Surface Engineering for Enhanced Triboelectric Nanogenerator

Triboelectric nanogenerator (TENG) is the new technique that can convert low-frequency mechanical energy into effective electricity. As an energy collector, the pursuit of high output characteristics is understandable. Although high charge density has been achieved by working in high vacuum or charge pumping techniques, it remains challenging to obtain the high output performance directly in the atmosphere. Herein, surface-engineering of the triboelectric layer for enhancing output performance has been reviewed carefully. By constructing surface morphology or developing surface modification, high performance of TENGs is finally presented in the review.

Charged sequence motifs increase affinity towards liquid-liquid phase separation

Protein phase separation has been shown to be a major governing factor in multiple cellular processes, especially ones concerning RNA and RNA-binding proteins. Despite many key observations, the exact structural characteristics of proteins involved in the process are still not fully deciphered. In this work we show that proteins harbouring sequences with specific regions of charged residues are significantly associated with phase separation phenomena. In particular, regions with repetitive arrays of alternating charges (termed charged residue repeats, CRRs) show the strongest association, whereas segments with generally high charge density (charge-dense regions, CDRs) and single alpha-helices (SAHs) show also detectable but weaker connections.It is known to contribute to the formation of membrane-less organelles (MLOs) and to an extent the aggregation of proteins. The causes and consequences of phase separation has been a rigorously researched topic in the last few years, as the condensation of specific phase-separating proteins is known to promote several diseases.In this work we carried out a computational analysis to examine the presence of repetitive segments with high charge density in proteins prone to phase separation. Free resources such as the Charged Single α-Helix (CSAH) web server and the PhaSepDB online database were used to examine possible links between the charged side-chain content of protein sequences and their partition into membrane-less condensates. Furthermore, we carried out the development of a novel algorithm aimed to detect a larger variety of charged protein segments, in order to examine their relationship to the phenomenon. Fisher’s exact test of independence was implemented on several generated data sets to confirm correlation between charged residue repeats (CRRs) and charge-dense regions (CDRs) within human protein sequences and their affinity for phase separation.

Iron-Containing Poly(ionic liquid)s Membrane: Heterogeneous Fenton Reaction and Enhanced Anti-fouling Ability

Poly(ionic liquid)s (PILs) are widely used to improve the anti-fouling ability of membranes due to their high charge density and excellent hydrophilicity. However, it is difficult to eradicate the irreversible...

Development of Greener D-Metal Inorganic Crosslinkers for Polymeric Gels Used in Water Control in Oil and Gas Applications

Crosslinkable polymers, such as polyacrylamide (PAM), are widely applied for water control in oil and gas reservoirs. Organic and inorganic crosslinkers are used to formulate a gel with PAM. Although chromium has a high level of toxicity, it has been implemented as an effective crosslinker combined with carboxylates because of the controllability of crosslinking time at low temperatures. The objective of this work was to develop greener d-metal inorganic crosslinkers based on cobalt, copper, and nickel to replace chromium for application at reservoir conditions. The obtained results showed that the gelation chemistry of the developed systems depends on the metal charge density. The gelation of PAM with d-metals depends on pH and temperature for low- and high-charge density, respectively. Cobalt (II) acetate (CoAc) was effective at high temperatures (130–150 °C) and forms (4% CoAc + 9%PAM) stable, and strong gels at a pH > 7 with a storage modulus exceeding 4300 Pa. However, Nickel Acetate and Cupper Acetate formed stable weak gels at low temperatures (50–70 °C) and a pH > 6 and gel decomposition was observed upon increasing the temperature. The developed formulations were compatible with low-salinity water (1000 ppm NaCl).