ultrasonic time increases, and then become invariable when the ultrasonic time exceeds 6 h. Combining with the TEM results, it can be concluded that the FM in- creases as the size for the nanosheets decreases. Zero- field-cooled (ZFC) and field-cooled (FC) measurements are performed on the sample which has the maximum M s , and the results are shown in Figure 4d. Results indi-
HDAC1 and KRAS siRNAs (against a G12D mutant KRAS gene for Panc-1 cells) for in vitro pancreatic cancer therapy. The unique function of Histone deacetylase 1 (HDAC1) in sustaining the pluripotency of embryonic and cancer stem cells underlines its important role in epigenetics [52, 53]. Furthermore, the appreciable expression of HDAC1 in pancreatic cancer and other forms of cancers  promote cell transformation, survival, invasion, and metastasis [55-57]. Thus, HDAC1 is considered as a promising target for cancer therapy. Moreover, the mutational KRAS gene has been shown to predominate more than 90% of pancreatic cancers and is thus, a major target for addressing cancer therapy . In this work, we utilized functionalized MoS 2 nanosheets with folic
16 Read more
More recently it has been demonstrated that liquid exfoliation can be achieved by exposing graphite to high shear rates 34 using either rotor-stator high shear mixers 35, 36 or simple kitchen blenders. 37, 38 This gives graphene nanosheets of similar size and quality to those produced using sonication. The advantage of this technique is that much higher volumes can be produced compared to sonication and so much higher production rates can be achieved. Such work has allowed liquid phase exfoliation of graphite to be scaled up towards an industrial process for graphene production. However, to date only preliminary results have been demonstrated for the scale-up of liquid phase exfoliation of inorganic layered materials such as MoS 2 , WS 2 and BN. 34, 35 To facilitate scaleup, it will be important to demonstrate an
31 Read more
combination of hole-electron pairs. Successive reactions lead to the oxidation of RhB dye and the complete photodegradation. Generally, RhB is very stable under the light irradiation when no catalyst is available. A possible mechanism for the degradation of RhB is suggested to involve three steps: 1) N-deethylation, 2) cleavage of chromophore and 3) mineralization of the dye . MoS 2 nanosheets in the nanocomposite have a
 G. Zhao, S. Han, A. Wang, Y. Wu, M. Zhao, Z. Wang, X. Hao. “Chemical weathering” exfoliation of atom-thick transition metal dichalcogenides and their ultrafast saturable absorption properties. Adv. Funct. Mater. 2015, 25(33), 5292-5299.  H. Li, G. Lu, Y. Wang, Z. Yin, C. Cong, Q. He, L. Wang, F. Ding, T. Yu, H. Zhang. Mechanical exfoliation and characterization of single- and few-layer nanosheets of WSe 2 , TaS 2 and TaSe 2 . Small, 2013, 9(11), 1974-1981.
18 Read more
29. Coleman JN, Lotya M, O ’ Neill A, Bergin SD, King PJ, Khan U, Young K, Gaucher A, De S, Smith RJ, Shvets IV, Arora SK, Stanton G, Kim H-Y, Lee K, Kim GT, Duesberg GS, Hallam T, Boland JJ, Wang JJ, Donegan JF, Grunlan JC, Moriarty G, Shmeliov A, Nicholls RJ, Perkins JM, Grieveson EM, Theuwissen K, McComb DW, Nellist PD, et al: Two-dimensional nanosheets produced by liquid exfoliation of layered materials. Science 2011, 331:568 – 571. 30. Ramakrishna Matte HSS, Gomathi A, Manna AK, Late DJ, Datta R, Pati SK,
Hematoxylin–eosin (H&E) staining was performed to ana- lyze the long-term in vivo biosafety of SP-MoS 2 nanosheets. Briefly, KM mice were anesthetized and IV injected with 200 μ L saline or SP-MoS 2 dispersion ([Mo] = 200 μ g/mL, in saline). The body weight of KM mice was recorded every 2 days. After 4 weeks of feeding, KM mice were euthanized, and major organs (heart, liver, spleen, lung, and kidney) were fixed with 10% neutral buffered formalin, embed- ded in paraffin, and sectioned into slices with a thickness of 8 μ m. These slices were finally stained with H&E and photographed using a Leica DM IL LED, inverted phase contrast microscope. For the in vivo hemocompatibility assessment, KM mice were anesthetized, and the heart was punctured to collect blood 14 days after IV injec- tion. Routine blood parameters including white blood cell (WBC) and red blood cells (RBC) count, mean corpuscular hemoglobin (MCH), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (HGB), mean corpuscular volume (MCV), and red cell distribu- tion width (RDW) were recorded with a Sysmex XS-800i automated hematology analyzer (Sysmex, Kobe, Japan).
15 Read more
1-dodecanethiol (DDT) was used not only as a sulfur source but also as the surface ligand. The sheet-like morphology was confirmed by the transmission electron microscopy (TEM) and atomic force microscopy (AFM) results, and the X-ray diffraction (XRD) patterns and Raman spectrum were employed to characterize the structure of the as-synthesized MoS 2 nanosheets. The as-obtained MoS 2 nanosheets blending with a polymer could be used
51. Coleman JN, Lotya M, O ’ Neill A, Bergin SD, King PJ, Khan U, Young K, Gaucher A, De S, Smith RJ, Shvets IV, Arora SK, Stanton G, Kim HY, Lee K, Kim GT, Duesberg GS, Hallam T, Boland JJ, Wang JJ, Donegan JF, Grunlan JC, Moriarty G, Shmeliov A, Nicholls RJ, Perkins JM, Grieveson EM, Theuwissen K, McComb DW, Nellist PD, Nicolosi V (2011) Two-dimensional nanosheets produced by liquid exfoliation of layered materials. Science 331:568 – 71 52. Nicolosi V, Chhowalla M, Kanatzidis MG, Strano MS, Coleman JN (2013)
14 Read more
This work is supported by the NSFC (Grant No. 51202101, 11474137), the Specialized Research Fund for the Doctoral Program of Higher Education (20120211120005), the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China, the Open Project of Key Laboratory for Magnetism, and the Magnetic Materials of the Ministry of Education of Lanzhou University (LZUMMM2014015). Table 1 ICP results for the MoS 2 nanosheets
Vis and FT-IR spectra indicated that HRP retained its original structure. Cyclic voltammograms showed that HRP accomplished the direct electron transfer on the modified electrode. Moreover, the modified electrode had an excellent electrocatalytic activity toward TCA with a lower detection limit and smaller K M app value. This work extended the application of MoS 2 nanosheets in the field of
10 Read more
excellent performance and Li + storage and insertion dynamics. The Nyquist plots of electrodes before and after 100 cycles at a current density of 0.1 A/g are displayed in Fig. 8a. It can be obtained that the charge transfer resistance reduced after 100 cycles. The Nyquist plots are also fitted by the equivalent circuit model as displayed in Fig. 8b. The fitting parameters of the impedance are listed in Table 1. For the MoS2/CFP electrode before cycles and after cycles, the Rs value is dropped from 23.3 Ω to 22.5 Ω; the Rct value is dropped from 547.9 Ω to 323.0 Ω; and the Rf value is 153.6 Ω after cycles. It is confirmed that the combination of MoS 2 and carbon fiber significantly enhances the electrical conductivity of MoS 2
14 Read more
Under a special set of conditions, when the Volmer re- action is the rate-determining step of HER, a slop of ca. 120 mV dec −1 should result, while a rate-determining Heyrovsky of Tafel reaction should produce slope of ca. 30 and 40 mV dec − 1 , respectively [52, 53]. In this work, it seems that free energy barrier of discharge step is reduced to be comparable with that of the following desorption or combination step, resulting in the slope of 43 mV dec −1 for vertical 1T-WS 2 nanosheets. Mean-
reinforced composites, 40, 41 lithium ion batteries, 42 photodetectors, 43 and printed micro- supercapacitors 44 to name but a few. However, this method has not been extended beyond the limited number of materials described above. As mentioned earlier, there are numerous layered materials, 4 many of which are potentially amenable to solvent (or surfactant or polymer) based exfoliation. In order to exploit the potential of layered compounds to become the source of a diverse array of 2D nanosheets, it will be necessary to demonstrate that many different types of layered materials can be exfoliated in liquids – ideally by solvent exfoliation.
35 Read more
Abstract— In the present study, based on the literature review the individual aluminium alloy and combined effect of reinforcements on aluminium alloy discussed. For preparation of composites Al6061 taken as base metal and varying weight percentage of Molybdenum disulphide (MoS2). The composite of Al6061 and MoS2 is prepared by stir casting technique. A series of mechanical tests are conducted on fabricated composite specimen and compare the result of different percentage composition with the base alloy. Optical microscope is used for microstructure studies and grain size measurement. Mechanical and tribology properties like stiffness, tensile strength and hardness improved due to composite fabrication. Due to this aluminium metal matrix composite with reinforcement increase application in aerospace, underwater, high temperature application and automobile.
Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to observe the lateral sizes of the MSNs. Figure 1A shows the thickness of the MSNs was in the range of 1 – 2 nm, suggesting they probably were mainly two or three-layered nanomaterials. According to the TEM micro- graphs, the lateral sizes of the two materials were 100 – 250 nm for the S-MSNs and 400 – 500 nm for the L-MSNs (Figure 1B). The X-ray diffraction (XRD) pattern indicated that the nanosheets exhibited the typical crystal structure of MSNs (Figure 1C). For the S-MSNs and the L-MSNs, the Zeta poten- tials in water were − 42.53 ± 2.23 mV and − 42.43 ± 1.34 mV, respectively, while in 1640 medium, they were elevated to − 9.79 ± 0.73 mVand − 8.82 ± 0.65 mV (Table S1). The formation of the protein corona by adsorption of the protein components onto the surface of the MSNs might be responsible for the decreased absolute potential values in 1640 medium. In Figure 1D, we observed that the nanosheets could be swallowed by DCs and were mainly located in intracellular vesicles in the cytoplasm, suggesting a direct interaction between DCs and MSNs existed.
16 Read more
and tune the bandgaps with facile process. Several methods, such as mechanical exfoliation (the so-called Scotch tape method), liquid exfoliation, colloidal synthe- sis, chemical vapor deposition, chemical exfoliation, and electrochemical exfoliation have been developed to pre- pare ultrathin MoS 2 nanosheets [2, 20 – 30]. Among
Two-dimensional (2D) hybrid materials have been studied for use in photovoltaics, water splitting, sensors, batter- ies, and many other applications, often in the form of heterojunctions or three-dimensional (3D) frameworks [1–6]. Benefiting from their unique 2D structures and tunable band-gaps, 2D hybrid materials can offer both a high specific surface area and a suitable work func- tion [1, 7–10]. For most electrochemical applications, such as in dye-sensitized solar cells (DSSCs) and hydro- gen evolution reaction (HERs), the high electronic con- ductivity and the strong redox reactivity of transition metal dichalcogenides (TMDs)/graphene hybrids are extremely attractive. In these hybrids, graphene nano- sheets possess high electronic conductivity, mechanical strength [11, 12], and serve as growth centers for TMD nanosheets. Earlier studies have shown that the hybrid structures offer enhanced catalytic activity with more active sites .
7 Shown in figure 2A is an I-V curve for an ITO/MoS2/Au sandwich structure device taken in the dark. This curve is symmetric around the origin, as expected if both contacts are Ohmic. 34 The dark conductivity is ~210 -10 S/m, three orders of magnitude lower than measured for similar films but with in-plane current flow. 23 This is consistent with the anisotropy between in-plane and out of plane conductivities in graphite and suggests the current to be limited by inter-flake transport. 35
17 Read more
TMDs in device manufacturing industry. For the solvent and surfactant assisted exfoliation, the presence of solvents and surfactants residues as well as the byproducts formed during ultrasonication results in some problems for achieving pure TMD nanosheets. On the other hand, the randomly distributed defects in exfoliated TMDs are unfavorable for practical use in electronic and optoelectronic devices, thus employing other milder external forces to replace the high intensity ultrasonic tip and exploring new synthetic strategies to avoid defects formation are desperately required for high quality TMD nanosheets production. What’s more, the chemistry underlying the exfoliation techniques such as the TMDs/surfactants interactions and the sonochemistry involved in exfoliation process is still elusive, which makes the controllable preparation of defect-free TMDs with uniform size and thickness for practical applications even more challenging.
206 Read more