1
|
Iqbal A, Saeed A, Kausar A, Arshad M, Mahar J. Synthesis and characterization of DGEBA composites reinforced with Cu/Ag modified carbon nanotubes. Heliyon 2019; 5:e01733. [PMID: 31193713 PMCID: PMC6541883 DOI: 10.1016/j.heliyon.2019.e01733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/16/2019] [Accepted: 05/10/2019] [Indexed: 11/16/2022] Open
Abstract
Carbon nanotubes (CNTs) are among the strongest and stiffest contender to be used as filler to elevate the properties of epoxy. The aim of this research work is to evaluate the structural, thermal, and morphological properties of multiwalled carbon nanotubes (MWCNTs) hybridized with silver, copper and silver/copper nanoparticles (Ag/CuNP) obtained via chemical reduction of aqueous salts assisted with sodium dodecyl sulphate (SDS) as stabilizing agent. The MWCNTs/NP was further incorporated in DGEBA (epoxy) using ethyl cellulose as hardener. Scanning electron microscopy (SEM) reveals micro structural analysis of the MWCNTs/NP hybrids. The Fourier transform infrared (FTIR) spectra prove the interactions between the NP and MWCNTs. Thermogravimetric analysis (TGA) shows that the MWCNTs/NP hybrids decompose at a much faster rate and the weight loss decreased considerably due to the presence of NP. X-ray diffraction (XRD) confirms the formation of NP on the surface of MWCNTs and X-ray photoelectron spectroscopy (XPS) confirms the full covering of MWCNTs/NP hybrids with DGEBA.
Collapse
Affiliation(s)
- Anila Iqbal
- Department of Chemistry, Quaid-i-Azam University, Islamabad, 45320, Pakistan.,National Centre for Physics, QAU Campus, Shahdra Valley Road.P.O. Box No. 2141, Islamabad, 44000, Pakistan
| | - Aamer Saeed
- Department of Chemistry, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Ayesha Kausar
- National Centre for Physics, QAU Campus, Shahdra Valley Road.P.O. Box No. 2141, Islamabad, 44000, Pakistan
| | - Muhammad Arshad
- National Centre for Physics, QAU Campus, Shahdra Valley Road.P.O. Box No. 2141, Islamabad, 44000, Pakistan
| | - Jamaluddin Mahar
- Department of Chemistry, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| |
Collapse
|
2
|
Skountzos EN, Mermigkis PG, Mavrantzas VG. Molecular Dynamics Study of an Atactic Poly(methyl methacrylate)–Carbon Nanotube Nanocomposite. J Phys Chem B 2018; 122:9007-9021. [DOI: 10.1021/acs.jpcb.8b06631] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emmanuel N. Skountzos
- Department of Chemical Engineering, University of Patras & FORTH/ICE-HT, Patras GR 26504, Greece
| | - Panagiotis G. Mermigkis
- Department of Chemical Engineering, University of Patras & FORTH/ICE-HT, Patras GR 26504, Greece
| | - Vlasis G. Mavrantzas
- Department of Chemical Engineering, University of Patras & FORTH/ICE-HT, Patras GR 26504, Greece
- Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
| |
Collapse
|
3
|
Nazarychev VM, Larin SV, Lyulin AV, Dingemans T, Kenny JM, Lyulin SV. Atomistic Molecular Dynamics Simulations of the Initial Crystallization Stage in an SWCNT-Polyetherimide Nanocomposite. Polymers (Basel) 2017; 9:polym9100548. [PMID: 30965851 PMCID: PMC6418835 DOI: 10.3390/polym9100548] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/13/2017] [Accepted: 10/19/2017] [Indexed: 01/23/2023] Open
Abstract
Crystallization of all-aromatic heterocyclic polymers typically results in an improvement of their thermo-mechanical properties. Nucleation agents may be used to promote crystallization, and it is well known that the incorporation of nanoparticles, and in particular carbon-based nanofillers, may induce or accelerate crystallization through nucleation. The present study addresses the structural properties of polyetherimide-based nanocomposites and the initial stages of polyetherimide crystallization as a result of single-walled carbon nanotube (SWCNT) incorporation. We selected two amorphous thermoplastic polyetherimides ODPA-P3 and aBPDA-P3 based on 3,3′,4,4′-oxydiphthalic dianhydride (ODPA), 2,3′,3,4′-biphenyltetracarboxylic dianhydride (aBPDA) and diamine 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene (P3) and simulated the onset of crystallization in the presence of SWCNTs using atomistic molecular dynamics. For ODPA-P3, we found that the planar phthalimide and phenylene moieties show pronounced ordering near the CNT (carbon nanotube) surface, which can be regarded as the initial stage of crystallization. We will discuss two possible mechanisms for ODPA-P3 crystallization in the presence of SWCNTs: the spatial confinement caused by the CNTs and π–π interactions at the CNT-polymer matrix interface. Based on our simulation results, we propose that ODPA-P3 crystallization is most likely initiated by favorable π–π interactions between the carbon nanofiller surface and the planar ODPA-P3 phthalimide and phenylene moieties.
Collapse
Affiliation(s)
- Victor M Nazarychev
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol'shoi pr. 31 (V.O.), St. Petersburg 199004, Russia.
| | - Sergey V Larin
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol'shoi pr. 31 (V.O.), St. Petersburg 199004, Russia.
| | - Alexey V Lyulin
- Theory of Polymers and Soft Matter Group, Technische Universiteit Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - Theo Dingemans
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Murray Hall 1113, 121 South Road, Chapel Hill, NC 27599-3050, USA.
| | - Jose M Kenny
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol'shoi pr. 31 (V.O.), St. Petersburg 199004, Russia.
- Materials Science and Technology Centre, University of Perugia, Loc. Pentima, 4, 05100 Terni, Italy.
| | - Sergey V Lyulin
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol'shoi pr. 31 (V.O.), St. Petersburg 199004, Russia.
| |
Collapse
|
4
|
Tam LH, Wu C. Molecular Mechanics of the Moisture Effect on Epoxy/Carbon Nanotube Nanocomposites. NANOMATERIALS 2017; 7:nano7100324. [PMID: 29027979 PMCID: PMC5666489 DOI: 10.3390/nano7100324] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/08/2017] [Accepted: 10/09/2017] [Indexed: 01/19/2023]
Abstract
The strong structural integrity of polymer nanocomposite is influenced in the moist environment; but the fundamental mechanism is unclear, including the basis for the interactions between the absorbed water molecules and the structure, which prevents us from predicting the durability of its applications across multiple scales. In this research, a molecular dynamics model of the epoxy/single-walled carbon nanotube (SWCNT) nanocomposite is constructed to explore the mechanism of the moisture effect, and an analysis of the molecular interactions is provided by focusing on the hydrogen bond (H-bond) network inside the nanocomposite structure. The simulations show that at low moisture concentration, the water molecules affect the molecular interactions by favorably forming the water-nanocomposite H-bonds and the small cluster, while at high concentration the water molecules predominantly form the water-water H-bonds and the large cluster. The water molecules in the epoxy matrix and the epoxy-SWCNT interface disrupt the molecular interactions and deteriorate the mechanical properties. Through identifying the link between the water molecules and the nanocomposite structure and properties, it is shown that the free volume in the nanocomposite is crucial for its structural integrity, which facilitates the moisture accumulation and the distinct material deteriorations. This study provides insights into the moisture-affected structure and properties of the nanocomposite from the nanoscale perspective, which contributes to the understanding of the nanocomposite long-term performance under the moisture effect.
Collapse
Affiliation(s)
- Lik-Ho Tam
- School of Transportation Science and Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China.
| | - Chao Wu
- School of Transportation Science and Engineering, Beihang University, 37 Xueyuan Road, Beijing 100191, China.
| |
Collapse
|
5
|
Jana B, Inamdar SR, H M SK. Effect of quencher and temperature on fluorescence intensity of laser dyes: DETC and C504T. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 170:124-130. [PMID: 27423111 DOI: 10.1016/j.saa.2016.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
Fluorescence quenching of 7- Diethylamino-3-thenoylcoumarin (DETC) and 2,3,6,7-tetrahydro-1,1,7,7-tetramethyl11-oxo-1H,5H,11H- [1]benzopyrano[6,7,8-ij]quinolizine-10-carboxylic acid, ethyl ester (C504T) by aniline(AN), dimethylaniline (DMA) and diethylaniline (DEA) was investigated in toluene by steady state and transient methods. The quenching parameters like frequency of encounter (kd), probability of quenching per encounter (p), quenching rate parameters (kq) and activation energy of quenching (Ea) were determined experimentally. The kq values determined by steady state and time-resolved methods for the both dyes were found to be same, indicating the dynamic nature of interaction. Magnitudes of p and Ea suggested that the quenching reaction is predominantly controlled by material diffusion. The quenching mechanism is rationalized in terms of electron transfer (ET) from donors (aromatic amines) to the acceptors (coumarin derivatives) confirmed by correlating kq with free energy changes (ΔG°). Further, an effect of temperature on fluorescence intensity was carried out in toluene and methanol solvents. Fluorescence intensity of both the dyes decreases with increase in temperature. Temperature quenching in case of C504T is due to intersystem crossing S1→T2, whereas for DETC, quenching is due to intersystem crossing S1→T2 and ICT→TICT transition.
Collapse
Affiliation(s)
- Basavaraja Jana
- Department of Physics, Siddaganga Institute of Technology, Tumkur 572 103, India
| | - S R Inamdar
- Laser Spectroscopy Programme, Department of Physics, Karnatak University, Dharwad 580003, India
| | - Suresh Kumar H M
- Department of Physics, Siddaganga Institute of Technology, Tumkur 572 103, India.
| |
Collapse
|
6
|
Vadivelan V, Chandar Shekar B. Fabrication of a phase transmission holographic optical element in polycarbonate and its characterization. APPLIED OPTICS 2016; 55:6452-6457. [PMID: 27534494 DOI: 10.1364/ao.55.006452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The phase transmission holographic optical element in silver halide holographic emulsion, especially for holographic collimator sights, is fabricated and the desired diffraction efficiency is obtained with very high transmission. One of the main drawbacks of these holograms are that they become dark by being exposed under sunlight, and this darkness drastically reduces the visible transmission and diffraction efficiency of a holographic optical element, hence it is not suitable for weapon sight application. To overcome this problem, we transferred a holographic optical element with a reticle image from silver halide into polycarbonate by using copying, electroforming, and recombination techniques. The holographic optical element in polycarbonate has many advantages; the detailed method of fabrication, transfer, and its characterization are presented. The very interesting result of diffraction efficiency variation with angle obtained in polycarbonate is discussed.
Collapse
|
7
|
Choudhury CK, Carbone P, Roy S. Scalability of Coarse-Grained Potentials Generated from Iterative Boltzmann Inversion for Polymers: Case Study on Polycarbonates. MACROMOL THEOR SIMUL 2016. [DOI: 10.1002/mats.201500079] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Paola Carbone
- School of Chemical Engineering and Analytical Science; The University of Manchester; Manchester UK
| | - Sudip Roy
- Physical Chemistry Division; National Chemical Laboratory; Pune India
| |
Collapse
|
8
|
Sharma P, Roy S, Karimi-Varzaneh HA. Validation of Force Fields of Rubber through Glass-Transition Temperature Calculation by Microsecond Atomic-Scale Molecular Dynamics Simulation. J Phys Chem B 2016; 120:1367-79. [DOI: 10.1021/acs.jpcb.5b10789] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pragati Sharma
- Physical
Chemistry Division, National Chemical Laboratory, Pune, India
| | - Sudip Roy
- Physical
Chemistry Division, National Chemical Laboratory, Pune, India
| | | |
Collapse
|
9
|
Karatrantos A, Clarke N, Kröger M. Modeling of Polymer Structure and Conformations in Polymer Nanocomposites from Atomistic to Mesoscale: A Review. POLYM REV 2016. [DOI: 10.1080/15583724.2015.1090450] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
10
|
Chakraborty S, Roy S. Structure of Nanorod Assembly in the Gyroid Phase of Diblock Copolymer. J Phys Chem B 2015; 119:6803-12. [DOI: 10.1021/acs.jpcb.5b01338] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Souvik Chakraborty
- Physical Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| | - Sudip Roy
- Physical Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| |
Collapse
|
11
|
DeSalvo SC, Liu Y, Choudhary GS, Ren D, Nangia S, Sureshkumar R. Signaling factor interactions with polysaccharide aggregates of bacterial biofilms. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:1958-1966. [PMID: 25607640 DOI: 10.1021/la504721b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Biofilms are surface-attached colonies of bacteria embedded in an extracellular polymeric substance (EPS). Inside the eukaryotic hosts, bacterial biofilms interact with the host cells through signaling factors (SFs). These signaling processes play important roles in the interaction between bacteria and host cells and the outcome of infections and symbiosis. However, how host immune factors diffuse through biofilms is not well understood. Here, we describe synergistic molecular dynamics and experimental approaches for studying the translocation of signaling factors through polysaccharide chain aggregates present in the extracellular matrix of bacterial biofilms. The effect of polysaccharide chain degradation on the energetics of SF-EPS interactions was examined by simulating an EPS consisting of various polysaccharide chain lengths. It is shown that the SF stabilization energy, defined as the average potential of mean force difference between the environments outside and within the matrix, increases linearly with decreasing chain length. This effect has been explained based on the changes in the polysaccharide configurations around the SF. Specifically, shorter chains are packed tightly around the SF, promoting favorable SF-EPS interactions, while longer chains are packed loosely resulting in screening of interactions with neighboring chains. We further investigated the translocation of SFs through the host cell membrane using molecular dynamics simulations. Further, simulations predict the existence of energy barriers greater than 1000 kJ mol(-1) associated with the translocation of the signaling factors necrosis factor-alpha (TNF-α) and granulocyte macrophage colony stimulating factor (GM-CSF) across the lipid bilayer. The agreement of computational and experimental findings motivates future computational studies using a more detailed description of the EPS aimed at understanding the role of the extracellular matrix on biofilm drug resistance.
Collapse
Affiliation(s)
- Stephen C DeSalvo
- Department of Biomedical and Chemical Engineering, §Department of Civil and Environmental Engineering, ∥Department of Biology, ⊥Department of Physics, ‡Syracuse Biomaterials Institute, Syracuse University , Syracuse, New York 13244, United States
| | | | | | | | | | | |
Collapse
|
12
|
Larin SV, Glova AD, Serebryakov EB, Nazarychev VM, Kenny JM, Lyulin SV. Influence of the carbon nanotube surface modification on the microstructure of thermoplastic binders. RSC Adv 2015. [DOI: 10.1039/c5ra07851b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The structural properties of polymer nanocomposites based on thermoplastic polyimides filled with surface-modified carbon nanotubes (CNT) have been studied by means of fully-atomistic molecular-dynamics simulations.
Collapse
Affiliation(s)
- S. V. Larin
- Institute of Macromolecular Compounds
- Russian Academy of Sciences
- St. Petersburg
- Russia
| | - A. D. Glova
- Department of Physics
- St. Petersburg State University
- St. Petersburg
- Russia
| | - E. B. Serebryakov
- Department of Physics
- St. Petersburg State University
- St. Petersburg
- Russia
| | - V. M. Nazarychev
- Institute of Macromolecular Compounds
- Russian Academy of Sciences
- St. Petersburg
- Russia
| | - J. M. Kenny
- Institute of Macromolecular Compounds
- Russian Academy of Sciences
- St. Petersburg
- Russia
- Materials Science and Technology Centre
| | - S. V. Lyulin
- Institute of Macromolecular Compounds
- Russian Academy of Sciences
- St. Petersburg
- Russia
- Department of Physics
| |
Collapse
|
13
|
Larin SV, Falkovich SG, Nazarychev VM, Gurtovenko AA, Lyulin AV, Lyulin SV. Molecular-dynamics simulation of polyimide matrix pre-crystallization near the surface of a single-walled carbon nanotube. RSC Adv 2014. [DOI: 10.1039/c3ra45010d] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
|
14
|
Chakraborty S, Choudhury CK, Roy S. Morphology and Dynamics of Carbon Nanotube in Polycarbonate Carbon Nanotube Composite from Dissipative Particle Dynamics Simulation. Macromolecules 2013. [DOI: 10.1021/ma302425s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Souvik Chakraborty
- Physical Chemistry Division, National Chemical Laboratory, Pune 411008, India
| | | | - Sudip Roy
- Physical Chemistry Division, National Chemical Laboratory, Pune 411008, India
| |
Collapse
|