Layered structures of shear-oriented and multilayered PEO/silicate nanocomposite films

Malwitz, Matthew M.; Dundigalla, Avinash; Ferreiro, Vincent; Butler, Paul D.; Henk, Margaret C.; Schmidt, Gudrun

doi:10.1039/b401892c

Cited by 41 publications

(41 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This interpretation is supported by the nm size layered structures we have observed for films at higher salt concentration studied by us in the past. 46 Here large amounts of excess PEO may cover up any blob-like chains and lead to a different type of layered structure. 46 Due to higher polymer concentrations neither height nor phase imaging can distinguish between individual platelets at CNA40%-PEO60% concentrations studied in the past.…”

Section: Resultsmentioning

confidence: 99%

“…46 Here large amounts of excess PEO may cover up any blob-like chains and lead to a different type of layered structure. 46 Due to higher polymer concentrations neither height nor phase imaging can distinguish between individual platelets at CNA40%-PEO60% concentrations studied in the past. 46 Although the -2D SANS data for both, the CNA40%-PEO60% films studied in the past 46 and the CNA60%-PEO40% films presented here look qualitatively very similar, the local morphology such as the interconnected blobs vs layers, is very different.…”

Section: Resultsmentioning

confidence: 99%

“…44,45 Multilayered films were prepared from solution via gel/ solution exfoliation while exfoliated and stable solutions were obtained for a particular polymer clay ratio, pH and ionic strength as described before. [16][17][18]46 Here multilayered films are discussed that have been prepared from an aqueous solution containing mass fractions of 3% clay and 2% PEO at ambient temperature. The solution pH and ionic strength were controlled by the addition of NaOH (pH = 9-10) and NaCl (1 mM), respectively.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Supramolecular structures in nanocomposite multilayered films

Stefanescu

Dundigalla

Ferreiro

et al. 2006

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

We investigate the multilayered structures of poly(ethylene)oxide/montmorillonite nanocomposite films made from solution. The shear orientation of a polymer-clay network in solution combined with simultaneous solvent evaporation leads to supramolecular multilayer formation in the film. The resulting films have highly ordered structures with sheet-like multilayers on the micrometer length scale. The polymer covered clay platelets were found to orient in interconnected blob-like chains and layers on the nanometer length scale. Inside the blobs, scattering experiments indicate the polymer covered and stacked clay platelets oriented in the plane of the film. The polymer is found to be partially crystalline although this is not visible by optical microscopy. Atomic force microscopy suggests that the excess polymer, which is not directly adsorbed to the clay, is wrapped around the stacked platelets building blobs and the polymer also interconnects the polymer-clay layers. Overall our results suggest the re-intercalation of clay platelets in films made from exfoliated polymer-clay solutions as well as the supramolecular order and hierarchical structuring on the nanometer, via micrometer to the centimeter length scale.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Supramolecular structures in nanocomposite multilayered films

Stefanescu

Dundigalla

Ferreiro

et al. 2006

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, FIC behaviour in nanocomposites has received so far little attention; few studies dealing with the flow effects on the crystallization of nano-filled polymeric materials have been reported [35][36][37][38][39][40][41][42]. In particular, most of them focus on the flow induced crystallization in polypropylene nanocomposites.…”

Section: Introductionmentioning

confidence: 99%

Flow induced crystallization of LDPE nanocomposites: A rheological and morphological characterization

Azzurri

Stagnaro²,

Conzatti³

et al. 2011

E-Polymers

View full text Add to dashboard Cite

Abstract:The flow induced crystallization behaviour of a LDPE:PE-g-MA:D72T 90:9:1 nanocomposite has been investigated by in-situ Rheo-SALS technique and data have been compared with those obtained from a reference LDPE:PE-g-MA 90:9 sample. Rheo SALS results, confirming thermal analysis findings, indicate that under mild shear flow fields the organoclay exhibits a negligible nucleating effect. Both nucleation density and, as a consequence, crystallization rate, are not appreciably affected by the application of external flow field for both the examined systems, revealing that no evident synergic effects between the organoclay and the shear flow are present. On the other hand, Rheo SALS analysis indicates that the nanocomposite submitted to flow exhibits a higher level of crystal orientation. TEM morphological analyses support this observation suggesting that the orientation of the nanofiller along the flow direction templates the growth of oriented crystals.

show abstract

“…Thus, apart from the investigation of clay dispersion AFM can provide information about surface topography of the samples. In addition, AFM can also measure fundamental properties of sample surfaces, e.g., local adhesive or elastic properties on nanoscale (Malwitz et al, 2004), (McNally et al, 2003), (Jiang et al, 2005).…”

Section: Techniques Used For the Characterization Of Nanocompositesmentioning

confidence: 99%