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Irradiation by light ions may change the mechanical properties of nanofoams. Using molecular-dynamics simulation, we study the effect of irradiating a Au foam (porosity, 50%, and ligament diameter, 3 nm) with heavy ions: here, 10 keV Au ions up to a dose of 4 × 1016 m−2. We demonstrate that in consequence, the ligament morphology changes in the irradiated region, caused by local melting. The changes in mechanical properties are monitored by simulated nanoindentation tests. We find that the foam hardness is only around 1/3 of the hardness of a bulk Au crystal. Irradiation increases the hardness of the foam by around 10% in the central irradiated area. The plastic zone extends to only 1.5 ac, where ac denotes the contact radius; this value is unchanged under irradiation. The hardness increase after irradiation is attributed to two concurring effects. To begin with, irradiation induces melting and annealing of the ligaments, leading to their coarsening and alleviating surface stress, which in turn increases the dislocation nucleation threshold. In addition, irradiation introduces a stacking fault forest that acts as an obstacle to dislocation motion. [ABSTRACT FROM AUTHOR]

Grain growth during sintering of nanomaterial is one of the main drawback is this process. Since the nanomaterials maintain their unique performance as long as their size dos not exceed a specific size range, various strategies, including the addition of oxide particles, are adopted to prevent this phenomenon and to slow down grain growth. In this research, titanium oxide particles were used to prevent the growth of NiTi nanostructured alloy grains during sintering operations due to their suitable thermal stability with amount of 10 wt.%. The effect of titanium oxide particles was investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses. For this purpose, two groups of samples including with and without presence of titanium oxide were prepared and studied. The results of kinetic analysis on both sample groups showed that grain growth occurred after the process, in the presence of this oxide, up to twice the initial size and before sintering. But the growth rate in the absence of titanium oxide increased up to five times. The reason for this is the amount of activation energy required for grain growth. This energy was 31.85 kJ in the sample without titanium oxide and 47.96 kJ in the sample with the presence of 10% of this oxide. Also, based on DSC data, the barrier energy were calculated as 9.93 and 7.75 kJ, and the grain growth activation energy were calculated as 13.4 and 14.4 kJ, for the samples with out and with titanium oxide respectively. [ABSTRACT FROM AUTHOR]

The one-dimensional propagation of magnetic domain walls in an isotropic, linearly elastic, magnetostrictive material is investigated in the framework of the extended Landau-Lifshitz-Gilbert equation where the effects of a spin-polarized current and a rate-independent dry-friction dissipation are taken into account. In our analysis, it is assumed that the ferromagnet is subject to a spatially uniform biaxial in-plain stress generated by a piezoelectric substrate combined with the former in a multiferroic heterostructure. Moreover, a possible connection between the dry-friction mechanism and the piezo-induced strains is conjectured. By adopting the traveling waves ansatz, the effect of such a stress on the domain wall dynamics is explored in both steady and precessional regimes. In particular, it is proved that the magnetoelastic contribution, while it does not formally modify the classical solution, affects both the propagation threshold and the Walker Breakdown conditions involved in the steady regime, in agreement with recent experimental results. In the precessional regime, it is shown that the existence of a correlation between the piezo-induced strains and dry-friction leads to an upward shift of the domain wall velocity. [ABSTRACT FROM AUTHOR]

Magnetocaloric effect (MCE) is the change in temperature or entropy of a material due to the application of external magnetic field. The temperature dependence of MCE shows maximum value near the ferromagnetic transition of the material. Material with large MCE near room temperature will make revolutionary change in cooling technology and will have large impact in human society. We have transformed antiferromagnetic bulk manganite material La0.48Ca0.52MnO3 to ferromagnetic material by the reduction of the particle size in nanometer scale. MCE, as well as the Relative cooling power (RCP) of the material at room temperature (RT) systematically increase with the reduction of the particle sizes. The RCP value for the 45 nm particle size sample at RT is about 400% larger compared with the bulk counterpart. Our detail study on the nano form of the compound highlights an effective way to enhance the MCE. It opens up a vast possibility of achieving giant enhancement of MCE of several already known materials just by the reduction of the particle size in nanometer scale. [ABSTRACT FROM AUTHOR]

The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface and show how the operation of the arc is self-organised process. Our results suggest that the arc can operate in two different ablationdeposition regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat. [ABSTRACT FROM AUTHOR]

The system Mg(NH2)2 + 2LiH is considered as an interesting solid-state hydrogen storage material owing to its low thermodynamic stability of ca. 40 kJ/mol H2 and high gravimetric hydrogen capacity of 5.6 wt.%. However, high kinetic barriers lead to slow absorption/desorption rates even at relatively high temperatures (>180 °C). In this work, we investigate the effects of the addition of K-modified LixTiyOz on the absorption/desorption behaviour of the Mg(NH2)2 + 2LiH system. In comparison with the pristine Mg(NH2)2 + 2LiH, the system containing a tiny amount of nanostructured K-modified LixTiyOz shows enhanced absorption/desorption behaviour. The doped material presents a sensibly reduced (∼30 °C) desorption onset temperature, notably shorter hydrogen absorption/desorption times and reversible hydrogen capacity of about 3 wt.% H2 upon cycling. Studies on the absorption/desorption processes and micro/nanostructural characterizations of the Mg(NH2)2 + 2LiH + K-modified LixTiyOz system hint to the fact that the presence of in situ formed nanostructure K2TiO3 is the main responsible for the observed improved kinetic behaviour. [ABSTRACT FROM AUTHOR]

Nanotechnology is an emerging technology and it brings a tremendous change to human life and economy. When the size of a material is reduced to the nanoscale, its properties may change significantly and becomes a new substance. A fullerene is a molecule of carbon in the shape of a hollow sphere, ellipsoid, tube, and many other geometrical structures. For example, buckyballs are spherical fullerenes and carbon nanotubes are cylindrical fullerenes. Fullerenes have been under intensive investigation for their expanding applications in electronics, energy, medicine, and many other research fields. Nanostructure analysis is very important for understanding the formation of different materials and their properties. In this study, a virtual laboratory is developed for learning fullerene production and its nanostructure analysis. The learners can use the arc discharge equipment to produce fullerenes and then use the transmission electron microscope (TEM) to observe the nanostructures of different fullerene samples. The high interactivity and 3D visual effects of the virtual laboratory enable the learners to become familiar with the geometrical structures and properties of fullerenes. A teaching experiment has been conducted and the results show that the virtual laboratory can improve their learning motivation and effectiveness. [ABSTRACT FROM AUTHOR]

BILBY is a recently constructed and commissioned time‐of‐flight small‐angle neutron scattering instrument, operated by the Australian Centre for Neutron Scattering at the Australian Nuclear Science and Technology Organisation (ANSTO). BILBY provides a wide accessible q range (q ≃ 1.0 × 10−3 Å−1 to ∼1.8 Å−1) and variable wavelength resolution (Δλ/λ ≃ 3–30%) to complement the other small‐angle and ultra‐small‐angle neutron scattering capabilities available at ANSTO. Since its construction, BILBY has been used to study samples from a wide range of scientific disciplines, including biology, chemistry, physics and materials science. This article describes the BILBY design and components, and shows data collected from a number of reference samples. A description is presented of the instrument design and performance of BILBY, the new time‐of‐flight small‐angle neutron scattering instrument located at the Australian Nuclear Science and Technology Organisation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Newly developed fabrication strategies of g-C 3 N 4 nanosheets are introduced. • g-C 3 N 4 nanosheets show superior photocatalytic properties to bulk g-C 3 N 4. • Performance optimization of 0D nanomaterials/g-C 3 N 4 nanosheets is deeply discussed. • Binary systems based on 0D nanomaterials/g-C 3 N 4 nanosheets are elaborated. • Enhanced light absorption and improved charge carriers separation are realized. Abstract Over the past years, two dimensional (2D) graphitic carbon nitride nanosheets (CNNs) have attained increasing interest in the study of graphitic carbon nitride (g-C 3 N 4) due to their superior physical-optical properties as photocatalyst. More and more researchers attempt to design photocatalytic systems based on CNNs to realize the control of photocatalyst morphology for enhancing performance. Hence their combination with zero dimensional (0D) nanomaterials, which frequently serve as guest materials, has witnessed great progress. Therefore this review introduces the latest fabrication strategies of CNNs based on conventional strategies and firstly summarizes their photocatalytic properties systematically. More important, typical advanced examples combining CNNs with 0D nanomaterials like carbon nanodots, noble metal atoms and semiconductor nanoparticles are presented for their characteristic 0D/2D nanostructures, which have never been reported in any previous reviews up to now. Their preparation, photocatalytic mechanisms and performance influence factors are deeply discussed. In addition, three kinds of multicomponent complex systems, which take advantages of 0D nanomaterials/CNNs ingeniously, are elaborated on their charge-transfer pathways in our review. Finally, the current challenges and development ideas of 0D nanomaterials/CNNs systems in photocatalytic applications are proposed. This review enriches the knowledge in the applications of CNNs and paves road to the combination of 0D materials with CNNs and even other 2D materials. [ABSTRACT FROM AUTHOR]

Abstract This work investigated changes in the chemical composition, structure and porosity of hollow spherical allophane under alkaline conditions, which are significant not only for understanding its fate in natural environment but also for its functional applications. Hollow spherical allophane with a silicon/aluminium (Si/Al) molar ratio of 0.77 was hydrothermally synthesised followed by treatment with dilute sodium hydroxide (NaOH) solutions with different concentrations (indicated by pH values). The allophane and its alkali-treated products were then characterized using a combination of techniques, such as Fourier-transform infrared spectroscopy, nuclear magnetic resonance and nitrogen physisorption analysis. Allophane showed a weak structural stability in alkaline conditions. At pH ≤ 11.0, the framework of allophane particles was almost intact; its polymerised silicates showed only slight dissolution. At a higher pH (> 11.0), desilication and dealumination enhanced, resulting in the destruction of the imogolite local structure (ImoLS) along the edges of defect pores and the formation of amorphous materials. Most of the defect pores increased in size, becoming accessible to nitrogen and the textural parameters of the micropores reached their maximum values at a pH of 12.5. However, the damage to some secondary pores and the collapse of some hollow spherules reduced total pore volume (V total). At a pH of 13.0, most of the hollow spherules were observed to have collapsed, resulting in remarkable decrease in the textural parameters. However, some unbroken and/or mildly broken allophane particles might remain, deduced from the relatively high BET specific surface area (SSA) and V total and the considerable proportion of micropores for Allo 13.0. These results reveal the dissolution behaviour of allophane in alkaline conditions and the mechanism underlying this behaviour, providing essential insights into the mineral's potential applications. Highlights • Allophane showed a weak structural stability under alkaline conditions. • At pH ≤ 11.0, the framework of the hollow spherule kept almost intact. • At pH > 11.0, dissolution of the ImoLS enlarged the defect pores. • At pH =12.5, most of defect pores became N 2 accessible. • At pH = 13.0, most of hollow spherules collapsed, reducing porosity remarkably. [ABSTRACT FROM AUTHOR]

Abstract This work proposes an environmentally low cost route for nano copper oxide functionalization of cotton in order to impart antibacterial and photocatalytic properties for the first time. This method only includes utilization of metal precursor with no additional chemicals such as reducing agent, pH adjusting, solvent and others as well as no use of physical power or high temperature and pressure conditions. Images of FESEM and mapping, EDX analysis, X-ray diffraction, UV–visible spectrum and FTIR analysis were proved the existence of copper oxide nanoparticles on the cotton surface. The prepared samples demonstrated excellent antibacterial performance (100%) against both Staphylococcus aureus and Escherichia coli bacteria that was adjusted to be low-toxic for human dermal fibroblast. The remarkable photocatalytic properties toward discoloration of methylene blue solution under sunlight irradiation were also originated for the prepared samples. In addition, the prepared samples illustrated a variety of color from light to dark brown due to surface plasmon vibrations of copper oxide nanoparticles. They also pointed out an improvement in tensile strength and crease recovery angle properties. All in all, the introduced approach can be performed as an environmentally friendly and low cost route in order to nano copper oxide functionalization of cellulosic based materials designed for antibacterial and photocatalytic applications. Graphical abstract Image Highlights • Introducing environmentally friendly and low cost approach for nano copper oxide functionalization of cotton fabric. • Copper oxide functionalization of cotton substrate without using hazardous chemicals or external physical power. • Excellent antibacterial performances with no negative influence on human dermal fibroblasts. • Very good photocatalytic performances toward degradation the solution of methylene blue dye under sunlight irradiation. • Creating a variety of color from light to dark brown using copper oxide nanoparticles on cotton. [ABSTRACT FROM AUTHOR]

Abstract In parallel with the progressing technological improvements witnessed in cement industry, nuclear industry also faces the need to address the prevailing issue of handling radioactive waste. Waste management is among the major environmental concerns all around the world, which need optimization in order to preserve our planet. The objective of the present study is getting rid of the hazardous waste cement kiln dust in an advanced fashion; in parallel, this material is upgraded by blending it with proper additives to produce a modified paste suitable for stabilization of radioactive waste in the future. This study presents an in-depth investigation covering incorporation of different additive materials individually or as mix of two constituents with cement kiln dust as a composite material. Mechanical properties like compressive strength and porosity of the hardened cement kiln dust and modified composites were assessed. Moreover, the physical appearance of the produced blocks including Portland cement or some by-products such as slag and silica fume, as well as nano-materials (nano-sized alumina, silica, titanium dioxide, calcium oxide, zinc oxide) was evaluated. We demonstrate that adding merely 0.1% of nanomaterials to 20% slag increases the mechanical integrity of the solidified cement kiln dust samples fourfold (more than 13 MPa). Based on the experimental results, a new composite of cement kiln dust and nano-silica is a proficient material with significant ecological and economical advantages for constructions applications, and should be suitable for safe stabilization of radioactive waste in forthcoming studies. Graphical abstract Image [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A new 2D crystal, P 2 S 3 , is found based on extensive evolutionary algorithm driven structural search. Furthermore, P 2 S 3 is confirmed to be stable by the computed phonon spectrum and ab initio molecular dynamics simulations. This 2D crystalline phase of P 2 S 3 corresponds to the global minimum in the Born-Oppenheimer surface of the phosphorus sulfide monolayers with 2:3 stoichiometry. It is a wide band gap (4.55 eV) semiconductor with PsbndS σ bonds. The electronic properties of P 2 S 3 structure can be fine-tuned by stacking into multilayer P 2 S 3 structures, forming P 2 S 3 nanoribbons or P 2 S 3 nanotubes, expanding its potential applications in the emerging field of 2D electronics. [ABSTRACT FROM AUTHOR]

Abstract Castable nanostructured alloys (CNAs) are being developed as a new generation of reduced-activation ferritic-martensitic (RAFM) steels to overcome certain limitations of the current RAFM steels, such as their narrow operating temperature range and associated low strength at high temperatures. Six CNAs were developed and examined, exhibiting noticeably increased yield strength, tensile strength and creep resistance as compared to the current RAFM steels, which are comparable to ODS-Eurofer (0.3% Y 2 O 3) at 650 °C. The enhanced strength of CNAs is also associated with a beneficial increase in Charpy impact upper-shelf energies, up to ∼2.5 times that of the current RAFM steels, with comparable ductile-brittle transition temperatures. A broad analysis of microstructure, alloy chemistry and grain size analyses clearly support the mechanisms that explain the mechanical property improvements of these CNAs, providing essential insight for further development of advanced RAFM steels to meet the challenges of future fusion reactors. [ABSTRACT FROM AUTHOR]

Abstract After its introduction just over twenty years ago, single-drop microextraction (SDME) became a widely applied solvent-based microextraction procedure as a practical sample preparation tool in support of chemical and biological, food, pharmaceutical, clinical and forensic analysis. In general, SDME is inexpensive, easy to operate, nearly solvent-free, and can be conducted using very basic apparatus. It can be used to realize high analyte enrichment in a relatively short time, and be easily combined with various instrumental techniques (e.g., GC-MS, HPLC-UV) for analysis. Recently, continuing strong interest in SDME has spawned new developments such as its implementation in microfluidic chip technologies, and operational processes (e.g., new devices, automation), engagement with materials chemistry (e.g., nanomaterials), and, of course, an expanding range of applications. In this review, we present a short historical overview of SDME, and then focus on its most recent (ca. 2017-2018) developments and advances. Future trends are also discussed and predicted. Highlights • A historical account of single-drop microextraction is given. • The most recent SDME developments are reviewed. • Future trends and directions are discussed. • Discussions are mainly centred on devices, materials, processes and applications. [ABSTRACT FROM AUTHOR]

Nanomaterials have assumed a prominent role in biomedical field during the past years. Particularly, the gold-core silica shell nanoparticles present unique physical and chemical properties that make nanodevices appealing for theragnostic applications. The gold core characteristic X-ray attenuation, surface enhanced raman scattering and tunable absorption in the near-infrared region supports the applicability of these systems in X-ray, photoacoustic and thermal imaging as well as in photothermal and photodynamic based therapies. Additionally, the inclusion of the silica shell stabilizes the gold core, protecting it from premature degradation and aggregation, and also provides additional cargo capacity for therapeutic molecules. Further, both silica and gold are described as biocompatible, inert and nontoxic materials. In this review, an overview of the gold core-silica shell nanoparticles applications in nanomedicine is provided, highlighting the different particle shapes and their application in bioimaging and therapy. Further, the basics of the gold core-silica shell nanoparticles synthesis procedures, general properties, and biosafety are also described. [ABSTRACT FROM AUTHOR]

Converting biomass into valuable products has great benefits in terms of both economic and environmental considerations, and has attracted considerable attention in recent years. Rice husk biomass was initially utilized to produce bulk materials for conventional applications while a variety of advanced nanostructures (NSs) have been fabricated over the past few years. In addition to their low cost and environmental friendliness, RH‐derived NSs (RH‐NSs) exhibit versatile properties, which are promising for broad applications in various fields. In this Review, we summarize the latest research on RH‐NSs, covering their design, fabrication, properties, and applications in the modern energy field. Based on the unique structure and components of RHs, a series of carbon/silicon‐based novel NSs with outstanding performances have been exploited, which are difficult to be synthesized using conventional chemical reagents. We also discuss perspective uses of RH‐NSs on the basis of the current research progress. Made from rice: Owing to its unique three‐dimensional net structure and chemical composition, rice husk biomass can be used to prepare versatile carbon‐ and silicon‐based nanostructures, as well as nanocomposites. Nanostructures derived from rice husks exhibit excellent optical, electrical, and electrochemical properties, with broad application prospects in lithium ion batteries, supercapacitors, solar cells, and triboelectric nanogenerators. [ABSTRACT FROM AUTHOR]

Tissue engineering using soft materials has become a very promising approach for repairing damaged cartilage and bone tissue. In this study, novel in situ forming composite hydrogels were synthesized based on chitosan and gelatin biopolymers associated with bioactive glass nanoparticles. The zeta potential at 37 °C ranged from +3.1 ± 1.4 mV to +6.9 ± 3.2 mV and showed the cationic nature of these hydrogels, which are capable of interacting with negatively charged molecules from native extracellular matrix (ECM). Moreover, the zeta potential analysis and FTIR spectra confirmed that network formation of the hydrogels occurs predominantly by molecular interactions. Rheological results revealed that the elastic modulus (G') increased from 5.4 Pa for pure chitosan hydrogels to 12.4 Pa for hydrogel composites with higher contents of gelatin and bioactive glass. Syringeability and injectability tests showed that all formulations can be smoothly expelled from a syringe and needle with the use of moderate force with a maximum value of 4.0 N. These hydrogel nanocomposites were cytocompatible based on the live cell viability responses of human osteosarcoma cell line (SAOS). These results suggest that these nanocomposites are a promising temporary injectable matrix for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Abstract The continuing increase of cancer morbidity and death rate requires efficient therapeutic strategies. The traditional chemotherapy usually fails to treat cancer or prolong survival rate due to its toxicity to normal cells, side effects and lack of targeting capacity. In recent years, nanomaterials have shown great potentials to treat various cancers efficiently. Graphene-based nanomaterials, especially graphene oxide (GO) and reduced GO (rGO), have arisen as promising candidates for cancer therapy. Due to their unique physicochemical and optical properties including the extremely large surface area, modifiable active groups, great biocompatibility and strong photothermal effect, they can act either as tunable carriers or active agents for advanced chemotherapeutics delivery and cancer therapy. Therefore, combing the photothermal therapy, targeted drug delivery and chemotherapy would have great potentials for efficient cancer therapy. Herein, the comprehensive understandings of the physicochemical properties and various anti-cancer applications of GO and rGO as drug delivery systems or photothermal agents are described. Also, the concerns in using GO and rGO, such as the nano-protein interaction, and possible solutions are discussed. Graphical abstract Unlabelled Image Highlights • Graphene-based nanomaterials have great potentials in drug delivery. • GO/rGO is readily available by many means. • The photothermal effect of GO/rGO can be used for heat treatment of cancer. • GO/rGO can be chemically modified for advanced drug delivery and therapy. • Corona formation and biodegradation are two challenges for the use of GO/rGO. [ABSTRACT FROM AUTHOR]

Abstract: Fischer–Tropsch synthesis (FTS) is a heterogeneous catalytic process for the production of fuels or chemicals from synthesis gas (CO + H2), which can be derived from nonpetroleum feedstocks such as natural gas, coal, or biomass. Co, Ru, Fe and Ni are all active in FTS, but only cheaper Fe and Co based catalysts are used in industry because the price of Ru is relatively high. However, the industrial Fe‐ and Co‐ based FTS catalysts normally work at a relatively high temperature range of 493—623 K in order to get a reasonable space time yield. Moreover, the product selectivity of FTS is governed by the law of polymerization, i.e., a so‐called Anderson‐Schulz‐Flory distribution holds, which restricts its industrial application. In this account, we highlight some of our progress toward the design/fabrication of nanostructured Fe, Co and Ru catalysts to improve FTS activity at the low temperature and to change the product selectivity and confine the product distribution into a certain range. [ABSTRACT FROM AUTHOR]

Flexoelectricity, which represents the spontaneous electric polarization induced by the strain gradient, is a universal electromechanical coupling effect regardless of symmetry in all dielectric material. In solid dielectric material, the contribution from flexoelectricity can be due to four related phenomena: static and dynamic bulk flexoelectricity, surface flexoelectricity and surface piezoelectricity. While the surface flexoelectric effect can be negligible, the magnitude of the remaining three phenomena are comparable. Presently, the role of the static bulk flexoelectric and surface piezoelectric effects in the energy harvesters has been intensively studied, the contribution from dynamic flexoelectric effect remains unclear. In this work, based on the conventional beam theory, equations of motion considering dynamic flexoelectric effect are investigated. Consequently, the free vibration of the simply supported beam is studied in order to examine the influence of the dynamic flexoelectricity on natural frequency. From the numerical studies, it is found that dynamic flexoelectric effect is more influential on thick beam model and higher vibration modes. In addition, the results show that the relation between the static and dynamic flexoelectric coefficients can also alter the free vibration response. [ABSTRACT FROM AUTHOR]

Herein, we introduce the application of nickel hydroxide nanosheets on the electro-etched carbon fiber (ECF) formed via a direct electrodeposition, for fabrication of asymmetric supercapacitor. To confirm the practical applicability of prepared Ni(OH)2-ECF, an asymmetric device was assembled using Ni(OH)2-ECF in combination with an activated carbon (AC) electrode. Our results showed a substantial cycling stability (96% capacitance retention after 10000 cycles) and considerable rate capability at large discharge currents (60% capacitance retention at 8 A g− 1) for this asymmetric supercapacitor that may have originated from the good contact between Ni(OH)2 and ECF. A maximum specific capacitance of 88.1 F g− 1 was achieved for Ni(OH)2-ECF//AC/CF device and showed considerable rate capability at large discharge currents (60% capacitance retention at 8 A g− 1). The results of this study suggest the Ni(OH)2-ECF electrode is an excellent material for fabrication of supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Nitrobenzene (NB) is one of the most challenging pollutants for groundwater remediation due to its great harm and recalcitrance. Emulsified nanoscale zero-valent iron (EZVI) is considered as a promising agent for in-situ remediation of contaminated groundwater for its high reactivity, good durability and low cost. In this paper, 2D tank experiment was conducted to evaluate the effectiveness of enhanced remediation of NB-contaminated groundwater with EZVI. 9 L of EZVI solution was injected into aquifer to establish in-situ reactive zone (IRZ) before 40 d of NB contamination. Results indicate that injection of EZVI leads to 90% reduction of total NB, which is mainly converted to aniline (AN). NB concentration decreases along the flow path in the tank. Fe 2+ is generated from Fe 0 oxidation. Significant acetate and bicarbonate are released due to emulsified oil decomposition during the whole operation time. Groundwater pH maintains in neutral value (6.6–8.2) owing to the balance between organic acids and OH − released after iron oxidation. Drastic decrease of ORP and DO indicates the transformation from oxidizing to reducing condition, leading to the reduction of oxidative species (e.g. sulfate, nitrate) in subsurface. Calculation of reducing equivalents suggests that microbial breakdown of emulsified oil provides more electrons than Fe 0 oxidation does to the system. Both biotic and abiotic processes are involved in the enhanced degradation of NB. [ABSTRACT FROM AUTHOR]

The mechanochemical covalent functionalization of carbon-encapsulated iron nanoparticles (CEINs) is reported. Unprotected sugars (mannose, galactose, β-cyclodextrin) and amino sugars (glucosamine and chitosan) were successfully conjugated to the surface of CEINs. The developed grinding-induced methods employ (i) the 1,3-dipolar cycloadditions of nitrile oxides or azomethine ylides and (ii) amidation-type reactions with the inclusion of carboxyl-functionalized CEINs and amino sugars. All the developed mechanochemical processes are fast (reaction time 10 min) and result in high degrees of coverage (7.3–31.5 wt%). The presented functionalization routes also constitute easy to perform and environmentally improved protocols. Moreover, the use of toxic organic solvents is not required. A comprehensive study on the colloidal stability of the sugar-functionalized CEINs is also included in this work. The results of the turbidimetric analyses reveal that both grinding-induced formation of amide bonds and the cycloadditions of sugar moieties to the surface of CEINs result in the significant improvement of their colloidal stability. The highest stability of the aqueous dispersion was found for CEINs functionalized with β-cyclodextrin. The comparative studies between the classical wet approach and the grinding-induced functionalization of CEINs show that the herein developed environmentally improved method increases the colloidal stability three times. The crucial role of the mechanochemical approach in the covalent functionalization of CEINs and the improvement of their colloidal stability is discussed in this work. [ABSTRACT FROM AUTHOR]

Abstract: Exploitation of plasmonic nanomaterials with high efficiency and selectivity presents the most significant challenge for their potential applications. A one‐step arc discharge to synthesize graphitic carbon‐encapsulated copper nanomaterials (Cu@G NMs) functionalized with nitrogen‐containing groups uniformly is reported. Combined with the temporal optical emission spectra, it is found that the NH3 introduces H radicals to tailor the core/shell nanostructures of Cu@G NMs inducing the morphological evolution from spherical nanoparticles (NPs) to linear nanowires (NWs), as well as provides dissociated nitrogen‐containing species (amino N, pyridinic N, pyrrolic N, and quaternary N) to construct the surface nanoarchitectures. With a localized surface plasmon resonance‐based method, the trace Cu2+ ions can be detected rapidly with excellent sensitivity (as low as 10 × 10−6 m linearly) and selectivity against other metal ions by Cu@G NPs in water samples. Moreover, remarkably enhanced catalytic activities for the reduction of aromatic organic pollutants (i.e., 4‐nitrophenol, methylene blue, and methyl orange) are also achieved by Cu@G NWs. This strategy enables the synergistic integration of efficient/selective adsorption capability of graphene shells and plasmonic/catalytic multifunctions of Cu cores in Cu@G platform, exhibiting a great potential in environmental monitoring and management. [ABSTRACT FROM AUTHOR]

Silicene, the ultimate scaling of a silicon atomic sheet in a buckled honeycomb lattice, represents a monoelemental class of two-dimensional (2D) materials similar to graphene but with unique potential for a host of exotic electronic properties. Nonetheless, there is a lack of experimental studies largely due to the interplay between material degradation and process portability issues. This review highlights the state-of-the-art experimental progress and future opportunities in the synthesis, characterization, stabilization, processing and experimental device examples of monolayer silicene and its derivatives. The electrostatic characteristics of the Ag-removal silicene field-effect transistor exhibit ambipolar charge transport, corroborating with theoretical predictions on Dirac fermions and Dirac cone in the band structure. The electronic structure of silicene is expected to be sensitive to substrate interaction, surface chemistry, and spin–orbit coupling, holding great promise for a variety of novel applications, such as topological bits, quantum sensing, and energy devices. Moreover, the unique allotropic affinity of silicene with single-crystalline bulk silicon suggests a more direct path for the integration with or revolution to ubiquitous semiconductor technology. Both the materials and process aspects of silicene research also provide transferable knowledge to other Xenes like stanene, germanene, phosphorene, and so forth. [ABSTRACT FROM AUTHOR]

Among two dimensional (2D) van der Waals (vdW) layered materials such as graphene, which is used like a metal, and transition metal chalcogenides (TMdCs), which are used as semiconductors and metals, hexagonal boron nitride (hBN), which is used as an insulator, is ubiquitous as a building block to construct 2D vdW electronics for versatile tunneling devices. Monolayer and few-layer hBN films have been prepared with flake sizes of a few hundred micrometer via mechanical exfoliation and transfer methods. Another approach used to synthesize hBN films on a large scale is chemical vapor deposition (CVD). Although the single-crystal film growth of hBN on the wafer scale is the key to realizing realistic electronic applications, the various functionalities of hBN for 2D electronics are mostly limited to the microscale. Here, we review the recent progress for the large-area synthesis of hBN and other related vdW heterostructures via CVD, and the artificial construction of vdW heterostructures and 2D vdW electronics based on hBN, in terms of charge fluctuations, passivation, gate dielectrics, tunneling, Coulombic interactions, and contact resistances. The challenges and future perspectives for practical applications are also addressed. [ABSTRACT FROM AUTHOR]

Extensive research on two-dimensional (2D) materials has triggered the renaissance of an old topic, that is, the intercalation and exfoliation of layer materials. Such top-down exfoliation produced 2D materials and their dispersions have several advantages including low cost, scalable production capability, solution processability, and versatile functionalities stemming from the large number of species of layer materials, and show promising potential in many applications. In recent years, many new methods have been developed for exfoliating layer materials to 2D materials for different application purposes. In this review the different exfoliation approaches are first systematically analyzed from the viewpoint of methodology, and the advantages and disadvantages of each method are compared. Second, the assembly of exfoliated 2D materials into macrostructures by solution-based techniques is summarized. Third, the state-of-the-art applications of 2D material dispersions and their assemblies in electronics and optoelectronics, electrocatalysis, energy storage, etc., are discussed. Finally, insights and perspectives on current research challenges and future opportunities regarding the exfoliation and applications of 2D materials in dispersions are considered. [ABSTRACT FROM AUTHOR]

The past decade has witnessed tremendous research efforts devoted to two-dimensional (2D) materials and great progress made in both their fundamental studies and technique development. 2D light-emitting materials such as transition-metal dichalcogenides (TMDs) and phosphorene are receiving particular attention as a result of their intriguing electronic, optical and optoelectronic properties. The ability to tune their layer numbers, engineer their dielectric environment, form alloys, create van der Waals heterostructures, etc. provides further means to modulate their properties which have led to a number of interesting luminescence features and potential applications in lighting, imaging and sensing. As the map of 2D materials has expanded over the past few years, 2D organic and organic–inorganic hybrid materials, such as 2D polymers, metal–organic frameworks (MOFs), and organic–inorganic hybrid perovskites, have also emerged with merits of low cost, chemical versatility and solution processibility. Importantly, the wide tunability of their functional properties is enabled by the rational design and controlled modification of their compositions and structures at the molecular level. Herein, we present a critical review of 2D light-emitting materials by categorizing them into three main groups, namely 2D inorganic light-emitting materials, 2D organic light-emitting materials, and 2D organic–inorganic hybrid light-emitting materials. Within each group, we will describe their preparation methods and discuss their structural and chemical properties. Significant emphasis will be placed on strategies that can tune their luminescence properties, and their potential applications in various fields. Finally, we will summarize by stating the current challenges and future opportunities in the development of 2D light-emitting materials. [ABSTRACT FROM AUTHOR]

Two-dimensional semiconductors (2DSCs) have attracted considerable attention as atomically thin channel materials for field-effect transistors. Each layer in 2DSCs consists of a single- or few-atom-thick, covalently bonded lattice, in which all carriers are confined in their atomically thin channel with superior gate controllability and greatly suppressed OFF-state current, in contrast to typical bulk semiconductors plagued by short channel effects and heat generation from static power. Additionally, 2DSCs are free of surface dangling bonds that plague traditional semiconductors, and hence exhibit excellent electronic properties at the limit of single atom thickness. Therefore, 2DSCs can offer significant potential for the ultimate transistor scaling to single atomic body thickness. Earlier studies of graphene transistors have been limited by the zero bandgap and low ON–OFF ratio of graphene, and transition metal dichalcogenide (TMDC) devices are typically plagued by insufficient carrier mobility. To this end, considerable efforts have been devoted towards searching for new 2DSCs with optimum electronic properties. Within a relatively short period of time, a large number of 2DSCs have been demonstrated to exhibit unprecedented characteristics or unique functionalities. Here we review the recent efforts and progress in exploring novel 2DSCs beyond graphene and TMDCs for ultra-thin body transistors, discussing the merits, limits and prospects of each material. [ABSTRACT FROM AUTHOR]

As a two-dimensional (2D) material, molybdenum disulfide (MoS2) exhibits unique electronic and optical properties useful for a variety of optoelectronic applications including light harvesting. In this article, we review recent progress in the synthesis, properties and applications of MoS2 and related heterostructures. Heterostructured materials are developed to add more functionality or flexibility compared to single component materials. Our focus is on their novel properties and functionalities as well as emerging applications, especially in the areas of light energy harvesting or conversion. We highlight the correlation between structural properties and other properties including electronic, optical, and dynamic. Whenever appropriate, we also try to provide fundamental insight gained from experimental as well as theoretical studies. Finally, we discuss some current challenges and opportunities in technological applications of MoS2. [ABSTRACT FROM AUTHOR]

Graphene, despite being the best known strong and electrical/thermal conductive material, has found limited success in practical applications, mostly due to difficulties in the formation of desired large-scale highly organized structures. Our discovery of a liquid crystalline phase formation in graphene oxide dispersion has enabled a broad spectrum of highly aligned graphene-based structures, including films, fibers, membranes, and mesoscale structures. In this review, the current understanding of the structure–property relationship of graphene oxide liquid crystals (GOLCs) is overviewed. Various synthetic methods and parameters that can be optimized for GOLC phase formation are highlighted. Along with the results from different characterization methods for the identification of the GOLC phases, the typical characteristics of different types of GOLC phases introduced so far, including nematic, lamellar and chiral phases, are carefully discussed. Finally, various interesting applications of GOLCs are outlined together with the future prospects for their further developments. [ABSTRACT FROM AUTHOR]

The discovery of graphene opened a door for manufacturing and investigating two-dimensional (2D) materials. After more than ten years of development, 2D materials have become one of the most important topics in materials research, with dozens of new materials having been synthesized experimentally and even more predicted theoretically. In this review, we provide a comprehensive overview of the fabrication of 2D materials based on epitaxial growth in an ultra-high vacuum (UHV) experimental environment and the investigation of their physical and chemical properties. In particular, we focus on techniques like intercalation, templated molecular adsorption, and direct selenization and tellurization of metal substrates. We discuss progress in fabrication methods of monatomic and binary 2D materials and highlight their interesting and quite unusual physical properties. Finally, we assess future directions of research in this field, where breakthroughs can be expected, and indicate where investments in additional research might be most rewarding scientifically. [ABSTRACT FROM AUTHOR]

The sp3-hybridized group 14 graphane analogues are a unique family of 2D materials in which every atom requires a terminal ligand for stability. Consequently, the optical, electronic, and thermal properties of these materials can be manipulated via covalent chemistry. Herein, we review the methodologies for preparing these materials, and compare their functionalization densities to Si/Ge(111) surfaces and other covalently terminated 2D materials. We discuss how the electronic structure, optical properties, and thermal stability of the 2D framework can be broadly tuned with the ligand identity and framework element. We highlight their recent application in electronics, optoelectronics, photocatalysis, and batteries. Overall, these materials are an intriguing regime in materials design in which both surface functionalization and solid-state chemistry can be uniquely exploited to systematically design properties and phenomena. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) metal–organic framework (MOF) nanosheets are attracting increasing research attention due to their unique properties originating from their ultrathin thickness, large surface area and high surface-to-volume atom ratios. Many great advances have been made in the synthesis and application of 2D MOF nanosheets over the past few years. In this review, we summarize the recent advances in the synthesis of 2D MOF nanosheets by using top-down methods, e.g. sonication exfoliation, mechanical exfoliation, Li-intercalation exfoliation and chemical exfoliation, and bottom-up methods, i.e. interfacial synthesis, three-layer synthesis, surfactant-assisted synthesis, modulated synthesis, and sonication synthesis. In addition, the recent progress in 2D MOF nanosheet-based nanocomposites is also briefly introduced. The potential applications of 2D MOF nanosheets in gas separation, energy conversion and storage, catalysis, sensors and biomedicine are discussed. Finally, we give our personal insights into the challenges and opportunities for the future research of 2D MOF nanosheets and their composites. [ABSTRACT FROM AUTHOR]

Two-dimensional layered materials (2DLMs) have attracted a tremendous amount of attention as photodetectors due to their fascinating features, including high potentials in new-generation electronic devices, wide coverage of bandgaps, ability to construct van der Waals heterostructures, extraordinary light–mass interaction, strong mechanical flexibility, and the capability of enabling synthesis of 2D nonlayered materials. Until now, most attention has been focused on the well-known graphene and transition metal dichalcogenides (TMDs). However, a growing number of functional materials (more than 5619) with novel optoelectronic and electronic properties are being re-discovered, thereby widening the horizon of 2D libraries. In addition to showing common features of 2DLMs, these new 2D members may bring new opportunities to their well-known analogues, like wider bandgap coverage, direct bandgaps independence with thickness, higher mechanical flexibility, and new photoresponse phenomena. The impressive results communicated so far testify that they have shown high potentials with photodetections covering THz, IR, visible, and UV ranges with comparable or even higher performances than well-known TMDs. Here, we give a comprehensive review on the state-of-the-art photodetections of two-dimensional materials beyond graphene and TMDs. The review is organized as follows: fundamentals of photoresponse first are discussed, followed by detailed photodetections of new 2D members including both layered and non-layered ones. After that, photodiodes and hybrid structures based on these new 2D materials are summarized. Then, the integration of these 2D materials with flexible substrates is reviewed. Finally, we conclude with the current research status of this area and offer our perspectives on future developments. We hope that, through reading this manuscript, readers will quickly have a comprehensive view on this research area. [ABSTRACT FROM AUTHOR]

Highly sensitive and selective detection of various biomolecules is critical for biological research and diagnostics. Herein, we have fabricated an in situ hierarchically self-assembled hybrid electrode based on graphene nanoplatelets (GNP) functionalized with silver nanorods (AgNRs) followed by electrochemical polymerization of 4-amino-1-1ʹ-azobenzene-3,4ʹ-disulfonic acid dye (acid yellow 9, poly(AY)) for in vitro electroanalysis of biomolecules in biological samples. The UV–vis spectroscopy, FT-IR, XRD and FE-SEM were used to characterize the AgNRs and its incorporation into the graphene nano-interfaces. The GNP/AgNR/poly(AY) nanocomposite (NC) hybrid interface was introduced to modify the surface of glassy carbon electrode (GCE) to study in vitro electroanalysis of important biomolecules such as dopamine (DA) and ascorbic acid (AA) using cyclic voltammetry (CV) and amperometry. The GNP/AgNR/poly(AY) NC coated electrode exhibited high electrocatalytic activity towards DA and AA in physiological condition (pH∼7) and separated their oxidation peaks at different potentials with reasonably good peak separation. As-prepared sensor showed linear response for the electro-catalytic oxidation of DA and AA from 1 to 200 μM with a detection limit of 0.42 μM and 0.88 μM, respectively. Furthermore, the effects of pH, scan rate and interferences on the detection of DA using human serum and urine samples are reported. Thus, the GNP/AgNR/poly(AY) hybrid film modified electrode may be utilized for the development of biomolecule transducers of various disease biomarkers. [ABSTRACT FROM AUTHOR]

Composites of carbon nanostructures (CNSs) and biocompatible polymers are promising materials for a series of advanced technological applications, ranging from biomedicine and bioelectronics to smart packaging and soft robotics. In this work, we present three types of organic-functionalized CNSs, namely p -methoxyphenyl functionalized multi-walled carbon nanotubes, carbon nanohorns and reduced graphene oxide, used as nanofillers for the preparation of homogeneous and well-dispersed composites of poly( l -lactic acid), a biocompatible and biodegradable FDA-approved polymer. A thorough characterization of the composites is given in terms of calorimetric response, electrical and mechanical properties. Significant differences are observed among the different types of CNS nanofillers, underlying the key role played by the nanoscale shape and distribution of the components in driving the macroscopic behavior of the composite material. Surface properties are probed through advanced atomic force microscopy techniques, on both flat substrates (films) and confined systems (nanofibers). All these composites proved to be biocompatible and to support as scaffolds the proliferation of human neuronal precursor cell line SH-SY5Y, opening the route to a future comparative analysis on their ability to boost neuronal differentiation. [ABSTRACT FROM AUTHOR]

Plasmonic metal nanoparticles have been explored as a new class of chemical read-outs for assaying of a variety of chemical and biological species because of their unique physico-chemical and size dependent properties. Metal nanoparticles-based optical technologies are based on either new class of organic molecular assembly or with aggregation-induced optical changes features, which can also improve the sensitivity of drug assays in pharmaceutical analysis. This review describes the advantages of surface chemistry of plasmonic metal nanoparticles (e.g., silver, copper, gold, and platinum) for tuning of their colorimetric sensing applications in various drugs assays in pharmaceutical and biological samples. It provides insights of various plasmonic metal nanoparticles-based sensing strategies for the selective, sensitive and simultaneous colorimetric assay of drugs in pharmaceutical samples. Finally, we listed some research challenges to accelerate the development of plasmonic metal nanoparticles-based colorimetric sensors that are directly applicable for assaying drugs in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) is and a colorless, corrosive, flammable, and toxic gas with a characteristic rotten egg smell. Although its detection can be conducted by conventional methods (like gas chromatography), highly effective and sensitive detection of H 2 S has been realized with the usage of various nanomaterials (e.g., carbon nanostructures, metal nanoparticles, metal oxide nanoparticles, and quantum dots). Metal-organic frameworks (MOFs), as employed for such applications either in their pristine or modified forms, have been recognized as the effective media for sensing of H 2 S due to synergistic effects in addition to their well-known merits (e.g., the large specific surface). This review has been organized to describe the potential applicability of MOF-based sensing against H 2 S through comparative evaluation of their capability against other materials or tools. We also discuss the present obstacles and outline the future scope of research on MOF-based sensing tools. [ABSTRACT FROM AUTHOR]

Nanozyme, a term defined for nanomaterial with enzyme-like properties, has attracted significant research attention owing to its striking merits. Recently, a surge of nanozymes have been demonstrated to catalyze some typical enzymatic reactions mimicking oxidase, peroxidase and catalase. Especially, nanozymes with peroxidase-like activity have grown into a big family due to their broad range of applications in the field of biosensing and immunoassay. Since inorganic nanoparticles possess the advantages of high stability and easy surface modification, nanozymes have been emerging alternatives to natural enzymes to some extent. In this Review, we briefly summarize several typical nanozymes and then focus our attention on their enormous applications with respect to analytical chemistry. Representative examples would be discussed in detail from the literatures of last 10 years. Additionally, the current challenges and future directions about nanozymes are speculated at the end of this review. [ABSTRACT FROM AUTHOR]

The existence of heavy metals in the natural waters poses serious threats to human health and the environment. Therefore, development of detection methods for monitoring of these heavy metals is crucial. The nanomaterial-based electrochemical sensors have been extensively employed for heavy metal ions detection. The fabricated electrodes offer several advantages and improved performance due to the design of electrode surface at the nanoscale that render increased catalytic activity and conductivity, active large surface area and fast electrode kinetics. Moreover, integration of electrochemical devices in automatic fluidic structures has also been used for a wide range of heavy metals monitoring. This review will provide a detailed account of recent progress in the development of nanomaterial-based electrochemical sensors for the detection of heavy metals in real water samples from 2013 onwards. The design of these sensors is based on the deployment of nanoparticles-modified electrodes, microelectrode and nanoelectrode arrays, and microfluidic electrochemical devices. [ABSTRACT FROM AUTHOR]

Molybdenum carbide and Ni 0 nanoparticles (NPs) embedding into N-doped carbon materials (Mo x Ni y @N-C) were prepared by one-step thermolysis of Ni, Mo, N, C precursors, and then loaded on poly (vinylidene fluoride) (PVDF) film to obtain the catalytic membranes (Mo x Ni y @N-C/PVDF). The membranes effectively catalyzed the reduction of toxic Cr VI to benign Cr III by employing formic acid (FA) as the reducing agent. The effects of parameters, such as initial concentrations of Cr VI (5–25 mg/L) and FA (0.117–0.702 M), solution pHs (2.12–5.43) and temperatures (15–55 °C), as well as HCOONa concentrations (0–0.20 M) on Cr VI reduction were analyzed in view of scalable industrial applications. Owing to the synergistic effects amongst Ni 0 , Mo x C, doped nitrogen, and oxygen groups as catalytic active sites, and carbon shell protection of metal NPs from leaching out, Mo x Ni y @N-C/PVDF catalysts exhibited excellent catalytic activity and recyclable capability for Cr VI reduction. The membrane’s unique porous structure and large chemically active surface area not only minimize the NPs agglomeration, but also allow the facile transport of catalytic reactants to the active surface without suffering from high mass-transfer resistance. This study demonstrates Mo x Ni y @N-C/PVDF catalytic membranes with the morphological and structural features provide a green, economic, and fast method for the treatment of Cr VI containing waters. [ABSTRACT FROM AUTHOR]

We report a novel and versatile fabrication strategy for functional nanonetwork-structured carbon nitride with Au nanoparticle yolks (FNNS-C3N4-Au) based on hairy poly(acrylic acid)-grafted SiO2 nanospheres (Au@SiO2-g-PAA). Benefiting from the three-dimensional nanonetwork structure and well-distributed Au nanoparticles, the as-prepared nanocomposites demonstrated excellent photocatalysis performances (degradation rate constant: 1.8 × 10−2 min−1). [ABSTRACT FROM AUTHOR]

Co 3 O 4 , a type of transition metal oxide, is known as a promising anode material for high-performance Li-ion batteries (LIBs), attracting wide research attention because of its high theoretical specific capacity, high tapped density as well as stable chemical properties. In this review, we first discuss the synthesis of pure Co 3 O 4 with different morphologies, such as 1D nanostructures (nanorods and nanowires), 2D nanostructures (nanosheets), 3D nanostructures (nanocubes, nanoboxes, polyhedral and fusiform nanostructures), and multistage nanostructures (flower-like nanostructures). Then, we focus on the application of pure Co 3 O 4 and its composites, such as Co 3 O 4 /C, Co 3 O 4 /graphene, and Co 3 O 4 /metal oxide, in LIBs. [ABSTRACT FROM AUTHOR]

The phase diagrams and the magnetic properties of a spin-1 Blume-Capel nanoisland are investigated by the use of the effective-field theory based on the probability distribution technique. The influence of the random crystal field and the system parameters on the critical behaviors of the nanoisland are examined. The results show that the system can exhibit a first-order phase transition, a tricritical point, and a re-entrant or even a double re-entrant phenomenon. [ABSTRACT FROM AUTHOR]

Abstract: A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof‐of‐principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels–Alder and azide–alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels–Alder product was exploited to induce the on‐demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

Peptide self-assembled nanostructures have attracted attention recently owing to their promising applications in diversified avenues. To validate the importance of sidechains in supramolecular architectural stabilization, herein this report describes the self-assembly propensities involving weak interactions in a series of model tripeptides Boc-Xaa - Aib-Yaa-OMe I–IV , (where Xaa = 4-F-Phe/NMeSer/Ile & Yaa = Tyr in peptide I–III respectively and Xaa = 4-F-Phe & Yaa = Ile in peptide IV) differing in terminal side chains. The solid state structural analysis reveals that tripeptide ( I ) displays supramolecular preference for double helical architecture. However, when slight modification has been introduced in the N-terminal side chains disfavour the double helical organisation (Peptide II and III ). Indeed the peptides display sheet like ensemble within the framework. Besides replacement of C-terminal Tyr by Ile in peptide I even do not promote the architecture, emphasizing the dominant role of balance of side chains in stabilizing double helical organisation. The CD measurements, concentration dependant studies, NMR titrations and ROESY spectra are well in agreement with the solid state conformational investigation. Moreover the morphological experiments utilizing FE-SEM, support the heterogeneity present in the peptides. Thus this work may not only hold future promise in understanding the structure and function of neurodegenerative diseases but also assist in rational design of protein modification in biologically active peptides. [ABSTRACT FROM AUTHOR]