There has been a rapid growth in research and innovation of bio-based adhesives in the engineered wood product industry. This article reviews the recent research published over the last few decades on the synthesis of bio-adhesives derived from such renewable resources as lignin, starch, and plant proteins. The chemical structure of these biopolymers is described and discussed to highlight the active functional groups that are used in the synthesis of bio-adhesives. The potentials and drawbacks of each biomass are then discussed in detail; some methods have been suggested to modify their chemical structures and to improve their properties including water resistance and bonding strength for their ultimate application as wood adhesives. Moreover, this article includes discussion of techniques commonly used for evaluating the petroleum-based wood adhesives in terms of mechanical properties and penetration behavior, which are expected to be more widely applied to bio-based wood adhesives to better evaluate their prospect for wood composites application.

A template‐free benign approach to modify polypyrrole (PPy) with bioinspired catechol derivatives dopamine (DA), 1,2‐dihydroxybenzene or catechol (CA), and l‐3,4‐dihydroxyphenylalanine (DOPA) is reported. It is found that PPy functionalized with these catechol derivatives (DA, CA, and DOPA) exhibited fibrous structure, smaller particle size, good water dispersibility, and enhanced film adhesion. Surprisingly, it is found that adding a small amount of catechols can also improve PPy's electrical conductivity. This rapid, one‐step, in situ, template‐free method provided an alternative strategy to the facile production of PPy fibers. Among these three catechols, functionalized PPy and DA‐PPy exhibits the smallest particle size and best performance in both adhesion and electrical conductivity. In contrast, the control phenylethlamine (PA) modification had almost negligible influence on the PPy properties, which provides strong evidence that instead of amine functional group or coexistence of both catechol and amine moieties, catechol itself is responsible for the successful functionalization of PPy and overall performance improvement. Furthermore, catechol‐PPy nanofibers are blended into polyvinyl alcohol (PVA) aqueous solution and casted to form thin films; as‐synthesized conductive films are found able to bond strongly onto the surface and may find broad applications in manufacturing biosensors and electronic devices.

Oil spills and the emission of oily wastewater have triggered serious water pollution and environment problems. Effectively separating oil and water is a world-wide challenge and extensive efforts have been made to solve this issue. Interfacial super-wetting separation materials e.g., sponge, foams, and aerogels with high porosity tunable pore structures, are regarded as effective media to selectively remove oil and water. This review article reports the latest progress of polymeric three dimensional porous materials (3D-PMs) with super wettability to separate oil/water mixtures. The theories on developing super-wetting porous surfaces and the effects of wettability on oil/water separation have been discussed. The typical 3D porous structures (e.g., sponge, foam, and aerogel), commonly used polymers, and the most reported techniques involved in developing desired porous networks have been reviewed. The performances of 3D-PMs such as oil/water separation efficiency, elasticity, and mechanical stability are discussed. Additionally, the current challenges in the fabrication and long-term operation of super-wetting 3D-PMs in oil/water separation have also been introduced.

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We report the functionalization of polypyrrole (PPy) with a "sticky" biomolecule dopamine (DA), which mimics the essential component of mussel adhesive protein. PPy is one of the most promising electrically conductive polymers with good biocompatibility. The research findings reveal that the DA functionalization enhances the dispersibility and stability of PPy in water and its film adhesion to substrate surface significantly. The electrical conductivity of PPy increases to a maximum value and then decreases with the increasing DA concentration. An optimal DA to pyrrole (Py) mole ratio is found to be between 0.1 and 0.2, at which both conductivity and adhesion of DA-functionalized PPy has been improved.