A convenient method to determine the Rayleigh ratio with uniform polystyrene oligomers

Itakura, Masanao; Shimada, Kayori; Matsuyama, Shigetomo; Saito, Tetsuya; Kinugasa, Shinichi

doi:10.1002/app.22695

Cited by 25 publications

(25 citation statements)

References 14 publications

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“…Static and dynamic light scattering experiments were simultaneously performed at 25°C on a compact ALV/CGS-3 instrument, equipped with a He-Ne laser with a wavelength of 632.8 nm. The absolute intensity was obtained using toluene a standard, where a Rayleigh ratio of 1.34 × 10 −5 cm −1 was used 65 . Experiments were performed at variable scattering angles between 21°and 145°, thus covering a q-range of 4.8 × 10 −3 -2.3 × 10 −2 nm −1 .…”

Section: Methodsmentioning

confidence: 99%

One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings

Micciulla

Hayward

Gerelli³

et al. 2019

Commun Chem

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Soft, stratified, amphiphilic systems are recurrent motifs in nature, e.g., in myelin sheaths or thylakoid stacks, and synthetic analogues are increasingly being exploited in the areas of biocatalysis, biosensing, and drug delivery. The synthesis of such complex multilayered systems usually requires lengthy preparation protocols. Here, we demonstrate the formation of multilayered fatty acid/polysaccharide thin films prepared via a single step protocol, which exploits the spontaneous self-assembly of the components into vesicular systems in aqueous solution. The solutions are characterized by light and neutron scattering experiments and the thin films by neutron reflectometry, optical ellipsometry, atomic force microscopy, and x-ray diffraction. The thin films exhibit structural features with sub-10 nm dimensions, stemming from the ordered sequence of hydrophilic and hydrophobic layers and respond strongly to changes in ambient humidity. Using this approach, films with a total thickness varying from tens to hundreds of nanometers can be easily prepared.

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Section: Methodsmentioning

confidence: 99%

One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings

Micciulla

Hayward

Gerelli³

et al. 2019

Commun Chem

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“…All measurements were performed in a thermostatted toluene bath (AE0.1 C) for aqueous polymer solutions (0.1 g L À1 ) at 15 C, 25 C, 30 C, and 50 C. The scattering intensity was normalized using the scattering of toluene at 25 C as a reference, having a Rayleigh ratio of 1.34 Â 10 À5 cm À1 at 632.8 nm. 45 The radius of gyration R g and the scattering intensity (I) for q / 0 were obtained by means of the Guinier approximation:…”

Section: Laser Light Scattering Studiesmentioning

confidence: 99%

Structure-related differences in the temperature-regulated fluorescence response of LCST type polymers

et al. 2013

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We demonstrate new fluorophore-labelled materials based on acrylamide and on oligo(ethylene glycol) (OEG) bearing thermoresponsive polymers for sensing purposes and investigate their thermally induced solubility transitions. It is found that the emission properties of the polarity-sensitive (solvatochromic) naphthalimide derivative attached to three different thermoresponsive polymers are highly specific to the exact chemical structure of the macromolecule. While the dye emits very weakly below the LCST when incorporated into poly(N-isopropylacrylamide) (pNIPAm) or into a polyacrylate backbone bearing only short OEG side chains, it is strongly emissive in polymethacrylates with longer OEG side chains.Heating of the aqueous solutions above their cloud point provokes an abrupt increase of the fluorescence intensity of the labelled pNIPAm, whereas the emission properties of the dye are rather unaffected as OEG-based polyacrylates and methacrylates undergo phase transition. Correlated with laser light scattering studies, these findings are ascribed to the different degrees of pre-aggregation of the chains at low temperatures and to the extent of dehydration that the phase transition evokes. It is concluded that although the temperature-triggered changes in the macroscopic absorption characteristics, related to large-scale alterations of the polymer chain conformation and aggregation, are well detectable and similar for these LCST-type polymers, the micro-environment provided to the dye within each polymer network differs substantially. Considering sensing applications, this finding is of great importance since the temperature-regulated fluorescence response of the polymer depends more on the macromolecular architecture than the type of reporter fluorophore.

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“…K is the optical constant given by: where N a is the Avogadro number, and dn/dc is the specific refractive index increment of the solution, which was set at 0.185 mg⋅mL -1 , the corresponding value for proteins, and the laser wavelength, λ 0 = 633 nm. The Rayleigh ratio, R θ , was calculated by subtracting the solvent intensity from the solution intensity (I A = I Solution -I Solvent ) using toluene as the standard (I T ) for which R T = 1.41×10 −5 cm -1 at T = 298 K and λ 0 = 633 nm [ 35 ]: where n 0 and n T are the refractive index of the solvent and toluene, respectively. Each final R θ data point was based on averaging not less than 10 statistically consistent measurements.…”

Section: Methodsmentioning

confidence: 99%

Evidences of Changes in Surface Electrostatic Charge Distribution during Stabilization of HPV16 Virus-Like Particles

et al. 2016

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The stabilization of human papillomavirus type 16 virus-like particles has been examined by means of different techniques including dynamic and static light scattering, transmission electron microscopy and electrophoretic mobility. All these techniques provide different and often complementary perspectives about the aggregation process and generation of stabilized virus-like particles after a period of time of 48 hours at a temperature of 298 K. Interestingly, static light scattering results point towards a clear colloidal instability in the initial systems, as suggested by a negative value of the second virial coefficient. This is likely related to small repulsive electrostatic interactions among the particles, and in agreement with relatively small absolute values of the electrophoretic mobility and, hence, of the net surface charges. At this initial stage the small repulsive interactions are not able to compensate binding interactions, which tend to aggregate the particles. As time proceeds, an increase of the size of the particles is accompanied by strong increases, in absolute values, of the electrophoretic mobility and net surface charge, suggesting enhanced repulsive electrostatic interactions and, consequently, a stabilized colloidal system. These results show that electrophoretic mobility is a useful methodology that can be applied to screen the stabilization factors for virus-like particles during vaccine development.

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A convenient method to determine the Rayleigh ratio with uniform polystyrene oligomers

Cited by 25 publications

References 14 publications

One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings

One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings

Structure-related differences in the temperature-regulated fluorescence response of LCST type polymers

Evidences of Changes in Surface Electrostatic Charge Distribution during Stabilization of HPV16 Virus-Like Particles

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