Investigations on several empirical rules for entangled polymers based on a self-consistent full-chain reptation theory

Hua, Chi C.

doi:10.1063/1.481418

Cited by 15 publications

(4 citation statements)

References 30 publications

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“…Such correspondence between dynamic and steady-state viscosities is referred to as the Cox-Merz rule. [40][41][42][43] Another empiricism is the Gleissle relation, according to which the steady-state viscosity is equal to the transient viscosity measured during approach to steady state at the limiting shear rate, 44 η ss (γ ) ) lim γ f0 η + (t, γ )| t -1 )γ . The subscript denotes that the startup viscosity is taken at a shearing time equal to the reciprocal of the corresponding shear rate.…”

Section: Resultsmentioning

confidence: 99%

Reentanglement Kinetics in Sheared Polybutadiene Solutions

et al. 2004

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Interrupted shear measurements were used to follow the reentanglement kinetics and associated molecular weight dependence for solutions of near-monodisperse polybutadiene (PB). The timedependent recovery of the overshoot in the shear stress was measured for PB having weight-average molecular weights (M w) equal to 61, 90, 107, and 167 kg/mol, corresponding to a range of 17-47 entanglements per chain in solution. The times for recovery of the stress overshoot were 1.5 decades longer (30 times greater) than the corresponding linear viscoelastic relaxation times, the latter determined from dynamic shear data or from stress relaxation following cessation of flow. Notwithstanding the differing time scales, the M w dependences for entanglement recovery and linear viscoelastic relaxation were equivalent (power law exponent ∼ 3.4).

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Section: Resultsmentioning

confidence: 99%

Reentanglement Kinetics in Sheared Polybutadiene Solutions

et al. 2004

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“…It was applicable for concentrated polymer solution (included moderately concentrated solutions) and sometimes not for polydisperse systems (polymer systems contained different molar masses); it was applicable for concentrated polymer solutions (included moderately concentrated solutions) and sometimes not for dilute solutions (Yasuda et al., 1981), but this rule was frequently applied beyond its scope of applicability. Therefore, it was important to study the applicability of the Cox–Merz rule in SDF solutions (Hua, 2000). It could be seen from Figure 5g that the Cox–Merz rule was not applicable to either GSDF solution or OSDF solution.…”

Section: Resultsmentioning

confidence: 99%

Dietary fiber extraction from citrus peel pomace: Yield optimization and evaluation of its functionality, rheological behavior, and microstructure properties

Chen

Jiang

et al. 2023

Journal of Food Science

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Citrus fruits were widely used in processing and production, generating a large amount of peel pomace and a low utilization rate, resulting in substantial economic losses and environmental risks. It was important to extract compounds from citrus peel pomaces and find suitable preparation methods to improve their yield and physicochemical properties. Grapefruit peel pomace (GP) and navel orange peel pomace (OP) were used as raw materials in this study to prepare green and edible soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). Analysis was done on the effects of solid–liquid ratio, cellulase hydrolysis time, cellulase dosage, and ultrasonic time on dietary fiber (DF) yield. To obtain the best DF preparation conditions, we used range analysis, variance analysis, and orthogonal experimental design. We also analyzed the structural, physicochemical, and rheological characteristics of SDF and IDF. According to the study's findings, SDF and IDF showed a loose and expansive structure with reduced particle size, higher specific surface area, and noticeably better physical and chemical properties after treating GP and OP with ultrasound‐assisted composite enzyme method. Both SDF solution and IDF suspension were discovered through rheological analysis to be non‐Newtonian pseudoplastic fluids, which was advantageous for expanding their applications in the field of food packaging. In conclusion, DF prepared using the ultrasound‐assisted composite enzyme method was an excellent source of edible packaging materials, offering a benchmark for the recycling of other citrus peel wastes and ultimately paving the way for new methods of recycling citrus waste.

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“…Accordingly, the apparent validity of the Cox–Merz rule for the AlSiNT/PVA dispersions may be rationalized as follows: As discussed above, good AlSiNT-PVA interactions contribute to an excellent nanotube dispersion in the PVA matrix. Under this circumstance, the shear-thinning behavior that results principally from flow-induced nanotube alignment may be likened to that of entangled polymer chains, both contributing to the additional stress by way of “linear responses” (see, for example, discussions in prior work). , Namely, the Cox–Merz rule is expected to hold true when nonlinear responses (such as those arising from significant chain stretch for entangled polymers) and certain formation/destruction in microstructures are absent or play only minor roles. Of course, the above arguments should be left open to further assessments.…”

Section: Resultsmentioning

confidence: 99%

Properties of Single-Walled Aluminosilicate Nanotube/Poly(vinyl alcohol) Aqueous Dispersions

Yang

Jiang

et al. 2017

J. Phys. Chem. B

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The properties of (synthesized) single-walled aluminosilicate nanotube (AlSiNT; light-scattering characterized length ∼2000 ± 230 nm and diameter ∼35 ± 4 nm) dispersed in an aqueous poly(vinyl alcohol) (PVA) solution (10 wt %) are systematically explored using a comprehensive combination of (polarized/depolarized) dynamic light scattering, rheological, rheo-optical, and scanning electron microscopy analysis schemes. The nanotube/polymer dispersions under investigation are promising for their fair nanotube dispersion in pristine aqueous media (e.g., without salt or acid addition), as well as for the optical transparency that greatly facilitates systematic exploration of structural features and dispersion state that are practically inaccessible for many of their (opaque) companions such as carbon nanotube dispersions. We provide the first in-depth analysis revealing excellent dispersion state of (unmodified) AlSiNT in the PVA matrix, giving rise to (critical) gel-like features and substantially promoted elasticity that can be utilized, as a practical assessment, to produce uniform and defect-free electrospun nanofibers. Additionally, there is unambiguous evidence of nematic liquid crystal-like "wagging" (strain-invariant, periodic oscillation) under steady shear flow, a phenomenon previously unreported for nanotube composite materials. Overall, the present findings suggest that AlSiNT/PVA dispersions possess promising rheological, optical, and electrospinning properties that are highly desirable for current nanotechnological applications, and may serve as an ideal model system for establishing structure-performance relationships for like nanotube/polymer composite materials.

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Investigations on several empirical rules for entangled polymers based on a self-consistent full-chain reptation theory

Cited by 15 publications

References 30 publications

Reentanglement Kinetics in Sheared Polybutadiene Solutions

Reentanglement Kinetics in Sheared Polybutadiene Solutions

Dietary fiber extraction from citrus peel pomace: Yield optimization and evaluation of its functionality, rheological behavior, and microstructure properties

Properties of Single-Walled Aluminosilicate Nanotube/Poly(vinyl alcohol) Aqueous Dispersions

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