Fully Biobased Shape Memory Material Based on Novel Cocontinuous Structure in Poly(Lactic Acid)/Natural Rubber TPVs Fabricated via Peroxide-Induced Dynamic Vulcanization and in Situ Interfacial Compatibilization

Shape memory polymers (SMPs) based on fully biobased poly­(lactide) (PLA)/natural rubber (NR) thermoplastic vulcanizates (TPVs) were fabricated via peroxide-induced dynamic vulcanization. Simultaneously, in situ reactive compatibilization was achieved by PLA molecule grafting onto NR chains. Differing from the general concept of spherical rubber particles being formed after dynamic vulcanization, the cross-linked NR was found to be a “netlike” continuous phase in the PLA matrix. This novel structure explained the surprising shape memory property of PLA/NR TPVs well (shape fixities ∼ 100%, shape recoveries > 95%, and fast recovery speed < 15 s at the switching temperature, ∼60 °C): the cross-linked NR continuous phase offers strong resilience and the PLA phase serves as the heat-control switch. We envision that the “green” raw materials and excellent shape memory properties of the dynamically vulcanized PLA/NR SMPs will open up a wide range of potential applications in intelligent medical devices

Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics

Superhydrophobic materials integrating stretchability with conductivity have huge potential in the emerging application horizons such as wearable electronic sensors, flexible power storage apparatus, and corrosion-resistant circuits. Herein, a facile spraying method is reported to fabricate a durable superhydrophobic coating with excellent stretchable and electrical performance by combing 1-octadecanethiol-modified silver nanoparticles (M-AgNPs) with polystyrene-<i>b</i>-poly­(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a prestretched natural rubber (NR) substrate. The embedding of M-AgNPs in elastic SEBS matrix and relaxation of prestretched NR substrate construct hierarchical rough architecture and endow the coating with dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity with water contact angle larger than 160° and a high conductivity with resistance of about 10 Ω. The coating not only maintains superhydrophobicity at low/high stretch ratio for the newly generated small/large protuberances but also responds to stretching and bending with good sensitivity, broad sensing range, and stable response cycles. Moreover, the coating exhibits excellent durability to heat and strong acid/alkali and mechanical forces including droplet impact, kneading, torsion, and repetitive stretching–relaxation. The findings conceivably stand out as a new tool to fabricate multifunctional superhydrophobic materials with excellent stretchability and conductivity for flexible electronics under wet or corrosive environments

Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics

Superhydrophobic materials integrating stretchability with conductivity have huge potential in the emerging application horizons such as wearable electronic sensors, flexible power storage apparatus, and corrosion-resistant circuits. Herein, a facile spraying method is reported to fabricate a durable superhydrophobic coating with excellent stretchable and electrical performance by combing 1-octadecanethiol-modified silver nanoparticles (M-AgNPs) with polystyrene-<i>b</i>-poly­(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a prestretched natural rubber (NR) substrate. The embedding of M-AgNPs in elastic SEBS matrix and relaxation of prestretched NR substrate construct hierarchical rough architecture and endow the coating with dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity with water contact angle larger than 160° and a high conductivity with resistance of about 10 Ω. The coating not only maintains superhydrophobicity at low/high stretch ratio for the newly generated small/large protuberances but also responds to stretching and bending with good sensitivity, broad sensing range, and stable response cycles. Moreover, the coating exhibits excellent durability to heat and strong acid/alkali and mechanical forces including droplet impact, kneading, torsion, and repetitive stretching–relaxation. The findings conceivably stand out as a new tool to fabricate multifunctional superhydrophobic materials with excellent stretchability and conductivity for flexible electronics under wet or corrosive environments

Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics

Superhydrophobic materials integrating stretchability with conductivity have huge potential in the emerging application horizons such as wearable electronic sensors, flexible power storage apparatus, and corrosion-resistant circuits. Herein, a facile spraying method is reported to fabricate a durable superhydrophobic coating with excellent stretchable and electrical performance by combing 1-octadecanethiol-modified silver nanoparticles (M-AgNPs) with polystyrene-<i>b</i>-poly­(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a prestretched natural rubber (NR) substrate. The embedding of M-AgNPs in elastic SEBS matrix and relaxation of prestretched NR substrate construct hierarchical rough architecture and endow the coating with dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity with water contact angle larger than 160° and a high conductivity with resistance of about 10 Ω. The coating not only maintains superhydrophobicity at low/high stretch ratio for the newly generated small/large protuberances but also responds to stretching and bending with good sensitivity, broad sensing range, and stable response cycles. Moreover, the coating exhibits excellent durability to heat and strong acid/alkali and mechanical forces including droplet impact, kneading, torsion, and repetitive stretching–relaxation. The findings conceivably stand out as a new tool to fabricate multifunctional superhydrophobic materials with excellent stretchability and conductivity for flexible electronics under wet or corrosive environments

Synthesis of phenyl silicone resin with epoxy and acrylate group and its adhesion enhancement for addition-cure silicone encapsulant with high refractive index

<p>A novel phenyl silicone resin with epoxy and acrylate group (PSREA) was successfully synthesized via the non-hydrolytic sol-gel condensation reaction of 3-glycidoxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, and diphenylsilanediol, and was employed as the adhesion promoter for addition-cure silicone encapsulant (ASE) with high refractive index. The structure of PSREA was confirmed by Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy, and ²⁹Si nuclear magnetic resonance spectroscopy. The influence of PSREA on the properties of ASE was studied. It was found that PSREA could markedly enhance the adhesion strength of ASE to aluminum (Al) and poly(p-phenylene terephthamide) (PPA) substrate. When the content of PSREA was 1.5 phr, the shear strength of ASE was 4.43 and 2.27 MPa for Al and PPA substrate, which was about 71 and 266% higher than that of ASE without the adhesion promoter, respectively. In addition, PSREA had little effect on the mechanical properties, refractive index, and viscosity of ASE.</p

Tissue Metabolic Responses to Salt Stress in Wild and Cultivated Barley

<div><p>A thorough understanding of the mechanisms underlying barley salt tolerance and exploitation of elite genetic resource are essential for utilizing wild barley germplasm in developing barley varieties with salt tolerance. In order to reveal the physiological and molecular difference in salt tolerance between Tibetan wild barley (<em>Hordeum spontaneum</em>) and cultivated barley (<em>Hordeum vulgare</em>), profiles of 82 key metabolites were studies in wild and cultivated barley in response to salinity. According to shoot dry biomass under salt stress, XZ16 is a fast growing and salt tolerant wild barley. The results of metabolite profiling analysis suggested osmotic adjustment was a basic mechanism, and polyols played important roles in developing salt tolerance only in roots, and high level of sugars and energy in roots and active photosynthesis in leaves were important for barley to develop salt tolerance. The metabolites involved in tolerance enhancement differed between roots and shoots, and also between genotypes. Tibetan wild barley, XZ16 had higher chlorophyll content and higher contents of compatible solutes than CM72, while the cultivated barley, CM72 probably enhanced its salt tolerance mainly through increasing glycolysis and energy consumption, when the plants were exposed to high salinity. The current research extends our understanding of the mechanisms involved in barley salt tolerance and provides possible utilization of Tibetan wild barley in developing barley cultivars with salt tolerance.</p> </div

Relative concentration and fold changes of major metabolites in roots of CM72 and XZ16 after 21 days of 300 mM salinity treatment.

<p>The relative concentration of each metabolite is an average of data from six biological replicates using GC-MS. The fold changes was calculated using the formula log₂^{(salt/control)}.</p>* and **<p>indicate significant (P<0.05) and highly significant difference (P<0.01), respectively.</p

Principal component analysis (PCA) of metabolic profiles in roots and leaves of CM72 and XZ16 under control and high salinity conditions (six biological replicates).

<p>(A) PCA in roots; (B) PCA in leaves. CK: control; T: salt treatment; PC1, the first principal component; PC2, the second principal component.</p

Change in metabolites of the metabolic pathways in roots of CM72 and XZ16 after 21 days of salinity treatment.

<p>Numbers 1–4 on the X-axis indicate CM72-control, CM72-salt treatment, XZ16-control and XZ16-salt treatment, respectively. The concentration of metabolites on the Y-axis is presented as normalized values transformed by Metaboanalyst software (<a href="http://www.metaboanalyst.ca/" target="_blank">www.metaboanalyst.ca/</a>), and the box plots show centered means and standard deviation of each variable. Metabolites in red indicate significant (P<0.05) up-accumulation in both CM72 and XZ16, in purple mean significant (P<0.05) up-accumulation in CM72 or XZ16, in light blue show significant (P<0.05) down-accumulation in CM72 or XZ16, and in dark blue represent significant (P<0.05) down-accumulation in CM72 and XZ16.</p

Global comparison of metabolic profiles in roots and leaves between CM72 and XZ16 under control and high salinity conditions.

<p>There are eighty-two metabolites identified in this study and the numbers in the figure indicate the numbers of metabolites with no significant difference in their contents for each comparison.</p