scholarly journals Impacts of Different Functional Groups on the Kinetic Rates of α-Amine Ketoximesilanes Hydrolysis in the Preparation of Room Temperature Vulcanized Silicone Rubber

Materials ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 790 ◽  
Author(s):  
Huihui Xu ◽  
Zihou Liu ◽  
Qingyang Liu ◽  
Yiling Bei ◽  
Qingzeng Zhu
Keyword(s):  
Functional Groups ◽  
Silicone Rubber ◽  
Room Temperature ◽  
Kinetic Rates

scholarly journals Properties of Silicone Rubber-Based Composites Reinforced with Few-Layer Graphene and Iron Oxide or Titanium Dioxide

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1550
Author(s):  
Vineet Kumar ◽  
Anuj Kumar ◽  
Minseok Song ◽  
Dong-Joo Lee ◽  
Sung-Soo Han ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Titanium Dioxide ◽  
Iron Oxide ◽  
Stress Relaxation ◽  
Silicone Rubber ◽  
Room Temperature ◽  
Relaxation Rates ◽  
Layer Graphene ◽  
Few Layer Graphene ◽  
Mechanical Actuation

The increasing demand for polymer composites with novel or improved properties requires novel fillers. To meet the challenges posed, nanofillers such as graphene, carbon nanotubes, and titanium dioxide (TiO2) have been used. In the present work, few-layer graphene (FLG) and iron oxide (Fe3O4) or TiO2 were used as fillers in a room-temperature-vulcanized (RTV) silicone rubber (SR) matrix. Composites were prepared by mixing RTV-SR with nanofillers and then kept for vulcanization at room temperature for 24 h. The RTV-SR composites obtained were characterized with respect to their mechanical, actuation, and magnetic properties. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to investigate the composite raw materials and finished composites, and X-ray photoelectron spectroscopy (XPS) analysis was used to study composite surface elemental compositions. Results showed that mechanical properties were improved by adding fillers, and actuation displacements were dependent on the type of nanofiller used and the applied voltage. Magnetic stress-relaxation also increased with filler amount and stress-relaxation rates decreased when a magnetic field was applied parallel to the deformation axes. Thus, this study showed that the inclusion of iron oxide (Fe3O4) or TiO2 fillers in RTV-SR improves mechanical, actuation, and magnetic properties.

scholarly journals Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 623
Author(s):  
Monika Gupta ◽  
Huzein Fahmi Hawari ◽  
Pradeep Kumar ◽  
Zainal Arif Burhanudin ◽  
Nelson Tansu
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Functional Groups ◽  
Recovery Time ◽  
Room Temperature ◽  
Co2 Gas ◽  
Reduced Graphene ◽  
Response And Recovery

The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.

Sc(OTf)3-Mediated Silylation of Hydroxy Functional Groups on a Solid Surface: A Catalytic Grafting Method Operating at Room Temperature

2008 ◽  
Vol 47 (1) ◽  
pp. 109-112 ◽  
Author(s):  
Ye-Rim Yeon ◽  
Young Jun Park ◽  
Ji-Sung Lee ◽  
Jung-Woo Park ◽  
Sin-Gun Kang ◽  
...  
Keyword(s):  
Functional Groups ◽  
Solid Surface ◽  
Room Temperature

Ni-catalyzed cascade coupling reactions: synthesis and thermally-activated delayed fluorescence characterization of quinazolinone derivatives

2021 ◽  
Author(s):  
Zhongyan Chen ◽  
Lepeng Chen ◽  
Shou-Feng Zhang ◽  
Qianqian Zhen ◽  
Wenzhang Xiong ◽  
...  
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Delayed Fluorescence ◽  
Coupling Reactions ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Quinazolinone Derivatives

A nickel-catalyzed synthesis of 1,3-diaryl-6H-pyrazino[2,1-b]quinazolin-6-one was developed. This method enabled to access valuable pyrazino-fused quinazolinones with tolerance of many functional groups even at room temperature. The desired pyrazino-fused quinazolinones emit...

Thermooxidative Aging Studies on Silicone Rubber and Lifetime Prediction

2013 ◽  
Vol 777 ◽  
pp. 11-14
Author(s):  
You Shan Wang ◽  
Sha Sha Jiang ◽  
Yu Peng Liu
Keyword(s):  
Silicone Rubber ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Activation Energies ◽  
Lifetime Prediction ◽  
Arrhenius Behavior ◽  
Compression Set ◽  
Degradation Processes ◽  
Aging Studies ◽  
Significant Compression

Silicone rubber have been aged in air while under 25% compression at temperature up to 250°C. These studies examined the compression set of silicone rubber at accelerated (elevated) temperatures and were then used to make predictions about compression set at room temperature. The data obtained could be amenable to timetemperature superposition and Arrhenius treatment. The results suggest the presence of two degradation processes with activation energies of 71.6 kJ mol-1 (for temperatures above 165 °C) and 26.08 kJ mol-1 (for temperatures below 165 °C). Based on the extrapolation of the non-Arrhenius behavior, it was estimated that significant compression set loss would occur after around 67 years at 25 °C.

scholarly journals PENGARUH WAKTU CURING TERHADAP KUAT TEKAN GEOPOLIMER BERBASIS FLY ASH

2019 ◽  
Vol 2 (1) ◽  
pp. 50
Author(s):  
Andrie Harmaji ◽  
Claudia Claudia ◽  
Lia Asri ◽  
Bambang Sunendar ◽  
Ahmad Nuruddin
Keyword(s):  
Compressive Strength ◽  
Fourier Transform ◽  
Fly Ash ◽  
Power Plant ◽  
Functional Groups ◽  
Room Temperature ◽  
Three Dimensional ◽  
Fine Aggregate ◽  
Alkali Activator ◽  
Infra Red

Abstract:. Suralaya power plant produces fly ash about 219.000 ton per year. Fly ash contents of silica and alumina as major components that can be used as precursors for geopolymer, a three dimensional networks aluminosilicate polymers. This research aim is to utilize fly ash for geopolymer made by mixing fly ash, fine aggregate, and alkali activator in a cubic mould and curing was carried out at room temperature for 7 and 28 days. After 28 days of curing the compressive strength of geopolymer reached 41.70 MPa. XRD characterization shows Albite (NaAlSi3O8) formation which has similarity to geopolymer compound. Fourier Transform Infra Red spectra show siloxo and sialate bond. These are typical functional groups that are found in geopolymer materials.Keyword: geopolymer, fly ash, aluminosilicate, alkali activator, albite, siloxo, sialateAbstrak: Pembangkit Listrik Tenaga Uap (PLTU) Suralaya menghasilkan fly ash (abu terbang) sekitar 219.000 ton per tahun. Fly ash memiliki silika dan alumina sebagai komponen utama yang dapat digunakan sebagai prekursor untuk geopolimer, suatu material polimer aluminosilikat tiga dimensi. Penelitian ini bertujuan untuk memanfaatkan fly ash untuk geopolimer yang dibuat dengan mencampur fly ash, agregat halus, dan aktivator alkali dalam cetakan kubik dan pengawetan dilakukan pada suhu kamar selama 7 dan 28 hari. Setelah 28 hari curing kekuatan tekan geopolimer mencapai 41,70 MPa. Karakterisasi XRD menunjukkan pembentukan Albite (NaAlSi3O8) yang memiliki kemiripan dengan senyawa geopolimer. Hasil spektroskopi Fourier Transform Infra Red (FTIR) menunjukkan ikatan siloxo dan sialate yang merupakan gugus fungsional khas yang ditemukan dalam geopolimer.Kata Kunci: geopolimer, abu terbang, aluminosilikat, alkali aktivator, albite, siloxo, sialate

Charge Transfer Driven by Redox Dye Molecules on Graphene Nanosheets for Room-Temperature Gas Sensing

Nanoscale ◽  
2021 ◽  
Author(s):  
Wenbo Liu ◽  
Junwei Zeng ◽  
Yixun Gao ◽  
Hao Li ◽  
Nicolaas Frans de Rooij ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Functional Groups ◽  
Room Temperature ◽  
Gas Sensing ◽  
Graphene Nanosheets ◽  
Dye Molecules ◽  
Transfer Enhancement

Special functional groups to modify the surface of graphene has received much attention since it enables the charge transfer enhancement, thus realizing the gas-sensing at room temperature. In this work,...

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