Enhancement of poly(vinyl alcohol) using delaminated layered double hydroxide for the formulation of mechanically strong nanocomposite hydrogel

Review of two-dimensional nanomaterials in tribology: Recent developments, challenges and prospects

From our ordinary lives to various mechanical systems, friction and wear are often unavoidable phenomena that are heavily responsible for excessive expenditures of nonrenewable energy, the damages and failures of system movement components, as well as immense economic losses. Thus, achieving low friction and high anti-wear performance is critical for minimization of these adverse factors. Two-dimensional (2D) nanomaterials, including transition metal dichalcogenides, single elements, transition metal carbides, nitrides and carbonitrides, hexagonal boron nitride, and metal-organic frameworks have attracted remarkable interests in friction and wear reduction of various applications, owing to their atomic-thin planar morphologies and tribological potential. In this paper, we systematically review the current tribological progress on 2D nanomaterials when used as lubricant additives, reinforcement phases in the coatings and bulk materials, or a major component of superlubricity system. Additionally, the conclusions and prospects on 2D nanomaterials with the existing drawbacks, challenges and future direction in such tribological fields are briefly provided. Finally, we sincerely hope such a review will offer valuable lights for 2D nanomaterial-related researches dedicated on tribology in the future.

Preparation and application of layered double hydroxide nanosheets

Layered double hydroxides (LDH) with unique structure and excellent properties have been widely studied in recent years. LDH have found widespread applications in catalysts, polymer/LDH nanocomposites, anion exchange materials, supercapacitors, and fire retardants. The exfoliated LDH ultrathin nanosheets with a thickness of a few atomic layers enable a series of new opportunities in both fundamental research and applications. In this review, we mainly summarize the LDH exfoliation methods developed in recent years, the recent developments for the direct synthesis of LDH single-layer nanosheets, and the applications of LDH nanosheets in catalyzing oxygen evolution reactions, crosslinkers, supercapacitors and delivery carriers.

Layered double hydroxides (LDHs) with unique structure and excellent properties have been widely studied in recent years.

Mathematical modeling of cinnamon (Cinnamomum verum) bark oil release from agar/PVA biocomposite film for antimicrobial food packaging: The effects of temperature and relative humidity

Antimicrobial biocomposite films were prepared using agar (AG) and polyvinyl alcohol (PVA) as polymer matrix materials and cinnamon bark oil (CBO) as antimicrobial agent. AG and PVA were blended with different mixing ratios. The addition of AG improved the overall water resistance properties of the composite films. To evaluate the effects of temperature and relative humidity (RH) on the release kinetics of CBO from films, CBO release kinetics were analyzed under the 9 combinations of temperature and RH. Then, mathematical modeling of obtained data was conducted using Peleg, Ritger-Peppas, and Peppas-Sahlin models to investigate the release mechanisms of CBO. Consequently, the CBO release rate proportionally increased with the temperature and RH, with the RH being the main factor affecting the release behavior of CBO. In vitro antimicrobial activity tests against gram-positive and gram-negative bacteria showed that the developed composite films have high applicability as an antimicrobial food packaging material.