Nature and effects of nonexponential correlation functions in probe diffusion experiments by quasielastic light scattering

Mustafa, Mazidah; Russo, Paul S.

doi:10.1016/0021-9797(89)90436-0

Cited by 31 publications

(60 citation statements)

References 40 publications

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“…3 The polymer studied in this work is hydroxypropylcellulose (HPC), which is an electrically neutral, semi-stiff, rod-like polysaccharide with a persistence length of 100. 12,13 HPC is soluble in a wide range of solvents including water, but has an easily achievable pseudotheta conditions at a critical temperature of T c = 41…”

Section: Introductionmentioning

confidence: 99%

“…• C. [13][14][15][16] At room temperature (T ≤ T c ) water is a good solvent to HPC chains and solutions are homogeneous. Above T c hydrophobic interactions are favorable and water becomes a poor solvent for HPC chains.…”

Section: Introductionmentioning

confidence: 99%

“…19 Because of its convenient physical properties and wide accessibility HPC has been used extensively in studies of polymer dynamics. 13,15,18,[20][21][22][23] The polymer has numerous pharmaceutical and food industry applications as it is FDA-approved for food and clinical consumption. 24,25 In particular, HPC polymer is used as a tablet binder 26,27 due to its high cohesiveness, binding strength, hardness, and low friability.…”

Section: Introductionmentioning

confidence: 99%

“…References 13,21 Therefore, the usage of cumulants in these systems is not advisable. In addition, refs.…”

Section: Introductionmentioning

confidence: 99%

“…13 Reference 28 meticulously examined the highly nonexponential light scattering spectra of microgels synthesized using the recipe of ref. 17.…”

Section: Introductionmentioning

confidence: 99%

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Spectral time moment analysis of microgel deswelling. Effect of the heating rate

Streletzky¹,

McKenna²

2008

J Polym Sci B Polym Phys

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Microgel nanoparticles were synthesized in aqueous solutions of neutral polymer hydroxypropylcellulose (HPC) through the self-association of amphiphilic HPC molecules and the subsequent cross linking at room temperature. Dynamic Light Scattering was used to study the transport properties of HPC microgels below and above the volume phase transition. Highly nonexponential, multimodal microgel spectra were observed and successfully analyzed by spectral time moment analysis. This article expands earlier results and focuses on the effect of the heating rate on microgel deswelling. During the fast heating two identified microgel modes with apparent hydrodynamic radii (R H ) of 25-30 nm and 400-650 nm collapse into one mode with R H = 100−150 nm. This indicates the shrinkage of microgel size distribution and an apparent decrease in the radius of larger microgels. During the slow heating, however, both microgel-identified modes remain present above T c . Although equally represented below the transition, the dominance of larger microgels' mode increases almost two fold with rising temperature above 40• C. Moreover, R H for this mode increases from 250-300 nm to about 800-850 nm with a multi-step temperature change from 40 to 42.5• C, indicating the growth (and not shrinkage) of microgels. The second mode is represented by the temperature independent R H , but its contribution goes down from about 50% to less than 10%.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…References 13,21 Therefore, the usage of cumulants in these systems is not advisable. In addition, refs.…”

Section: Introductionmentioning

confidence: 99%

“…13 Reference 28 meticulously examined the highly nonexponential light scattering spectra of microgels synthesized using the recipe of ref. 17.…”

Section: Introductionmentioning

confidence: 99%

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Spectral time moment analysis of microgel deswelling. Effect of the heating rate

Streletzky¹,

McKenna²

2008

J Polym Sci B Polym Phys

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Measurement of protein diffusion in Dextran solutions by holographic interferometry

Kosar

Phillips

1995

AIChE Journal

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Theories and experimental measurements related to the diffusion of globular macromolecules and small spheres in polymer solutions are discussed. It is shown that the Kirkwood-Riseman point scatterer and Brinkman models, two theoretical approaches that lead to hydrodynamic screening, are equivalent. Holographic interferometry is presented as a new method for measuring gradient diffusion of proteins in transparent polymer solutions and gels. This method is used to examine the effect of ionic strength, polymer concentration and polymer molecular weight on the diffusion of bovine serum albumin (BSA) in dextran solutions. The data are interpreted in light of the hydrodynamic screening and Stokes-Einstein models of diffusion. In particular, it is shown that while the Stokes-Einstein equation may be appropriate for the diffusion of relatively large latex spheres in polymer solutions, it is inappropriate for predicting diffusion coefficients of BSA and comparable proteins in such solutions. D

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Effect of trichlorobenzene additive on the performance and morphology of polyfluorene and fullerene derivative bulk heterojunction solar cells

et al. 2011

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The influence of additive, namely 1,3,5‐trichlorobenzene (TCB), on the morphology and performance of bulk heterojunction (BHJ) organic solar cells was studied based on a 1:2 (w/w) blend of benzothiadiazole/thiophene‐based copolymers (PFTBzTT) to [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM). The active layers were deposited by spin‐coating from solutions using chloroform, with different additive concentrations from 0 to 36 mg/ml. The addition of solvent additive into the polymer solution was able to improve the performance of BHJ solar cells. The maximum power conversion efficiency (%PCE) of 0.85% was obtained for a cell with the TCB concentration of 12 mg/ml after annealing at 180°C for 20 min. From atomic force microscopy (AFM) images, the films processed without TCB appear smoother than those with the TCB additive. A large extent of segregation was also observed in the films processed with a high TCB concentration. The optical images of the thin films suggest that the optimum concentrations of the additive cause the polymer self‐organisation, resulting in some aggregation of large PCBM crystals. © 2011 Canadian Society for Chemical Engineering

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Nature and effects of nonexponential correlation functions in probe diffusion experiments by quasielastic light scattering

Cited by 31 publications

References 40 publications

Spectral time moment analysis of microgel deswelling. Effect of the heating rate

Spectral time moment analysis of microgel deswelling. Effect of the heating rate

Measurement of protein diffusion in Dextran solutions by holographic interferometry

Effect of trichlorobenzene additive on the performance and morphology of polyfluorene and fullerene derivative bulk heterojunction solar cells

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