1
|
Nandimath M, Bhajantri RF, Naik J. Spectroscopic and color chromaticity analysis of rhodamine 6G dye-doped PVA polymer composites for color tuning applications. Polym Bull (Berl) 2020. [DOI: 10.1007/s00289-020-03332-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
2
|
Zuo B, Xu Q, Jin T, Xing H, Shi J, Hao Z, Zhang L, Tanaka K, Wang X. Suppressed Surface Reorganization in a High-Density Poly(methyl methacrylate) Brush. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14890-14895. [PMID: 31646872 DOI: 10.1021/acs.langmuir.9b02581] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A high-density poly(methyl methacrylate) (PMMA) brush (σ = 0.77 chain/nm2) with a lower molecular weight distribution was prepared onto a silicon wafer by surface-initiated atom transfer radical polymerization. The surface of the PMMA brush chains was characterized upon the process of the environmental change, from air to water, using contact angle measurements in conjunction with sum-frequency generation spectroscopy. The surface structure and properties altered less with the changing environment from air to water for the PMMA brush than for a spin-coated film; that is, the extent of surface reorganization could be suppressed by grafting densely-packed chains onto a substrate. Also, the water penetration into the brush surface was inhibited because of the densely packed chain structure.
Collapse
Affiliation(s)
- Biao Zuo
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Quanyin Xu
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Tiancheng Jin
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Huimin Xing
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Jiacheng Shi
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Zhiwei Hao
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Li Zhang
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| | - Keiji Tanaka
- Department of Applied Chemistry , International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) , and Center for Polymer Interface and Molecular Adhesion Science , Kyushu University , 744 Motooka , Nishi-ku, Fukuoka 819-0395 , Fukuoka , Japan
| | - Xinping Wang
- Department of Chemistry , Zhejiang Sci-Tech University , 928 Second Avenue, Xiasha Higher Education Zone , Hangzhou 310018 , Zhejiang , China
| |
Collapse
|
3
|
Fang QR, Makal TA, Young MD, Zhou HC. RECENT ADVANCES IN THE STUDY OF MESOPOROUS METAL-ORGANIC FRAMEWORKS. COMMENT INORG CHEM 2010. [DOI: 10.1080/02603594.2010.520254] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
4
|
Pakula C, Zaporojtchenko V, Strunskus T, Zargarani D, Herges R, Faupel F. Reversible light-controlled conductance switching of azobenzene-based metal/polymer nanocomposites. NANOTECHNOLOGY 2010; 21:465201. [PMID: 20972322 DOI: 10.1088/0957-4484/21/46/465201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present a new concept of light-controlled conductance switching based on metal/polymer nanocomposites with dissolved chromophores that do not have intrinsic current switching ability. Photoswitchable metal/PMMA nanocomposites were prepared by physical vapor deposition of Au and Pt clusters, respectively, onto spin-coated thin poly(methylmethacrylate) films doped with azo-dye molecules. High dye concentrations were achieved by functionalizing the azo groups with tails and branches, thus enhancing solubility. The composites show completely reversible optical switching of the absorption bands upon alternating irradiation with UV and blue light. We also demonstrate reversible light-controlled conductance switching. This is attributed to changes in the metal cluster separation upon isomerization based on model experiments where analogous conductance changes were induced by swelling of the composite films in organic vapors and by tensile stress.
Collapse
Affiliation(s)
- Christina Pakula
- Institut für Materialwissenschaft-Materialverbunde, Technische Fakultät der Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | | | | | | | | | | |
Collapse
|
5
|
Colby KA, Burdett JJ, Frisbee RF, Zhu L, Dillon RJ, Bardeen CJ. Electronic energy migration on different time scales: concentration dependence of the time-resolved anisotropy and fluorescence quenching of Lumogen Red in poly(methyl methacrylate). J Phys Chem A 2010; 114:3471-82. [PMID: 20170138 DOI: 10.1021/jp910277j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electronic energy transfer plays an important role in many types of organic electronic devices. Forster-type theories of exciton diffusion provide a way to calculate diffusion constants and lengths, but their applicability to amorphous polymer systems must be evaluated. In this paper, the perylenediimide dye Lumogen Red in a poly(methyl methacrylate) host matrix is used to test theories of exciton motion over Lumogen Red concentrations (C(LR)'s) ranging from 1 x 10(-4) to 5 x 10(-2) M. Two experimental quantities are measured. First, time-resolved anisotropy decays in films containing only Lumogen Red provide an estimate of the initial energy transfer rate from the photoexcited molecule. Second, the Lumogen Red lifetime decays in mixed systems where the dyes Malachite Green and Rhodamine 700 act as energy acceptors are measured to estimate the diffusive quenching of the exciton. From the anisotropy measurements, it is found that theory accurately predicts both the C(LR)(-2) concentration dependence of the polarization decay time tau(pol), as well as its magnitude to within 30%. The theory also predicts that the diffusive quenching rate is proportional to C(LR)(alpha), where alpha ranges between 1.00 and 1.33. Experimentally, it is found that alpha = 1.1 +/- 0.2 when Malachite Green is used as an acceptor, and alpha = 1.2 +/- 0.2 when Rhodamine 700 is the acceptor. On the basis of the theory that correctly describes the anisotropy data, the exciton diffusion constant is projected to be 4-9 nm(2)/ns. By use of several different analysis methods for the quenching data, the experimental diffusion constant is found to be in the range of 0.32-1.20 nm(2)/ns. Thus the theory successfully describes the early time anisotropy data but fails to quantitatively describe the quenching experiments which are sensitive to motion on longer time scales. The data are consistent with the idea that orientational and energetic disorder leads to a time-dependent exciton migration rate, suggesting that simple diffusion models cannot accurately describe exciton motion within this system.
Collapse
Affiliation(s)
- Kathryn A Colby
- Department of Chemistry, University of California, Riverside, Riverside, California 92521, USA
| | | | | | | | | | | |
Collapse
|
6
|
The diverse effect of antiplasticizer in the molecular dynamics of an organic dye-doped polymer observed at different motional lengthscales. Eur Polym J 2009. [DOI: 10.1016/j.eurpolymj.2009.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
7
|
Hernández MC, Suárez N, Martínez LA, Feijoo JL, Lo Mónaco S, Salazar N. Effects of nanoscale dispersion in the dielectric properties of poly(vinyl alcohol)-bentonite nanocomposites. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:051801. [PMID: 18643091 DOI: 10.1103/physreve.77.051801] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 02/20/2008] [Indexed: 05/26/2023]
Abstract
We investigate the effects of clay proportion and nanoscale dispersion in the dielectric response of poly(vinyl alcohol)-bentonite nanocomposites. The dielectric study was performed using the thermally stimulated depolarization current technique, covering the temperature range of the secondary and high-temperature relaxation processes. Important changes in the secondary relaxations are observed at low clay contents in comparison with neat poly(vinyl alcohol) (PVA). The high-temperature processes show a complex peak, which is a combination of the glass-rubber transition and the space-charge relaxations. The analysis of these processes shows the existence of two segmental relaxations for the nanocomposites. Dielectric results were complemented by calorimetric experiments using differential scanning calorimetry. Morphologic characterization was performed by x-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM and XRD results show a mixture of intercalated and exfoliated clay dispersion in a trend that promotes the exfoliated phase as the bentonite content diminishes. Dielectric and morphological results indicate the existence of polymer-clay interactions through the formation of hydrogen bounds and promoted by the exfoliated dispersion of the clay. These interactions affect not only the segmental dynamics, but also the secondary local dynamics of PVA.
Collapse
Affiliation(s)
- María C Hernández
- Departamento de Física, Universidad Simón Bolívar, Apartado 89000, Caracas 1080-A, Venezuela.
| | | | | | | | | | | |
Collapse
|
8
|
Fang QR, Zhu GS, Jin Z, Ji YY, Ye JW, Xue M, Yang H, Wang Y, Qiu SL. Mesoporous metal-organic framework with rare etb topology for hydrogen storage and dye assembly. Angew Chem Int Ed Engl 2007; 46:6638-42. [PMID: 17654638 DOI: 10.1002/anie.200700537] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Qian-Rong Fang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012, China
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Fang QR, Zhu GS, Jin Z, Ji YY, Ye JW, Xue M, Yang H, Wang Y, Qiu SL. Mesoporous Metal–Organic Framework with Rare etb Topology for Hydrogen Storage and Dye Assembly. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200700537] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Barranco A, Aparicio F, Yanguas-Gil A, Groening P, Cotrino J, González-Elipe A. Optically Active Thin Films Deposited by Plasma Polymerization of Dye Molecules. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/cvde.200606552] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
11
|
Barranco A, Groening P. Fluorescent plasma nanocomposite thin films containing nonaggregated rhodamine 6G laser dye molecules. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:6719-22. [PMID: 16863208 DOI: 10.1021/la053304d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This letter reports a novel methodology for the synthesis of dye-containing nanocomposite thin films containing fluorescent rhodamine 6G (Rh6G) laser dye molecules. The nanocomposites are deposited in one step at room temperature in a downstream microwave plasma operating at low pressure and power. By controlling the plasma chemistry, it is possible to reduce the formation of dye dimers and higher aggregates that quench the fluorescence of the dye molecules. The films are intensely absorbent and fluorescent, insoluble in water, mechanically stable, and present good adhesion to the substrate. Besides, the method is compatible with the present silicon technology and therefore particularly interesting for the fabrication of integrated optoelectronic devices.
Collapse
Affiliation(s)
- A Barranco
- Nanotech@surfaces Laboratory, EMPA Materials Science and Technology, Feuerwerkerstrasse 39, CH-3602 Thun, Switzerland.
| | | |
Collapse
|
12
|
Lee JY, Jung WT, Lee WJ. Molecular design, synthesis, and electro-optic properties of novel Y-type polyesters with high thermal stability of second harmonic generation. POLYM INT 2006. [DOI: 10.1002/pi.1965] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Kalogeras IM, Roussos M, Vassilikou-Dova A, Spanoudaki A, Pissis P, Savelyev YV, Shtompel VI, Robota LP. Structure and relaxation dynamics of poly(amide urethane)s with bioactive transition metal acetyl acetonates in hard blocks. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2005; 18:467-81. [PMID: 16331340 DOI: 10.1140/epje/e2005-00048-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Indexed: 05/05/2023]
Abstract
Structural characteristics, thermal transitions and molecular dynamics of selected poly(amide urethane)s with transition metal acetyl acetonates Me(AcAc)(2) (Me = Sn(4+), Zn(2+), Cu(2+), Pb(2+)) as chain extenders, were comparatively investigated using small- and wide-angle X-ray scattering (SAXS, WAXS), differential scanning calorimetry (DSC), and dielectric techniques (dielectric relaxation spectroscopy, DRS; thermally stimulated currents, TSC). We studied the influence of metal chelates on the mixing of the soft-segment (SS) and hard-segment (HS) domains and the related degree of microphase separation (DMS). The reactivity of Me(AcAc)(2) with macrodiisocyanate was found to decrease in the order Sn(AcAc)(2)Cl(2) > Cu(AcAc)(2) > Zn(AcAc)(2) > Pb(AcAc)(2). While Pb(AcAc)(2) shows a higher tendency for crystallisation, both the dielectric and calorimetric results suggest that the corresponding polyurethane has comparatively low DMS. The type of the transition metal has moderate effect on the glass transition temperature and no influence on the shape of the dielectric alpha relaxation signal, indicating weak interactions between metal ions and SS domains. In contrast, structural parameters and the dielectric behaviour of the beta relaxation suggest preference for hydrogen-bonding interactions between Sn(4+) and Cu(2+) metal-chelates and HS domains. The temperature dependence of dc conductivity sigma(dc) is described by the Vogel-Tammann-Fulcher equation and signifies the coupling between the mobility of polymeric chains and charges' motion. It may be expected that the present combination of techniques and particular results with respect to DMS will contribute to the development and testing of novel biodegradation-resistant and antibacterial metal-polyurethanes for biotechnological and industrial applications.
Collapse
Affiliation(s)
- I M Kalogeras
- Department of Solid State Physics, University of Athens, 15784 Zografos, Greece.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Kalogeras IM, Neagu ER. Interplay of surface and confinement effects on the molecular relaxation dynamics of nanoconfined poly(methyl methacrylate) chains. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2004; 14:193-204. [PMID: 15254839 DOI: 10.1140/epje/i2004-10015-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The thermally stimulated current (TSC) signatures of the primary (alpha) transition and its precursor, the Johary-Goldstein (beta) relaxation, are used to probe effects of nanoconfinement on the dielectric relaxation dynamics of poly(methyl methacrylate) (PMMA) radically polymerised in situ 50 angstroms mean pore size silica-gel. Nanoconfinement leads to a broadened and low-temperature-shifted beta band (peaking at Tbeta, with deltaTbeta = T(conf.)beta - T(bulk)beta = -15 degrees C for a heating rate of 5 deg/min), signifying the occurrence of faster relaxing moieties compared to the bulk-like PMMA film. Furthermore, both TSCs and differential scanning calorimetry (DSC) estimate a rise of the glass transition temperature for the confined phase ([Formula: see text]= +13 degrees C) and an increased width for the corresponding transition signals, relative to the signals in the bulk. Simple free-volume and entropy models seem inadequate to provide a collective description of the above perturbations. The observation of a spatial heterogeneity regarding the relaxation dynamics is discussed in terms of the presence of a motional gradient, with less mobile segments near the interface and more mobile segments in the core, and the interplay of adsorption ( e.g., strong physical interactions that slow down molecular mobilities) and confinement effects ( e.g., lower entanglements concentration and local density fluctuations that provide regions of increased free space). The results suggest that in the case of high-molecular-weight polymers confined in small-pore systems, adsorption effects have considerable bearing on the glass transition phenomenon whereas confinement primarily influences side-chains' rotational mobilities. The confinement effect is expected to dominate over adsorption for PMMA phases occluded in higher pore sizes and silanised walls.
Collapse
Affiliation(s)
- I M Kalogeras
- Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, 157 84, Zografos, Greece.
| | | |
Collapse
|