Biocompatible microcapsules functionalized with inorganic nanoparticles for enhanced external triggering via light and ultrasound

Designing and fabricating functional composite capsules are of considerable interest to both academic and industrial fields. Inorganic nanoparticles (NPs) have great potential to modify properties of Layer-by-layer (LbL) polyelectrolyte (PE) capsules, but using prefabricated NPs to functionalize capsules still has considerable challenges such as poor distribution in the capsule walls. The present work proposed and validated a novel approach of fabricating functional capsules with in situ formation and incorporation of inorganic carbon dots (CDs), TiO2 and SiO2 NPs in PAH/PSS multilayers.[1,2] CDs were synthesized within capsule shells through autoclaving the PE capsules in dextran solution, while SiO2 and TiO2 NPs functionalized capsules were fabricated by hydrolysis of Titanium butoxide (TIBO), Tetraethyl orthosilicate (TEOS) respectively. The morphology, composition, shell thickness, permeability and stimuli sensitivity, etc. of the formed capsules with different composition were investigated, and characterized by SEM, TEM, EDX, FTIR, and CLSM. The three types of capsules demonstrated prominent properties compared with the traditional capsule without hybrid with inorganic NPs: i) the PE/CDs capsules displayed a rigid bowl-like morphology (Figure 1A), increased shell thickness (178.4nm, Figure 1B) and an excellent fluorescent property originated from the CDs (Figure 1D, E), and it can efficiently prevent the penetration of a small molecule Rhodamine B (Figure 1F); ii) the PE/SiO2 capsules showed a free-standing sphere morphology and a reduced permeability; iii) the capsules in situ composited with TiO2 NPs were found as a sphere shape and susceptible to UV irradiation (320-400nm, ~110 mW cm-2). Ultrasound irradiation tests demonstrated that all these three types of capsules possessed effective ultrasound sensitivity. It was validated by the fragmentation of PE/SiO2 and PE/TiO2 capsules in a few seconds of 50W ultrasound irradiation and the completely break of PE/CDs capsules in a few minutes of the treatment (Figure 1C). Besides, the cell viability data demonstrated that all the three types of composite capsules possessed good biocompatibility. In summary, those innovative composite capsules were demonstrated with great capability of small molecule encapsulation, high mechanical strength, good biocompatibility and high sensitivity to ultrasound and UV, which could be promising for various applications such as cosmetics, environment and biomedicine areas. Please click Additional Files below to see the full abstract

Operando visualisation of battery chemistry in a sodium-ion battery by 23Na magnetic resonance imaging

© 2020, The Author(s). Sodium-ion batteries are a promising battery technology for their cost and sustainability. This has led to increasing interest in the development of new sodium-ion batteries and new analytical methods to non-invasively, directly visualise battery chemistry. Here we report operando 1H and 23Na nuclear magnetic resonance spectroscopy and imaging experiments to observe the speciation and distribution of sodium in the electrode and electrolyte during sodiation and desodiation of hard carbon in a sodium metal cell and a sodium-ion full-cell configuration. The evolution of the hard carbon sodiation and subsequent formation and evolution of sodium dendrites, upon over-sodiation of the hard carbon, are observed and mapped by 23Na nuclear magnetic resonance spectroscopy and imaging, and their three-dimensional microstructure visualised by 1H magnetic resonance imaging. We also observe, for the first time, the formation of metallic sodium species on hard carbon upon first charge (formation) in a full-cell configuration

Direct Evidence of the Exfoliation Efficiency and Graphene Dispersibility of Green Solvents toward Sustainable Graphene Production

Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale

Direct evidence of exfoliation efficiency and graphene dispersibility of green solvents towards sustainable graphene production

Achieving sustainable production of pristine high-quality graphene and other layered materials at low cost is one of the bottlenecks that needs to be overcome for reaching 2D materials applications at scale. Liquid Phase Exfoliation (LPE) in conjunction with N-methyl-2-pyrrolidone (NMP) is recognised as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors we show that the exfoliation efficiency of a given solvent is independent of its dispersibility. Here we show that isopropanol can be used to exfoliate graphite as efficiently as NMP. This finding is corroborated by the matching ratio between the polar and dispersive energy of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at scale

Direct evidence of the exfoliation efficiency and graphene dispersibility of green solvents toward sustainable graphene production

Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale

A diverse view of science to catalyse change:Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. we must value diversity not only in words, but also in actions

No abstract available.publishe

A diverse view of science to catalyse change

Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions

2021 roadmap for sodium-ion batteries

Abstract: Increasing concerns regarding the sustainability of lithium sources, due to their limited availability and consequent expected price increase, have raised awareness of the importance of developing alternative energy-storage candidates that can sustain the ever-growing energy demand. Furthermore, limitations on the availability of the transition metals used in the manufacturing of cathode materials, together with questionable mining practices, are driving development towards more sustainable elements. Given the uniformly high abundance and cost-effectiveness of sodium, as well as its very suitable redox potential (close to that of lithium), sodium-ion battery technology offers tremendous potential to be a counterpart to lithium-ion batteries (LIBs) in different application scenarios, such as stationary energy storage and low-cost vehicles. This potential is reflected by the major investments that are being made by industry in a wide variety of markets and in diverse material combinations. Despite the associated advantages of being a drop-in replacement for LIBs, there are remarkable differences in the physicochemical properties between sodium and lithium that give rise to different behaviours, for example, different coordination preferences in compounds, desolvation energies, or solubility of the solid–electrolyte interphase inorganic salt components. This demands a more detailed study of the underlying physical and chemical processes occurring in sodium-ion batteries and allows great scope for groundbreaking advances in the field, from lab-scale to scale-up. This roadmap provides an extensive review by experts in academia and industry of the current state of the art in 2021 and the different research directions and strategies currently underway to improve the performance of sodium-ion batteries. The aim is to provide an opinion with respect to the current challenges and opportunities, from the fundamental properties to the practical applications of this technology