Solvothermal Preparation of Crystal Seeds and Anisotropy-Controlled Growth of Silver Nanoplates.

We synthesized silver nanoplates using the solvothermal method and, for the first time, placed them as crystal seeds in a water-based growth solution, thereby successfully achieving the large-scale production of silver nanoplates. The synthesis method enabled independent control of the lateral size and vertical size of the silver nanoplates. More specifically, the lateral size could be adjusted within the range of 565 nm-1.682 µm, while the vertical size was achieved by introducing Cl- as a capping agent and the vertical size was thickened from 18.28 to 40.41 nm.

Initiator-Free Photocuring 3D-Printable PVA-Based Hydrogel with Tunable Mechanical Properties and Cell Compatibility.

Poly(vinyl alcohol) (PVA)-based hydrogels have attracted great attention and been widely used in biological tissue engineering. With the development of modern medicine, precision medicine requires the customization of medical materials. However, lacking of photocurable functional groups or the performance of rapid phase transition makes PVA-based hydrogels difficult to be customizable molded through photocuring 3D printing technique. In this research, customizable PVA-based hydrogels with high performance through 3D photocurable printing and freezing-thawing (F-T) process are obtained. The ability of 3D-printable is endowed by the introduction of polyvinyl alcohol-styrylpyridine (PVA-SBQ), which can be photo-crosslinked quickly without photoinitiator. Meanwhile, the tunable mechanical properties are achieved by adjusting the mass ratio of PVA-SBQ to PVA, and PVA can offer the physical crosslinking points through freezing-thawing (F-T) process. The hydrogels with high resolution are prepared by digital light procession 3D printing with the mass ratio 1:1 of PVA-SBQ to PVA solution. Attributed to the absence of initiator, and no small molecule residues inside the hydrogels, the hydrogels have good biocompatibility and have the potential to be applicated in the field of biological tissue engineering.

Patterned Magnetofluids via Magnetic Printing and Photopolymerization for Multifunctional Flexible Electronic Sensors.

Liquid conductor-based flexible sensors with high mechanical deformability and reliable electrical reversibility have aroused great interest in electronic skin, soft robotics, environmental monitoring, and other fields. Herein, we develop a novel strategy to fabricate liquid conductor-based flexible sensors by combining ionic liquid-based magnetofluids (IL-MFs), magnetic printing, and photopolymerization techniques. The as-prepared sensors exhibit excellent electromechanical properties, such as a wide detection range, low hysteresis, fast response time, good durability, etc. Moreover, the gauge factors (GFs) of the sensor could be easily adjusted by changing the modulators with different line widths or patterns, and the strain sensors can also be designed for anisotropic monitoring. Apart from serving as strain sensors, the magnetofluid-based flexible sensors can be used to detect external pressure, human activities, and changes in temperature, illumination, and magnetic field as well. This work provides a facile strategy to fabricate liquid conductor-based multifunctional sensors. Such a magnetofluid-based sensor has a great promising future.

Macrocyclic Photoinitiator Based on Prism[5]arene Matching LEDs Light with Low Migration.

In this work, a naphthalene-based macrocycle prism[5]arene (NP5 OCH3 ) is developed as a novel kind of photoinitiator. When NP5 OCH3 is irradiated under light, the bond between methylene and naphthalene can be quickly broken owning to the existence of ring tension. The macrocycle is cleaved to linear oligomer biradicals, which can effectively initiate the free radical photopolymerization of acrylate monomers. Compared with conventional photoinitiators, NP5 OCH3 has strong light absorption in the wavelength range of 365-405 nm, so it can well match the environment-friendly light-emitting diodes (LEDs) light source to realize highly efficient initiation. In addition, there is no small molecule fragment generated during NP5 OCH3 fracture, and the resulted linear oligomer biradicals can be immobilized in the polymer after initiating polymerization, so NP5 OCH3 photoinitiators show much lower migration rate and cytotoxicity. Cleavable macrocycle prismarene may provide a new idea for the design of safe and efficient photoinitiators matching long wavelength light.

Pillar[6]arene: Light Cleaves Macrocycle to Linear Oligomer Biradical to Initiate Photopolymerization.

A novel kind of photoinitiator based on the macrocyclic molecule pillar[6]arene (P6OC2H5) is reported. Under light irradiation, P6OC2H5 was cleaved to a linear oligomer biradical, which could efficiently initiate free-radical photopolymerization. Owing to the absence of small molecular fragment generation, the macrocyclic photoinitiator exhibited a much lower migration rate and cytotoxicity than commercial photoinitiators. This is the first time that a macrocyclic molecule has been developed as a photoinitiator based on the macrocycle fracture mechanism.