Article
Polymer Science
Russell K. W. Spencer, Bae-Yeun Ha
Summary: Inclusions in a brush disrupt the brush structure and introduce effective particle-particle interactions mediated by the brush. The brush promotes clustering of inclusions when the grafting point is mobile, while inclusions tend to be dispersed when the grafting point is fixed. These findings have biological implications for interactions between antimicrobial peptides and bacterial lipopolysaccharides, as well as clustering of integrin on cancerous cell membranes.
Article
Polymer Science
Sergei A. Egorov
Summary: The Density Functional Theory is employed to investigate structural properties and interactions between solvent-free polymer-grafted nanoparticles, focusing on the effects of grafting density, grafted chain length, and stiffness on brush-brush overlap and attractive interaction strength. The theory results are compared with simulation data, showing good quantitative agreement.
Article
Mechanics
Fong Yew Leong, Duc-Vinh Le
Summary: The study reveals that the behavior of oil droplets on polymer brushes is influenced by flow velocity, with a critical velocity determining droplet detachment.
Article
Polymer Science
Diego Antonioli, Riccardo Chiarcos, Valentina Gianotti, Margherita Terragno, Michele Laus, Gianmarco Munao, Giuseppe Milano, Antonio De Nicola, Michele Perego
Summary: In this study, the grafting reaction of copolymers with different compositions onto a silicon wafer showed that lower molecular weight components are selectively incorporated into the polymeric brush. The time, temperature, and composition of blends were found to systematically affect the final brush layer composition. Hybrid particle-field simulations suggested that the preference of short chains to react with the silicon surface is influenced by the number of chains in contact with silica and the substrate surface area occupied by a single chain.
Article
Engineering, Biomedical
Matthew Lanaro, Maximilion P. Mclaughlin, Matthew J. Simpson, Pascal R. Buenzli, Cynthia S. Wong, Mark C. Allenby, Maria A. Woodruff
Summary: The use of melt electro-writing has enabled the creation of geometrically relevant in vitro scaffold models to study cellular spatial-temporal kinetics, revealing that cells proliferate faster in smaller pores. This study provides insights for designing more effective synthetic tissue engineering scaffolds.
ACTA BIOMATERIALIA
(2021)
Article
Polymer Science
Constantinos J. Revelas, Aristotelis P. Sgouros, Apostolos T. Lakkas, Doros N. Theodorou
Summary: We have developed a three-dimensional self-consistent field-theoretic approach (3D-SCFT) to study polymer matrix nano composites with different geometries. By using the finite element method (FEM), we discretized Edwards's diffusion equation in space and time. The accuracy of the smearing approximation (SA), which treats grafting points as delocalized across a spherical shell, was assessed by comparing it with the 3D-SCFT. The SA is able to reproduce important structural and thermodynamic properties of the nano composites, but deviations are observed in the mushroom regime. The 3D-SCFT, which fixes grafting points in space, provides a more accurate description of chain stretching and offers detailed visualization of the brush transition.
Article
Chemistry, Multidisciplinary
Chengmei Gui, Haodong Ma, Ruxia Zhang, Yulei Liu, Honglin Li, Junjun Huang, Peng Li
Summary: The study investigates the role of silanes in preparing a catalytic solution for Ag nanoparticles/polymer brush, finding that Ag/PB with 75% KH560 content exhibits the best stability with 56.7% relative Ag surplus after testing. The generated Ag/PB serves as catalytic centers for electroless copper plating, providing a simple method for preparing Cu/PET composite material and potential applications in green processes for metal/polymer composite materials.
Article
Chemistry, Multidisciplinary
Fei Jia, Joshua M. Kubiak, Michika Onoda, Yuping Wang, Robert J. Macfarlane
Summary: Brush polymers show great potential in enhancing gelation kinetics and stiffness of hydrogels without the need to change polymer composition or crosslinking chemistry. Their unique structure also results in restricted or nonswelling behavior of gels at different temperatures.
Article
Chemistry, Physical
Fengchang Lin, Shintaro Itoh, Kenji Fukuzawa, Hedong Zhang, Naoki Azuma
Summary: In this study, the lubrication mechanism of a hydrated MPC polymer brush was investigated. It was found that the mechanism depends on the shear gap, with two states exhibiting low coefficients of friction: one where the osmotic pressure supports the load and allows flexible deformation of the brush film, and the other where the brush film undergoes compression and transitions to a fully elastic state.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2024)
Article
Engineering, Mechanical
Qiangbing Wei, Huan Liu, Xiaoduo Zhao, Weiyi Zhao, Rongnian Xu, Shuanhong Ma, Feng Zhou
Summary: Surface modification is crucial for improving the interfacial properties of bioimplants, such as friction and wear of artificial joint materials. In this study, a hydrogel-polymer brush bilayered coating was developed to functionalize rigid PEEK material, resulting in a material with similar structure and properties to natural articular joint. The obtained material exhibited excellent lubrication, load-bearing capability, and wear resistance, making it potentially valuable in artificial joint replacement.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Polymer Science
Yucheng He, Dan Liu, Jiping Wang, Pengju Pan, Wenbing Hu
Summary: This study investigates the crystallization kinetics and crystal polymorphism of PLA blends with different molecular weights using Flash DSC measurement and confocal Raman spectroscopy. The results show that high molecular weights affect the crystal morphology and suppress the nucleation rates of stereocomplex crystals, resulting in the dominance of homocrystals.
Article
Polymer Science
Chenxuan Sun, Ying Zheng, Shanshan Xu, Lingling Ni, Xing Li, Guorong Shan, Yongzhong Bao, Pengju Pan
Summary: This study demonstrates the crucial role of chain entanglement in regulating stereocomplex (SC) crystallization of polymer enantiomers. Deentangling was shown to promote both the crystallization rate and crystallinity of SCs, providing deep insight into the SC crystallization mechanism of polymers and paving the way for future research in preparing SC materials.
Article
Polymer Science
Lingling Ni, Shanshan Xu, Chenxuan Sun, Yanan Qin, Ying Zheng, Jian Zhou, Chengtao Yu, Pengju Pan
Summary: This study focuses on the role of chain entanglement in polymorphic crystallization and crystal phase transition of polymers. By preparing samples with different entanglement degrees, it is found that chain disentangling can suppress the crystallization kinetics but promote the phase transition rate and degree. This work advances the understanding of the formation and transition mechanisms of polymorphic polymer crystals at the molecular level.
Article
Chemistry, Multidisciplinary
Nikita G. Gaidhani, Sabyasachi Patra, Hemant S. Chandwadkar, Debasis Sen, Chiranjib Majumder, Shobha Ramagiri, Jayesh R. Bellare
Summary: This study successfully probed the galvanic replacement of silver ions with nickel nanoparticles in a polymer membrane using small-angle X-ray scattering (SAXS) and radiolabeling methods, supported by density functional theory (DFT) computations. The silver-nickel system was chosen for its high degree of bulk immiscibility and weak adhesive interaction, making it a perfect model system for immiscible metal pairs. The membrane host medium played a crucial role in retarding the kinetics of atomic and particle rearrangements during the process. The study demonstrated, for the first time, a sequential nucleation model for the formation of mixed metallic nanoparticles via galvanic replacement, opening up possibilities for size-controlled synthesis in mixed systems.
Article
Biochemical Research Methods
Monika Conrad, Peter Fechner, Guenther Proll, Guenter Gauglitz
Summary: This study compares different approaches and algorithms for determining kinetic rate constants in biomolecular interaction analysis. It evaluates five mathematical methods for binding curve evaluation and analyzes reflectometric interference spectroscopy measurements to determine antibody binding kinetics. The advantages and disadvantages of each approach are discussed in detail, emphasizing the importance of using different methods for evaluating BIA results.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Applied
Rohit Srivastava, Veronique Bosc, Frederic Restagno, Carole Tournier, Paul Menut, Isabelle Souchon, Vincent Mathieu
Summary: A biomimetic tribological set-up was developed to integrate physiological characteristics in oral friction studies, allowing for the measurement of how food properties, TMS properties and operational parameters affect friction coefficient values. The results showed that the presence of particles led to an increase in friction coefficient values, while food viscosity had a less significant impact. Additionally, increasing surface roughness and bulk rigidity of the TMSs markedly augmented the friction coefficient values.
FOOD HYDROCOLLOIDS
(2021)
Article
Nutrition & Dietetics
Daniela Freitas, Francois Boue, Mourad Benallaoua, Gheorghe Airinei, Robert Benamouzig, Evelyne Lutton, Laurene Jourdain, Rose-Marie Dubuisson, Xavier Maitre, Luc Darrasse, Steven Le Feunteun
Summary: This study investigated the gastric emptying, appetite perceptions, and glycemic responses to bread consumed with water, tea, or lemon juice. The results showed that compared to water, lemon juice increased gastric volume and emptying rate, and reduced the glycemic response. Tea had no effect. Changes in appetite perceptions and gastric volumes were correlated.
EUROPEAN JOURNAL OF NUTRITION
(2022)
Article
Chemistry, Physical
Q. Chen, F. Restagno, D. Langevin, A. Salonen
Summary: Research shows that in micellar solutions, the rise velocity of bubbles decreases with increasing bubble volume fraction in low NaSal concentration Newtonian solutions, following the Richardson-Zaki prediction. However, in shear thinning viscoelastic solutions, bubble clustering leads to faster rise velocities and a weaker dependence on the bubble volume fraction. The peculiar dependence of rise velocity on bubble volume fraction in shear thinning viscoelastic solutions can have important implications in flotation.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Youngju Kim, Jacopo Valsecchi, Ohsung Oh, Jongyul Kim, Seung Wook Lee, Francois Boue, Evelyne Lutton, Matteo Busi, Christopher Garvey, Markus Strobl
Summary: Scattering studies of milk and milk products are important for understanding the microscopic structural differences between dairy samples, which determine the physical properties and consumer experience. This study explores the potential of small-angle neutron scattering and neutron dark-field imaging to investigate the structures of fat globules and milk gel.
APPLIED SCIENCES-BASEL
(2022)
Article
Polymer Science
Chang Liu, Wenhong Yang, Hanqiu Jiang, Baoqing Zhang, Guoming Liu, Erqiang Chen, Francois Boue, Dujin Wang
Summary: In this study, the chain conformation and solid-state structure of a high-performance conjugated polymer, PBTTT_C14, were investigated using small-angle neutron scattering and Fourier transform infrared spectroscopy. The results showed that PBTTT_C14 has a more rigid backbone compared to P3HT. The structural evolution of PBTTT_C14 during heating was also studied, revealing the transitions and structural changes of side chains and backbones. Additionally, two different liquid crystalline phases were identified in PBTTT_C14.
Article
Polymer Science
Tiago Outerelo Corvo, Antoine Jourdain, Shona O'Brien, Frederic Restagno, Eric Drockenmuller, Alexis Chenneviere
Summary: This study investigates the influence of nanostructure of poly(ionic liquid)s on the macromolecular conformation of polymer chains using small-angle neutron scattering. The results show that the nanostructure of poly(ionic liquid)s leads to an increase in the radius of gyration of polymer chains in solution and a nonmonotonic evolution in bulk. Furthermore, evidence of interdigitation of alkyl side chains is observed.
Article
Food Science & Technology
Maja Napieraj, Annie Brulet, Evelyne Lutton, Urielle Randrianarisoa, Adeline Boire, Francois Bou
Summary: We investigated the rheology and nanostructures of heat-set canola seed protein gels prepared at pH 8 and pH 11. The stronger gels prepared at pH 11 showed local folded and compact conformations close to native ones. Surprisingly, during gastric digestion, the modulus increased for pH 11 gels while decreased for pH 8 gels. In intestinal digestion, both gels showed protein re-compaction and modulus decrease. Additional interactions could result from crossing one or two isoelectric points towards gastric pH 2. External erosion of the gel was observed in larger times for both gels.
FOOD STRUCTURE-NETHERLANDS
(2022)
Article
Polymer Science
Anne-Sophie Robbes, Jacques Jestin, Florian Meneau, Florent Dalmas, Francois Boue, Fabrice Cousin
Summary: In this study, we conducted a detailed monitoring of the evolution of filler structure and polymer chain conformation in a nanocomposite during uniaxial stretching using SAXS and SANS techniques. The application of a magnetic field during processing of the nanocomposite resulted in a highly anisotropic filler structure before stretching. The structure of fillers evolved differently depending on whether the stretching was parallel or perpendicular to the chains of nanoparticles. The conformation of polymer chains was directly obtained through SANS and showed similar deformation to the reference PS matrix without fillers.
Article
Nanoscience & Nanotechnology
Xavier Chevalier, Gwenaelle Pound-Lana, Cindy Gomes Correia, Sebastien Cavalaglio, Benjamin Cabannes-Boue, Frederic Restagno, Guillaume Miquelard-Garnier, Sebastien Roland, Christophe Navarro, Guillaume Fleury, Marc Zelsmann
Summary: In this study, the self-assembly of a lamellar block copolymer (BCP) was investigated under different wetting conditions. The chemical composition of under-layers and top-coats was found to influence the thin film stability, self-assembly kinetics, and BCP domain orientation. The dewetting of the BCP layer and the self-organization kinetics were explored using controlled wetting configurations.
Article
Physics, Multidisciplinary
Gabriel Guyard, Frederic Restagno, Joshua D. McGraw
Summary: Hydrodynamic flows in compliant channels have significant implications in physiology and microfluidics. This study investigates the relaxation dynamics of thin and soft rectangular microfluidic channels and provides a complete description of the experimental results. The findings contribute to the understanding of elastohydrodynamic coupling and the time-dependent behavior of compliant channel networks.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mechanics
Marie Corpart, Frederic Restagno, Francois Boulogne
Summary: The origin of the difference between the deposition of suspended particles in a sessile droplet and in an axisymmetric droplet deposited on a fiber is analyzed. The shape of the droplet on a fiber and its evaporative flux are modeled to derive analytical calculations. The hydrodynamics equations in the liquid phase are solved under the lubrication approximation to determine the flow velocity toward the contact lines. The substrate curvature plays a role in contact line depinning, local evaporative flux, and liquid flow field.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Physics, Fluids & Plasmas
Marina Pasquet, Frederic Restagno, Isabelle Cantat, Emmanuelle Rio
Summary: This article investigates the production, drainage, and stability of foam films, focusing on the regime of large velocities and large film sizes. The thickness profile of the film is found to follow an exponential pattern influenced by gravity and surface elasticity. A proposed model takes into account the interplay between gravity, film elasticity, and film extraction, and accurately predicts experimental data.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Nanoscience & Nanotechnology
Li Shi, Florent Carn, Francois Boue, Eric Buhler
Summary: By electrostatic complexation between water-soluble semi-flexible polyelectrolytes and functionalized gold nanoparticles, colloidal crystals with different morphologies and compactness can be assembled. The assembled structure can have high short-range order at low ionic strength and crystalline order when screened by salt addition. This approach provides a low-cost and promising method for the one-step production of gold colloidal crystals with potential applications in nanophotonics.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Fluids & Plasmas
Suzanne Lafon, Alexis Chenneviere, Frederic Restagno, Samy Merabia, Laurent Joly
Summary: The effect of temperature on friction and slip at the liquid-solid interface has been studied both numerically and experimentally over the past 20 years. However, the role of temperature on slip close to the glass transition has not been well explored. In this study, molecular dynamics simulations were used to investigate the effect of temperature on friction and slip length in a bidisperse atomic fluid. The results showed that at high temperatures, an Arrhenius law fits well, while in the supercooled state, the viscosity becomes super-Arrhenian and the interfacial friction can drastically decrease, leading to a significant increase in slip length.
Article
Chemistry, Physical
Marina Pasquet, Francois Boulogne, Julien Sant-Anna, Frederic Restagno, Emmanuelle Rio
Summary: In this paper, the thinning dynamics of evaporating surfactant-stabilised surface bubbles are investigated. The role of physical-chemistry of solutions used in a liquid bath is considered. It is found that the initial thickness is limited by surface elasticity and the drainage dynamics are independent of surfactant concentration. The physical-chemistry impacts the thinning dynamics through evaporation, and an increase in surfactant concentration decreases the impact of evaporation. The addition of glycerol increases the stability of the bubbles.
