Mechanically Strong, Heat-Resistant, Water-Induced Shape Memory Poly(vinyl alcohol)/Regenerated Cellulose Biocomposites via a Facile Co-precipitation Method

Abstract

In this work, poly(vinyl alcohol) (PVA) biocomposites with regenerated cellulose-softwood pulp (RC-SP) as a green reinforcement were prepared via coprecipitation method. Simultaneous precipitation of the two components promotes uniform dispersion of the RC-SP and constructs strong molecular chain entanglements and hydrogen bonding network inside the composites. This physical cross-linking network reduces the water absorption and improves the water resistance of the composites. The incorporation of RC-SP not only improves the thermal decomposition properties of the composites, but also enhances the mechanical properties and dynamic mechanical properties, attributed to the strong interaction between the filler and the matrix. Moreover, the fabricated PVA/RC-SP composites exhibit good water-induced shape memory effect, and shape recovery rate of 10% RC-SP reinforced composite reaches 95.3% after immersing for 35 min. This work provides useful information for the implementation of co-precipitation method and the application of renewable cellulose resources.

Intrinsically Conductive Bifunctional Nanocellulose-Reinforced Robust and Self-Healable Electronic Skin: Deep Insights into Multiple Bonding Network, Property Reinforcement, and Sensing Mechanism

“…A synergistic mechanism can explain the strong adhesion between SCGC films and various substrates due to the formation of noncovalent cross-links, including dynamic hydrogen bonding and electrostatic attraction. In addition, the entangled physical network and the constructed hydrogen bond network inside the film form a stable structure, which hinders the penetration of external water molecules to a certain extent to maintain the internal structural stability of the SCGC composite film. , The adhesion of SCGC under liquid nitrogen was studied, and the SCGC film could maintain a specific viscosity even at low temperatures. It was found that weights stuck with SCGC in liquid nitrogen took 138 s to separate from each other (Figure n and Video S1) and that SCGC regained its stickiness less than 30 s after leaving the liquid nitrogen, offering the possibility of its use as an adhesive at low temperatures (Figure S5).…”

Molecular‐Scale Design of Cellulose‐Based Functional Materials for Flexible Electronic Devices

“…[ 88 ] Copyright 2017, American Chemical Society; memory material: Reproduced with permission. [ 30 ] Copyright 2019, American Chemical Society; gel electrolyte: Reproduced with permission. [ 29 ] Copyright 2020, Springer Nature; mesoporous membrane: Reproduced with permission.…”

“…[4] Meanwhile, nanomaterials such as conductive polymer sheets, metal oxide nanoparticles, 2D covalent layers, and responsive polymer molecules, can be well-integrated with cellulose macromolecules during self-assembly processes to create functional materials with conductive, magnetic, electrochemical, and stimuli responsiveness. [28][29][30][31] These properties offer huge opportunities for creating cellulose materials, such as transparent substrates, flexible conductors, electronic-ionic gels, electrolytes, and dielectric layers, in flexible sensors, conductive transistors, supercapacitors, optoelectronic devices, and bioelectronics. [29,[32][33][34][35][36][37][38][39][40] In this review, we discuss the properties of cellulose and green dissolution systems.…”

Fractionation of Lignin for Selective Shape Memory Effects at Elevated Temperatures

“…Shape memory materials have been reported for various applications in biomedicine [1], packaging [2], actuation [3] (particularly in soft robots [4]), and flexible electronic devices [5]. Materials' shapes can be programmed and recovered by external stimuli such as light [6][7][8][9], heat [2,5,10], magnetic fields [11], water [12][13][14], pH [3,15], or combination(s) of multiple stimuli [4,[16][17][18][19]. One-way shape memory effects using heat to program the material shape is of interest due to its simplicity.…”