Microstructure and properties of novel SPEEK/PVDF-g-PSSA blends for proton exchange membrane with improved compatibility

Huang

2020

Sensors

In this work, micro-modified polyvinylidene fluoride (PVDF) and its copolymer poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)) with salient enhancement in current output are demonstrated. The influence of surface-modified structure characteristics on electrical properties of energy harvester is systematically analyzed based on the finite element method. For vertical load mode, eight structures consisting of banded and disjunctive groups are compared to evaluate the voltage performance. The cylinder is proved to be the best structure of 3.25 V, compared to the pristine structure of 0.99 V (P(VDF-TrFE)). The relevant experiment has been done to verify the simulation. The relationship between radius, height, force and distance to the voltage output of the cylinder allocation is discussed. For periodical changing load mode, the cylinder modified structure shows a conspicuous enhancement in current output. The suitable resistance, current–voltage and frequency, the relationship between loading speed and current, and the ductility of current loading are studied. For 30 kHz, the peak current is 20 times larger than the flat plate structure. Tip shape mode and fusiform shape mode are found, which show the different shapes of the peak current-frequency curves. Four electrical loading circuit properties are also discussed: the suitable resistance of the system, synchronism of current and voltage, time delay nature of energy harvester and current-loading relationship. The simulation results can provide some theoretical basis for designing the energy harvester and piezoelectric nanogenerator (PENG).

Section: Introductionmentioning

confidence: 99%

Improved Design via Simulation of Micro-Modified PVDF and Its Copolymer Energy Harvester with High Electrical Outputs

Huang

2020

Sensors

Polymers for Advanced Techs

“…An account of a great backbone similarity between PVDF and commercial perfluorinated membranes such as Nafion, Dow, Aciplex, and Flemion membranes, the study of PVDF and its copolymers as a replacement for the costly fluorinated membranes has become one of the research priorities of researchers in the field of PEM. Different approaches such as blend modification and application of various nanofillers have been introduced to prepare PVDF‐based polymer electrolyte membranes as advanced PEMs. However, attaining a durable polymeric electrolyte that improves thermal, mechanical, electrochemical stability, and proton conductivity and so on needs considerable investigation.…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of PVDF‐based blend membranes as polymer electrolyte membranes in fuel cells: Study of factor affecting the proton conductivity behavior

Ahmadian‐Alam

Mahdavi

2018

There is a huge demand especially for polyvinylidene fluoride (PVDF) and its copolymers to provide high performance solid polymer electrolytes for use as an electrolyte in energy supply systems. In this regard, the blending approach was used to prepare PVDF-based proton exchange membranes and focused on the study of factor affecting their proton conductivity behavior. Thus, a series of copolymers consisting of poly (methyl methacrylate) (PMMA), polyacrylonitrile (PAN), and poly(2-acrylamido-2methyl-l-propanesulfonic acid) (PAMPS) as sulfonated segments were synthesized and blended with PVDF matrix in order to create proton transport sites in PVDF matrix.It was found that addition of PMMA-co-PAMPS and PAN-co-PAMPS copolymers resulted in a significant increase in porosity, which favored the water uptake and proton transport at ambient temperature. Furthermore, crystallinity degree of the PVDF-based blend membranes was increased by addition of the related copolymers, which is mainly attributed to formation of hydrogen bonding interaction between PVDF matrix and the synthesized copolymers, and led to a slight decrease in proton conductivity behavior of blend membranes. From impedance data, the proton conductivity of the PVDF/PMMAco-PAMPS and PVDF/PAN-co-PAMPS blend membranes increases to 10 and 8.4 mS cm −1 by adding only 50% of the related copolymer (at 25°C), respectively. Also, the blend membranes containing 30% sulfonated copolymers showed a power density as high as 34.30 and 30.10 mW cm −2 at peak current density of 140 and 79.45 mA cm −2 for the PVDF/PMMA-co-PAMPS and PVDF/PAN-co-PAMPS blend membranes, respectively. A reduction in the tensile strength was observed by the addition of amphiphilic copolymer, whereas the elongation at break of all blend membranes was raised. up, low operation temperature, and simplicity. Polymer electrolyte membrane (PEM), as one of the important parts of a PEMFC, has attracted a considerable attention. The performances of this part of PEMFCs are affected by its proton conductivity, electrical insulating, chemical and thermal stability, electro-osmotic drag coefficient, and good mechanical properties. Perfluorinated polymer membrane, known as Nafion, has been widely used as the proton exchange membrane in PEMFCs due to its excellent performances and stabilities. 6 However, the main limitation of Nafion is its high cost and decreasing proton conductivity at temperature above 100°C and low humidity condition, which limit its application. For this reason, introducing a new polymeric membrane is one of the key issues and research priorities in the field of PEMFCs.Recently, there is an enormous request especially for polyvinylidene fluoride (PVDF) and its copolymers to prepare superior PEM for PEMFC application. 2,7-9 An account of a great backbone similarity between PVDF and commercial perfluorinated membranes such as Nafion, Dow, Aciplex, and Flemion membranes, the study of PVDF and its copolymers as a replacement for the costly fluorinated membranes has become one of the research pri...

J of Applied Polymer Sci

“…The proton exchange membrane (PEM) is a key component of PEMFC, and it can transfer protons and separate the oxidant streams from the fuels. PEMs developed so far can be classified into three groups: (1) perfluorosulfonic acid (PFSA) membranes, such as Nafion and Dow membranes; (2) sulfonated aromatic hydrocarbon polymers and their composite membranes, such as sulfonated polysulfone (SPSF), sulfonated polyether sulfone (SPES), sulfonated poly(ether ether ketone) (SPEEK), polybenzimidazole (PBI), and polyvinylidene fluoride (PVDF); and (3) inorganic‐organic polymer membranes, such as phosphoric acid (PA) doped polybenzimidazole (PBI) composite membranes and nanoparticle enhanced polymers . Inorganic‐organic polymer membranes have drawn considerable research attention because of their potential applications in high temperature proton exchange membrane fuel cell (HT‐PEMFC).…”

Section: Introductionmentioning

confidence: 99%

A novel polybenzimidazole composite modified by sulfonated graphene oxide for high temperature proton exchange membrane fuel cells in anhydrous atmosphere

Cai

Yue

2017

A novel functional graphene with high ion exchange capacity (IEC) was prepared by grafting reaction induced by 60 Co g-ray irradiation using graphene oxide. Then, polybenzimidazole/radiation grafting graphene oxide (PBI/RGO) composite membranes were prepared by the solution-casting method and doped with phosphoric acid (PA) to improve their proton conductivity. The properties of PBI/GO/PA and PBI/RGO/PA membranes including the PA doping level, chemical stability, proton conductivity and mechanical properties were evaluated and compared. The tensile strength of PBI/RGO/PA membranes (ranging from 27.3 to 38.5 MPa) increases at first and then decreases with the increase of the RGO content, and is significantly higher than that of other PA doped PBI-based membranes. The proton conductivity of PBI/RGO-3/PA membrane is 28.0 mS cm 21 at 170 8C without humidity, with an increase of 72.0% compared with that of PBI/PA membrane. These results suggest that PBI/RGO/PA membranes have the potential to be used as high-temperature proton exchange membranes.