Simple and easy aqueous synthesis of highly aniotropic nanoplates future bio-application

임지수,방석호,( Aasim Shahzad ),정지영 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

We have demonstrated a simple, fast, and room temperature aqueous-phase synthesis of Ag nanoplates with controllable sizes from 1 to 17 mm via reduction of PEI-stabilized AgCl nanoparticles using H2O2 in the presence of PVP. Compared with typical synthetic methods for Ag nanoplates, the present synthesis has three strong advantages; short reaction time, low reaction temperature, and formation of large-sized Ag nanoplates. The synthesis is conducted at room temperature and only 10 min is needed to obtain the Ag nanoplates with highly crystalline nature. Furthermore, the synthesized Ag nanoplates have large side dimension of around 17 mm. Additionally, our Ag nanoplates showed less cytotoxicity compared to Ag nanoparticle. This modality may lead to further bio-application based on Ag nanoplates.

Fabrication of porous β-Bi₂O₃ nanoplates by phase transformation of bismuth precursor via low-temperature thermal decomposition process and their enhanced photocatalytic activity

Jung, Hyeon Jin,Park, Soojong,Kim, Kwang Dong,Kim, Tae Ho,Choi, Myong Yong,Lee, Kang Yeol Elsevier 2018 Colloids and surfaces. A, Physicochemical and engi Vol.550 No.-

<P><B>Abstract</B></P> <P>Direct phase transformation of bismuth complex nanoplates to β-Bi<SUB>2</SUB>O<SUB>3</SUB> ones was induced by low-temperature annealing at 250 °C. The β-Bi<SUB>2</SUB>O<SUB>3</SUB> nanoplates showed a nanoporous structure, which retained the tetragonal framework of the original bismuth complex nanoplates while releasing gas molecules produced during thermal decomposition, thereby enabling the formation of nanoporous structures extending through the nanoplate surfaces. The sizes, structures, optical properties, and composition distributions of the synthesized bismuth-organic complex and porous β-Bi<SUB>2</SUB>O<SUB>3</SUB> nanoplates were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, infrared spectroscopy, UV–vis diffuse reflectance spectroscopy, and x-ray diffraction. The porous β-Bi<SUB>2</SUB>O<SUB>3</SUB> nanoplates prepared by low-temperature annealing at 250 °C for 3, 5, and 7 h showed photocatalytic activities for the photodegradation of methylene blue. The porous β-Bi<SUB>2</SUB>O<SUB>3</SUB> nanoplates annealed for 7 h showed the best photocatalytic activity. To confirm the nanoplate photocatalyst cytotoxicity, cell viability tests were performed by treating HEK293 normal kidney cells with the porous β-Bi<SUB>2</SUB>O<SUB>3</SUB> nanoplates.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nonlocal bending, vibration and buckling of one-dimensional hexagonal quasicrystal layered nanoplates with imperfect interfaces

Haotian Wang,Junhong Guo 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.6

Due to interfacial ageing, chemical action and interfacial damage, the interface debonding may appear in the interfaces of composite laminates. Particularly, the laminates display a side-dependent effect at small scale. In this work, a threedimensional (3D) and anisotropic thick nanoplate model is proposed to investigate the effects of imperfect interface and nonlocal parameter on the bending deformation, vibrational response and buckling stability of one-dimensional (1D) hexagonal quasicrystal (QC) layered nanoplates. By combining the linear spring model with the transferring matrix method, exact solutions of phonon and phason displacements, phonon and phason stresses of bending deformation, the natural frequencies of vibration and the critical buckling loads of 1D hexagonal QC layered nanoplates are derived with imperfect interfaces and nonlocal effects. Numerical examples are illustrated to demonstrate the effects of the imperfect interface parameter, aspect ratio, thickness, nonlocal parameter, and stacking sequence on the bending deformation, the vibrational response and the critical buckling load of 1D hexagonal QC layered nanoplate. The results indicate that both the interface debonding and nonlocal effect can reduce the stiffness and stability of layered nanoplates. Increasing thickness of QC coatings can enhance the stability of sandwich nanoplates with the perfect interfaces, while it can reduce first and then enhance the stability of sandwich nanoplates with the imperfect interfaces. The biaxial compression easily results in an instability of the QC layered nanoplates compared to uniaxial compression. QC material is suitable for surface layers in layered structures. The mechanical behavior of QC layered nanoplates can be optimized by imposing imperfect interfaces and controlling the stacking sequence artificially. The present solutions are helpful for the various numerical methods, thin nanoplate theories and the optimal design of QC nano-composites in engineering practice with interfacial debonding.

Zigzag-Shaped Silver Nanoplates: Synthesis via Ostwald Ripening and Their Application in Highly Sensitive Strain Sensors

Kim, Jinwoo,Lee, Sang Woo,Kim, Mun Ho,Park, O Ok American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.45

<P>Zigzag-shaped Ag nanoplates display unique anisotropic planar structures with unusual jagged edges and relatively large lateral dimensions. These characteristics make such nanoplates promising candidates for metal inks in printed electronics, which can be used for realizing stretchable electrodes. In the current work, we used a one-pot coordination-based synthetic strategy to synthesize zigzag-shaped Ag nanoplates. In the synthetic procedure, cyanuric acid was used both as a ligand of the Ag<SUP>+</SUP> ion, hence producing complex structures and controlling the kinetics of the reduction of the cation, and as a capping agent that promoted the lateral growth of the Ag nanoplates. Hence, cyanuric acid played a crucial role in the formation of zigzag-shaped nanoplates. In contrast to previous studies that reported oriented attachment to be the predominant mechanism responsible for the growth of zigzag-shaped nanoplates, Ostwald ripening was the dominant growth mechanism in the current work. Our findings on the particle morphology and crystalline structure of the Ag nanoplates motivated us to use them as conductive materials for stretchable strain sensors. Strain sensors based on nanocomposites of our zigzag-shaped Ag nanoplate and polydimethylsiloxane in the form of a sandwich structure were successfully produced by following a simple, low-cost, and solution-processable method. The strain sensors exhibited extremely high sensitivity (gauge factor ≈ 2000), high stretchability with a linear response (≈27%), and high reliability, all of which allowed the sensor to monitor diverse human motions, including joint movement and phonation.</P> [FIG OMISSION]</BR>

Triangular Silver Nanoplates-Based Sensing Platform for Detection of Melamine

( Alexander David Ardianrama ),김문호 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

The fascinating plasmonic properties of triangular silver nanoplates has been widely used for chemical and biological sensing application because of this intrinsic instability. These plasmonic properties are dependent on the size, shape and the structure of the nanoplates. However, most of these applications have relied on toxic and harmful etchants to control the shape of the triangular silver nanoplates. In this work, we introduce the eco-friendly etchant to control the shape of the triangular silver nanoplates. In the presence of the etchant, triangular nanoplates were rapidly transformed into spheroidal shape. But in the presence of melamine, the shape of the nanoplates was preserved and the colour of the solution did not change. Based on these correlations, we can develop the colorimetric detection probe for the melamine.

Synthesis of rare earth oxide nanoplates with single unit cell thickness using a thermal decomposition method

김우식,Euiyoung Jung,유태경 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

We report the colloidal synthesis of rare earth oxide nanoplates with square and disk shapes using thermal decomposition of Ln(CH3CO2)3·xH2O in the presence of a mixture of oleylamine and oleic acid (Ln=La, Pr, Nd, Dy, Er, and Y). In this synthesis, oleylamine plays an important role in the formation of ultra-thin nanoplates with thickness of 1.1 nm, which corresponds to a single unit cell dimension of rare earth oxides, and oleic acid serves as a capping agent for the formation of nanoplates having nano-sized side dimension (around 15-40 nm). By varying the rare earth precursors, we obtained square-shaped nanoplates (La2O3, Pr2O3, and Nd2O3) and disk-shaped nanoplates (Dy2O3, Er2O3, and Y2O3), respectively, confirming that our synthesis could be extended to the synthesis of various rare earth oxide nanoplates.

Fabrication of novel polyethersulfone based nanofiltration membrane by embedding polyaniline-co-graphene oxide nanoplates

Mojtaba Moochani,Abdolreza Moghadassi,Sayed Mohsen Hosseini,Ehsan Bagheripour,Fahime Parvizian 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.9

Mixed matrix polyethersulfone (PES) based nanofiltration membrane was prepared through phase inversion method by using of polyvinylpyrrolidone (PVP) as pore former and N, N dimethylacetamide (DMAc) as solvent. Polyaniline-co-graphene oxide nanoplates (PANI/GO) were utilized as additive in membrane fabrication. The PANI/ GO nanoplates were prepared by polymerization of aniline in the presence of graphene oxide nanoplates. FTIR analysis, scanning electron microscopy (SEM), scanning optical microscopy (SOM), 3D images surface analysis, water contact angle, water content tests, tensile strength tests, porosity tests, salt rejection and flux tests were used in membrane characterization. FT-IR results verified formation of PANI on graphene oxide nanoplates. SOM images showed uniform particles distribution for the mixed matrix membranes. SEM images also showed formation of wide pores for the modified membranes. Water flux showed constant trend nearly by use of PANI/GO in the casting solution. Opposite trend was found for the membrane surface hydrophilicity. Salt rejection was enhanced sharply by utilizing of PANI/ GO. The membrane’s tensile strength was improved by increase of PANI/GO concentration. The water content was increased initially by use of PANI/GO nanoplates up to 0.05%wt into the casting solution and then decreased. Membrane porosity was also enhanced by using of PANI/GO nanoplates. Modified membrane containing 0.5%wt PANI/ GO nanoplates showed more appropriate antifouling characteristic compared to others.

Thermal buckling of FGM nanoplates subjected to linear and nonlinear varying loads on Pasternak foundation

Ebrahimi, Farzad,Ehyaei, Javad,Babaei, Ramin Techno-Press 2016 Advances in materials research Vol.5 No.4

Thermo-mechanical buckling problem of functionally graded (FG) nanoplates supported by Pasternak elastic foundation subjected to linearly/non-linearly varying loadings is analyzed via the nonlocal elasticity theory. Two opposite edges of the nanoplate are subjected to the linear and nonlinear varying normal stresses. Elastic properties of nanoplate change in spatial coordinate based on a power-law form. Eringen's nonlocal elasticity theory is exploited to describe the size dependency of nanoplate. The equations of motion for an embedded FG nanoplate are derived by using Hamilton principle and Eringen's nonlocal elasticity theory. Navier's method is presented to explore the influences of elastic foundation parameters, various thermal environments, small scale parameter, material composition and the plate geometrical parameters on buckling characteristics of the FG nanoplate. According to the numerical results, it is revealed that the proposed modeling can provide accurate results of the FG nanoplates as compared some cases in the literature. Numerical examples show that the buckling characteristics of the FG nanoplate are related to the material composition, temperature distribution, elastic foundation parameters, nonlocality effects and the different loading conditions.

Shape-controlled Electrodeposition of Standing Pt Nanoplates on Gold Substrates as a Sensor Platform for Nitrite Ions

안세진,SHANMUGAMMANIVANNAN,서예지,김규원 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.6

Electrochemically deposited standing platinum (Pt) nanoplates were fabricated on gold (Au) substrate assisted by the amine functionalized silane and L-glutamic acid (LG) as nucleating and structure directing agents, respectively. Various win over factors responsible for the electrodeposition of the Pt nanoplates was methodologically analyzed. The treatment time with the thiol functionalized silane (M) and the role of LG were found to be decisive for the demonstration of Pt nanoplates display at the Au substrate. Plausible growth mechanism was proposed for the vertical growth and random orientation of the Pt nanoplates. Constructed Pt nanoplates displayed substrate were applied as a sensor platform toward the nitrite ion detection; improved performance was noted than that of the controlled experiments. Furthermore, sensor platform had exhibited recent selectivity toward the nitrite ions from the mixture of possible interferences.

Size-dependent buckling behaviour of FG annular/circular thick nanoplates with porosities resting on Kerr foundation based on new hyperbolic shear deformation theory

Amirmahmoud Sadoughifar,Fatemeh Farhatnia,Mohsen Izadinia,Sayed Behzad Talaeetaba 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.3

This work treats the axisymmetric buckling of functionally graded (FG) porous annular/circular nanoplates based on modified couple stress theory (MCST). The nanoplate is located at the elastic medium which is simulated by Kerr foundation with two spring and one shear layer. The material properties of the porous FG nanostructure are assumed to vary through the nanoplate thickness based on power-law rule. Based on two variables refined plate theory, the governing equations are derived by utilizing Hamilton's principle. Applying generalized differential quadrature method (GDQM), the buckling load of the annular/circular nanoplates is obtained for different boundary conditions. The influences of different involved parameters such as boundary conditions, Kerr medium, material length scale parameter, geometrical parameters of the nanoplate, FG power index and porosity are demonstrated on the nonlinear buckling load of the annular/circular nanoplates. The results indicate that with increasing the porosity of the nanoplate, the nonlinear buckling load is decreased. In addition, with increasing the material length scale parameter to thickness ratio, the effect of spring constant of Kerr foundation on the buckling load becomes more prominent. The present results are compared with those available in the literature to validate the accuracy and reliability. A good agreement is observed between the two sets of the results.