be attractive for low salt valence and become repulsive for high salt valence. The non-monotonic salt-valence dependence of the effective repulsions is influenced by the interplay between ion translational entropy and electrostatic energy.
FRONTIERS IN PHYSICS
(2021)
Article
Engineering, Chemical
Sean Friedowitz, Jian Qin
Summary: Polyelectrolytes can have rod- or coil-like conformations depending on intrachain repulsion and charge density, influenced by both small ion binding and interactions with oppositely charged chains. A coupled variational approach is introduced to study reversible ion binding, adaptive chain structure, and electrostatic correlations simultaneously, revealing distinct regimes in polyelectrolyte coacervation. In weak binding regimes, solution properties depend on polyelectrolyte conformations, while in strong binding regimes, thermodynamics are dominated by short-range ion-binding equilibrium.
Article
Polymer Science
Thi Hai Yen Doan, Tien Duc Pham, Johan Hunziker, Thu Ha Hoang
Summary: In this study, the different desorption concepts of the two polyelectrolytes with similar molecular weights but significantly different charge densities on PSL particles were systematically investigated. For highly charged PTMA5M, desorption continued for 4 hours and re-adsorption proceeded after a longer incubation time, while for lowly charged PTMC5M, an adsorption-desorption equilibrium was observed.
Article
Chemistry, Physical
Jonas Wessen, Tanmoy Pal, Hue Sun Chan
Summary: This study investigates the phase separation of several overall neutral polyampholyte species in solution with oppositely charged ions. It provides a field theory description of the system that considers electrostatic interactions and excluded volume effects. The analysis shows evidence of a re-entrant polyampholyte phase separation at high ion concentrations. Several phase diagrams are presented to explain the dependence of phase separation behavior on various factors.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Thu Thao Pham, Rintaro Takahashi, Tien Duc Pham, Shin-ichi Yusa
Summary: Stable PIC micelles with a small hydrodynamic radius of approximately 20 nm were prepared in water by mixing double hydrophilic oppositely charged diblock copolymers. The stability of these micelles is attributed to the combined driving forces of electrostatic and hydrophobic interactions.
Article
Chemistry, Multidisciplinary
Artem M. Rumyantsev, Frans A. M. Leermakers, Ekaterina B. Zhulina, Igor I. Potemkin, Oleg V. Borisov
Article
Polymer Science
Artem M. Rumyantsev, Juan J. de Pablo
Article
Polymer Science
Artem M. Rumyantsev, Alexey A. Gavrilov, Elena Yu. Kramarenko
Article
Polymer Science
Artem M. Rumyantsev, Nicholas E. Jackson, Boyuan Yu, Jeffrey M. Ting, Wei Chen, Matthew V. Tirrell, Juan J. de Pablo
Article
Polymer Science
Artem M. Rumyantsev, Juan J. de Pablo
Article
Polymer Science
Boyuan Yu, Phillip M. Rauscher, Nicholas E. Jackson, Artem M. Rumyantsev, Juan J. de Pablo
Article
Polymer Science
Lu Li, Artem M. Rumyantsev, Samanvaya Srivastava, Siqi Meng, Juan J. de Pablo, Matthew Tirrell
Summary: The study provides insights into the thermodynamics and kinetics of polyelectrolyte complexation by systematically comparing experimental and theoretical phase diagrams of PECs with different backbone-solvent interactions. Results show the influence of backbone chemistry on the compositions and salt resistance of complexes, with predictions aligning well with experimental observations.
Article
Polymer Science
Artem M. Rumyantsev, Nicholas E. Jackson, Albert Johner, Juan J. de Pablo
Summary: The primary sequence of charged monomers in a polyampholyte significantly affects its conformational properties. The study uses theory and simulations to predict the influence of sequence on the behavior of globally neutral polyampholytes under salt-free conditions. The results show that the charge blockiness along the chain plays a crucial role in determining the internal structure and coil-globule transition of polyampholytes.
Article
Polymer Science
Angelika E. Neitzel, Yan N. Fang, Boyuan Yu, Artem M. Rumyantsev, Juan J. de Pablo, Matthew Tirrell
Summary: Polyelectrolyte complex coacervates were synthesized using homologous (co)polyelectrolytes with a near-ideally random distribution of a charged and neutral ethylene oxide comonomer, allowing for investigation of phase behavior and salt partitioning. Experimental results were in good agreement with simulation predictions, showing consistency in trends and behaviors across different charge fractions.
Article
Physics, Multidisciplinary
Debra J. Audus, Samim Ali, Artem M. Rumyantsev, Yuanchi Ma, Juan J. de Pablo, Vivek M. Prabhu
Summary: This study investigates the effect of molecular mass on the interfacial tension of coacervates through experiments and molecular dynamics simulations, deriving a formula to describe this relationship.
PHYSICAL REVIEW LETTERS
(2021)
Article
Polymer Science
Artem M. Rumyantsev, Albert Johner, Juan J. de Pablo
Summary: A scaling theory of statistical polyampholytes is developed to understand how sequence correlations influence conformational behavior. The increase in charge patchiness leads to stronger correlation attractions and higher charge imbalance, inducing different conformations in the polyampholyte. The sequence-dependent structure of polyampholyte necklaces is confirmed by molecular dynamics simulations.
Article
Polymer Science
Artem M. Rumyantsev, Albert Johner, Matthew Tirrell, Juan J. de Pablo
Summary: We propose an analytical approach that can consistently describe weak and strong charge correlations in self-coacervate phases of polyampholytes and disordered proteins. The approach improves the random phase approximation by considering the discreteness of charges in polymer chains and a finite number of wave modes of charge density fluctuations. The developed theory reproduces the free energy of strongly correlated Wigner liquid and can quantitatively describe electrostatic interactions in coil-to-globule transitions of single-chain polyampholytes.
Article
Polymer Science
Boyuan Yu, Heyi Liang, Artem M. Rumyantsev, Juan J. de Pablo
Summary: Recent interest in complex coacervation between oppositely charged polyelectrolytes (PEs) has been fueled by its relevance to biology in the context of membraneless organelle formation within living cells. In this work, coarse-grained molecular dynamics simulations were used to study the underlying physics of this phenomenon, revealing that Coulomb interactions in coacervates facilitate orientational ordering.
Article
Multidisciplinary Sciences
Yan N. Fang, Artem M. Rumyantsev, Angelika E. Neitzel, Heyi Liang, William T. Heller, Paul F. Nealey, Matthew V. Tirrell, Juan J. de Pablo
Summary: Polyelectrolyte complexation plays a crucial role in materials science and biology. Small-angle scattering experiments have revealed structural similarities between polyelectrolyte complexes (PECs) and semidilute solutions of neutral polymers. The positional correlations between polyanion and polycation charges have been investigated using small-angle neutron scattering profiles, and the results indicate the existence of Coulomb repulsions between polyanion fragments and their attractions to polycations. The addition of salt leads to the disappearance of these correlations, reverting the scattering functions to an Ornstein-Zernike form.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Physical
Boyuan Yu, Artem M. Rumyantsev, Nicholas E. Jackson, Heyi Liang, Jeffrey M. Ting, Siqi Meng, Matthew Tirrell, Juan J. de Pablo
Summary: Advances in synthetic chemistry have allowed for greater control over the sequence of polymeric materials, creating patterns reminiscent of biological macromolecules. Charged monomers enhance the tendency towards complex coacervation and increase the stability of coacervates with the addition of salt. High charge blockiness leads to the formation of microphase separated coacervates, resulting in a non-monotonic dependence of density on charge blockiness.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2021)
Article
Chemistry, Physical
Sergey Yu. Ketkov, Sheng-Yuan Tzeng, Elena A. Rychagova, Anton N. Lukoyanov, Wen-Bih Tzeng
Summary: Metallocenes, including methylcobaltocene, play important roles in various fields of chemistry. The ionization energy and vibrational structure of (Cp ')(Cp)Co can be influenced by introducing methyl substituents. The mass-analyzed threshold ionization spectrum and DFT calculations provide accurate information about the properties and transformations of (Cp ')(Cp)Co.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Review
Chemistry, Physical
Qifeng Mu, Jian Hu
Summary: Polymer mechanochemistry has experienced a renaissance due to the rapid development of mechanophores and principles governing mechanochemical transduction or material strengthening. It has not only provided fundamental guidelines for converting mechanical energy into chemical output, but also found applications in engineering and smart devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Da Hye Yang, Francesco Ricci, Fredrik L. Nordstrom, Na Li
Summary: Through systematic evaluation of the oiling-out behavior of procaine, we identified both stable and metastable liquid-liquid phase separation, and established phase diagrams to assist in rational selection of crystallization strategies.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Vikki Anand Varma, Simmie Jaglan, Mohd Yasir Khan, Sujin B. Babu
Summary: Designing engineering structures like nanocages, shells, and containers through self-assembly of colloids is a challenging problem. This work proposes a simple model for the subunit, which leads to the formation of monodispersed spherical cages or containers. The model with only one control parameter can be used to design cages with the desired radius.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Hainan Jiang, Yaolong He, Xiaolin Li, Zhiyao Jin, Huijie Yu, Dawei Li
Summary: The cycling lifespan and coulombic efficiency of lithium-ion batteries are crucial for high C-rate applications. The Li-ion concentration plays a crucial role in determining the mechanical integrity and structural stability of electrodes. This study focuses on graphite as the working electrode and establishes an experimental system to investigate the mechanical properties of composite graphite electrode at different C-rates. Considering the effect of Li-ion concentration in stress analysis is found to be significant.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Zhiye Wang, Yunchuan Li, Mingjun Sun
Summary: This study investigates the influence of intramolecular pi-pi interactions on the electronic transport capabilities of molecules. By designing and analyzing three pi-conjugated molecules, the researchers observe that different pi-conjugated structures have varying effects on electron transport. The findings provide a theoretical foundation for designing single-molecule electronic devices with multiple electron channels based on intramolecular pi-pi interactions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Yuandong Xu, Haoyang Feng, Chaoyang Dong, Yuqing Yang, Meng Zhou, Yajun Wei, Hui Guo, Yaqing Wei, Jishan Su, Yingying Ben, Xia Zhang
Summary: Hollow MoS2 cubes and spheres were successfully synthesized using a one-step hydrothermal method with the hard template method. The hollow MoS2 cubes exhibited higher specific capacitance and energy density compared to the hollow MoS2 spheres. The symmetrical supercapacitors assembled with these hollow structures showed good performance and high capacity retention after multiple cycles. These findings suggest that controlling the pore structure and surface characteristics of MoS2 is crucial for enhancing its electrochemical properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Ainhoa Oliden-Sanchez, Rebeca Sola-Llano, Joaquin Perez-Pariente, Luis Gomez-Hortiguela, Virginia Martinez-Martinez
Summary: The combination of photoactive molecules and inorganic structures is important for the development of advanced materials in optics. In this study, bulky dyes were successfully encapsulated in a zeolitic framework, resulting in emission throughout the visible spectrum.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Miaomiao Zhang, Cunyuan Pei, Qiqi Xiang, Lintao Liu, Zhongxu Dai, Huijuan Ma, Shibing Ni
Summary: The design of a solid electrolyte interphase (SEI) plays a crucial role in improving the electrochemical performance of anode materials. In this study, lithium difluoro(oxalate)borate (LiDFOB) is used as an electrolyte additive to form a protective SEI film on Li3VO4 (LVO) anodes. The addition of LiDFOB results in a dense, uniform, stable, and LiF-richer SEI, which enhances the Li-ion storage kinetics. The generated SEI also prevents further decomposition of the electrolyte and maintains the morphology of LVO anodes during charge/discharge processes. This work demonstrates the effectiveness of LiDFOB as a multi-functional additive for LiPF6 electrolytes and provides insights into SEI construction for high-performance LVO anodes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
B. V. Andryushechkin, T. V. Pavlova, V. M. Shevlyuga
Summary: The atomic structure of the Ag(111)-p(4 x 4)-O phase was reexamined and two phases with the same periodicity were discovered. It was demonstrated that the accepted Ag6 model is incompatible with high-resolution oxygen-sensitive STM images.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
S. L. Romo-Avila, D. Marquez-Ruiz, R. A. Guirado-Lopez
Summary: In this study, we used density functional theory (DFT) calculations to investigate the interaction between model graphene oxide (GO) nanostructures and chlorine monoxide ClO. We aimed to understand the role of this highly oxidizing species in breaking C-C bonds and forming significant holes on GO sheets. Our results showed that C-C bonds in a single graphene oxide sheet can be broken through a simple mechanism involving the dissociation of two chemically attached ClO molecules. The formation of carbonyl groups and holes on the GO surface was also observed. This study provides important insights into the degradation of carbon nanotubes and the stability of GO during the myeloperoxidase (MPO) catalytic cycle.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Alberto Garcia-Fernandez, Birgit Kammlander, Stefania Riva, Hakan Rensmo, Ute B. Cappel
Summary: In this study, the X-ray stability of five different lead halide perovskite compositions (MAPbI3, MAPbCl3, MAPbBr3, FAPbBr3, CsPbBr3) was investigated using photoelectron spectroscopy. Different degradation mechanisms and resistance to X-ray were observed depending on the crystal composition. Overall, perovskite compositions based on the MA+ cation were found to be less stable than those based on FA+ or Cs+. Metallic lead formation was most easily observed in the chloride perovskite, followed by bromide, and very little in MAPbI3. Multiple degradation processes were identified for the bromide compositions, including ion migration, formation of volatile and solid products, as well as metallic lead. CsBr was formed as a solid degradation product on the surface of CsPbBr3.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Timofei Rostilov, Vadim Ziborov, Alexander Dolgoborodov, Mikhail Kuskov
Summary: The shock-loading behavior of nanomaterials is investigated in this study. It is found that shock compaction waves exhibit a distinct two-step structure, with the formation of faster precursor waves that travel ahead of the main compaction waves. The complexity of the shock Hugoniot curve of the tested nanomaterial is described, and the effect of initial porosity on the compressed states is demonstrated.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Sergey S. Nikitin, Alexander D. Koryakov, Elizaveta A. Antipinskaya, Alexey A. Markov, Mikhail V. Patrakeev
Summary: The stability of La1/3Sr2/3Fe1-xMnxO3-delta, a perovskite-type oxide, under reducing conditions is dependent on the manganese content. Increasing the manganese content leads to a decrease in stability. The behavior of iron and manganese in the oxide shows distinct differences, which can be attributed to the difference in the enthalpy of oxidation reactions. Additionally, the change in the La/Sr ratio affects the concentration of iron and manganese ions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Mosayeb Naseri, Shirin Amirian, Mehrdad Faraji, Mohammad Abdur Rashid, Maicon Pierre Lourenco, Venkataraman Thangadurai, D. R. Salahub
Summary: Inspired by the successful transfer of freestanding ultrathin films of SrTiO3 and BiFeO3, this study assessed the structural stability and investigated the electronic, optical, and thermoelectric properties of a group of two-dimensional perovskite-type materials called perovskenes. The findings revealed that these materials are wide bandgap semiconductors with potential application in UV shielding. Moreover, they exhibit better electrical and thermal conductivity at high temperatures, enabling efficient power generation in thermoelectric devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)