Effect of monomer sequence distribution in 2-vinylnaphthalene-maleic acid copolymers on energy migration and excimer formation in aqueous solution

Morishima, Yotaro; Lim, Hak Sang; Nozakura, Shun‐ichi; Sturtevant, John L.

doi:10.1021/ma00193a026

Cited by 18 publications

(11 citation statements)

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“…A number of experimental techniques − have been utilized to study the nature of microphase-separated domains in aqueous media, including viscometry, − light scattering, − and NMR. , Photophysical methods − have been especially useful in studying hydrophobic domain organization and dynamics for both nonionic − and polyelectrolyte systems. ,,,− Fluorescence quenching studies have been designed, not only to establish aggregation behavior ,,,,− but also to estimate the size of domains formed by hydrophobic association in aqueous media. − In addition, nonradiative energy transfer studies, − ,,,− have provided convincing evidence regarding the morphology of phase-separated microdomains.…”

Section: Introductionmentioning

confidence: 99%

Water Soluble Polymers. 74. pH Responsive Microdomains in Labeled n-Octylamide-Substituted Poly(sodium maleate-alt-ethyl vinyl ethers): Synthesis, Steady-State Fluorescence, and Nonradiative Energy Transfer Studies

Smith

Richardson

et al. 1997

Macromolecules

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n-Octylamide-substituted copoly(sodium maleate-alt-ethyl vinyl ethers) [poly(SM-EVEs)] have been synthesized and fluorescently labeled with naphthyl and/or dansyl chromophores attached to the polymer backbone with either a long (C8) or short (C2) carbon spacer. The chromophores serve as monitors of the local environmental character of these amphiphilic macromolecules as they undergo the "polysoap-to-polyelectrolyte" transition. Intramolecular (closed) associations tend to predominate over a wide range of environmental conditions in aqueous media. The extent and reversibility of these interactions have been investigated by conducting viscometric measurements, light scattering, nonradiative energy transfer (NRET) quantum efficiency, and fluorescence quenching studies as a function of the solution pH. The results obtained for the 30% n-octylamide-modified poly(SM-EVE) in aqueous media have been contrasted with results obtained for 30% n-octylamide-modified poly(SM-EVE) in 6 M urea solution and unmodified poly(SM-EVE) in aqueous media to provide meaningful information concerning the effect of hydrophobic modification and pH responsiveness. The octylamide-modified polymer in aqueous media at low pH collapses into a compact aggregate due to the loss of polyelectrolyte character and an increase in hydrogen bonding. At moderate pH values, the modified polymer coil becomes slightly more expanded, as indicated by fluorescence and reduced viscosity measurements. At pH values between 7.0 and 8.0, the most expanded conformation is observed as determined by hydrodynamic size and nonradiative energy transfer (NRET) quantum efficiency measurements. NRET studies of both singlyand doubly-labeled, hydrophobically modified polymer solutions and fluorescence quenching in aqueous media are consistent with a globule-to-extended chain transition with increasing pH. At low pH, however, multichain complexes appear to form, even in dilute solution. At higher concentrations, above C*, multichain interactions are observed, consistent with associative thickening observed by viscometry. The onset values of C* in these systems as sensed by NRET are nearly one order of magnitude lower than those observed by viscometry. Also, the labels with long spacers are more sensitive than those with short spacers in detecting organized microdomains.

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Section: Introductionmentioning

confidence: 99%

Water Soluble Polymers. 74. pH Responsive Microdomains in Labeled n-Octylamide-Substituted Poly(sodium maleate-alt-ethyl vinyl ethers): Synthesis, Steady-State Fluorescence, and Nonradiative Energy Transfer Studies

Smith

Richardson

et al. 1997

Macromolecules

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“…Upon exciting compounds I to III (10 −5 M) at 280 nm, naphthalene monomer emission was observed between 300 and 375 nm. [16][17][18] However, photoexcitation at the shoulder band absorption resulted in a strong structureless and broad emission of naphthalene excimer centred at 440 nm. Figure 4 contains the emission spectrum of PAMAM-(Np) 8 dendrimer at two different excitation wavelengths.…”

Section: Steady State Fluorescence Properties Of Pamam-(np) N Aggregatesmentioning

confidence: 99%

Utilizing dendritic scaffold for feasible formation of naphthalene excimer

2011

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Peripheral functionalization of PAMAM dendrimers with naphthalene units leads to significant ground state aggregation in the system above the critical aggregation concentrations (CAC). Upon photoexcitation of the ground state aggregates, static type excimer formation of naphthalene moiety is observed. Significant red-shifted emission from naphthalene excimers is achieved through generating the static type excimers in polar solvents such as methanol and acetonitrile-water mixtures. Control experiments suggest that the presence of dendritic scaffold in the system play a pivotal role in generating intense static excimer emission in naphthalene modified PAMAM dendrimers, in solution phase at room temperature.

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“…They have particularly focused on the macromolecular architecture which results in the two extreme cases, (i) completely intramolecular associations leading to singlemacromolecular self-assemblies independent of polymer concentration and (ii) highly preferential interpolymer associations leading to multipolymeric "transient" networks. From the studies by Morishima et al [15,16] and others [17][18][19], it has been revealed that the sequence distribution of charged and hydrophobic units along the polymer chain is a very important structural factor to determine whether the hydrophobic self-association is an intra-or interpolymer event. Block sequences have a strong tendency for interpolymer association, whereas random and alternating sequences tend to associate in an intrapolymer mode.…”

Section: Introductionmentioning

confidence: 99%

Self-Assembly of Cholesterol-Containing Water-Soluble Polymers

Yusa

2012

International Journal of Polymer Science

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Self-assembly of amphiphilic polymers containing cholesteryl groups has proved to be attractive in the field of nanotechnology research. Some cholesterol derivatives are known to form ordered structures which indicate thermotropic and lyotropic liquid-crystalline, monolayers, multilayers, micelles, and liposomes. This paper involves the synthesis and characterization of various kinds of amphiphilic polymers bearing cholesteryl moieties.

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Effect of monomer sequence distribution in 2-vinylnaphthalene-maleic acid copolymers on energy migration and excimer formation in aqueous solution

Cited by 18 publications

References 1 publication

Water Soluble Polymers. 74. pH Responsive Microdomains in Labeled n-Octylamide-Substituted Poly(sodium maleate-alt-ethyl vinyl ethers): Synthesis, Steady-State Fluorescence, and Nonradiative Energy Transfer Studies

Water Soluble Polymers. 74. pH Responsive Microdomains in Labeled n-Octylamide-Substituted Poly(sodium maleate-alt-ethyl vinyl ethers): Synthesis, Steady-State Fluorescence, and Nonradiative Energy Transfer Studies

Utilizing dendritic scaffold for feasible formation of naphthalene excimer

Self-Assembly of Cholesterol-Containing Water-Soluble Polymers

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