Study of viscoelastic properties of nanocomposites of SiO2–acrylonitrile–butadiene–styrene

Nanocomposites of acrylonitrile–butadiene–styrene (ABS) and nanosilica with different nanoparticle sizes and various loadings are prepared. Rheological experiments such as frequency sweep, strain sweep, and rotational test are performed to investigate the influence of nanoparticle loading and size on the viscoelastic properties of the nanocomposites. The results show that nanocomposites with higher filler loading and smaller particle size have both higher storage and loss moduli. Moreover, the results indicate that the storage modulus is more sensitive than loss modulus to filler loading and nanoparticle size. The smaller nanoparticles and higher filler loadings lead to the enhancement of nanoparticle surface area so that the viscoelastic properties are intensified through increase of polymer chain adsorption on nanoparticle, and creation of a network structure in the nanocomposites. The network structure causes changes to the rheological behavior of the nanocomposite such as solid‐like behavior in the low‐frequency region and reduction of the Newtonian region. The scanning electron microscopy micrographs revealed that the particle aggregates increase with particle size reduction and increasing nanoparticle content. We also used a nonlinear optimization to obtain the parameters of a multimode Maxwell model for low nanofiller content ABS/SiO₂ nanocomposites and found the relaxation times of the polymer chains increased with increasing nanoparticle content. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

A fuzzy histogram weighting method for efficient image contrast enhancement

Multimedia Tools and Applications - Image contrast enhancement is an important step in digital image processing applications. In this paper, we present an efficient contrast enhancement approach,...     

A novel MEMS capacitive microphone using spring-type diaphragm

Microsystem Technologies - In this paper, we present a new design of diaphragm that supported by frog arms for MEMS capacitive microphone structure. The proposed diaphragm reduces the air damping...     

Design and modeling of a frog-shape MEMS capacitive microphone using SOI technology

Microsystem Technologies - In this paper, a novel micro electro mechanical systems (MEMS) capacitive microphone is designed and modeled using SOI technology. We present static linear spring...     

Novel synthesis of Zirconyl Schiff base complex-functionalized MCM-48 using in oxidation of sulfides and Knoevenagel condensation reaction

In this study the new metal complex functionalized MCM-48 was synthesized and characterized by a number of techniques including TEM, XRD, TGA, IR, EDX, BET and ICP-AES. Zirconyl Schiff base complex of MCM-48 catalyzed the selective oxidation of a variety of sulfides to the corresponding sulfoxides in high yields. Also this modified MCM-48 could have potential application as catalyst for Knoevenagel condensation of various aldehydes with malononitrile and ethyl cyanoacetate. The catalyst could readily be separated from the reaction mixture and reused for several runs without significant loss in catalytic efficiency.     

Design and fabrication of high performance condenser microphone using C-slotted diaphragm

Microsystem Technologies - In this paper, we present a new design of MEMS condenser microphone using SOI wafer. To improve the performance of the microphone, a perforated diaphragm with C-shape...