Degradation of chain molecules. 1. Exact solution of the kinetic equations

Ballauff, M.; Wolf, B. A.

doi:10.1021/ma50004a039

Cited by 93 publications

(50 citation statements)

References 6 publications

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“…For the typical microsphere of PLGA, systems with low water content showed such an autocatalyzed reaction. 28 In our case, the triblock copolymer gels had a high water content and the generated acid was quickly neutralized by surrounding buffer systems. The degradation of ester groups in the polymer can be expressed as follows:…”

Section: Resultsmentioning

confidence: 71%

In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof

Jeong

Bae

Kim

2000

J. Biomed. Mater. Res.

257

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Aqueous solutions of poly(ethylene glycol-b-[DL-lactic acid-co-glycolic acid]-b-ethylene glycol) (PEG-PLGA-PEG) triblock copolymers form a free-flowing sol at room temperature and become a gel at body temperature. In this study, in situ gel formation was investigated in rats. Upon subcutaneous injection of 33 wt % aqueous solutions of PEG-PLGA-PEG triblock copolymer into rats, transparent gels were observed. The gel showed good mechanical strength and the integrity of gels persisted longer than 1 month. The gel underwent degradation by hydrolysis and turned opaque. Degradation study showed preferential mass loss of PEG-rich segment from the in situ formed gel. Number average molecular weight determined by gel permeation chromatography decreased from 3300 to 1900 and 30% mass loss was observed over 1 month.

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Section: Resultsmentioning

confidence: 71%

In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof

Jeong

Bae

Kim

2000

J. Biomed. Mater. Res.

257

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“…9B), Sup35 NW region [44] Generally speaking, fragmentation rates are length-dependent. In literature, several assumptions have been proposed, including the random scission, the central scission, and the Gaussian scission [106,107] and modified partially random scission [108] etc. The latter two got supports from fiberlike PI264-b-PFS48 micelles under sonication [109], thermodynamically induced shear degradation of polystyrene in semiconcentrated solutions [107], singlestranded random-coiled poly-(uridylic acid), double-stranded helical DNA, and triple-stranded helical poly-(adenylic acid)·2poly(inosinic acid) [108].…”

Section: Monomer-independent Secondary Nucleation: Fragmentation and mentioning

confidence: 99%

Statistical Mechanics and Kinetics of Amyloid Fibrillation

Hong

Lee

Huang

2017

World Scientific Lecture and Course Notes in Chemistry

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Amyloid fibrillation is a protein self-assembly phenomenon that is intimately related to wellknown human neurodegenerative diseases. During the past few decades, striking advances have been achieved in our understanding of the physical origin of this phenomenon and they constitute the contents of this review. Starting from a minimal model of amyloid fibrils, we explore systematically the equilibrium and kinetic aspects of amyloid fibrillation in both dilute and semi-dilute limits. We then incorporate further molecular mechanisms into the analyses. We also discuss the mathematical foundation of kinetic modeling based on chemical mass-action equations, the quantitative linkage with experimental measurements, as well as the procedure to perform global fitting.

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“…Most theoretical investigations of polymer degradation have focused on determining the rate of change of average molecular weight [13][14][15][16][17][18][19][20][21][22]. The main assumptions of the theory are that each link in a long chain molecule has equal strength and equal accessibility, that they are broken at random, and that the probability of rupture is proportional to the number of links present.…”

Section: Introductionmentioning

confidence: 99%

Thermal decomposition of a honeycomb-network sheet: A molecular dynamics simulation study

Paturej

Popova

Milchev

et al. 2012

The Journal of Chemical Physics

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The thermal degradation of a graphene-like two-dimensional honeycomb membrane with bonds undergoing temperature-induced scission is studied by means of Molecular Dynamics simulation using Langevin thermostat. We demonstrate that at lower temperature the probability distribution of breaking bonds is highly peaked at the rim of the membrane sheet whereas at higher temperature bonds break at random everywhere in the hexagonal flake. The mean breakage time τ is found to decrease with the total number of network nodes N by a power law τ ∝ N −0.5 and reveals an Arrhenian dependence on temperature T . Scission times are themselves exponentially distributed. The fragmentation kinetics of the average number of clusters can be described by first-order chemical reactions between network nodes ni of different coordination. The distribution of fragments sizes evolves with time elapsed from initially a δ-function through a bimodal one into a single-peaked again at late times. Our simulation results are complemented by a set of 1 st -order kinetic differential equations for ni which can be solved exactly and compared to data derived from the computer experiment, providing deeper insight into the thermolysis mechanism.

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Degradation of chain molecules. 1. Exact solution of the kinetic equations

Cited by 93 publications

References 6 publications

In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof

In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof

Statistical Mechanics and Kinetics of Amyloid Fibrillation

Thermal decomposition of a honeycomb-network sheet: A molecular dynamics simulation study

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