Nanomaterials and Nanotechnology最新文献

{"title":"Substitutional impurities in monolayer hexagonal boron nitride as single-photon emitters","authors":"Michele Re Fiorentin, Kiptiemoi Korir Kiprono, Francesca Risplendi","doi":"10.1177/1847980420949349","DOIUrl":"https://doi.org/10.1177/1847980420949349","url":null,"abstract":"Single-photon emitters in hexagonal boron nitride have attracted great attention over the last few years due to their excellent optoelectronical properties. Despite the vast range of results reported in the literature, studies on substitutional impurities belonging to the 13th and 15th groups have not been reported yet. Here, through theoretical modeling, we provide direct evidence that hexagonal boron nitride can be opportunely modified by introducing impurity atoms such as aluminum or phosphorus that may work as color centers for single-photon emission. By means of density functional theory, we focus on determining the structural stability, induced strain, and charge states of such defects and discuss their electronic properties. Nitrogen substitutions with heteroatoms of group 15 are shown to provide attractive features (e.g. deep defect levels and localized defect states) for single-photon emission. These results may open up new possibilities for employing innovative quantum emitters based on hexagonal boron nitride for emerging applications in nanophotonics and nanoscale sensing devices.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420949349","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48648251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain gauge properties of Pd+-ion-implanted polymer","authors":"F. Di Benedetto, C. Esposito, M. Protopapa, E. Piscopiello, M. Massaro, G. Cassano, Valentino Filiberto, M. Palmisano, L. Tapfer","doi":"10.1177/1847980420947975","DOIUrl":"https://doi.org/10.1177/1847980420947975","url":null,"abstract":"Pd+ ions (90 keV) were implanted at normal incidence and at room temperature in different highly insulating (>200 GΩ) thermoplastic polymers (poly(methyl methacrylate), polypropylene, polyethylene terephthalate glycol-modified, and polycarbonate). At high fluence and optimized process parameters, the ion implantation gives rise to the formation of a nanocomposite thin surface layer constituted by Pd nanoclusters and carbonaceous material (nanographite/amorphous carbon). The morphological, microstructural, and microanalytical properties of the nanocomposite layers were investigated by He-ion microscopy, glancing incidence X-ray diffraction, and Raman scattering, respectively. The electrical properties were characterized by resistance, van der Pauw, and Hall measurements. We performed accurate simultaneous deformation/bending experiments and electrical resistance measurements. We show that the electrical resistance varies linearly with the mechanical deformation (beam deflection) applied. The experimental results are interpreted by “hopping conductivity” model considering the nanostructure configuration of the nanocomposite layers. A gauge factor in the range between 4 and 8, depending on the ion-implanted polymer, was obtained for prototype strain gauge devices.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420947975","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43121880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of different preparation processes on tribological properties of graphene","authors":"Yong Liu, Yi Dong, Yangang Zhang, Siyuan Liu, Yu Bai","doi":"10.1177/1847980420946655","DOIUrl":"https://doi.org/10.1177/1847980420946655","url":null,"abstract":"Two processes of physical liquid phase stripping and chemical redox reduction were used to obtain graphene sheets. Fourier transform infrared spectroscopy and Raman spectroscopy test methods were used to compare and analyze the structure and disorder of graphene. The obtained graphene was modified with oleic acid and stearic acid. The dispersion stability of graphene as a lubricating oil additive was investigated by natural sedimentation method and spectrophotometry. The tribological properties of the graphene dispersion were investigated by a four-ball friction and wear tester. Scanning electron microscope and energy spectrometer were used to characterize and analyze the microscopic morphology and composition of the worn surface. The results showed that the modified liquid phase stripping graphene demonstrated the best anti-wear and anti-friction properties of the dispersion, the lowest friction coefficient is 0.0677, and the average friction coefficient is reduced by about 26%.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420946655","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42249085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon-based fully printable self-powered ultraviolet perovskite photodetector: Manganese-assisted electron transfer and enhanced photocurrent","authors":"Shuhong Xu, Guangguang Huang, Chunlei Wang, Haibao Shao, Yiping Cui","doi":"10.1177/1847980420925674","DOIUrl":"https://doi.org/10.1177/1847980420925674","url":null,"abstract":"In this work, we improved the photocurrent of self-powered ultraviolet photodetector via doping manganese in CsPbCl3 perovskite nanocrystals light harvester. The doped manganese in nanocrystals has the following three features to assist electron transfer from CsPbCl3 nanocrystals to titanium dioxide: (i) the fast exciton-to-manganese energy transfer process benefits for competing electrons with perovskite exciton recombination, (ii) the charge carrier lifetime is very long for manganese d-states due to its spin and orbital forbidden transition, and (iii) the electrons can effectively transfer to the titanium dioxide layer from 4T1 of manganese d-states due to the smaller energy barrier. Based on the above, the self-powered photocurrent density of photodetectors has nearly twice enhancement from 0.08 mA·cm−2 to 0.14 mA·cm−2 and a high responsivity up to 7.3 mA·W−1 was achieved at 340 nm.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420925674","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41446445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wideband absorber based on conductive ink frequency selective surface with polarization insensitivity and wide-incident-angle stability","authors":"G. Deng, Kun Lv, Hanxiao Sun, Yuan Hong, Xiaoying Zhang, Zhiping Yin, Jun Yang","doi":"10.1177/1847980420935718","DOIUrl":"https://doi.org/10.1177/1847980420935718","url":null,"abstract":"In this article, a wideband, polarization-insensitive, and wide-incident-angle stable absorber based on conductive ink frequency selective surface is presented. The presented absorber is compatible with screen printing technology. The design and absorption principle of the proposed absorber is presented, and simulation analysis is conducted. The simulation results show that in the frequency range 6.58–16.38 GHz, the absorptivity of the proposed absorber is greater than 90%, while the relative absorption bandwidth is 85.4%. The whole absorber structure is relatively thin, having a total thickness of 3.3 mm, corresponding to 0.126λ0 at its center frequency. In addition, for both transverse electric and transverse magnetic incident waves, the proposed absorber achieves the absorptivity of more than 80% at the incident angle of up to 45°. A prototype of the proposed absorber is fabricated and used in experimental verification. The obtained experimental results show a good agreement with the numerical simulations. This absorber has great potential applications in the field of microwave sensing and absorbing.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420935718","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49522812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of crystallization behavior induced by different mineral fillers in polypropylene nanocomposites","authors":"L. Castillo, S. Barbosa","doi":"10.1177/1847980420922752","DOIUrl":"https://doi.org/10.1177/1847980420922752","url":null,"abstract":"A comparative analysis of crystallization behavior induced by several mineral fillers in polypropylene nanocomposites was performed. Morphological changes and thermal properties of nanocomposites were evaluated, considering the influence of shape, crystalline morphology, and concentration of mineral particles. For this study, hydrated magnesium silicates with different particle morphologies, such as platelets (talc) and fibers (sepiolite), were used for nanocomposites. In addition, to analyze the effect of mineral crystallinity on nanocomposites, talc and sepiolite from different origin and genesis were selected. Nanocomposites were compounded and injection molded, using different filler concentration (0, 1, and 3% w/w) for each mineral particle. To evaluate the particle influence on nanocomposite crystallinity, X-ray diffraction was used to determine crystalline phases and crystal orientation, meanwhile differential scanning calorimetry was performed to obtain thermal properties. Main results revealed that talc has a higher nucleating effect on polypropylene matrix than sepiolite fibers, regardless of their origin and genesis. Meanwhile, a transcrystalline layer that surrounds the fiber surface is observed for nanocomposite containing sepiolite. Moreover, Argentinean talc induces different crystalline phases in nanocomposite with respect to Australian one, which partly influences on mechanical properties.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420922752","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49643427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dispersion of chitosan nanoparticles stable over a wide pH range by adsorption of polyglycerol monostearate","authors":"Hyo-Sun Kim, S. Lee, Chae-Jung Eun, Jeseung Yoo, Y. Seo","doi":"10.1177/1847980420917260","DOIUrl":"https://doi.org/10.1177/1847980420917260","url":null,"abstract":"We have developed stable chitosan colloids over a wide pH range without cross-linkers or gelling agents. The colloid was prepared using chitosan nanoparticle obtained from pulverization of bulk chitosan powder, followed by surface treatment using small amount of ascorbic acid (AA) and polyglycerol monostearate (PGMS) in water. Chitosan nanoparticles were well dispersed in a diluted AA solution due to the protonation of the chitosan chain on the surface. And then, the addition of PGMS led them to exhibit highly stable dispersion even in alkali conditions and 50 °C. The hydrodynamic diameter of the colloid was monitored using dynamic light scattering and the real image of the colloid was obtained using cryo-electron microscope measurement. This chitosan colloid will be useful for developing food ingredients or drug carrier templates that should be stable over a wide pH range.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420917260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44828957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on modification mechanism of workability and mechanical properties for graphene oxide-reinforced cement composite","authors":"Y. Suo, R. Guo, H. Xia, Yang Yang, Feng Yan, Qianmin Ma","doi":"10.1177/1847980420912601","DOIUrl":"https://doi.org/10.1177/1847980420912601","url":null,"abstract":"Graphene oxide/cement composite was prepared using a graphene oxide aqueous solution. The workability and mechanical properties of graphene oxide/cement composite with different concentrations for graphene oxide and the ratio of water to cement were investigated. The results observed were the fluidity of cement pastes decreased noticeably with the addition of graphene oxide and increased with the increase in the ratio of water to cement for all tested samples of different graphene oxide contents. It is indicated that a noticeable inverse correlation between the concentration of graphene oxide and fluidity was observed, and a positive linear relationship between the ratio of water to cement and fluidity was also obtained. The compressive strength of cement pastes significantly improved in the presence of an appropriate concentration of graphene oxide as compared to that of the cement paste without graphene oxide; this difference was due to the denser microstructure of graphene oxide/cement composite than that of the control specimens. With the combined analysis of X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry, the results showed that graphene oxide could promote and regulate the formation and connection of calcium hydroxide and calcium silicate hydrate during the hydration reaction, forming numerous regular and extremely compact plate-shaped crystals, and the compact plate-shaped microstructures constituted of not only calcium hydroxide and calcium silicate hydrate but also wrapped ettringite. This investigation will provide a flexible way to preparation of graphene oxide/cement composite with wanted fluidity and optimized compressive strength that promote the industry application of graphene oxide/cement composite.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420912601","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46437629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation, characterization, and in vitro evaluation of amphiphilic peptide P12 and P12-DOX nanomicelles as antitumor drug carriers","authors":"Ping Song, W. Du, Wanzhen Li, Longbao Zhu, Weiwei Zhang, Xinxing Gao, Yugui Tao, Fei Ge","doi":"10.1177/1847980420911519","DOIUrl":"https://doi.org/10.1177/1847980420911519","url":null,"abstract":"Polymerized polypeptide nanomicelles have attracted much attention as novel drug carriers because of their good biocompatibility and degradability. To prepare doxorubicin (DOX)-loaded nanomicelles, an amphiphilic peptide, FFHFFH-KKGRGD (P12), was synthesized by solid-phase synthesis, and the physicochemical and drug-release properties, as well as the cytotoxicity of the nanomicelles, were evaluated in vitro. The P12-DOX polymer micelles were prepared by dialysis. The morphology and particle size were characterized by transmission electron microscopy and dynamic light scattering. The critical micelle concentration (CMC) of the polymer was determined by the probe method, and the drug-release characteristics of the micelles were studied by dynamic dialysis. The cytotoxicity and uptake of the P12-DOX micelles were evaluated against mouse breast cancer cells (4T1) and human umbilical vein endothelial cells. The peptide polymer micelles containing DOX were uniformly sized and had a spherical core–shell structure with an average particle size of 128.6 nm. The CMC of the polymer was low (0.0357 mg/mL). The in vitro release of DOX from the micelles is slow and is consistent with first-order kinetics. The copolymer micelles of the P12 polypeptide and DOX can be used as nanoscale spherical carriers of hydrophobic drugs and have broad applicability.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420911519","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47678584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of modified paints with nano-structured additives and its potential applications","authors":"R. Solano, D. Patiño-Ruiz, A. Herrera","doi":"10.1177/1847980420909188","DOIUrl":"https://doi.org/10.1177/1847980420909188","url":null,"abstract":"Recently, an increase in the production of intelligent nanomaterials has been reported for the application of solid surface coating. These nanomaterials provide a wide number of functionalities such as anticorrosive, antibacterial, and self-cleaning properties. Hence, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles were synthesized using a green chemistry approach. These nanoparticles were fully characterized by scanning electron microscopy, energy-dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet (UV)–visible spectroscopy, Brunauer–Emmett–Teller test, and nitrogen adsorption–desorption isotherm. Then, a commercial enamel-type paint was modified by using different concentrations (2, 3.5, and 5 w/v%) of nanoparticles. These nanofilled paints were then brushed onto the surface of different types of materials such as carbon steel sheets, wood sheets, and aluminum disks. Anticorrosive, self-cleaning, and antibacterial properties of the nanofilled paints were evaluated, with the aim to determine the capability for this application. According to the characterization results, TiO2 and ZnO nanoparticles exhibited similar physicochemical properties compared to those synthesized using traditional methods. The anticorrosion results revealed that nanofilled paints provide a barrier using low concentrations of nanoparticles, due to the decrease of agglomerates on the surface avoiding the presence of high porosity. In the case of self-cleaning, a proposed mechanism of degradation demonstrated that the presence of both nanoparticles in the paint provided high degradation of methylene blue due to the high surface area offered by the nanoparticles. On the other hand, antibacterial activity under UV light was observed only for ZnO nanoparticles, which may be related to the diffusion of nanoparticles into the cell membrane of the bacteria, affecting the normal function. These results showed to be promising for the modification of paints with TiO2 and ZnO nanoparticles, and the application on solid surfaces for the construction, and even in textile fields.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420909188","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44193321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}