The intrinsic negative Poisson’s ratio effect at the level of molecule in two-dimensional nanomaterials, especially in the perfect planar nanostructures with a single atom thickness, is really rare and has attracted a lot of research interests because of its unique mechanical properties in the nanoscale and extensive applications in mechanical nanodevices. In this work, a novel ideal planar carbon nanostructure (PCNS) framework with a single atom thickness composed by carbon and hydrogen atoms is proposed and studied by means of first-principles density functional calculation. The results showed that the PCNS is, simultaneously, of excellent thermodynamic, molecular dynamic and mechanical stabilities. In addition, the electronic structure, mechanical characters, and optical-electronic characteristics of PCNS are also explored. Excitedly, it is found that the PCNS has a significant negative Poisson’s ratio effect in plane, and the maximum value of Poisson’s ratio is as high as − 2.094. Meanwhile, the material has a wide range of elastic mechanics. Moreover, the PCNS presents an ideal UV absorption performance. It is hoped that this work could be a useful structural design strategy for the development of the ideal 2D carbon-based nanomechanical devices with the intrinsic negative Poisson’s ratio effect and other electronic functions.

In this work, TiO2 3D nanostructures (TF30) were prepared via a facile wet chemical process using ammonium hexafluorotitanate. The synthesized 3D TiO2 nanostructures exhibited well-defined crystalline and hierarchical structures assembled from TiO2 nanorods with different thicknesses and diameters, which comprised numerous small beads. Moreover, the maximum specific surface area of TiO2 3D nanostructures was observed to be 191 m2g-1, with concentration of F ions on the surface being 2 at%. The TiO2 3D nanostructures were tested as photocatalysts under UV irradiation using Rhodamine B solution in order to determine their photocatalytic performance. The TiO2 3D nanostructures showed a higher photocatalytic activity than that of the other TiO2 samples, which was likely associated with the combined effects of a high crystallinity, unique features of the hierarchical structure, a high specific surface area, and the advantage of adsorbing F ions.

Cu/PET composite films are widely used in a variety of wearable electronics. Lifetime of the electronics is determined by adhesion between the Cu film and the PET substrate. The formation of an anisotropic nanostructure on the PET surface by surface modification can enhance Cu/PET interfacial adhesion. The shape and size of the anisotropic nanostructures of the PET surface can be controlled by varying the surface modification conditions. In this work, the effect of Cu/PET interface nanostructures on the failure mechanism of a Cu/PET flexible composite film is studied. From observation of the morphologies of the anisotropic nanostructures on plasma-treated PET surfaces, and cross-sections and surfaces of the fractured specimens, the Cu/PET interface area and nanostructure width are analyzed and the failure mechanism of the Cu/PET film is investigated. It is found that the failure mechanism of the Cu/PET flexible composite film depends on the shape and size of the plasmatreated PET surface nanostructures. Cu/PET interface nanostructures with maximal peel strength exhibit multiple craze-crack propagation behavior, while smaller or larger interface nanostructures exhibit single-path craze-crack propagation behavior.

Core-shell structured nanoparticles are garnering attention because these nanoparticles are expected to have a wide range of applications. The objective of the present study is to improve the coating efficiency of gold shell formed on the surface of silica nanoparticles for SiO2@Au core-shell structure. For the efficient coating of gold shell, we attempt an in-situ synthesis method such that the nuclei of the gold nanoparticles are generated and grown on the surface of silica nanoparticles. This method can effectively form a gold shell as compared to the conventional method of attaching gold nanoparticles to silica particles. It is considered possible to form a dense gold shell because the problems caused by electrostatic repulsion between the gold nanoparticles in the conventional method are eliminated.

목 적: 곡률이 없는 안경렌즈 위에 나노 구조 층을 포함한 안경렌즈 3층 코팅 막의 반사방지에 관한 연구 를 하였다. 방 법: 시뮬레이터 설계에서 안경렌즈 위에 하드코팅 막을, 그 위에 Al2O3/ ZrO2/Al2O3(나노 구조) 막을 쌓았다. 원기둥 hole 반경, 두께, 주기와 ZrO2 막의 두께에 따른 반사율 스펙트럼을 관찰하여 최적의 반사 방지막을 찾았다. 결 과: 나노 원기둥 hole 주기와 두께를 고정하고 반경을 변화시키면서 반사율 스펙트럼을 관찰한 결과, 반경이 70 nm일 때 파장 450 nm에서 650 nm까지 반사율이 0%에 가까웠다. 그리고 나노 원기둥 hole 주기와 반경을 고정하고 두께를 변화시키면서 반사율 스펙트럼을 관찰한 결과, 나노 원기둥 hole 높이가 약 100 nm 에서 최적의 반사율 스펙트럼을 얻을 수 있었다. 또한 나노 원기둥 hole 주기와 반경을 변화시키면서 반사율 스펙트럼을 관찰한 결과, 주기 200 nm 이하에서는 최적의 반사율 스펙트럼을 나타내었다. ZrO2 막의 두께를 변화시킨 결과 130 nm에서 반사방지막 코팅이 최적화됨을 알 수 있었다. 결 론: Al2O3/ ZrO2/Al2O3(나노 구조) 막으로 이루어진 안경렌즈 3층 코팅 막의 반사방지막에 관한 연구 한 결과, 나노 원기둥 hole 반경은 70 nm에서, 높이는 100 nm에서, 주기는 200 nm 이하에서, ZrO2 막의 두께는 130 nm에서 반사율 스펙트럼이 최적이 되었다.

There have been many efforts to modify and improve the properties of functional thin films by hybridization with nano-sized materials. For the fabrication of electronic circuits, micro-patterning is a commonly used process. For photochemical metal-organic deposition, photoresist and dry etching are not necessary for microscale patterning. We obtained direct-patternable SnO2 thin films using a photosensitive solution containing Ag nanoparticles and/or multi-wall carbon nanotubes (MWNTs). The optical transmittance of direct-patternable SnO2 thin films decreased with introduction of nanomaterials due to optical absorption and optical scattering by Ag nanoparticles and MWNTs, respectively. The crystallinity of the SnO2 thin films was not much affected by an incorporation of Ag nanoparticles and MWNTs. In the case of mixed incorporation with Ag nanoparticles and MWNTs, the sheet resistance of SnO2 thin films decreased relative to incorporation of either single component. Valence band spectral analyses of the nano-hybridized SnO2 thin films showed a relation between band structural change and electrical resistance. Direct-patterning of SnO2 hybrid films with a line-width of 30 μm was successfully performed without photoresist or dry etching. These results suggest that a micro-patterned system can be simply fabricated, and the electrical properties of SnO2 films can be improved by incorporating Ag nanoparticles and MWNTs.

[ ] nanotubes for photocatalytic application have been synthesized by hydrothermal method. nanotubes are formed by washing process after reaction in alkalic solution. Nanotubes with different morphology have been fabricated by changing NaOH concentration, temperature and time. nanoparticles were treated inside NaOH aqueous solution in a Teflon vessel at for 20 h, after which they were washed with HCl aqueous solution and deionized water. Nanotube with the most perfect morphology was formed from 0.1 N HCl washing treatment. nanotube was also obtained when the precursor was washed with other washing solutions such as , NaCl, , and . Therefore, it was suggested that ion combined inside the precursor compound slowly comes out from the structure, leaving nanosheet morphology of compounds, which in turn become the nanotube in the presence of hydroxyl ion. To stabilize the sheet morphology, the different type of washing treatment solution might be considered such as amine class compounds.

The nanostructure control of ceramics can be achieved by using fine starting powder and retardation of grain growth. The spark plasma sintering technique is useful to retard the grain growth by rapid heating. In the present work, the change of microstructure was investigated with emphasis on the particle size of starting powder, the amount of sintering additive and the heating schedule. The rapid heating by spark plasma sintering gave the fine microstructure consisting of equiaxed grains with the same size as starting particles. The spark plasma sintering of fine powder was effective to control the microstrucutre on nano-meter level.

In this study the nanostructured ceramics have been fabricated by the combined application of magnetic pulsed compaction (MPC) and subsequent spark plasma sintering (SPS), and their density and hardness properties were investigated. The prepared by the combined processes showed an increase by in density, approaching the value close to the true density, and an enhancement by in hardness, compared to those fabricated by MPC or static compaction method followed by sintering treatment.