Hydrodynamic, optical, and electrooptical properties of macromolecules of third-generation cylindrical dendrimers in chloroform and dichloroacetic acid

Цветков, Н. В.; Андреева, Л. Н.; Filippov, Sergey K.; Bushin, S. V.; Безрукова, М. А.; Marchenko, Iryna; Strelina, I. A.; Alyab’eva, V. P.; Girbasova, N. V.; Bilibin, A. Yu.

doi:10.1134/s0965545x10010025

Cited by 2 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Diffusion coefficients were theoretically calculated from statistical TEM data and compared with the experimental values. Two simple models have been tested, the Perrin theory for ellipsoids (with the retrospective corrections made by Koenig) ,, and the theories for spherocylindrical particles, developed by Norisuye et al and Yoshizaki et al Both models look promising, as they are analytical, do not require time-consuming numerical simulation, and allow describing the dynamics of nanoscale systems of different nature. ,− The final expressions, given in the Appendix, were algebraically simplified and transformed to a form where length L and aspect ratio p = L / d are the two free parameters which determine the particle shape.…”

Section: Resultsmentioning

confidence: 99%

Hydrodynamic Properties of Magnetic Nanoparticles with Tunable Shape Anisotropy: Prediction and Experimental Verification

et al. 2011

View full text Add to dashboard Cite

We describe the characterization of the hydrodynamic properties of anisotropic magnetic nanoparticles using a combination of transmission electron microscopy (TEM) and dynamic as well as depolarized dynamic light scattering (DLS/DDLS). The particles used are nearly monodisperse hematite spindles with an average length of 280 nm and a minor axis of 57 nm, coated with a layer of silica of variable thickness that allows us to tune the particle aspect ratio between 5 and 2. Their geometrical dimensions can thus be determined easily and quantitatively from TEM. Moreover, their size is ideal to employ DLS and DDLS to measure the translational and rotational diffusion coefficients D(T) and D(R), while the presence of a magnetic core opens a plethora of opportunities for future studies and applications. We demonstrate that we can successfully predict the hydrodynamic properties of the different particles based on a TEM characterization of their size distribution and using established theoretical models for the hydrodynamic properties of anisotropic particles. When compared with the theoretical predictions, our light scattering measurements are in quantitative agreement. This agreement between theory and experiment is achieved without having to invoke any adjustable free parameter, as the TEM results are used to calculate the corresponding diffusion coefficients on an absolute scale. We demonstrate that this is achieved due to a new and simple method for the statistical weighting of the TEM information, and the use of the correct hydrodynamic models for the observed particle shape. In addition, we also demonstrate an enhanced sensitivity of the rotational diffusion for the surface properties of ellipsoidal nanoparticles, and point out that this may serve as an ideal tool toward characterizing functionalized surfaces.

show abstract

Section: Resultsmentioning

confidence: 99%

Hydrodynamic Properties of Magnetic Nanoparticles with Tunable Shape Anisotropy: Prediction and Experimental Verification

et al. 2011

View full text Add to dashboard Cite

show abstract

“…It is interesting to compare the macromolecular size of different comb‐like polymers studied earlier: poly(lauryl methacrylate),5 graft polystyrene,77 graft copolymers of poly(methyl methacrylate) and polystyrene,8, 9 graft polymers resulting from the reaction of the poly( m ‐halomethylstyrene) backbone with polystyrene,78 poly( n ‐alkyl methacrylates),11 poly(fluoroalkyl methacrylate)s,79 poly[ N ‐octadecylmaleimide],75 polystyrene macromonomers,80 poly( ω ‐norbornenylpolystyrene) polymacromonomers,81 cylindrical dendrimers based on L ‐aspartic acid,82, 83 arborescent graft polybutadienes,84 and PHPhEPhM studied in this paper. For this purpose, the approach proposed earlier85 can be used, which does not require a priori knowledge of any hydrodynamic parameters and deals only with the experimental values (molar mass and intrinsic viscosity).…”

Section: Resultsmentioning

confidence: 99%

“… Double logarithmic plot of the dependence of [ η ] M on M , for different polymer systems, a: extra‐rigid polymers, b: flexible chain in thermodynamically good solvents, c: globular and short‐highly branched polymer systems. The points are the experimental data obtained for different brush‐like macromolecules, 1: PHPhEPhM (data from Table 2 of this paper), 2: copolymers of poly(methyl methacrylate) and polystyrene,8 3: poly(docosyl methacrylate)s,10 4–6: poly( ω ‐norbornenylpolystyrene) polymacromonomers,81 7: polystyrene macromonomers,78 8: poly(fluoroalkyl methacrylate),79 9: poly(lauryl methacrylate),5 10: graft polymers resulting from the reaction of the poly(m‐halomethylstyrene) backbone with the polystyryllithiums,80 11: poly[ N ‐octadecylmaleimide],75 12: graft polystyrene,77 13,14: cylindrical dendrimers based on L ‐aspartic acid,82, 83 and 15: arborescent graft polybutadienes 84…”

Section: Resultsmentioning

confidence: 99%

Hydrodynamic and Molecular Study of Poly{4‐[4‐(hexyloxy)phenyl]ethynylphenyl methacrylate} in Dilute Solutions and Conformational Peculiarities of Brush‐Like Macromolecules

Breul¹,

Hager²,

Schubert³

2012

Macro Chemistry & Physics

View full text Add to dashboard Cite

Brush-like poly{4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate}s are synthesized using RAFT polymerization, fractionated and studied by molecular hydrodynamic methods. The values of the velocity sedimentation coeffi cient, the frictional ratio, and the intrinsic viscosity are obtained in toluene. The conformational and structural parameters of the studied poly mer chains are estimated by the use of theories that describe the hydrodynamic behavior of the wormlike cylinders without intra-chain excluded volume effects and the hydrodynamic behavior of bending rods. The intrinsic viscosity data obtained for poly{4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate}s and for other brush-like macromolecules are discussed in terms of a doubly-normalized scaling plot. erties of a common polymer, poly{4-[4-(hexyloxy)phenyl] ethynylphenyl methacrylate}s (PHPhEPhMs) were synthesized. The aim of this work is the investigation of the hydrodynamic, molecular and conformational characteristics of a PHPhEPhM homologous series in toluene solutions and the comparison to the hydrodynamic data obtained for various brush-like polymers on the base of the concept of normalized scaling relations. In the Supporting Information to this article, the graphic materials for handling the initial experimental data are summarized. Experimental Section Materials and MethodsAll chemicals used were purchased from Biosolve, Fluka, Aldrich, Acros Organics, as well as Alfa Aesar and were used without further purifi cation unless otherwise specifi ed. The solvents were purchased from Biosolve, Aldrich, or Acros Organics and were dried and distilled according to standard procedures. The synthesis of the monomer 4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate is described elsewhere. [ 48 ] Macromol. Chem. Phys. 2012, 213, 904−916

show abstract

Hydrodynamic, optical, and electrooptical properties of macromolecules of third-generation cylindrical dendrimers in chloroform and dichloroacetic acid

Cited by 2 publications

References 10 publications

Hydrodynamic Properties of Magnetic Nanoparticles with Tunable Shape Anisotropy: Prediction and Experimental Verification

Hydrodynamic Properties of Magnetic Nanoparticles with Tunable Shape Anisotropy: Prediction and Experimental Verification

Hydrodynamic and Molecular Study of Poly{4‐[4‐(hexyloxy)phenyl]ethynylphenyl methacrylate} in Dilute Solutions and Conformational Peculiarities of Brush‐Like Macromolecules

Contact Info

Product

Resources

About