Viscometric investigations on the intrinsic viscosity of polyvinylpyrrolidone affected by polymer-polymer interactions in solution

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Omar Melad Al-Azhar
Keyword(s):  
Intrinsic Viscosity ◽  
Vinylidene Fluoride ◽  
Solvent System ◽  
Repulsive Interaction ◽  
Solvent Method ◽  
Poly Vinyl Chloride ◽  
Poly Vinylidene Fluoride ◽  
Polymer Interactions ◽  
High Concentrations ◽  
Polymer Solvent

AbstractThe intrinsic viscosity of polyvinylpyrrolidone (PVP) and various added polymers was investigated by the polymer-solvent method. It has been found that both polymer-polymer interactions and the concentration of the added polymer affect the intrinsic viscosity of PVP. In the ‘polymer-solvent’ system poly(methyl methacrylate) + dimethylformamide (PMMA+DMF), the intrinsic viscosity of PVP decreases as the concentration of PMMA increases, showing that the repulsive interaction between PVP and PMMA originates from the contraction of PVP coils in solution due to the intermolecular excluded volume. However, in the polymersolvent systems poly(vinyl chloride) (PVC) + DMF or poly(vinylidene fluoride) (PVDF) + DMF, the attractive interactions between PVP and PVC or PVDF cause an expansion of PVP coils in solution at high concentrations of PVC or PVDF. The polymer-solvent method allows estimating the compatibility of the used polymers.

scholarly journals A Review on Porous Polymeric Membrane Preparation. Part I: Production Techniques with Polysulfone and Poly (Vinylidene Fluoride)

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1160 ◽  
Author(s):  
XueMei Tan ◽  
Denis Rodrigue
Keyword(s):  
Phase Separation ◽  
Vinylidene Fluoride ◽  
Solvent System ◽  
Processing Parameters ◽  
Membrane Preparation ◽  
Polymeric Membrane ◽  
Ambient Conditions ◽  
Membrane Fabrication ◽  
Core Technology ◽  
Poly Vinylidene Fluoride

Porous polymeric membranes have emerged as the core technology in the field of separation. But some challenges remain for several methods used for membrane fabrication, suggesting the need for a critical review of the literature. We present here an overview on porous polymeric membrane preparation and characterization for two commonly used polymers: polysulfone and poly (vinylidene fluoride). Five different methods for membrane fabrication are introduced: non-solvent induced phase separation, vapor-induced phase separation, electrospinning, track etching and sintering. The key factors of each method are discussed, including the solvent and non-solvent system type and composition, the polymer solution composition and concentration, the processing parameters, and the ambient conditions. To evaluate these methods, a brief description on membrane characterization is given related to morphology and performance. One objective of this review is to present the basics for selecting an appropriate method and membrane fabrication systems with appropriate processing conditions to produce membranes with the desired morphology, performance and stability, as well as to select the best methods to determine these properties.

scholarly journals On fabrication of nanoscale non-smooth fibers with high geometric potential and nanoparticle’s non-linear vibration

2020 ◽  
Vol 24 (4) ◽  
pp. 2491-2497 ◽  
Author(s):  
Xin Yao ◽  
Ji-Huan He
Keyword(s):  
Smooth Surface ◽  
Vinylidene Fluoride ◽  
High Surface ◽  
Solvent System ◽  
Binary Solvent ◽  
Linear Vibration ◽  
Multi Wall Carbon Nanotubes ◽  
Micro Scale ◽  
Poly Vinylidene Fluoride ◽  
High Surface Energy

Non-smooth surface of a nano or micro-scale fiber has an extremely large surface area and a tremendously high surface energy (geometric potential). This paper focuses on the formation mechanism of fabrication of a non-smooth surface by electrospinning through controlling solvent evaporation and nanoscale adhesion of nanoparticles on the surface. Poly(vinylidene fluoride), multi-wall carbon nanotubes and a binary solvent system are adopted in the experiment to elucidate how to fabricate nanoscale porous nanofibers and lotus-surface-like nanofibers. A nanoparticle?s vibration near its equilibrium is also discussed, which also affects greatly the surface morphology.

Preparation and characterization of anti-fouling PVDF membrane modified by chitin

2017 ◽  
Vol 37 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Manman Xie ◽  
Xia Feng ◽  
Juncheng Hu ◽  
Zhengyi Liu ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Solvent System ◽  
Pvdf Membrane ◽  
Blend Membrane ◽  
Poly Vinylidene Fluoride ◽  
And Performance ◽  
Membrane Structure And Performance ◽  
Precipitation Phase

Abstract Poly(vinylidene fluoride) (PVDF)/chitin (CH) blend membranes were prepared via the method of immersion-precipitation phase transformation with the solvent system N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl) as solvent and water as coagulant. The effect of CH on membrane structure and performance was investigated. Owing to the strong hydrophilicity, CH chains enriched on the blend membrane surface and improved the hydrophilicity of the membrane. The addition of CH also led to the formation of finger-like pores and the increase of pore size and porosity. The flux and the flux recovery ratio (FRR) of the blend membrane were higher than that of pure PVDF membrane. The fouling resistance of the blend membrane was lower than that of PVDF original membrane. In a word, the addition of CH to PVDF membrane improved the hydrophilicity and the anti-fouling ability of PVDF membrane.

scholarly journals Tamisolve® NxG as an Alternative Non-Toxic Solvent for the Preparation of Porous Poly (Vinylidene Fluoride) Membranes

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2579
Author(s):  
Francesca Russo ◽  
Tiziana Marino ◽  
Francesco Galiano ◽  
Lassaad Gzara ◽  
Amalia Gordano ◽  
...  
Keyword(s):  
Pore Size ◽  
Vinylidene Fluoride ◽  
Water Solution ◽  
Chemical Properties ◽  
Solvent System ◽  
Solubility Parameters ◽  
Coagulation Bath ◽  
Separation And Purification ◽  
Pore Former ◽  
Poly Vinylidene Fluoride

Tamisolve® NxG, a well-known non-toxic solvent, was used for poly(vinylidene fluoride) (PVDF) membranes preparation via a non-solvent-induced phase separation (NIPS) procedure with water as a coagulation bath. Preliminary investigations, related to the study of the physical/chemical properties of the solvent, the solubility parameters, the gel transition temperature and the viscosity of the polymer–solvent system, confirmed the power of the solvent to solubilize PVDF polymer for membranes preparation. The role of polyvinylpyrrolidone (PVP) and/or poly(ethylene glycol) (PEG), as pore former agents in the dope solution, was studied along with different polymer concentrations (10 wt%, 15 wt% and 18 wt%). The produced membranes were then characterized in terms of morphology, thickness, porosity, contact angle, atomic force microscopy (AFM) and infrared spectroscopy (ATR-FTIR). Pore size measurements, pore size distribution and water permeability (PWP) tests placed the developed membranes in the ultrafiltration (UF) and microfiltration (MF) range. Finally, PVDF membrane performances were investigated in terms of rejection (%) and permeability recovery ratio (PRR) using methylene blue (MB) in water solution to assess their potential application in separation and purification processes.

scholarly journals Poly(vinylidene fluoride-trifluoroethylene) (72/28) interconnected porous membranes obtained by crystallization from solution

2011 ◽  
Vol 1312 ◽  
Author(s):  
Armando Ferreira ◽  
Jaime Silva ◽  
Vitor Sencadas ◽  
José Luís Gómez-Ribelles ◽  
Senentxu Lanceros-Méndez
Keyword(s):  
Room Temperature ◽  
Vinylidene Fluoride ◽  
Polymer Concentration ◽  
Porous Membranes ◽  
Membrane Thickness ◽  
Solvent Ratio ◽  
Scanning Calorimetry ◽  
Poly Vinylidene Fluoride ◽  
Crystallization From Solution ◽  
Polymer Solvent

ABSTRACTElectroactive macroporous poly[(vinylidene fluoride)-co-trifluoroethylene] membranes have been processed by solvent evaporation at room temperature with different polymer/solvent concentrations. The pore architecture consists on interconnected spherical pores and this morphology is independent of the membrane thickness. The porosity of the produced membranes increases from 72% for the higher polymer concentration in the polymer/solvent solution (15/85), up to 80% for the lowest polymer concentration in the polymer/solvent solution.Fourier transform infrared spectroscopy and differential scanning calorimetry measurements reveal that the polymer crystallizes in the ferroelectric phase and the polymer/solvent ratio does not influences the Curie transition and the melting temperature of the polymer.

scholarly journals Anion effects on the properties of OIPC/PVDF composites

2021 ◽  
Vol 2 (5) ◽  
pp. 1683-1694
Author(s):  
Frederick Nti ◽  
George W. Greene ◽  
Haijin Zhu ◽  
Patrick C. Howlett ◽  
Maria Forsyth ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Plastic Crystal ◽  
Ion Dynamics ◽  
Composite Electrolytes ◽  
Poly Vinylidene Fluoride ◽  
Polymer Interactions

Ion dynamics enhancements derived from anion–polymer interactions are proposed in organic ionic plastic crystal–poly(vinylidene fluoride)composite electrolytes.

Preparation and Characterization of Novel Hollow Fiber Membrane with Multicomponent Polymeric Materials

2012 ◽  
Vol 534 ◽  
pp. 8-12 ◽  
Author(s):  
Yun Qing Li ◽  
Dan Li Xi ◽  
Shun Li Fan
Keyword(s):  
Vinylidene Fluoride ◽  
Hollow Fiber Membrane ◽  
Polymeric Materials ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Cross Sectional ◽  
Poly Vinyl Chloride ◽  
Poly Vinylidene Fluoride ◽  
Coagulation Bath Temperature

Poly(vinylidene fluoride)(PVDF), poly(vinyl chloride)(PVC), and poly(methyl methacrylate)(PMMA) were used as the main materials in the preparation of novel blend five-hole membrane. Dimethylacetamide (DMAC) and polyvinyl pyrrolidone (PVP) were used as solvent and additive, respectively. The effect of some external coagulation conditions on the property of five-hole membrane was studied. The external coagulation conditions investigated in the work were the coagulation temperature and the DMAC content in coagulation bath. The result showed that the flux increased along with the increase of coagulation bath temperature and could reach the max at 35°C, then decreased gradually. The effect of the DMAC content in coagulation bath on flux is very similar to that of the temperature. The cross-sectional structures were examined by scanning electron microscopy.

Sign in / Sign up

Export Citation Format

Share Document