Specifically dedicated to polymer and biopolymer systems, Polymer Adhesion, Friction, and Lubricationguides readers to the scratch, wear, and lubrication properties of polymers and the engineering ...applications, from biomedical research to automotive engineering. Author Hongbo Zeng details different experimental and theoretical methods used to probe static and dynamic properties of polymer materials and biomacromolecular systems. Topics include the use of atomic force microscopy (AFM) to analyze nanotribology, polymer thin films and brushes, nanoparticles, rubber and tire technology, synovial joint lubrication, adhesion in paper products, bioMEMS, and electrorheological fluids.
Particulate matter (PM), which is the primary contributor to air pollution, has become a pervasive global health threat. When PM enters into a respiratory tract, the first body tissues to be directly ...exposed are the cells of respiratory tissues and pulmonary surfactant. Pulmonary surfactant is a pivotal component to modulate surface tension of alveoli during respiration. Many studies have proved that PM would interact with pulmonary surfactant to affect the alveolar activity, and meanwhile, pulmonary surfactant would be adsorbed to the surface of PM to change the toxic effect of PM. This review focuses on recent studies of the interactions between micro/nanoparticles (synthesized and environmental particles) and pulmonary surfactant (natural surfactant and its models), as well as the health effects caused by PM through a few significant aspects, such as surface properties of PM, including size, surface charge, hydrophobicity, shape, chemical nature, etc. Moreover, in vitro and in vivo studies have shown that PM leads to oxidative stress, inflammatory response, fibrosis, and cancerization in living bodies. By providing a comprehensive picture of PM-surfactant interaction, this review will benefit both researchers for further studies and policy-makers for setting up more appropriate regulations to reduce the adverse effects of PM on public health.
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•Long-term exposure to particulate matter (PM) reduces life expectancy.•Pulmonary surfactant is the initial tissues contacted with PM.•The interaction behaviors of PM and pulmonary surfactant are systematically reviewed.•Surface properties of PM determine PM-surfactant interactions.
Abstract
The development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to ...remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.
Selenium ions are toxic at concentrations of >40ppb (40μgL−1) which has been a very challenging environmental issue. Compared to Se (IV), Se (VI) is more bioavailable and much more difficult to ...remove from water. Conventional adsorbent materials only show well defined removal capacity for Se (IV) while performing poorly for Se (VI) (typical removal percentage <50%). In this report, functionalized water-dispersible magnetic nanoparticle–graphene oxide (MGO) composites were synthesized, characterized and applied to remove selenium ions (both Se (IV) and Se (VI)) in aqueous system. MGO (dosage 1gL−1) shows removal percentage of >99.9% for Se (IV) and ∼80% for Se (VI) from water (pH 6–7) within 10s. Effect of pH ranging from 2 to 11 was investigated, and the results show that acidic pH enhances the adsorption of selenium ions on MGO resulting in an increased removal percentage of Se (VI) to >95% at pH ∼2. MGO can be separated effectively under an external magnetic field and recycled for reuse in water treatment. Our results show that MGO composites have favorable removal capability of both selenite and selenate in water with important potential practical applications in removing selenium from wastewater.
Carbon capture and storage (CCS) is gaining momentum as a means for combating climate change. It is viewed as an important bridging technology, allowing emission targets to be met during fossil fuel ...dependence while sufficient renewable energy generation is installed. Mineral carbon sequestration is the only known form of permanent carbon storage and has the potential to capture and store CO
2 in a single step. It is based on the geologic process of natural rock weathering where CO
2 dissolved in rain water reacts with alkaline rocks to form carbonate minerals. While the reactions are thermodynamically favourable, in nature the process occurs over thousands of years. The challenge of mineral carbon sequestration is to accelerate carbonation and exploit the heat of reaction with minimal energy and material losses. Minerals commonly selected for carbonation include calcium and magnesium silicates. These minerals require energy-intensive pre-treatments, such as fine grinding, heat treatment, and chemical activation with strong acids, to provide adequate conversions and reaction kinetics. Industrial waste residues present alternative sources of mineral alkalinity that are more reactive than primary minerals and are readily and cheaply available close to CO
2 sources. In addition, the carbonation of waste residues often improves their environmental stability. This paper provides an overview of the types of industrials wastes that can be used for mineral carbon sequestration and the process routes available.
Hydrogels are three-dimensional cross-linked polymer networks which can absorb and retain large amount of water. As representative soft materials with tunable chemical, physical and biological ...properties, hydrogels with different functions have been developed and utilized in a broad range of applications, from tissue engineering to soft robotics. However, conventional hydrogels usually suffer from weak mechanical properties and they are easily deformed or damaged when they are subjected to mechanical forces. The accumulation of the damage may lead to the permanent structural change and the loss of the functional properties of the hydrogels. Therefore, it is important to develop mechanically robust hydrogels with autonomous self-healing property in order to extend their lifespan for various applications. In this mini review, we focus on the discussion about the appropriate molecular design of the hydrogel network for achieving self-healing and excellent mechanical properties, respectively as well as the corresponding self-healing and toughening mechanisms. We conclude with perspectives on the remaining challenges in the field as well as the recommendations for future development.
The outstanding water wettability and the capability of polyelectrolyte surfaces to spontaneously clean oil fouling are determined by their wetting mechanism in the surrounding medium. Here, we have ...quantified the nanomechanics between three types of polyelectrolyte surfaces (i.e. zwitterionic, cationic, and anionic) and water or oil drops using an atomic force microscope (AFM) drop probe technique, and elucidated the intrinsic wetting mechanisms of the polyelectrolyte surfaces in oil and water media. The measured forces between oil drops and polyelectrolyte surfaces in water can be described by the Derjaguin‐Landau‐Verwey‐Overbeek (DLVO) theory. Surprisingly, strong long‐range attraction was discovered between polyelectrolyte surfaces and water drops in oil, and the strongest interaction was measured for the polyzwitterion. This unexpected long‐range “hydrophilic” attraction in oil could be attributed to a strong dipolar interaction because of the large dipole moment of the polyelectrolytes. Our results provide new nanomechanical insights into the development of novel polyelectrolyte‐based materials and coatings for a wide range of engineering, bioengineering, and environmental applications.
Wetting phenomena: A long‐range hydrophilic attraction in an oil medium was discovered between water and zwitterionic, cationic, and anionic polyelectrolyte molecules using an atomic force microscopy technique. The unexpected strong attraction could possibly be attributed to a strong dipolar interaction due to the large dipole moment of the polyelectrolyte molecules.
Abstract
Aqueous zinc (Zn) chemistry features intrinsic safety, but suffers from severe irreversibility, as exemplified by low Coulombic efficiency, sustained water consumption and dendrite growth, ...which hampers practical applications of rechargeable Zn batteries. Herein, we report a highly reversible aqueous Zn battery in which the graphitic carbon nitride quantum dots additive serves as fast colloid ion carriers and assists the construction of a dynamic & self-repairing protective interphase. This real-time assembled interphase enables an ion-sieving effect and is found actively regenerate in each battery cycle, in effect endowing the system with single Zn
2+
conduction and constant conformal integrality, executing timely adaption of Zn deposition, thus retaining sustainable long-term protective effect. In consequence, dendrite-free Zn plating/stripping at ~99.6% Coulombic efficiency for 200 cycles, steady charge-discharge for 1200 h, and impressive cyclability (61.2% retention for 500 cycles in a Zn | |MnO
2
full battery, 73.2% retention for 500 cycles in a Zn | |V
2
O
5
full battery and 93.5% retention for 3000 cycles in a Zn | |VOPO
4
full battery) are achieved, which defines a general pathway to challenge Lithium in all low-cost, large-scale applications.
Metal-containing polymer networks are widespread in biology, particularly for load-bearing exoskeletal biomaterials. Mytilus byssal cuticle is an especially interesting case containing moderate ...levels of Fe³⁺ and cuticle protein--mussel foot protein-1 (mfp-1), which has a peculiar combination of high hardness and high extensibility. Mfp-1, containing 13 mol % of dopa (3, 4-dihydroxyphenylalanine) side-chains, is highly positively charged polyelectrolyte (pI ~ 10) and didn't show any cohesive tendencies in previous surface forces apparatus (SFA) studies. Here, we show that Fe³⁺ ions can mediate unusually strong interactions between the positively charged proteins. Using an SFA, Fe³⁺ was observed to impart robust bridging (Wad almost equal to 4.3 mJ/m²) between two noninteracting mfp-1 films in aqueous buffer approaching the ionic strength of seawater. The Fe³⁺ bridging between the mfp-1-coated surfaces is fully reversible in water, increasing with contact time and iron concentration up to 10 μM; at 100 μM, Fe³⁺ bridging adhesion is abolished. Bridging is apparently due to the formation of multivalent dopa-iron complexes. Similar Fe-mediated bridging (Wad almost equal to 5.7 mJ/m²) by a smaller recombinant dopa-containing analogue indicates that bridging is largely independent of molecular weight and posttranslational modifications other than dopa. The results suggest that dopa-metal interactions may provide an energetic new paradigm for engineering strong, self-healing interactions between polymers under water.
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