A Phase Diagram for the Binary Blends of Nearly Symmetric Diblock Copolymers. 1. Parameter Space of Molecular Weight Ratio and Blend Composition†

2001 ◽  
Vol 34 (18) ◽  
pp. 6495-6505 ◽  
Author(s):  
Daisuke Yamaguchi ◽  
Takeji Hashimoto
Keyword(s):  
Phase Diagram ◽  
Molecular Weight ◽  
Parameter Space ◽  
Diblock Copolymers ◽  
Weight Ratio ◽  
Binary Blends ◽  
Blend Composition

The Ordered Bicontinuous Double Diamond Structure in Binary Blends of Diblock Copolymer and Homopolymer.

1989 ◽  
Vol 171 ◽  
Author(s):  
Karen I. Winey ◽  
Edwin L. Thomas
Keyword(s):  
Molecular Weight ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Composition Range ◽  
Volume Fraction ◽  
Diamond Structure ◽  
Binary Blends ◽  
Resultant Effect ◽  
Strong Segregation ◽  
Double Diamond

ABSTRACTWe report the observation of the ordered bicontinuous double diamond (OBDD) structure in binary blends of poly(styrene-isoprene) diblock copolymer and homopolystyrene. The overall polystyrene volume fraction range is 64 - 67 PSvol% for the OBDD structure in binary blends of a lamellar diblock (SI 27/22) and a homopolymer (14.0 hPS). This composition range is approximately within the polystyrene volume fraction range established for pure diblock copolymers in the strong segregation regime having the OBDD structure. Ordered lamellae are observed at approximately 65 PSvol% when the homopolystyrene molecular weight is greater than the molecular weight of the polystyrene block of the copolymer. This observation is discussed in terms of the decreased degree of mixing between the homopolymer and the corresponding block and the resultant effect on the interfacial curvature.

Phase Behavior of Binary Blends of High Molecular Weight Diblock Copolymers with a Low Molecular Weight Triblock

2008 ◽  
Vol 41 (15) ◽  
pp. 5785-5792 ◽  
Author(s):  
Rafal A. Mickiewicz ◽  
Eleftherios Ntoukas ◽  
Apostolos Avgeropoulos ◽  
Edwin L. Thomas
Keyword(s):  
Molecular Weight ◽  
Phase Behavior ◽  
High Molecular Weight ◽  
Diblock Copolymers ◽  
Low Molecular Weight ◽  
Binary Blends

scholarly journals Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Ratio ◽  
Scanning Calorimetry ◽  
Minimal Inhibitory Concentrations ◽  
Dissolution Tests ◽  
Effective Combination ◽  
The Impact ◽  
High Molecular Weight Chitosan

Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.

COMPLEX BIFURCATION STRUCTURES IN THE HINDMARSH–ROSE NEURON MODEL

2007 ◽  
Vol 17 (09) ◽  
pp. 3071-3083 ◽  
Author(s):  
J. M. GONZÀLEZ-MIRANDA
Keyword(s):  
Phase Diagram ◽  
Bifurcation Diagram ◽  
Parameter Space ◽  
Neuron Model ◽  
Two Dimensional ◽  
Dimensional Parameter ◽  
Rapid Responses ◽  
Bifurcation Structures

The results of a study of the bifurcation diagram of the Hindmarsh–Rose neuron model in a two-dimensional parameter space are reported. This diagram shows the existence and extent of complex bifurcation structures that might be useful to understand the mechanisms used by the neurons to encode information and give rapid responses to stimulus. Moreover, the information contained in this phase diagram provides a background to develop our understanding of the dynamics of interacting neurons.

Mechanical Properties of Blends of Crystallizable Polybutadienes Containing Amorphous Polybutadiene Diblock Copolymers

1994 ◽  
Vol 67 (2) ◽  
pp. 342-347
Author(s):  
Moira Marx Nir ◽  
Robert E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Surface Area ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Tensile Failure ◽  
Interfacial Surface ◽  
Failure Properties ◽  
Enhanced Properties

Abstract Tensile failure properties of syndiotactic 1,2 polybutadiene/trans 1,4 polybutadiene crystalline blends are improved by addition of 5–10% amorphous 1,2 polybutadiene/1,4 polybutadiene diblock copolymer. The effect of block molecular weight and microphase behavior of the diblock copolymer was investigated. Heterogeneous diblocks enhance blend properties to a greater extent than homogeneous diblocks. In blends with enhanced properties, percent coverage of interfacial surface area by diblock is on the order of 10%.

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