The role of carbon nanoparticles in epoxy‐based nanocomposites modified with (poly[polypropylene oxide]‐ block ‐poly[ethylene oxide]‐ block ‐poly[propylene oxide]) triblock copolymers on phase morphology and mechanical properties

2020 ◽  
Vol 41 (10) ◽  
pp. 4243-4252
Author(s):  
Bruna L. Silva ◽  
Marcia B. Schuster ◽  
Roger H. Bello ◽  
Daniela Becker ◽  
Luiz A. F. Coelho
Keyword(s):  
Mechanical Properties ◽  
Ethylene Oxide ◽  
Carbon Nanoparticles ◽  
Triblock Copolymers ◽  
Polypropylene Oxide ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Propylene ◽  
Morphology And Mechanical Properties

scholarly journals Electrospun Alginate Fibers: Mixing of Two Different Poly(ethylene oxide) Grades to Improve Fiber Functional Properties

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 971 ◽  
Author(s):  
Barbara Vigani ◽  
Silvia Rossi ◽  
Giulia Milanesi ◽  
Maria Bonferoni ◽  
Giuseppina Sandri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ethylene Oxide ◽  
Electrospinning Process ◽  
Mechanical Resistance ◽  
Fiber Morphology ◽  
Chain Entanglement ◽  
Poly Ethylene Oxide ◽  
Alginate Fibers ◽  
Poly Ethylene ◽  
Morphology And Mechanical Properties

The aim of the present work was to investigate how the molecular weight (MW) of poly(ethylene oxide) (PEO), a synthetic polymer able to improve alginate (ALG) electrospinnability, could affect ALG-based fiber morphology and mechanical properties. Two PEO grades, having different MWs (high, h-PEO, and low, l-PEO) were blended with ALG: the concentrations of both PEOs in each mixture were defined so that each h-PEO/l-PEO combination would show the same viscosity at high shear rate. Seven ALG/h-PEO/l-PEO mixtures were prepared and characterized in terms of viscoelasticity and conductivity and, for each mixture, a complex parameter rH/rL was calculated to better identify which of the two PEO grades prevails over the other in terms of exceeding the critical entanglement concentration. Thereafter, each mixture was electrospun by varying the process parameters; the fiber morphology and mechanical properties were evaluated. Finally, viscoelastic measurements were performed to verify the formation of intermolecular hydrogen bonds between the two PEO grades and ALG. rH/rL has been proved to be the parameter that better explains the effect of the electrospinning conditions on fiber dimension. The addition of a small amount of h-PEO to l-PEO was responsible for a significant increase in fiber mechanical resistance, without affecting the nano-scale fiber size. Moreover, the mixing of h-PEO and l-PEO improved the interaction with ALG, resulting in an increase in chain entanglement degree that is functional in the electrospinning process.

Preparation of Gold Nanocrystals Having Various Morphologies under Polymeric Bulk Phase

2014 ◽  
Vol 548-549 ◽  
pp. 321-325
Author(s):  
Sang Ho Cha
Keyword(s):  
Ethylene Oxide ◽  
Functional Groups ◽  
Triblock Copolymer ◽  
Triblock Copolymers ◽  
Synthetic Approach ◽  
Gold Nanocrystals ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Propylene ◽  
Polymeric Template

A novel synthetic approach for gold nanocrystals using triblock copolymer as a polymeric template was described. The triblock copolymer used in this study was poly (ethylene oxide)20-poly (propylene oxide)70-poly (ethylene oxide)20 with hydroxy or thiol end-functional groups. The complexes of HAuCl4 and triblock copolymers were prepared by mixing and drying. After exposed to the sunlight for a few days, the gold nanocrystals, which have different sizes and shapes according to the ripening time, end functional groups, and gold salt concentrations, were obtained. The optical properties of the gold nanocrystals were also discussed.

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