TITLE

Synthesis and spectroscopy of CdS nanoparticles in amphiphilic diblock copolymer micelles

AUTHOR(S)
Mandal, Debabrata; Chatterjee, Uma
PUB. DATE
April 2007
SOURCE
Journal of Chemical Physics;4/7/2007, Vol. 126 Issue 13, p134507
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Amphiphilic diblock copolymers with the same hydrophilic but different hydrophobic blocks were used as stabilizing agents to prepare cadmium sulfide nanoparticles in aqueous solutions containing 5% of different nonaqueous solvents: methanol, THF, and acetone. Nearly spherical nanoparticles with a fair degree of monodispersity and quantum yields of 1.5%–2% were obtained. Optical absorption band edge of the CdS nanoparticles shows a >0.5 eV blueshift compared to that of bulk CdS, indicating a high degree of quantum confinement. The absorption spectra, while insensitive to the nature of the hydrophobic blocks, exhibited a clear dependence on the nature of the minor, nonaqueous solvents. The photoluminescence in all cases was broad and redshifted, indicating a predominance of surface trap-state emission. Time-resolved photoluminescence demonstrates that the trap states are populated within the first 500 fs, followed by decay with a broad range of time constants from 0.1 to >10 ns, low energy traps decaying at a slower rate than high-energy ones. Time-resolved photoluminescence anisotropy revealed that the nanoparticles experience a local microviscosity very similar to that of bulk water. The experimental observations suggest that nanoparticle formation takes place predominantly in the hydrophilic corona region of the micelles, around specific points with high local concentration of the Cd+2-coordinating basic amine groups of hydrophilic block and/or the minor, nonaqueous solvent component.
ACCESSION #
24660226

 

Related Articles

  • Nonconventional morphologies in two-length scale block copolymer systems beyond the weak segregation theory. Kriksin, Yury A.; Erukhimovich, Igor Ya.; Khalatur, Pavel G.; Smirnova, Yuliya G.; ten Brinke, Gerrit // Journal of Chemical Physics;6/28/2008, Vol. 128 Issue 24, p244903 

    The order-disorder and order-order transitions (ODT and OOT) in the linear multiblock copolymers with two-length scale architecture AfmN(BN/2AN/2)nB(1-f)mN are studied under intermediate cooling below the ODT critical point where a nonconventional sequence of the OOTs was predicted previously...

  • Mosaic two-lengthscale quasicrystals. Dotera, T.; Oshiro, T.; Ziherl, P. // Nature;2/13/2014, Vol. 506 Issue 7487, p208 

    Over the past decade, quasicrystalline order has been observed in many soft-matter systems: in dendritic micelles, in star and tetrablock terpolymer melts and in diblock copolymer and surfactant micelles. The formation of quasicrystals from such a broad range of 'soft' macromolecular micelles...

  • Micelles obtained by aggregation of gemini surfactants containing the CCK8 peptide and a gadolinium complex. Accardo, Antonella; Tesauro, Diego; Morisco, Anna; Mangiapia, Gaetano; Vaccaro, Mauro; Gianolio, Eliana; Heenan, Richard K.; Paduano, Luigi; Morelli, Giancarlo // Journal of Biological Inorganic Chemistry;Apr2009, Vol. 14 Issue 4, p587 

    Two gemini surfactants, [C18CysL5CCK8]2 and [C18CysDTPAGlu]2, containing, respectively, the CCK8 peptide and the DTPAGlu chelating agent or its gadolinium complex have been prepared by linking lipophilic chains through a disulfide bond between two cysteine residues. The two surfactants aggregate...

  • Vibrational dynamics of ice in reverse micelles. Dokter, Adriaan M.; Petersen, Christian; Woutersen, Sander; Bakker, Huib J. // Journal of Chemical Physics;1/28/2008, Vol. 128 Issue 4, p044509 

    The ultrafast vibrational dynamics of HDO:D2O ice at 180 K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions...

  • Synthesis and micellization of an amphiphilic biodegradable �-cyclodextrin/poly(?-benzyl L-glutamate) copolymer. Qiu Hua Wu; Fang Liang; Tian Zhu Wei; Xi Ming Song; Da Liang Liu; Guo Lin Zhang // Journal of Polymer Research;Mar2010, Vol. 17 Issue 2, p183 

    �-Cyclodextrin/poly(?-benzyl L-glutamate) (�-CD-PBLG) copolymers were synthesized by ring-opening polymerization of N-carboxy-?-benzyl L-glutamate anhydride (BLG-NCA) in N,N-dimethylformamide(DMF) initiated by mono-6-amino-�-cyclodextrin(H2N-�-CD). The structures of the...

  • A concise review of dynamical processes in polymorphic environments of a block copolymer: Rotational diffusion and photoisomerization. Mali, K. S.; Dutt, G. B. // Journal of Chemical Sciences;Mar2007, Vol. 119 Issue 2, p147 

    This article describes our ongoing efforts to understand dynamical processes such as rotational diffusion and photoisomerization in polymorphic environments of a block copolymer. The objective is to explore how the typical properties of a block copolymer solution such as critical micelle...

  • Spectroluminescent properties of cadmium selenide nanoparticles synthesized in AOT reverse micelles. Gak, V.; Brichkin, S.; Razumov, V. // High Energy Chemistry;Nov2010, Vol. 44 Issue 6, p524 

    Cadmium selenide nanoparticles have been synthesized in solutions of AOT/water/ n-heptane reverse micelles with average micelle water pool diameters of 25, 30, and 47 Ã… using cadmium sulfate (CdSO) and sodium selenosulfate (NaSeSO) as precursors. Absorption and fluorescence spectra of the...

  • Effect of CTAB and procain hydrochloride on neutral red microstructure in CTAB micelle. Liu, T.; Wu, J. // Colloid Journal;May2008, Vol. 70 Issue 3, p311 

    The effects of cationic surfactant (CTAB) and procaine hydrochloride on the microstructures of neutral red (NR) are studied by UV-Vis spectroscopy, fluorescence spectroscopy and surface tension and conductivity measurements. The obtained results show that the acidic structure of NR can be...

  • Utilizing inverse micelles to synthesize calcium phosphate nanoparticles as nano-carriers. Han, Jamie; Tan, Timothy; Loo, Joachim // Journal of Nanoparticle Research;Aug2011, Vol. 13 Issue 8, p3441 

    The aim of this study was to investigate the feasibility of the inverse micelles (IM) technique in producing protein-loaded calcium phosphate nanoparticles (CaP NPs), and to compare this technique with the conventional co-precipitation (co-ppt) technique. In this study, bovine serum albumin and...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics