STM images of PDLLA-PEG copolymer micelles

Hadi M. Zareie; Xu Kaitian; Erhan Pişkin

doi:10.1016/0927-7757(96)03556-X

STM images of PDLLA-PEG copolymer micelles

Hadi M. Zareie, Xu Kaitian, Erhan Pişkin

Biomedical Engineering

Research output: Contribution to journal › Article › peer-review

8 Scopus citations

Abstract

Poly(DL-lactic acid)-poly(ethylene glycol) (PDLLA-PEG) copolymers with micelle-forming abilities were produced by transesterification of PDLLA (M_n = 1866) prepared in this study with PEG (M_n = 3300-4000). Micelles of these copolymers were formed in aqueous media. Critical micelle concentrations were determined spectrophotometrically. Average values of molecular mass and diameter of the micelles were determined by light scattering. Scanning electron microscopy (SEM) photographs of micelles were obtained for comparison. Scanning tunneling microscopy (STM) images of these micelles on highly oriented pyrolytic graphite surfaces were also obtained. STM was operated in air at atmospheric pressure with a tip-to-substrate bias of 500 mV and tunnelling currents of < 100 pA, and in the constant current mode. The micelle sizes obtained by STM were of the same order, but larger than those determined from light scattering data and those obtained by SEM.

Original language	English (US)
Pages (from-to)	19-24
Number of pages	6
Journal	Colloids and Surfaces A: Physicochemical and Engineering Aspects
Volume	112
Issue number	1
DOIs	https://doi.org/10.1016/0927-7757(96)03556-X
State	Published - Jul 1 1996

All Science Journal Classification (ASJC) codes

Surfaces and Interfaces
Physical and Theoretical Chemistry
Colloid and Surface Chemistry

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10.1016/0927-7757(96)03556-X

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title = "STM images of PDLLA-PEG copolymer micelles",

abstract = "Poly(DL-lactic acid)-poly(ethylene glycol) (PDLLA-PEG) copolymers with micelle-forming abilities were produced by transesterification of PDLLA (Mn = 1866) prepared in this study with PEG (Mn = 3300-4000). Micelles of these copolymers were formed in aqueous media. Critical micelle concentrations were determined spectrophotometrically. Average values of molecular mass and diameter of the micelles were determined by light scattering. Scanning electron microscopy (SEM) photographs of micelles were obtained for comparison. Scanning tunneling microscopy (STM) images of these micelles on highly oriented pyrolytic graphite surfaces were also obtained. STM was operated in air at atmospheric pressure with a tip-to-substrate bias of 500 mV and tunnelling currents of < 100 pA, and in the constant current mode. The micelle sizes obtained by STM were of the same order, but larger than those determined from light scattering data and those obtained by SEM.",

author = "Zareie, {Hadi M.} and Xu Kaitian and Erhan Pi{\c s}kin",

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T1 - STM images of PDLLA-PEG copolymer micelles

AU - Zareie, Hadi M.

AU - Kaitian, Xu

AU - Pişkin, Erhan

PY - 1996/7/1

Y1 - 1996/7/1

N2 - Poly(DL-lactic acid)-poly(ethylene glycol) (PDLLA-PEG) copolymers with micelle-forming abilities were produced by transesterification of PDLLA (Mn = 1866) prepared in this study with PEG (Mn = 3300-4000). Micelles of these copolymers were formed in aqueous media. Critical micelle concentrations were determined spectrophotometrically. Average values of molecular mass and diameter of the micelles were determined by light scattering. Scanning electron microscopy (SEM) photographs of micelles were obtained for comparison. Scanning tunneling microscopy (STM) images of these micelles on highly oriented pyrolytic graphite surfaces were also obtained. STM was operated in air at atmospheric pressure with a tip-to-substrate bias of 500 mV and tunnelling currents of < 100 pA, and in the constant current mode. The micelle sizes obtained by STM were of the same order, but larger than those determined from light scattering data and those obtained by SEM.

AB - Poly(DL-lactic acid)-poly(ethylene glycol) (PDLLA-PEG) copolymers with micelle-forming abilities were produced by transesterification of PDLLA (Mn = 1866) prepared in this study with PEG (Mn = 3300-4000). Micelles of these copolymers were formed in aqueous media. Critical micelle concentrations were determined spectrophotometrically. Average values of molecular mass and diameter of the micelles were determined by light scattering. Scanning electron microscopy (SEM) photographs of micelles were obtained for comparison. Scanning tunneling microscopy (STM) images of these micelles on highly oriented pyrolytic graphite surfaces were also obtained. STM was operated in air at atmospheric pressure with a tip-to-substrate bias of 500 mV and tunnelling currents of < 100 pA, and in the constant current mode. The micelle sizes obtained by STM were of the same order, but larger than those determined from light scattering data and those obtained by SEM.

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STM images of PDLLA-PEG copolymer micelles

Abstract

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