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Laera AM, Resta V, Piscopiello E, Miceli V, Schioppa M, Scalone AG, Benedetto FD, Tapfer L. In situ growth of well-dispersed CdS nanocrystals in semiconducting polymers. NANOSCALE RESEARCH LETTERS 2013; 8:382. [PMID: 24015753 PMCID: PMC3847301 DOI: 10.1186/1556-276x-8-382] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 08/02/2013] [Indexed: 06/02/2023]
Abstract
A straight synthetic route to fabricate hybrid nanocomposite films of well-dispersed CdS nanocrystals (NCs) in poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) is reported. A soluble cadmium complex [Cd(SBz)2]2·MI, obtained by incorporating a Lewis base (1-methylimidazole, MI) on the cadmium bis(benzyl)thiol, is used as starting reagent in an in situ thermolytic process. CdS NCs with spherical shape nucleate and grow well below 200°C in a relatively short time (30 min). Photoluminescence spectroscopy measurements performed on CdS/MEH-PPV nanocomposites show that CdS photoluminescence peaks are totally quenched inside MEH-PPV, if compared to CdS/PMMA nanocomposites, as expected due to overlapping of the polymer absorption and CdS emission spectra. The CdS NCs are well-dispersed in size and homogeneously distributed within MEH-PPV matrix as proved by transmission electron microscopy. Nanocomposites with different precursor/polymer weight ratios were prepared in the range from 1:4 to 4:1. Highly dense materials, without NCs clustering, were obtained for a weight/weight ratio of 2:3 between precursor and polymer, making these nanocomposites particularly suitable for optoelectronic and solar energy conversion applications.
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Affiliation(s)
- Anna Maria Laera
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Vincenzo Resta
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Emanuela Piscopiello
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Valerio Miceli
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Monica Schioppa
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Anna Grazia Scalone
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Francesca Di Benedetto
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
| | - Leander Tapfer
- ENEA, Technical Unit for Material Technologies, Brindisi Research Centre, Strada Statale 7, Appia km 706, Brindisi, 72100, Italy
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Wilberforce SIJ, Finlayson CE, Best SM, Cameron RE. A comparative study of the thermal and dynamic mechanical behaviour of quenched and annealed bioresorbable poly-L-lactide/α-tricalcium phosphate nanocomposites. Acta Biomater 2011; 7:2176-84. [PMID: 21315187 DOI: 10.1016/j.actbio.2011.02.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/26/2011] [Accepted: 02/03/2011] [Indexed: 12/01/2022]
Abstract
Despite numerous reports on the degradation properties and biological efficacy of bioresorbable polymer nanocomposites intended for use in orthopaedics, there is currently limited literature addressing their thermal and load-bearing properties, which are of central importance to the successful design of these nanocomposites. Here we demonstrate that the storage moduli at 37°C and the glass transition temperatures of quenched poly-L-lactide/α-tricalcium phosphate nanocomposites were lower than those of annealed nanocomposites while the damping factor tanδ values of the quenched nanocomposites were higher than those of the annealed nanocomposites. This was due to the highly crystalline structure of the annealed samples, as confirmed by wide angle X-ray diffraction. The higher storage moduli and glass transition temperatures of the annealed nanocomposites implies that higher energy will be generated to resist deformation with the possibility for reduced polymer chain mobility during in vivo use. Therefore, the decision as to whether to use quenched or annealed nanocomposites depends on the load-bearing conditions prevailing at the site of implantation. The storage moduli of the nanocomposites at 37°C approached the lower range of the storage modulus for cortical bone and this may prevent stress shielding during bone regeneration.
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Affiliation(s)
- Samuel I J Wilberforce
- Cambridge Centre for Medical Materials, Department of Materials Science and Metallurgy, University of Cambridge, UK.
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Chen XC, Green PF. Control of morphology and its effects on the optical properties of polymer nanocomposites. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3659-3665. [PMID: 19957937 DOI: 10.1021/la903108u] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Chain-grafted Au nanoparticles were synthesized and incorporated into a fluorescent polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), host. We show that control of the Au nanoparticle distribution within MEH-PPV is achieved by manipulating the enthalpic and entropic interactions between the grafted brush layers and the host chains. Further, we show that the fluorescence of these Au/MEH-PPV nanocomposite thin films may be "tailored" by as much as an order of magnitude through changes in the nanoparticle distribution, brush length, and nanoparticle size. The ideas presented herein represent reliable strategies for materials design for devices.
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Affiliation(s)
- X Chelsea Chen
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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Tsukuda S, Seki S, Sugimoto M, Idesaki A, Tagawa S, Tanaka SI. Formation of Hybrid Nano-structures by Ion Beam Irradiation to the Sol-Gel Film. J PHOTOPOLYM SCI TEC 2009. [DOI: 10.2494/photopolymer.22.245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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