Diblock copolymer ultrathin films studied by high resolution electron energy loss spectroscopy

Rego, A.M. Botelho do; Pellegrino, Olivier; Martinho, J. M. G.; Silva, J Lopes da

doi:10.1016/s0039-6028(01)00880-9

“…[34][35][36][37] Our experiments compare well with the few existing studies performed on PS-PEO copolymers spun from chloroform, which found evidence of an enrichment of the PS block at the top surface in air. 6,12,29,30 However, our experiments disagree with the interpretation of the data presented by Thomas and O'Malley, 12 as we do not observe both blocks at the air/film interface. Reference 12 did consider the possibility for the presence of a thin PS overlayer, but the model was not consistent with their interpretation of the angular-dependent XPS data.…”

Section: Discussioncontrasting

confidence: 99%

“…The measured C1s and O1s core level spectra for both samples were identical, so Figure and insets illustrate the results on one of the samples. These spectra are similar to data previously measured on similar films. , The C 1s region at a binding energy of ca. 285 eV can be deconvoluted into two separate peaks.…”

Section: Resultssupporting

confidence: 89%

“…These spectra are similar to data previously measured on similar films. 12,29 The C 1s region at a binding energy of ca. 285 eV can be deconvoluted into two separate peaks.…”

Section: Downloaded By Australian National Univ On July 30 2009mentioning

confidence: 99%

“…27,28 Few publications have investigated specifically this aspect. 12,[29][30][31] It is well-known that a PEO layer is in contact with the supporting silicon substrate, given its higher polarity respect to PS. However, the situation is not as clear for the film/air interface.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the Composition of the Top Layer of Microphase Separated Thin PS-PEO Films

Neto

¹

,

James

²

,

Telford

³

2009

View full text Add to dashboard Cite

The topography and surface composition of thin films (ca. 100 nm) of a polystyrene-b-poly-(ethylene oxide) (PS-PEO) block copolymer are investigated using a suite of complementary techniques, namely tapping mode atomic force microscopy (AFM), optical microscopy, X-ray photoelectron spectroscopy (XPS), neutron reflectometry, and wettability measurements. The copolymer films separate into lamellar structures oriented parallel to the silicon substrate, and bicontinuous and island/hole morphologies characteristic of this arrangement appear. Even though the crystalline topography of the film's surface and its wettability properties suggest the presence of PEO on the top surface, XPS and neutron reflectometry data point undoubtedly to the presence of a top layer of PS at the air/film interface. Tapping mode AFM images unequivocally demonstrate that in air only one block is present at the air/film interface. Neutron reflectometry data identify the nature of each phase-separated layer within the film. This finding differs from a model of domain arrangement proposed in a classic and much-cited paper on these systems (Macromolecules 1979, 12, 323). After exposure to water, PEO blocks rearrange and access the top surface of the film. After many hours of thermal annealing, both PS and PEO blocks can be made to appear at the film/air interface, within isolated droplets formed upon film dewetting.

show abstract

High Resolution Electron Energy‐Loss Spectroscopy

Soriaga

¹

,

Chen

²

,

Ding

³

et al. 2005

Encyclopedia of Inorganic Chemistry

View full text Add to dashboard Cite

The determination of the identity and structure of molecular species present in no more than monolayer quantities at solid surfaces is one of the more difficult tasks in interfacial science. In this regard, vibrational spectroscopy is an invaluable technique; in the evaluation of the molecular integrity of surface‐bound compounds, it has few equals. Optical methods such as infrared spectroscopy, while rather uncomplicated for bulk materials, lack the high sensitivity needed for most surface species due to minuscule molecular amounts. A much more responsive alternative is based on the use of low‐energy electrons to interact with the molecular oscillators on the surface. If inelastic interactions occur, the energy of the backscattered electrons will be lower than that of the incident electrons, and the energy loss will correspond to a vibrational‐mode frequency. The present article briefly describes the fundamental principles of and instrumental considerations in high‐resolution electron energy‐loss spectroscopy (HREELS), and cites seminal applications in the study of the adsorption of organic and inorganic molecules at metal and semiconductor surfaces. A limited list of HREELS work published since the turn of the century is added in the last section.

show abstract

High Resolution Electron Energy‐Loss Spectroscopy

Soriaga

¹

,

Chen

²

,

Ding

³

et al. 2011

Encyclopedia of Inorganic and Bioinorganic Chemistry

0

View full text Add to dashboard Cite

The determination of the identity and structure of molecular species present in no more than monolayer quantities at solid surfaces is one of the more difficult tasks in interfacial science. In this regard, vibrational spectroscopy is an invaluable technique; in the evaluation of the molecular integrity of surface‐bound compounds, it has few equals. Optical methods such as infrared spectroscopy, while rather uncomplicated for bulk materials, lack the high sensitivity needed for most surface species due to minuscule molecular amounts. A much more responsive alternative is based on the use of low‐energy electrons to interact with the molecular oscillators on the surface. If inelastic interactions occur, the energy of the backscattered electrons will be lower than that of the incident electrons, and the energy loss will correspond to a vibrational‐mode frequency. The present article briefly describes the fundamental principles of and instrumental considerations in high‐resolution electron energy‐loss spectroscopy (HREELS), and cites seminal applications in the study of the adsorption of organic and inorganic molecules at metal and semiconductor surfaces. A limited list of HREELS work published since the turn of the century is added in the last section.

show abstract

Diblock copolymer ultrathin films studied by high resolution electron energy loss spectroscopy

Cited by 5 publications

References 19 publications

On the Composition of the Top Layer of Microphase Separated Thin PS-PEO Films

On the Composition of the Top Layer of Microphase Separated Thin PS-PEO Films

High Resolution Electron Energy‐Loss Spectroscopy

High Resolution Electron Energy‐Loss Spectroscopy

Contact Info

Product

Resources

About