Poly(lactic acid) (PLA) is a well known biodegradable thermoplastic with excellent mechanical properties that is a product from renewable resources. However, the brittleness of PLA limits its general applications. Using epoxidized soybean oil (ESO) as a novel plasticizer of poly (lactic acid), the composite blend with the twin-screw plastic extruder at five concentrations, 3, 6, 9, 12, and 15 wt %, respectively. Compared with pure PLA, all sets of blends show certain improvement of toughness to different extents. The concentration with 9 wt % ESO increases the elongation at break about 63%. The melt flow rates of these blends with respect to different ESO ratio have been examined using a melt flow indexer. Rheological behaviors about shear viscosity and melt strength analysis are discussed based on capillary rheology measurements. The tensile strength and melt strength of the blends with 6 wt % ESO simultaneity reach the maximums; whereas the elongation at break of the blends is the second highest level. ESO exhibits positive effect on both the elongation at break and melt strength. The results indicate that the blend obtained better rheological performance and melt strength. The content of 6 wt % ESO in PLA has been considered as a better balance of performance. The results have also demonstrated that there is a certain correlation between the performance in mechanical properties and melt rheological characterization for the PLA/ESO blends.
Poly(lactic acid)
(PLA) is well-known as a biocompatible and biodegradable
polymer that can be obtained from natural sources. However, the brittleness
of PLA is a significant drawback for its wide application. In this
study, a poly(lactic acid) (PLA)/polyurethane elastomer prepolymer
(PUEP) dynamically vulcanized system was introduced and studied in
detail. The torque, FTIR spectrum, and gel content demonstrated that
PUEP was vulcanized and that the isocyanate (−NCO) group in
PUEP was successfully reacted with the −OH groups at both sides
of the PLA. The scanning electron microscopy (SEM) revealed that a
relatively uniform phase morphology and good interfacial compatibilization
were achieved in the dynamically vulcanized blends. The interfacial
reaction and compatibilization between the component polymers resulted
in the formation of supertoughened PLA/PUEP blended materials.
The second near-infrared (NIR-II, 1000−1700 nm) light-based diagnosis and therapy have received extensive attention for neoplastic disease treatments because of the fact that light in the NIR-II window possesses less photon scattering along with deeper tissue penetration than that in the NIR-I (700−950 nm) window. Herein, we present a Gd-and copper sulfide (CuS)-integrated nanogel (NG) platform for magnetic resonance (MR)/photoacoustic (PA) imaging-guided tumor-targeted photothermal therapy (PTT). In our approach, we prepared cross-linked polyethylenimine (PEI) NGs via an inverse emulsion method, modified the PEI NGs with Gd chelates, targeting ligand folic acid (FA) through a polyethylene glycol (PEG) spacer and 1,3propanesultone, and finally loaded CuS nanoparticles (NPs) within the functional NGs. The as-synthesized Gd/CuS@PEI-FA-PS NGs with a mean size of 85 nm exhibit a good water dispersibility and protein resistance property, admirable r 1 relaxivity (11.66 mM −1 s −1 ), excellent NIR-II absorption feature, high photothermal conversion efficiency (26.7%), and FA-mediated targeting specificity to cancer cells overexpressing FA receptor (FAR). With these properties along with the good cytocompatibility, the developed Gd/
We report the synthesis and characterization of antifouling zwitterion carboxybetaine acrylamide (CBAA)-modified dendrimer-entrapped gold nanoparticles (Au DENPs) for enhanced CT imaging applications. The CBAA-modified nanodevice displays a better protein resistance property, less macrophage cellular uptake and liver accumulation, and longer blood half-delay time than the PEGylated counterpart material, thereby enabling enhanced blood pool, lymph node, and tumor CT imaging.
The rapid development of portable flexible electronic devices means a multifunctional composite film with excellent thermal management capability, high electromagnetic interference (EMI) shielding, and a strong fire safety performance is urgently required. In this paper, inspired by a "brick-mortar" sandwich structure, phase change capsules (PCCs) and MXene nanosheets are prepared. Subsequently, a one-step vacuum-assisted filtration method is used to fabricate a multifunctional flexible PCC/MXene/polyvinyl alcohol (PMP) phase change composite film with high light-to-thermal conversion efficiency, Joule heating generation, fire safety, and EMI shielding effects. The superior preparation technology endows the film with multi-source driven thermal management capabilities and excellent EMI shielding effectiveness values (43.13 dB). In addition, the PMP film exhibits good flexibility and high enthalpy (136.8 J g −1 ). Surprisingly, the PMP film's excellent fire safety properties improve its reliability and safety. In summary, the simple preparation technique and outstanding overall performance of the PMP films provide broad application prospects in advanced thermal management and EMI shielding in wearable products.
Large magnetostrictions of −1300 and +1100 ppm related in the different directions have been obtained in our stacked Fe85Ga15 ribbon samples. In the case of non-180° domain magnetization in the high anisotropic samples, the magnetostrictions are mainly attributed to the existence of Ga clusters which preferentially orient with the ribbon normal due to the ribbon grain texturing. Forming the modified DO3 structure, the Ga–Ga atom pairs distribute in the matrix and cause the x-ray diffraction peak split in melt-spun ribbons. As a special micromorphology, Ga clusters highly condensed in some nanoscale dots have also been experimentally observed.
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