Solid-Phase Molecular Self-Assembly Enabled Glue-Free Antifatigue Laminate Programmable Materials.

Repeated programmability has emerged as a desired property in smart device engineering, but the programmability will fatigue upon repeated applications due to the unmatched mechanical property between the layer materials and the polymeric glue that is required to integrate the two individual oriented layers. It is reported here that glue-free antifatigue programmable laminate materials can be made with films resulted from solid-phase molecular self-assembly (SPMSA). The SPMSA films are created by squeezing the precipitates of oppositely charged polyelectrolytes and DTAB with a noodle machine, where the hydrophobic DTAB molecules self-assembled into wormlike micelles and oriented along the squeezing direction.

Effect of the Molecular Weight of Polyelectrolyte and Surfactant Chain Length on the Solid-Phase Molecular Self-Assembly.

Solid-phase molecular self-assembly (SPMSA) is emerging as an efficient approach, leading to scale-span self-assembled supramolecular films. With SPMSA, freestanding macroscopic supramolecular films can be formed upon mechanically pressing the precipitates formed with polyelectrolytes and oppositely charged surfactants. Herein, we report that the film formation ability and the mechanical strength of the resultant film depend highly on the surfactant chain lengths and the molecular weight of polyelectrolytes.

Unprecedented Nonflammable Organic Adhesives Leading to Fireproof Wood Products.

We report an excellent water-based inflammable organic wood adhesive that is able to protect wood products from burning by generating inflammable gases, a porous thick char layer, and radicals that consume the oxygen and hydrogen radicals required in the burning process. The organic adhesive is obtained by the formation of hard supramolecular phases composed of high-density flame-retardant N and P elements through hydrogen bonding and acid-base interaction between the phytic acid and branched polyethylenimine (b-PEI). The phytic acid molecules are packed densely in the framework of the flexible b-PEI so that a porous char layer that would reduce heat conduction can be formed as the adhesive is heated.

Green Wood Adhesives from One-Pot Coacervation of Folic Acid and Branched Poly(ethylene imine).

Adhesives are extensively used in furniture manufacture, and most currently utilized furniture glues are formaldehyde-based chemicals, which emit formaldehyde throughout the entire life of the furniture. With increasing concerns about formaldehyde emission effects on human health, formaldehyde-free and environmentally friendly wood adhesives from bio-based resources are highly desired. In this study, we developed an eco-friendly, high-strength, and water-based wood adhesive from one-pot coacervation of the hierarchical self-assembly of folic acid (FA, a biomolecule, vitamin B9) with a commercially available biocompatible polymer-branched poly(ethylene imine) (b-PEI).

Wearable Sensors Based on Solid-Phase Molecular Self-Assembly: Moisture-Strain Dual Responsiveness Facilitated Extremely High and Damage-Resistant Sensitivity.

Wearable sensing technologies have gained increasing interest in biomedical fields because they are convenient and could efficiently monitor health conditions by detecting various physiological signals in real time. However, common film sensors often neglect body moisture and enhance the sensitivity by enhancing the conductive dopants and self-healing ability. We report in this work a supramolecular film sensor based on solid-phase molecular self-assembly (SPMSA), which smartly utilizes the body moisture to enhance the sensitivity for human-machine interaction.

Folic Acid-Based Coacervate Leading to a Double-Sided Tape for Adhesion of Diverse Wet and Dry Substrates.

Adhesives are crucial both in nature and in diversified artificial fields, and developing environment-friendly adhesives with economic procedures remains a great challenge. We report that folic acid-based coacervates can be a new category of excellent adhesives for all kinds of surfaces with long-lasting adhesiveness. Aided by the electrostatic interaction between the π-π stacked folic acid quartets and polycations, the resultant coacervates are able to interact with diversified substrates via a polyvalent hydrogen bond, coordination, and electrostatic interactions.