Quantitative analysis of atomic force microscopy topographs of biopolymer multilayers: Surface structure and polymer assembly modes

Marken, Endre; Maurstad, Gjertrud; Stokke, Bjørn Torger

doi:10.1016/j.tsf.2008.05.054

Cited by 13 publications

(4 citation statements)

References 62 publications

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“…Alternate CHI/HA films are composed of islets as found for CHI/HA films obtained by alternate dipping. , Alternate CHI/CS films appear granular, as simultaneous sprayed CHI/CS films. In the case of the CHI/ALG system, the films built by alternate spraying appear to be very smooth as in alternate dipping contrary to films built by simultaneous spraying that show a granular aspect. Polysaccharide films built by alternate spraying process are two or three times smoother than the ones obtained by simultaneous spraying (Table ).…”

Section: Resultsmentioning

confidence: 88%

Polysaccharide Films Built by Simultaneous or Alternate Spray: A Rapid Way to Engineer Biomaterial Surfaces

et al. 2012

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We investigated polysaccharide films obtained by simultaneous and alternate spraying of a chitosan (CHI) solution as polycation and hyaluronic acid (HA), alginate (ALG), and chondroitin sulfate (CS) solutions as polyanions. For simultaneous spraying, the film thickness increases linearly with the cumulative spraying time and passes through a maximum for polyanion/CHI molar charge ratios lying between 0.6 and 1.2. The size of polyanion/CHI complexes formed in solution was compared with the simultaneously sprayed film growth rate as a function of the polyanion/CHI molar charge ratio. A good correlation was found. This suggests the importance of polyanion/polycation complexation in the simultaneous spraying process. Depending on the system, the film topography is either liquid-like or granular. Film biocompatibility was evaluated using human gingival fibroblasts. A small or no difference is observed in cell viability and adhesion between the two deposition processes. The CHI/HA system appears to be the best for cell adhesion inducing the clustering of CD44, a cell surface HA receptor, at the membrane of cells. Simultaneous or alternate spraying of CHI/HA appears thus to be a convenient and fast procedure for biomaterial surface modifications.

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Section: Resultsmentioning

confidence: 88%

Polysaccharide Films Built by Simultaneous or Alternate Spray: A Rapid Way to Engineer Biomaterial Surfaces

et al. 2012

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“…Fit of the cascade mode at various functionalities (f) account for the existence of a lower critical concentration needed for gel formation. (i) Power spectral density analysis of the calculated mean height autocorrolation function of AFM topographs of eight layer pairs of scleraldehyde–chitosan . The peak at the spatial frequency q = 0.23 nm −1 is suggested to reflect the width of the individual strands as observed in the AFM topographs (inset).…”

Section: Xanthan: An Example Of a Polysaccharide Adopting A Duplex Stmentioning

confidence: 99%

“…Such hydrogels may display transition phenomena differing from that of other hydrogels undergoing critical swelling phenomena owing to the stiff nature of the scleroglucan . The scleraldehyde–chitosan is also suitable for the preparation of multilayers with porous structure differing from that accessible using more flexible polysaccharides …”

Section: Xanthan: An Example Of a Polysaccharide Adopting A Duplex Stmentioning

confidence: 99%

Structure–Function Relationships in Glycopolymers: Effects of Residue Sequences, Duplex, and Triplex Organization

Sletmoen

Stokke

2013

Biopolymers

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The importance of residue sequence and duplex and triplex structures as basis for establishing molecular understanding of the structure-function relationships within glycopolymers is highlighted. The copolysaccharide alginate is the selected example for elucidating effects of residue sequence on functional properties like ionotropic gelation. Xanthan and comblike branched β-D-glucans are used as examples of impact of duplex and triplex organization on global conformation and functional properties. Combined with further examples within self-interactions of mucins possessing different saccharide decorations, polyelectrolyte complexation and multilayer formation, the examples indicate that a molecular understanding of various properties related to impact of residue sequences, duplex, and triplex organization can be established. Strategies similar to those included in the highlighted examples, also combined with novel tools, for example single-molecule approaches, interrogated by combination of experimental and theoretical/numerical approaches, and investigated closer to the native biological state, are expected to further advance the field.

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“…Quantifying Phase Separation from Scanning Images. Spatial Fourier transforms and power spectral density (PSD) analysis of PISAe images provide quantitative information about phase separation in BHJ films that are affected by D–A ratios, solvents, additive factors, and annealing conditions. , Length scales obtained through PSD analysis are inversely related to spatial frequencies present in the film (Figure and Table ). PSD analysis of topography images of preannealed devices showed a peak frequency in the range of 0.95 ± 0.3 μm –1 , representing a domain periodicity of ∼1 μm.…”

mentioning

confidence: 99%

High-Resolution Photocurrent Imaging of Bulk Heterojunction Solar Cells

Mukhopadhyay

Das

Narayan

2012

J. Phys. Chem. Lett.

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Images obtained from photocurrent scanning of organic bulk heterojunction solar cell devices provide a direct measure of correlation of the morphology to the performance parameters. The peripheral photocurrent induced from light coupled to probe tips in the near-field regime of bulk heterojunction layers permits in situ scanning of active solar cells with asymmetric electrodes. We present a methodology involving a combination of atomic force microscopy, near-field optical microscopy, and near-field photocurrent microscopy to decipher the carrier generation and transport regions in the bulk heterojunction layer. The angular Fourier transformation technique is implemented on these images to rationalize the optimum blend concentration in crystalline and amorphous donor systems and provide insights into the role of the bulk heterojunction morphology.

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Quantitative analysis of atomic force microscopy topographs of biopolymer multilayers: Surface structure and polymer assembly modes

Cited by 13 publications

References 62 publications

Polysaccharide Films Built by Simultaneous or Alternate Spray: A Rapid Way to Engineer Biomaterial Surfaces

Polysaccharide Films Built by Simultaneous or Alternate Spray: A Rapid Way to Engineer Biomaterial Surfaces

Structure–Function Relationships in Glycopolymers: Effects of Residue Sequences, Duplex, and Triplex Organization

High-Resolution Photocurrent Imaging of Bulk Heterojunction Solar Cells

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