Sulphonated poly(ethersulfone)/carbon nano-onions-based nanocomposite membranes with high ion-conducting channels for salt removal via electrodialysis

Enhanced antihypertensive chicken by-product hydrolysate fraction after its separation by electrodialysis with ultrafiltration membrane (EDUF)

The environmental impact of poultry industry waste has led to the study of hydrolysates with potential health-promoting properties obtained from poultry by-products and their fractionation to increase the bioactivity of these hydrolysates. The aim of the present study was to separate a chicken by-product hydrolysate (CBH) by electrodialysis with ultrafiltration membranes (EDUF), providing peptide selective separation based on their charge and molecular weight, and to characterize the resulting fractions. Experimental results showed that during the peptide fractionation process the global peptide migration rate (MR) from CBH was 14.97 ± 0.14 g/m2•h with a relative energy consumption of 31.27 ± 2.61 Wh/g of total peptides. 164 peptides were identified in the initial CBH, and following EDUF, 39 migrated to the positively charged peptide fraction (PCC) and 9 to the negatively charge peptide fraction (NCC): 21 sequences were reported as bioactive for CBH, 6 for PCC and 1 for NCC. Analyses of ACE inhibition evidenced a 1.4 fold increase in antihypertensive activity of the PCC (IC50 0.46 ± 0.04 mg peptides /mL) in comparison to CBH (IC50 0.65 ± 0. 04 mg peptides /mL), despite the smaller number of bioactive sequences reported and the fact that it is possible to enhance the PCC recovery by modifying the EDUF configuration in further studies. These findings highlight the significance of EDUF as a sustainable method for obtaining specifically charged peptide fractions with enhanced bioactivity from the initial hydrolysate.

Nitrogen-doped carbon nano-onions/polypyrrole nanocomposite based low-cost flexible sensor for room temperature ammonia detection

One of the frontier research areas in the field of gas sensing is high-performance room temperature-based novel sensing materials, and new family of low-cost and eco-friendly carbon nanomaterials with a unique structure has attracted significant attention. In this work, we propose a novel low-cost flexible room temperature ammonia gas sensor based on nitrogen-doped carbon nano-onions/polypyrrole (NCNO-PPy) composite material mounted low-cost membrane substrate was synthesized by combining hydrothermal and in-situ chemical polymerization methods. The proposed flexible sensor revealed high sensing performance when employed as the sensing material for ammonia detection at room temperature. The NCNO-PPy ammonia sensor exhibited 17.32% response for 100 ppm ammonia concentration with a low response time of 26 s. The NCNO-PPy based flexible sensor displays high selectivity, good repeatability, and long-term durability with 1 ppm as the lower detection limit. The proposed flexible sensor also demonstrated remarkable mechanical robustness under extreme bending conditions, i.e., up to 90° bending angle and 500 bending cycles. This enhanced sensing performance can be related to the potential bonding and synergistic interaction between nitrogen-doped CNOs and PPy, the formation of defects from nitrogen doping, and the presence of high reactive sites on the surface of NCNO-PPy composites. Additionally, the computational study was performed on optimized NCNO-PPy nanocomposite for both with and without NH3 interaction. A deeper understanding of the sensing phenomena was proposed by the computation of several electronic characteristics, such as band gap, electron affinity, and ionization potential, for the optimized composite.