Article
Chemistry, Physical
Apostolos T. Lakkas, Aristotelis P. Sgouros, Constantinos J. Revelas, Doros N. Theodorou
Summary: Polymer/matrix nanocomposites have exceptional properties and promising applications in key industrial sectors. To ensure the best dispersion, nanoparticles are often stabilized by grafting polymer chains on their surface of the same chemical constitution as the matrix. A model is proposed to predict key structural and thermodynamic properties, exploring various regimes and extracting important quantities related to the distribution and configuration of polymer chains.
Article
Polymer Science
Wei You, Wenzhi Cui, Wei Yu
Summary: This study conducted experiments on silica nanoparticles with different surface modifications to understand their effects on the moduli of polymer nanocomposites. It was found that the interfacial layer volume fraction in PNCs showed a non-monotone variation with increasing particle concentrations. Additionally, the effective interfacial thickness was determined using hydrodynamic enhancement of the rubbery plateau modulus.
Article
Polymer Science
Connor R. Bilchak, Mayank Jhalaria, Sabin Adhikari, Jiarul Midya, Yucheng Huang, Zaid Abbas, Arash Nikoubashman, Brian C. Benicewicz, Michael Rubinstein, Sanat K. Kumar
Summary: We investigate the gas transport behavior of polymer-grafted nanoparticle (GNP) membranes and discover interesting and universal phenomena. Through theoretical analysis and experimental measurements, we propose a mechanism for the peak gas permeability based on the extension free energy of the polymer chains. Our findings suggest that the curved polymer brushes behave like a two-layer transport medium, with extended chains near the NP surface speeding up gas transport.
Article
Polymer Science
Siti Khumaira Mohd Jamari, Nur Azmah Nordin, U. Ubaidillah, Siti Aishah Abdul Aziz, Saiful Amri Mazlan, Nurhazimah Nazmi
Summary: The study involved grafting polystyrene-coated CIP into MRE, resulting in lower storage modulus compared to uncoated CIP MRE and a higher MR effect by 28.04%. The coated-CIP MRE exhibited higher damping behavior with a loss factor exceeding 0.14 compared to 0.12 of the uncoated sample.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Construction & Building Technology
Anastasiya Y. Yadykova, Sergey O. Ilyin
Summary: The improved adhesive and cohesive properties of bitumen blends with bio-oil and different types of silica nanoparticles were studied. The addition of bio-oil increased the thermodynamic work of adhesion and adhesive strength of the bitumen binder, while the addition of silica nanoparticles improved the stiffness, elasticity, and cohesive strength of the bitumen binder, with the hydrophobic nanoparticles doubling adhesion to steel and the hydrophilic nanoparticles halving it.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Azin Adibi, Leonardo Simon, Christian Lenges, Tizazu H. Mekonnen
Summary: Designed polysaccharides obtained from the enzymatic polymerization of sucrose are used as sustainable and functional reinforcing additives for rubber composites. In this study, epoxidized natural rubber (ENR) is melt-grafted onto the polysaccharide to enhance material properties. The resulting ENR-glucan composite using dicumyl peroxide (DCP) provides improved properties and can be used as a functional masterbatch for general NR composite formulations.
MATERIALS CHEMISTRY FRONTIERS
(2023)
Article
Polymer Science
Rodrigo Fiel, Ingrid D. Barcelos, Ricardo H. Goncalves, Mario R. S. Soares, Gabriel Rocha, Caio M. P. Silva, Valmor R. Mastelaro, Edson R. Leite
Summary: This study presents a simple one-pot approach to exfoliate and functionalize MoS2 to form nanocomposites with a polymer matrix, demonstrating improved thermal stability while affecting the glass transition temperature and mechanical properties.
Article
Thermodynamics
Roberta Motta Neves, Heitor Luiz Ornaghi, Felipe Gustavo Ornaghi, Sandro Campos Amico, Ademir Jose Zattera
Summary: This study investigated the thermal stability and lifetime prediction of nanocomposites by incorporating cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs) into polystyrene (PS). The research found that the reinforcement content did not affect the thermal degradation behavior, and lifetime prediction based on kinetic analysis was successfully applied. The nanocellulose morphology influenced the lifetime prediction of the nanocomposites.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Polymer Science
Yang Liu, Xun Zhang, Quanxin Gao, Hongliang Huang, Yongli Liu, Minghua Min, Lumin Wang
Summary: In this study, silver nanoparticles and MAH-g-POE were used as enhancement additives to improve the performance of POM homopolymer. The addition of MAH-g-POE improved the interfacial adhesion between silver nanoparticles and POM matrix, while the combined addition of both additives significantly enhanced the thermal stability, crystallization properties, and mechanical properties of the ternary nanocomposites. However, the storage modulus of the ternary nanocomposites decreased with the increase in Ag/MAH-g-POE content due to the reduction in rigidity caused by MAH-g-POE elastomer.
Article
Engineering, Chemical
Nazam Sakib, Yung P. Koh, Sindee L. Simon
Summary: The absolute heat capacity of a matrix-free polystyrene grafted silica nanocomposite system was investigated using Flash DSC and compared to a neat polystyrene sample. The results showed that the heat capacity of the polymer in the nanocomposite was 8% lower than that of the neat polystyrene, and there was a 15% lower change in heat capacity at the glass transition temperature. Moreover, there was a 2 nm-thick immobile layer of polymer around the nanoparticles, and the glassy layer remained immobile up to 300 degrees C.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Chemistry, Physical
A. Gomez-Merino, J. J. Jimenez-Galea, M. H. Spillman-Daniele, F. J. Rubio-Hernandez
Summary: The thermomechanical properties of a fluid can be enhanced by adding nanoparticles, with applications in various fields. The study found that solid concentration has a greater impact on thermal conductivity than temperature, and the shear-thickening effect weakens with increasing temperature.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Barbara Di Credico, Gerardo Odriozola, Simone Mascotto, Andreas Meyer, Laura Tripaldi, Arturo Moncho-Jorda
Summary: The significant improvements in polymer composites properties have been attributed to the ability of filler nanoparticles to self-assemble into anisotropic structures. In this study, the self-assembly behavior and mechanism of core-shell nanoparticles in solution was investigated. It was found that core-shell nanoparticles with a polymer shell can self-assemble into chain-like structures.
Article
Polymer Science
James H. Lettow, Richard Y. Kaplan, Paul F. Nealey, Stuart J. Rowan
Summary: This study successfully enhanced the ionic conductivity of nanoparticle films by preparing ionically conductive, hydrated polyelectrolyte nanocomposites, demonstrating significant improvement in iodide ion conductivity along the length of the cellulose nanocrystals in the films.
Article
Chemistry, Physical
Feng-Rui Xu, Rui Shi, Xiang-Meng Jia, Sheng-Chao Chai, Hao-Long Li, Hu-Jun Qian, Zhong-Yuan Lu
Summary: Coarse-grained molecular dynamics simulations were used to study the self-assembly behavior of polyoxometalate (POM) nanoparticles (NPs) decorated with mobile polymer ligands under melt conditions. The study demonstrated that due to the mobile nature of the grafted ligands on the NP surface, NPs have the ability to expose a part of their surfaces, leading to block-copolymer-like self-assembly behavior. This system can form long-range ordered structures such as block copolymers on a sub-10 nm scale, with the ability to manipulate the self-assembly structures of NPs decorated with mobile polymer ligands.
Article
Chemistry, Physical
Yilong Zhou, Sigbjorn Loland Bore, Andrea R. Tao, Francesco Paesani, Gaurav Arya
Summary: This article introduces a machine-learning approach to develop a many-body potential for describing effective interactions between spherical polymer-grafted nanoparticles in a polymer matrix. The potential significantly reduces computational cost and enables simulation of various assembly behaviors.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Environmental Studies
Adam J. Mallette, Aparajita Datta, Ramanan Krishnamoorti
Summary: Nuclear energy has significantly reduced carbon emissions in the US, but the accumulation of spent nuclear fuel poses challenges. A temporary storage facility in Texas provides a promising solution, although its viability depends on policy and societal considerations.
ENERGY & ENVIRONMENT
(2023)
Article
Polymer Science
Mayank Jhalaria, Andrew M. Jimenez, Reha Mathur, Marshall C. Tekell, Yucheng Huang, Suresh Narayanan, Brian C. Benicewicz, Sanat K. Kumar
Summary: This study reveals that nanoparticles in a polymer matrix undergo structural reorganization during thermal annealing, resulting in changes in the structure and properties of polymer nanocomposites.
Article
Polymer Science
Connor R. Bilchak, Mayank Jhalaria, Sabin Adhikari, Jiarul Midya, Yucheng Huang, Zaid Abbas, Arash Nikoubashman, Brian C. Benicewicz, Michael Rubinstein, Sanat K. Kumar
Summary: We investigate the gas transport behavior of polymer-grafted nanoparticle (GNP) membranes and discover interesting and universal phenomena. Through theoretical analysis and experimental measurements, we propose a mechanism for the peak gas permeability based on the extension free energy of the polymer chains. Our findings suggest that the curved polymer brushes behave like a two-layer transport medium, with extended chains near the NP surface speeding up gas transport.
Article
Engineering, Chemical
Nazam Sakib, Yung P. Koh, Sindee L. Simon
Summary: The absolute heat capacity of a matrix-free polystyrene grafted silica nanocomposite system was investigated using Flash DSC and compared to a neat polystyrene sample. The results showed that the heat capacity of the polymer in the nanocomposite was 8% lower than that of the neat polystyrene, and there was a 15% lower change in heat capacity at the glass transition temperature. Moreover, there was a 2 nm-thick immobile layer of polymer around the nanoparticles, and the glassy layer remained immobile up to 300 degrees C.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Engineering, Chemical
Evelyn Lopez, Yung P. Koh, John A. Zapata-Hincapie, Sindee L. Simon
Summary: In this study, the composition dependence of the glass transition temperature (T-g) in mixtures is revisited using three model systems. Entropy-based models are evaluated to determine the theoretical T-g, and the results are compared with experimental data. The findings suggest that the configurational entropy is not invariant at T-g or cannot be obtained from the integral of Delta C(p)dlnT.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Engineering, Chemical
Madhusudhan R. Pallaka, Rozana Bari, Sindee L. Simon
Summary: The glass transition behavior of polystyrene under different cooling rates was investigated using fast scanning nanocalorimetry. The results show that substrate and scan end temperature do not affect the endothermic overshoot associated with T-g, but do influence the broad endotherm at low temperatures. Moreover, comparing the results of crystalline materials suggests that the low-temperature endotherm is likely an artifact.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Chemistry, Applied
Yung P. Koh, Zachary T. Fondren, Aric A. Denton, Sindee L. Simon, Gregory B. McKenna
Summary: This study investigates the glass transition and crystallization behaviors of HNAB over a wide range of cooling rates. It quantifies the influence of thermal amorphization on the properties of HNAB and compares the behavior of HNAB prepared by different cooling methods. The study also reports the non-isothermal crystallization response as a function of cooling rate. Furthermore, it compares the thermal stability and decomposition energy of amorphous HNAB with the crystalline counterpart.
PROPELLANTS EXPLOSIVES PYROTECHNICS
(2022)
Article
Polymer Science
Qian Tian, Yung P. Koh, Sara Orski, Sindee L. Simon
Summary: The effect of nanoconfinement on the free radical polymerization of dodecyl methacrylate (DMA) was studied, revealing that the reaction rate is higher in nanopores compared to bulk conditions, with a lower activation energy. Specific interactions between the monomer and the pore surface were attributed as the cause of this difference.
Article
Engineering, Environmental
Aparajita Datta, Ramanan Krishnamoorti
Summary: Direct air capture (DAC) is a decarbonization solution that removes CO2 from the atmosphere. The challenges for deploying DAC are high energy requirements, capital costs, and finding low-risk and low-cost sequestration or utilization pathways. Proximal deployment to sequestration or use sites with abundant renewable electricity supply can minimize costs, and increased 45Q tax credits can incentivize DAC deployment.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Eric Ruzicka, Perry Pellechia, Brian C. Benicewicz
Summary: Diffusion-ordered spectroscopy (DOSY) 1H nuclear magnetic resonance (NMR) is a powerful tool for characterizing the molecular weights of polymers. Compared to common techniques, DOSY is faster and more cost-effective, and does not require purified samples. The study emphasizes the importance of proper preparation in generating calibration curves, including selecting the correct pulse sequence, optimizing parameters, and sample preparation. It also highlights the increasing significance of incorporating DOSY NMR into the polymer chemist's toolbox.
ANALYTICAL CHEMISTRY
(2023)
Article
Polymer Science
Jialin Qiu, Xuejian Chen, Amy N. Le, Carlos R. Lopez-Barron, Brian J. Rohde, Ronald P. White, Jane E. G. Lipson, Ramanan Krishnamoorti, Megan L. Robertson
Summary: Thermodynamic interactions were studied in blends of melts containing 1,4-polyisoprene (1,4-PI) and copolymers of 1,2-polybutadiene (1,2-PBD), poly(ethyl ethylene) (PEE), and/or polyethylene (PE) units. The Flory-Huggins interaction parameter, chi, was measured using small angle neutron scattering (SANS), and the data were analyzed through different models to understand the behavior. Random copolymer theory (RCT) successfully described the behavior in 1,2-PBD-co-PEE/1,4-PI blends, but failed in PE-co-PEE/1,4-PI blends. The locally correlated lattice model showed promise in describing the phase behavior of PE-co-PEE/1,4-PI blends.
Article
Nanoscience & Nanotechnology
Samuel Abiodun, Ramanan Krishnamoorti, Anil K. Bhowmick
Summary: The demand for thermally conductive dielectric composite materials for microwave frequency applications is increasing. Composites of PTFE and boron nitride show promise in meeting the requirements of high thermal conductivity and low dielectric loss. Surface-engineered boron nitride nanobarbs (BNNB) were evaluated in PTFE for the first time and achieved the desired properties with low filler content. Composites of modified BNNB and modified PTFE showed even higher thermal conductivity and excellent dielectric properties.
ACS APPLIED NANO MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Praveen Gupta, Eric Ruzicka, Brian C. Benicewicz, Ravishankar Sundararaman, Linda S. Schadler
Summary: This paper demonstrates a combined EFM and machine learning approach to measuring interfacial permittivity in polymer nanocomposites. ML models trained with finite-element simulations accurately determine the interface permittivity of functionalized nanoparticles. The approach fully accounts for the complex interplay of filler, matrix, and interface permittivity, providing a pathway to quantify and design nanoscale interface dielectric properties in nanodielectric materials.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Environmental Sciences
Aparajita Datta, Ramanan Krishnamoorti
Summary: Deforestation fires in Indonesia and Brazil have had a significant impact on climate change mitigation efforts, with a large portion of the greenhouse gas emissions originating from peatlands. However, real-time monitoring tools tend to underestimate these emissions, particularly in peatland-rich areas. To effectively protect forests and peatlands, there is a need for regular ground measurement, transparent data sharing, and robust policy enforcement.
FRONTIERS IN CLIMATE
(2022)
Article
Public, Environmental & Occupational Health
Drake Van Egdom, Christiane Spitzmueller, Xueqi Wen, Maryam A. Kazmi, Erica Baranski, Rhona Flin, Ramanan Krishnamoorti
Summary: The study found that cost-cutting announcements by organizations indirectly impact employees' attention, with supervisor support serving as a buffer by influencing job insecurity. Job insecurity is positively linked to attention, and supervisor support can mitigate the effects of job insecurity on employee attention.
OCCUPATIONAL HEALTH SCIENCE
(2022)