Chitosan biopolymer membranes reinforced with channel-selective ZIF-8 nanofillers were developed and thoroughly characterized as separators for bioelectrochemical systems. This study explores the synergistic effect of incorporating ZIF-8 into a chitosan matrix to enhance membrane performance. Key properties including water retention, chemical and thermal stability, surface resistance, antifouling capacity, and ionic conductivity were evaluated and benchmarked against commercial Nafion-117 and nanofiltration (NF) membranes. The ZIF-8/chitosan composite membranes (ZIF-8/CS) demonstrated excellent water retention and structural stability under harsh conditions, along with significantly reduced surface resistance and effective rejection of organic contaminants and salts (NaCl, Na2SO4). Notably, the composite ZIF-8/CS membranes achieved an ionic conductivity of 0.099 S/cm, approaching the value of Nafion-117 (0.13 S/cm) and substantially surpassing that of the NF membrane (0.013 S/cm). These results indicate that ZIF-8-reinforced chitosan membranes present a promising, sustainable, and cost-effective alternative to traditional separators in bioelectrochemical applications.
Every year the demand for energy worldwide is increasing. There are some alternatives to reduce these problems, such as clean energy or renewable energy. A particular alternative is the microbial fuel cells. These cells are biochemical reactors that convert chemical energy into electricity. The present research evaluated the dairy serum to produce bioelectricity from micro fuel cells (MFC) that were constructed with low-cost materials and with isolated bacteria in anaerobic sediments, located in Ecuadorian national territory, producing maximum voltages of 0.830 V in the circuit and a maximum power density of 30mW / m2. This low voltage was worked with 50 mL MFCs and with an output voltage of 300 mV. Under these conditions, a FLYBACK lift circuit isolated by the transformer was designed. This new circuit could increase the voltage from 30 mV to enough voltage to light a 2.5 V LED. Therefore, the energy produced by the MFC can be directly used to light a LED and to charge capacitors. This study shows that these MFCs, together with the designed circuit, could be used potentially to generate clean energy.
Chitosan biopolymer membranes reinforced with channel-selective ZIF-8 nanofillers were developed and characterized for use as separators in bioelectrochemical systems. The study focused on the application of biopolymer chitosan in combination with ZIF-8 as nano reinforcement agents to improve membrane performance. Key properties such as water retention, chemical and thermal stability, surface resistance, antifouling ability, and ionic conductivity of the mixed matrix membranes (Composite ZIF-8/chitosan) were evaluated and compared with commercial Nafion-117 and nanofiltration (NF) membranes. The composite ZIF-8/chitosan membranes exhibited excellent water retention and structural stability under harsh conditions, while reducing surface resistance and effectively rejecting organic contaminants and salts (NaCl, Na₂SO₄). Impressively, the ionic conductivity reached 0.105 S/cm, which is similar to that of Nafion-117. These results suggest that biopolymer chitosan reinforced with ZIF-8 nanofillers offers a sustainable and cost-effective alternative for use as separators in bioelectrochemical systems applications.
Bioelectrochemical systems (BESs) are technologies capable of converting chemical energy into electrical energy or producing value-added compounds. These systems typically employ Nafion membranes as proton exchange separators; however, Nafion is costly and prone to fouling. In this study, mixed-matrix membranes (MMMs) based on chitosan and its derivatives, incorporated with Er- and Al-doped ZnO nanoparticles, were synthesized and evaluated. Key properties assessed included antimicrobial activity, antifouling behavior, chemical stability, water retention, and proton conductivity. The results demonstrated that the chitosan-based membranes doped with Er/Al/ZnO outperformed Nafion in terms of antifouling properties, water retention, and a protective effect on the surface of the membrane against Escherichia coli and Staphylococcus aureus, while exhibiting comparable proton conductivity and chemical stability.
Bioelectrochemical systems are energy-efficient devices that transform chemical energy into electrical energy or synthesize products of interest. These technologies make use of Nafion membranes that function as proton exchangers; however, these separators have some problems, such as fouling. Therefore, this research explores mixed-matrix membranes of chitosan and chitosan derivatives to determine their antimicrobial, anti-fouling, chemical stability and high-water retention properties. The results showed that these membranes could be good candidates to be used as separators in bioelectrochemical systems.