Multifunctional Acrylic Polymers with Enhanced Adhesive Property Serving as Excellent Edge Encapsulant for Stable Optoelectronic Devices

Pendant groups in acrylic adhesive polymers (Ads) have a profound influence on adhesive and cohesive properties and additionally on encapsulant application. However, a systematic investigation to assess the impact of the pendant groups' length and bulkiness is rare, and there is not even a single report on applying Ads as interfacial adhesion promotors and encapsulation materials simultaneously. Herein, we have developed a series of multifunctional methacrylic polymers, namely, R-co-Ads, with varying pendant length and bulkiness (R = methyl (C1), ethyl (C2), propyl (C3), butyl (C4), pentyl (C5), hexyl (C6), isobutyl (iC4), and 2-ethylhexyl (2EH)). The adhesion-related experimental results reveal that R-co-Ads have high transparency, strong adhesion strength to the various contact surfaces, and a fast cure speed. In particular, C1-co-Ad shows a superior adhesion performance with an improved cross-cut index of 4B and a shear bonding strength of 1.56 MPa. We also have adopted C1-co-Ad for encapsulation of various emerging optoelectronic applications (e.g., perovskite solar cell-, charge transport-, and conductivity-related characteristics), demonstrating its excellent edge encapsulant served to improve the device stability against ambient air conditions. Our study establishes the structure-adhesion-surface relationships, advancing the better design of adhesives and encapsulants for various research fields.

Insecticidal and Behavioral Effect of Microparticles of Pimpinella anisum Essential Oil on Larvae of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

The Colorado potato beetle ranks as one of the most important potato pests, mainly due to its high feeding rate during all developmental stages, particularly third and fourth larval instar, and high fecundity. The effect of essential oil (EO) from anise (Pimpinella anisum L. [Apiales: Apiaceae]) prepared as conventional and encapsulated (EN) formulations on the mortality and antifeedant responses of young larvae of Colorado potato beetles was studied to evaluate the insecticidal and antifeedant effects of five concentrations of this EO and to assess the persistence of both formulations on potato plants. The EN formulation had a significantly higher residual amount compared with that of the conventionally formulated EO. Significantly different values of LC50 and LC90 (ppm) were established for the EO (LC50 = 1,700 and LC90 = 9500) and EN (LC50 = 3,100 and LC90 = 14,300) formulations. The effects of both P. anisum formulations (EO and EN) applied topically to Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) larvae were distinctly different from those observed with the contact treatment. At the highest concentration of 20,000 ppm, the mortality of the second instars of the L. decemlineata larvae did not exceed 25%. On the other hand, both tested formulations of P. anisum were highly effective when administered orally. The encapsulated EO formulation achieved a distinctly higher biological activity. Our results confirm that the EO from P. anisum, especially the encapsulated formulation, has high insecticidal properties that may lead to the development of new organic products for the control of Colorado potato beetles.

3D Printed Vascularized Device for Subcutaneous Transplantation of Human Islets

Transplantation of pancreatic islets or stem cell derived insulin secreting cells is an attractive treatment strategy for diabetes. However, islet transplantation is associated with several challenges including function-loss associated with dispersion and limited vascularization as well as the need for continuous immunosuppression. To overcome these limitations, here we present a novel 3D printed and functionalized encapsulation system for subcutaneous engraftment of islets or islet like cells. The devices were 3D printed with polylactic acid and the surfaces treated and patterned to increase the hydrophilicity, cell attachment, and proliferation. Surface treated encapsulation systems were implanted with growth factor enriched platelet gel, which helped to create a vascularized environment before loading human islets. The device protected the encapsulated islets from acute hypoxia and kept them functional. The adaptability of the encapsulation system was demonstrated by refilling some of the experimental groups transcutaneously with additional islets.