scholarly journals Hybrid Composite Membrane of Phosphorylated Chitosan/Poly (Vinyl Alcohol)/Silica as a Proton Exchange Membrane

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 675
Author(s):  
Nur Adiera Hanna Rosli ◽  
Kee Shyuan Loh ◽  
Wai Yin Wong ◽  
Tian Khoon Lee ◽  
Azizan Ahmad

Chitosan is one of the natural biopolymers that has been studied as an alternative material to replace Nafion membranes as proton change membranes. Nevertheless, unmodified chitosan membranes have limitations including low proton conductivity and mechanical stability. The aim of this work is to study the effect of modifying chitosan through polymer blending with different compositions and the addition of inorganic filler on the microstructure and physical properties of N-methylene phosphonic chitosan/poly (vinyl alcohol) (NMPC/PVA) composite membranes. In this work, the NMPC biopolymer and PVA polymer are used as host polymers to produce NMPC/PVA composite membranes with different compositions (30–70% NMPC content). Increasing NMPC content in the membranes increases their proton conductivity, and as NMPC/PVA-50 composite membrane demonstrates the highest conductivity (8.76 × 10−5 S cm−1 at room temperature), it is chosen to be the base membrane for modification by adding hygroscopic silicon dioxide (SiO2) filler into its membrane matrix. The loading of SiO2 filler is varied (0.5–10 wt.%) to study the influence of filler concentration on temperature-dependent proton conductivity of membranes. NMPC/PVA-SiO2 (4 wt.%) exhibits the highest proton conductivity of 5.08 × 10−4 S cm−1 at 100 °C. In conclusion, the study shows that chitosan can be modified to produce proton exchange membranes that demonstrate enhanced properties and performance with the addition of PVA and SiO2.

Author(s):  
Ruhilin Nasser ◽  
Siti Khadijah Hubadillah ◽  
Mohd Hafiz Dzarfan Othman ◽  
Arif Akmal Mohamed Hassan

The urge to find alternative sources of energy is crucial as the source of fossil fuel shows a high number of depletion over the year. Compared to other alternatives sources, fuel cell is high at rank as it generates no harmful gases to the surrounding and high in efficiency. The performance of this fuel cell is affected by several factors and one of it is the permeability of proton exchange membrane (PEM). Nafion® is known to be used as the PEM in fuel cells, however due to its high price, polyvinyl alcohol membrane was selected in this study to substitute the Nafion® as it was low in price and excellent in chemical and mechanical strength. Poly (vinyl alcohol) composite membrane was prepared and crosslinked with sulfosuccinic acid (SSA). To further increase the proton conductivity of the membrane, graphene oxide (GO) with 1, 2 and 3 weight percentage was incorporated into the polymer membrane. All the membranes were characterized by using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), water uptake measurement, contact angle, ion exchange capacity and proton conductivity respectively. Synthesized membranes show low water uptake and contact angle as GO loading was increased. IEC value and water swelling were found to be increased with increasing of GO loading. The proton conductivity of the membrane increases as more GO was incorporated into PVA-SSA and achieved its highest conductivity at 0.020746 S cm-1 with 2 wt. % of GO incorporation.


2013 ◽  
Vol 716 ◽  
pp. 98-102
Author(s):  
Ayhan Bozkurt ◽  
Ayşe Aslan

Novel proton conducting nanocomposite membranes included binary and ternary mixtures of acid modified nanotitania particles particles with polymers such as poly (vinyl alcohol) (PVA),pol (vinyl phosphonic acid), sulfonated polysulfone (SPSU) and poly (1-vinyl 1,2,4-triazole) (PVTri) . The interaction of functional nanoparticles with the host matrix were searched by FT-IR spectroscopy. The homogeneous distribution of functional nanoparticles in the membranes was confirmed by SEM micrographs. The spectroscopic measurements and water/methanol uptake studies suggested a complexation between polymers and sulphonic acid that inhibited the leaching out of acidic units. The TGA results verified that the presence of modified nanoparticles in the composite membranes the thermel stability of the membranes enhanced up to above 200 °C.


2016 ◽  
Vol 1 (1) ◽  
pp. 14
Author(s):  
Siti Wafiroh ◽  
Suyanto Suyanto ◽  
Yuliana Yuliana

AbstrakDi era globalisasi ini, kebutuhan bahan bakar fosil semakin meningkat dan ketersediannya semakin menipis. Oleh karena itu, dibutuhkan bahan bakar alternatif seperti Proton Exchange Membrane Fuel Cell (PEMFC). Tujuan dari penelitian ini adalah membuat dan mengkarakterisasi membran komposit kitosan-sodium alginat dari rumput laut coklat (Sargassum sp.) terfosforilasi sebagai Proton Exchange Membrane Fuel Cell (PEMFC). PEM dibuat dengan 4 variasi perbandingan konsentrasi antara kitosan dengan sodium alginat 8:0, 8:1, 8:2, dan 8:4 (b/b). Membran komposit kitosan-sodium alginat difosforilasi dengan STPP 2N. Karakterisasi PEM meliputi: uji tarik, swelling air, kapasitas penukar ion, FTIR, SEM, permeabilitas metanol, dan konduktivitas proton. Berdasarkan hasil analisis tersebut, membran yang optimal adalah perbandingan 8:1 (b/b) dengan nilai modulus young sebesar 0,0901 kN/cm2, swelling air sebesar 19,14 %, permeabilitas metanol sebesar 72,7 x 10-7, dan konduktivitas proton sebesar 4,7 x 10-5 S/cm. Membran komposit kitosan-sodium alginat terfosforilasi memiliki kemampuan yang cukup baik untuk bisa diaplikasikan sebagai membran polimer elektrolit dalam PEMFC. Kata kunci: kitosan, sodium alginat, terfosforilasi, PEMFC  AbstractIn this globalization era, the needs of fossil fuel certainly increases, but its providence decreases. Therefore, we need alternative fuels such as Proton Exchange Membrane Fuel Cell (PEMFC). The purpose of this study is preparationand characterization of phosphorylated chitosan-sodium alginate composite membrane from brown seaweed (Sargassum sp.) as Proton Exchange Membrane Fuel Cell (PEMFC). PEM is produced with 4 variations of concentration ratio between chitosan and sodium alginate 8:0, 8:1, 8:2, and 8:4 (w/w). Chitosan-sodium alginate composite membrane phosphorylated with 2 N STPP. The characterization of PEM include: tensile test, water swelling, ion exchange capacity, FTIR, SEM, methanol permeability, and proton conductivity. Based on the analysis result, the optimal membrane is ratio of 8:1 (w/w) with the value of Young’s modulus about 0.0901 kN/cm2, water swelling at 19.14%, methanol permeability about 72.7 x 10-7, and proton conductivity about 4.7 x 10-5 S/cm. The phosphorylated chitosan-sodium alginate composite membrane has good potentials for the application of the polymer electrolyte membrane in PEMFC. Keywords: chitosan, sodium alginate, phosphorylated, PEMFC


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1570 ◽  
Author(s):  
A. Rico-Zavala ◽  
J. L. Pineda-Delgado ◽  
A. Carbone ◽  
A. Saccà ◽  
E. Passalacqua ◽  
...  

The aim of this work is the evaluation of a Sulfonated Poly Ether-Ether Ketone (S-PEEK) polymer modified by the addition of pure Santa Barbara Amorphous-15 (SBA-15, mesoporous silica) and SBA-15 previously impregnated with phosphotungstic acid (PWA) fillers (PWA/SBA-15) in order to prepare composite membranes as an alternative to conventional Nafion® membranes. This component is intended to be used as an electrolyte in electrochemical energy systems such as hydrogen and methanol Proton Exchange Membrane Fuel Cell (PEMFC) and Electrochemical Hydrogen Pumping (EHP). The common requirements for all the applications are high proton conductivity, thermomechanical stability, and fuel and oxidant impermeability. The morphology of the composite membranes was investigated by Scanning Electron Microscopy- Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis. Water Uptake (Wup), Ion Exchange Capacity (IEC), proton conductivity, methanol permeability and other physicochemical properties were evaluated. In PEMFC tests, the S-PEEK membrane with a 10 wt.% SBA-15 loading showed the highest performance. For EHP, the inclusion of inorganic materials led to a back-diffusion, limiting the compression capacity. Concerning methanol permeability, the lowest methanol crossover corresponded to the composites containing 5 wt.% and 10 wt.% SBA-15.


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