Effects of genistein modification on miscibility and hydrogen bonding interactions in poly(amide)/poly(vinyl pyrrolidone) blends and membrane morphology development during coagulation

Polymer ◽  
2010 ◽  
Vol 51 (22) ◽  
pp. 5135-5144 ◽  
Author(s):  
Chandrasekaran Neelakandan ◽  
Thein Kyu
Keyword(s):  
Hydrogen Bonding ◽  
Vinyl Pyrrolidone ◽  
Membrane Morphology ◽  
Hydrogen Bonding Interactions ◽  
Morphology Development ◽  
Poly Vinyl Pyrrolidone

Ultrafine Cellulose Acetate Fibers with Nanoscale Structural Features

2008 ◽  
Vol 8 (9) ◽  
pp. 4461-4469 ◽  
Author(s):  
Lifeng Zhang ◽  
You-Lo Hsieh
Keyword(s):  
Hydrogen Bonding ◽  
Cellulose Acetate ◽  
Pore Volume ◽  
Structural Features ◽  
Fiber Formation ◽  
Vinyl Pyrrolidone ◽  
Chain Entanglement ◽  
Bicomponent Fibers ◽  
Micron Size ◽  
Poly Vinyl Pyrrolidone

Nano-structural features were introduced to ultrafine cellulose acetate (CA) fibers by electrospinning of its mixtures with either poly(vinyl pyrrolidone) PVP or β-cyclodextrin (β-CD) in DMF, followed by dissolution of the added PVP or β-CD. The presence of the charge-holding PVP enabled fiber formation from CA below its entanglement chain length and improved the electrospinning efficiency to produce bicomponent fibers with wide ranging diameters from 30 to 650 nm. At up to 50% contents, the PVP in the bicomponent fibers was phase-separated from CA and, upon removal, resulting in highly angulated fiber surfaces with nanometer-size spherulites and sub-micron size ridges and grooves. Adding β-CD to CA enabled fiber formation at concentrations below the chain entanglement concentration Ce (16.5%). Hydrogen bonding between β-CD and CA, as evident by FTIR, helped to distribute β-CD as individual molecules in the CA matrix and producing more uniform and finer (130–150 nm in diameters) fibers, irrespective of their β-CD contents. Removal of β-CD from the fibers originally containing 40% β-CD, generated nanoporous fibers with 2-nm nanopores and 70% increase in specific surface and doubled pore volume.

Solid-State Photoreversible Polymerization of n-Alkyl-Linked Bis-Thymines using Non-Covalent Polymer-Templating

2010 ◽  
Vol 63 (4) ◽  
pp. 631 ◽  
Author(s):  
Priscilla Johnston ◽  
Milton T.W. Hearn ◽  
Kei Saito
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Nucleic Acid ◽  
Green Chemistry ◽  
Vinyl Pyrrolidone ◽  
Acid Base ◽  
Polymer Templating ◽  
Nucleic Acid Base ◽  
Poly Vinyl Pyrrolidone

Procedures derived from bioinspired mechanisms are increasingly being used to create novel materials based on the principles of green chemistry. Thymine, a nucleic acid base in DNA, has the propensity to both hydrogen bond and photodimerize. Photodimerization of thymine occurs when irradiated at wavelengths of >270 nm and can be reversed by irradiation at wavelengths of <250 nm. In this investigation, n-alkyl-linked bis-thymines have been supramolecularly aligned with poly(vinyl pyrrolidone) templates by non-covalent hydrogen bonding, and photopolymerized in the solid state. Photo-depolymerization of the products was performed to complete the reversible polymerization.

Theoretical study of hydrogen bonding interactions in substituted nitroxide radicals

2021 ◽  
Author(s):  
Thufail M. Ismail ◽  
Neetha Mohan ◽  
P. K. Sajith
Keyword(s):  
Hydrogen Bonding ◽  
Interaction Energy ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Theoretical Study ◽  
Nitroxide Radicals ◽  
Hydrogen Bonding Interactions ◽  
Bonded Complexes ◽  
Hydrogen Bonded

Interaction energy (Eint) of hydrogen bonded complexes of nitroxide radicals can be assessed in terms of the deepest minimum of molecular electrostatic potential (Vmin).

scholarly journals Circular linkage of intramolecular multi-hydrogen bonding frameworks through nucleophilic substitutions of β-dicarbonyls onto cyanuric chloride and subsequent tautomerisation

RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 39033-39036
Author(s):  
Ayano Awatani ◽  
Masaaki Suzuki
Keyword(s):  
Hydrogen Bonding ◽  
Cyanuric Chloride ◽  
Nucleophilic Substitutions ◽  
Hydrogen Bonding Interactions ◽  
Triazine Derivatives

Triply β-dicarbonyl-embedded 1,3,5-triazine derivatives result in formation of circular linkage of resonance-assisted hydrogen bonding interactions, which can be regarded as well-delocalized resonance hybrids.

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