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Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers.

Torrisi V, Ruffino F, Licciardello A, Grimaldi MG, Marletta G - Nanoscale Res Lett (2011)

Bottom Line: The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg.The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition.The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemical Sciences, University of Catania and CSGI, Viale A, Doria 6, 95125, Catania, Italy. vanna.torrisi@gmail.com.

ABSTRACT
We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB) method. The morphology and the phase-separation of a film of poly-n-butylacrylate-block-polyacrylic acid (PnBuA-b-PAA) were studied at the nanometric scale by using atomic force microscopy (AFM) and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The templating capability of the PnBuA-b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs), forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

No MeSH data available.


Surface pressure versus molecular area isotherms obtained by 1, 3, 5 mg/ml chloroform solutions of PnBuA-b-PAA.
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Figure 1: Surface pressure versus molecular area isotherms obtained by 1, 3, 5 mg/ml chloroform solutions of PnBuA-b-PAA.

Mentions: Figure 1 reports the Langmuir isotherms obtained for PnBuA-b-PAA films at three different solution concentrations, i.e., 1, 3 and 5 mg/ml. The fact that at a given molecular area (for instance 7,5 nm2) the pressure at 3 mg/ml is lower than that one reported in the 1 mg/ml isotherm is unusual. It depends on the characteristic behaviour of block copolymers in Langmuir-Blodgett films and on their pressure-induced reorganization/reorientation phenomena at the air/water interface [32]. The lower surface pressure for the phase transitions of 3 mg/ml with respect to 1 mg/ml isotherm originates from chains reorientations of two blocks. Such reorientations are the result of the balance between block-block and block interface interactions.


Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers.

Torrisi V, Ruffino F, Licciardello A, Grimaldi MG, Marletta G - Nanoscale Res Lett (2011)

Surface pressure versus molecular area isotherms obtained by 1, 3, 5 mg/ml chloroform solutions of PnBuA-b-PAA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211219&req=5

Figure 1: Surface pressure versus molecular area isotherms obtained by 1, 3, 5 mg/ml chloroform solutions of PnBuA-b-PAA.
Mentions: Figure 1 reports the Langmuir isotherms obtained for PnBuA-b-PAA films at three different solution concentrations, i.e., 1, 3 and 5 mg/ml. The fact that at a given molecular area (for instance 7,5 nm2) the pressure at 3 mg/ml is lower than that one reported in the 1 mg/ml isotherm is unusual. It depends on the characteristic behaviour of block copolymers in Langmuir-Blodgett films and on their pressure-induced reorganization/reorientation phenomena at the air/water interface [32]. The lower surface pressure for the phase transitions of 3 mg/ml with respect to 1 mg/ml isotherm originates from chains reorientations of two blocks. Such reorientations are the result of the balance between block-block and block interface interactions.

Bottom Line: The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg.The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition.The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemical Sciences, University of Catania and CSGI, Viale A, Doria 6, 95125, Catania, Italy. vanna.torrisi@gmail.com.

ABSTRACT
We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB) method. The morphology and the phase-separation of a film of poly-n-butylacrylate-block-polyacrylic acid (PnBuA-b-PAA) were studied at the nanometric scale by using atomic force microscopy (AFM) and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The templating capability of the PnBuA-b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs), forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

No MeSH data available.