More spherical large fullerenes and multi-layer fullerene cages

Environmental Applications of Sorbents, High-Flux Membranes of Carbon-Based Nanomaterials

Carbon-based nanomaterials have unique and controllable properties, making it possible to find and treat environmental challenges. There are several environmental applications for carbon-based nanoparticles: sorbents, membranes, antimicrobial agents, and sensors. According to this review, carbon-based nanomaterials have a variety of environmental benefits. This article also looks at prospective uses of nanomaterials in environmental systems, utilizing carbonaceous nanoparticles as a guide for their physical, chemical, and electrical properties.

Exogenous application of NaBiF4 nanoparticle affects wheat root development

BACKGROUND

Nanoparticle causes soil pollution, which affected plant development and then resulted in biomass decreased, especially in crops. However, little is known how sodium nanoparticles affect wheat root development at plant physiological level.

RESULTS

We used NaBiF4 (size of 50-100 nm) to analyze the effect in wheat development at plant physiological level. Under exogenous application of 50 μM NaBiF4 for treatment, wheat root elongation was inhibited, but fresh weight and dry weight were increased. We also found that NaBiF4 induced that the plant had lower content of sodium than negative control. Used no-sodium nanoparticle of BiF3 for another negative control, it was also supported that NaBiF4 entered into cell to replace of sodium and exported sodium out of plant. These results implied NaBiF4 might induce sodium export to maintain the balance between sodium and potassium elements. Additionally, metabolism analysis demonstrated that SOD activity was increased, but CAT and POD activity reduced under exogenous treatment of NaBiF4 nanoparticles.

CONCLUSIONS

Sodium nanoparticles (NaBiF4) inhibited plant development by nanoparticle accumulation and sodium homeostasis broken, and then involved reactive oxygen species (ROS) signaling system response. These results provided more sights of sodium nanoparticle effect in plant development.

Onion-Like Carbon Nanostructures: An Overview of Bio-Applications

This article presents a brief review of the knowledge concerning onion-like carbons (OLCs). These nanostructures are some of the most fascinating carbon forms due to their unusual structure and physico-chemical properties. Generally, OLCs consist of a hollowspherical fullerene core surrounded by concentric graphitic layers with increasing diameter. Nevertheless, they can have different size, shape and type of core, which determine their physicochemical properties. In this article, we review the most important literature reports in this area and briefly describe these nanostructures, their physical and chemical properties and their potential uses with a focus on biomedicine.

One-step hydrothermal synthesis of chiral carbon dots and their effects on mung bean plant growth

Chiral compounds/materials have important effects on the growth of plants. Chiral carbon dots (CDs), as an emerging chiral carbon nanomaterial, have great potential in bio-application and bio-nanotechnology. Herein, we report a hydrothermal method to synthesize chiral CDs from cysteine (cys) and citric acid. These chiral CDs were further demonstrated to have systemic effects on the growth of mung bean plants, in which case both l- and d-CDs can promote the growth of the root in mung bean plants, stem length of mung bean sprouts and water absorption of bean seeds. The elongation of mung bean sprouts presented an increasing trend with the treatment of chiral CDs of increasing concentration (below 500 μg mL-1). Furthermore, in the optimal concentration (100 μg mL-1), the l-CDs can improve root vigor and the activity of the Rubisco enzyme of bean sprouts by 8.4% and 20.5%, while the d-CDs increased by 28.9% and 67.5%. Due to more superior properties in improving root vigor and the activity of the Rubisco enzyme of mung bean sprouts, d-CDs are able to enhance photosynthesis better and accumulate more carbohydrate in mung bean plants.

Morphology-Controlled Tensile Mechanical Characteristics in Graphene Allotropes

A number of graphene allotropes constructed by sp3, sp2, and sp hybrid orbitals have recently been proposed to provide the broad potential for practical applications. Here, using molecular dynamics simulation, the structural and tensile characteristics of nine distinct graphene allotropes have been investigated to understand their morphology-controlled mechanical properties. Results show that the averaged out-of-plane displacement is independent of nonhexagons while being dominated by the arrangement of carbon polygons on the sheets. Each sheet possesses unique surface morphology and in-plane tensile properties that significantly vary with morphology and anisotropic crystalline orientation. Brittle, semibrittle, or ductile failure is observed, depending on the evolution of their packed polygons in facilitating tension deformation and in dissipating energy. Particularly, pentagraphene exhibits superductility as a consequence of large-scale structural transformations, accommodating stress relaxation beyond initial failure. Two distinct plastic deformation patterns in overstretched pentagraphene are uncovered, depending on the tension directions: one is dominated by structural transition from sp3-carbon-contained penta-(C5) to mixed sp2-carbon polygons and the other is mainly controlled by a stepwise pentagon-to-hexagon transition. These findings provide physical insights into the structural evolvement of two-dimensional graphene allotropes and their effects on the mechanical properties.

Phytotoxicity, Uptake, and Translocation of Fluorescent Carbon Dots in Mung Bean Plants

Fluorescent carbon dots (CDs) have been widely studied in bioscience and bioimaging, but the effect of CDs on plants has been rarely studied. Herein, mung bean was adopted as a model plant to study the phytotoxicity, uptake, and translocation of red emissive CDs in plants. The incubation with CDs at a concentration range from 0.1 to 1.0 mg/mL induced physiological response of mung bean plant and imposed no phytotoxicity on mung bean growth. The lengths of the root and stem presented an increasing trend up to the treatment of 0.4 mg/mL. Confocal imaging showed that CDs were transferred from the roots to the stems and leaves by the vascular system through the apoplastic pathway. The uptake kinetics study was performed and demonstrated that the CDs were abundantly incubated by mung beans during both germination and growth periods. Furthermore, in vivo visualization of CDs provides potential for their successful application as delivery vehicles in plants based on the unique optical properties.

Carbon and fullerene nanomaterials in plant system

Both the functionalized and non functionalized carbon nanomaterials influence fruit and crop production in edible plants and vegetables. The fullerene, C60 and carbon nanotubes have been shown to increase the water retaining capacity, biomass and fruit yield in plants up to ~118% which is a remarkable achievement of nanotechnology in recent years. The fullerene treated bitter melon seeds also increase the phytomedicine contents such as cucurbitacin-B (74%), lycopene (82%), charantin (20%) and insulin (91%). Since as little as 50 μg mL-1 of carbon nanotubes increase the tomato production by about 200%, they may be exploited to enhance the agriculture production in future. It has been observed that, in certain cases, non functionalized multi-wall carbon nanotubes are toxic to both plants and animals but the toxicity can be drastically reduced if they are functionalized.

Graphene's potential in materials science and engineering

Materials have become an indispensable part of our modern life, which was tailored such as good mechanical, electrical, thermal properties, establish the basis and fundamentals and the governing rules for every modern technology.

Environmental applications of carbon-based nanomaterials

The unique and tunable properties of carbon-based nanomaterials enable new technologies for identifying and addressing environmental challenges. This review critically assesses the contributions of carbon-based nanomaterials to a broad range of environmental applications: sorbents, high-flux membranes, depth filters, antimicrobial agents, environmental sensors, renewable energy technologies, and pollution prevention strategies. In linking technological advance back to the physical, chemical, and electronic properties of carbonaceous nanomaterials, this article also outlines future opportunities for nanomaterial application in environmental systems.

Dipole polarizability of onion-like carbons and electromagnetic properties of their composites

Onion-like carbons (OLC) obtained by thermal transformation of nanodiamonds are agglomerates of multi-shell fullerenes, often covered by an external graphitic mantle. For the present work, elemental OLC units were constructed on the computer by coalescence of several two-layer fullerenes, in a structure similar to carbon peapods with a corrugated external wall. The electrical polarizability of such pod-of-peas fullerenes has been computed by a classical monopole-dipole atomistic theory. The description of pod-of-peas fullerenes was further simplified by representing them as linear arrays of point-like objects, whose polarizability matches that of the starting molecules. Calculations demonstrated that the static polarizability of spherically shaped assemblies of these arrays, modeling real OLC materials, is weakly dependent on the geometry of its constituent molecules and is chiefly proportional to the volume of the whole cluster. It increases with increasing filling fraction of the pod-of-peas fullerenes in the OLC aggregate. The polarizability so obtained can be used in Maxwell-Garnett theory to predict the permittivity of OLC-based composites, at least for static excitations. Experimental results obtained at GHz frequencies reveal a weak attenuation for OLC- and nanodiamond-based polydimethylsiloxane composites. In these silicone composites, we did not find long chains of coupled OLCs. Quite separated clusters were found instead, which contribute little to the polarizability and to the dielectric properties, in good agreement with our theoretical predictions.

Glass transition in fullerenes: Mode-coupling theory predictions

We report idealized mode-coupling theory results for the glass transition of ensembles of model fullerenes interacting via phenomenological two-body potentials. Transition lines are found for C60, C70, and C96 in the temperature-density plane. We argue that the observed glass transition behavior is indicative of kinetic arrest that is strongly driven by the interparticle attraction in addition to excluded-volume repulsion. In this respect, these systems differ from most standard glass-forming liquids. They feature arrest that occurs at lower densities and that is stronger than would be expected for repulsion-dominated hard-sphere-like or Lennard-Jones-type systems. The influence of attraction increases with increasing the number of carbon atoms per molecule. However, unrealistically large fullerenes would be needed to yield behavior reminiscent of recently investigated model colloids with strong short-ranged attraction (glass-glass transitions and logarithmic decay of time-correlation functions).