To obtain a new type of biodegradable material with high toughness and strength used for fused deposition modeling (FDM) printing, a series of poly(butylene succinate) (PBS)-based polymer materials was prepared via blending with polylactide (PLA). The rheological, thermal, and mechanical properties as well as FDM printing performances of the blends, such as distortion, cross section, and the interlayer bond strength, were characterized. The results show that with increasing PLA content, the blends possess higher melt viscosity, larger tensile strength, and modulus, which are more suitable for FDM printing. Especially, when the content of PLA is more than 40%, distortion due to residual stress caused by volume shrinkage disappears during the printing process and thus products with good dimensional accuracy and pearl-like gloss are obtained. The results demonstrate that the blend compositions with moderate viscosity, low degree of crystallinity, and high modulus are more suitable for FDM printing. Compared with the low elongation upon breaking of commercially FDM-printed material, the PBS/PLA blend materials exhibit a typical ductile behavior with elongation of 90–300%. Therefore, besides biodegradability, the PBS/PLA blends present excellent mechanical properties and suitability as materials for FDM printing. In addition, our study is expected to provide methods for valuating the suitability of whether a thermoplastic polymer material is suitable for FDM printing or not.

upon a change in relative humidity of the surrounding air. [ 13 ] Sun et al. have demonstrated the fabrication of an energetic walking device driven by a powerful humidity responsive bilayer actuator comprising an action layer of cross-linked poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) fi lms and a supporting layer of UV-cured Norland Optical Adhesive (NOA)-63. [ 8 ] Considering that graphene has many extraordinary characteristics, such as high thermal conductivity and excellent mechanical properties, it has also served as the smart water responsive actuators. [ 20 ] Ruoff et al. presented a macroscopic actuator based on graphene oxide/carbon nanotubes (GO/CNTs) bilayer fi lm to show obvious actuation that depends on variation of humidity onto water responsive materials of GO. [ 21 ] We have reported previously the asymmetric graphene/ graphene oxide (G/GO) fi ber structures obtained by positioned laser reduction of GO fi bers display well-controlled motion in a predetermined manner once exposed to moisture. [ 22 ] To realize the desired performance in a predefi ned fashion, bilayer materials or structures with different swelling behavior was necessary to mimic the strain transition among different material layers. However, as a moving component, bilayer actuators may also suffer from poor interlayer adhesion during frequent bending and complex fabrication process, etc. Moreover, concerns with respect to toughness, elasticity, and chemical/ physical stabilities also constitute a main barrier for the development of smart actuators. In this regard, from a manufacturing point of view, rational design and fabrication of actuators by refi ned control of the lateral microstructures of a solo material or even a single piece of thin fi lm might be a solution to the above-mentioned problems, but obviously, still remains big challenging. To overcome this limitation and further take advantage of the bilayer design of actuators, we present an alternative strategy in this article that a moisture gradients responsive reduced graphene oxide/polydopamine (RGO-PDA) thin fi lm, the uniform materials can serve as highly effi cient actuator driven by water absorption induced in situ formation of the bilayer structures in swelling difference. During the trigger of RGO-PDA fi lm by water with a gradient from one side, humidity-responsible hydrophilic PDA can absorb water on the surface layers of the RGO-PDA fi lm and act as soft "muscle" to active the swelling locomotion. The existing of rigid RGO sheets with relatively hydrophobic nature inside the fi lm hinders or delays the diffusion of water across the fi lm and construct the "skeleton" of the actuator which hold the PDA "muscle" to transfer the energy of water gradients to a mechanical motion.As energy transducers, actuators can provide controllable mechanical response into 2D or 3D motions upon the trigger by external stimuli, such as electric fi elds, [1][2][3][4] heat, [ 5,6 ] light, [ 7,8 ] and moisture. [ 9,10 ] Therefore, the fabrication of various actuators...

The middle Ediacaran Shuram excursion represents the most pronounced negative carbon isotopic shift in Earth history, and has been considered as evidence for a profound disturbance to the global carbon cycle and proposed as a key chemostratigraphic marker for Ediacaran stratigraphic subdivision and global correlation. Previous study has revealed a pronounced negative δ 13 C shift (EN3) in the upper Doushantuo Formation of South China, which has been interpreted as an equivalent of the Shuram excursion. Detailed δ 13 C investigation of multiple sections of the Ediacaran Doushantuo Formation around the Huangling Anticline, western Hubei Province, South China, indicates that the δ 13 C variations in the upper

Biobased, biodegradable copolymers containing isosorbide and 2,5-furandicarboxylic acid with high performance are successfully synthesized through a non-solvent and economical pathway.