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1.
Macromol Rapid Commun ; 36(6): 528-32, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25619193

RESUMEN

Well-defined ABC triblock copolymers based on two hydrophilic blocks, A and C, and a hydrophobic block B are synthesized and their self-assembly behavior is investigated. Interestingly, at the same solvent, concentration, pH, and temperature, different shape micelles are observed, spherical and worm-like micelles, depending on the preparation method. Specifically, spherical micelles are observed with bulk rehydration while both spherical and worm-like micelles are observed with film rehydration.


Asunto(s)
Técnicas de Química Sintética/métodos , Polímeros/síntesis química , Interacciones Hidrofóbicas e Hidrofílicas , Micelas , Polímeros/química , Temperatura
2.
Chem Commun (Camb) ; 50(54): 7114-6, 2014 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-24852704

RESUMEN

Well-defined "clickable" homo- and co-polymers were synthesised using a living polymerisation technique. Specifically propargyl methacrylate was successfully homo- and co-polymerised using group transfer polymerisation, GTP. This one-pot synthesis was performed without the need to protect the acetylenic group. Finally it was confirmed that the acetylenic functional group was unaffected by the polymerisation by clicking with azide 4-azidobenzoic acid.

3.
Langmuir ; 29(48): 14804-14, 2013 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-24224915

RESUMEN

Aqueous solutions containing a mixture of polyethylene glycol (PEG) and dextran homopolymers form an aqueous two-phase system which can be emulsified to give a water-in-water emulsion. We show how these emulsions can be stabilized using triblock polymers containing poly[poly(ethylene glycol) methyl ether methacrylate] (PEGMA), poly (n-butyl methacrylate) (BuMA), and poly[2-(dimethylamino) ethyl methacrylate] (DMAEMA) blocks of general structure Pp-Bb-Dd, in which the middle BuMA block is hydrophobic. Low-energy input stirring of mixtures containing equal volumes of PEG- and dex-rich aqueous phases plus 1 wt % of Pp-Bb-Dd stabilizer all form dex-in-PEG emulsions (for the range of Pp-Bb-Dd triblock polymers used here) which have a polymersome-like structure. In favorable cases, the emulsion drop (or templated polymersome) sizes are a few micrometers and are stable for periods in excess of 6 months. The emulsions can be inverted from dex-in-PEG to PEG-in-dex by increasing the volume fraction of dex-rich aqueous phase. We demonstrate that both high and low molecular weight fluorescent solutes "self-load" into either the dex- or PEG-rich regions and that solute mass transfer across the water-water interface occurs on a timescale of less than 1 min.

4.
Nanoscale ; 3(9): 3685-94, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21799994

RESUMEN

Prussian Blue (PB) analogue metal coordination nanocages comprised of mesoporous walls (ca. 3.5 nm pore width) encapsulating a cavity approaching ca. 100 nm in diameter (surfactant free) are presented as an advance in rational metal coordination polymer nanostructure design. The synthesis employs lanthanide ions (Gd(3+) or Er(3+)) which function initially as peripheral coordination crosslinkers of metallo-surfactant templated miniemulsion droplets, and, subsequently, as promoters in the removal of the organic component of those surfactants via metal-assisted ester hydrolysis. The success of this synthetic strategy relies entirely on the periphery coordination event occurring prior to the ester hydrolysis surfactant removal step. Crucially, this one-pot sequential synthesis was achieved using a newly developed metallo-surfactant designed to have a reduced ester hydrolysis rate. Syntheses of this innovative metallo-surfactant, intermediary PB analogue coordination polymer organo-nanoshells and the subsequent conversion to hollow metal coordination nanocages are fully characterised using a wide variety of techniques, including TEM, SEM, EFTEM, EDX, TGA, WAXD, NMR, N(2) adsorption, etc., and represent the first designed synthesis of hollow metal coordination nanocages containing a large nanoscale cavity (wall of hollow nanosphere is mesoporous; hence nanocage).


Asunto(s)
Ferrocianuros/química , Elementos de la Serie de los Lantanoides/química , Nanoestructuras/química , Hidrólisis , Nanoestructuras/ultraestructura , Tamaño de la Partícula , Polímeros/química , Porosidad , Tensoactivos/química
5.
Chem Commun (Camb) ; 47(24): 6831-3, 2011 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-21556403

RESUMEN

We fabricated PPy/PB core/shell nanoparticles via one-step miniemulsion polymerization using a metallosurfactant of EPE-Fe. The defined hollow structure endows PB nanoshells with an emission band at 612 nm. On incorporating PPy inside PB shells, a blue shift and enhanced fluorescence were observed due to charge transfer from PPy to PB.

6.
Chem Commun (Camb) ; 46(25): 4574-6, 2010 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-20458419

RESUMEN

Metal coordination polymer nanoboxes are reported for the first time. Initially spherical miniemulsion droplet templates were transformed to hollow cubic crystalline nanostructures via a miniemulsion periphery polymerization conducted under benign thermal and chemical conditions.


Asunto(s)
Ferrocianuros/química , Nanoestructuras/química , Compuestos Organometálicos/síntesis química , Cristalización , Modelos Moleculares , Estructura Molecular , Compuestos Organometálicos/química , Tamaño de la Partícula , Propiedades de Superficie , Temperatura
7.
Macromol Rapid Commun ; 31(9-10): 856-60, 2010 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-21590979

RESUMEN

Miniemulsion periphery polymerization (MEPP) has been used for the synthesis of Prussian blue (PB) nanocubes. Pentacyano ferrate functionalized surfactant in combination with a co-surfactant containing 4-(dimethylamino)-pyridine (DMAP) or OH end groups in lieu of ferrate functionality (EPE-DMAP or EPE-OH) were used to prepare a miniemulsion system comprising 20 wt.-% toluene and 0.5 wt.-% total surfactant. On addition of Fe(3+) to the miniemulsion, metal coordination polymerization occurred with nanocubes generated when the ratio of EPE-Fe:EPE-DMAP (or EPE-OH) was 60:40 (w/w). The resulting nanocubes are apparently amorphous. Particles with irregular shape have been observed on reacting EPE-Fe and Fe(3+) directly in water, thus suggesting that confinement of the polymerization field on the periphery of the miniemulsion droplets is a primary factor in the formation of cubic structures.

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