Directly Synthesis of Polymeric Nano-Composite from Waste Solid Absorbents of Treating Styrene Monomer-Containing Waste Gas

2009 ◽  
Vol 610-613 ◽  
pp. 61-63
Author(s):  
Wu Jang Huang ◽  
Ling Yin Chang ◽  
Hsiu Hsien Wu ◽  
Yan Jia Liou
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Nano Materials ◽  
Tio2 Powder ◽  
Nano Composite ◽  
Waste Gas ◽  
Styrene Monomer ◽  
Waste Solid

This study aimed to synthesize polystyrene (PS)-TiO2 nano-composite from the waste solid absorbent directly, so that the waste TiO2/PS solid absorbent could be used as nano-materials. TiO2 powder with a particle size of 12 nm was used for the solid absorbent. The TiO2 packed scrubbing tube was used for treating synthetic waste gas that contained styrene monomer. Experimental results confirmed that the concentrations of styrene in synthetic waste gas can be reduced by 62% after the activation of photocatalyst, and the lifetime of activated TiO2 catalyst is over 2 hours. From the NMR and DSC spectra of obtained products, PS is actually grafted on the surface of TiO2. The glass transition temperature of obtained PS in TiO2/PS solid absorbent is 100oC.

scholarly journals Predicting the influence of particle size on the glass transition temperature and viscosity of secondary organic material

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Markus Petters ◽  
Sabin Kasparoglu
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Critical Role ◽  
Particle Diameter ◽  
Cloud Formation ◽  
Melting Point Depression ◽  
Wide Range

Abstract Atmospheric aerosols can assume liquid, amorphous semi-solid or glassy, and crystalline phase states. Particle phase state plays a critical role in understanding and predicting aerosol impacts on human health, visibility, cloud formation, and climate. Melting point depression increases with decreasing particle diameter and is predicted by the Gibbs–Thompson relationship. This work reviews existing data on the melting point depression to constrain a simple parameterization of the process. The parameter $$\xi $$ ξ describes the degree to which particle size lowers the melting point and is found to vary between 300 and 1800 K nm for a wide range of particle compositions. The parameterization is used together with existing frameworks for modeling the temperature and RH dependence of viscosity to predict the influence of particle size on the glass transition temperature and viscosity of secondary organic aerosol formed from the oxidation of $$\alpha $$ α -pinene. Literature data are broadly consistent with the predictions. The model predicts a sharp decrease in viscosity for particles less than 100 nm in diameter. It is computationally efficient and suitable for inclusion in models to evaluate the potential influence of the phase change on atmospheric processes. New experimental data of the size-dependence of particle viscosity for atmospheric aerosol mimics are needed to thoroughly validate the predictions.

scholarly journals Microencapsulation and Characterization of Natural Polyphenols from PHF Extract

2018 ◽  
Author(s):  
Syed Ammar Hussain ◽  
Ahsan Hameed ◽  
Yusuf Nazir ◽  
Tahira Naz ◽  
Yang Wu ◽  
...  
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Beta Carotene ◽  
Alpha Amylase ◽  
Total Phenolic ◽  
Freeze Dried ◽  
Alpha Glucosidase

Microencapsulation of polyherbal formulation (PHF) extract was carried out by freeze drying method, by employing gum arabic (GA), gelatin (GE), and maltodextrin (MD) with their designated different combinations as encapsulating wall materials. Antioxidant components (i.e total phenolic contents (TPC),Total flavonoids contents (TFC), and total condensed contents (TCT)), antioxidant activity (i.e. DPPH, β-carotene & ABTS+ assays), moisture contents, water activity (aw), solubility, hygroscopicity, glass transition temperature (Tg), particle size, morphology, in vitro alpha-amylase and alpha-glucosidase inhibition and bioavailability ratios of the powders were investigated. Amongst all encapsulated products, TB (5% GA and 5% MD) and TC (10% GA) has proven to be the best treatments with respect to the highest preservation of antioxidant components and their antioxidant potential by DPPH and β-carotene assays and noteworthy for an ABTS+ assays, in addition, the aforesaid treatments also demonstrated lower moisture content, aw, particle size and higher solubility, hygroscopicity and glass transition temperature (Tg). All freeze dried samples showed irregular (asymmetrical) microcrystalline structures. Furthermore, TB and TC also illustrated the highest in vitro anti-diabetic potential due to great potency for inhibiting alpha-amylase and alpha-glucosidase activities. In the perspective of bioavailability, TA, TB and TC demonstrated the excellent bioavailability ratios (%).Futhermore, the phytochemo-profiling of ethanolic extract of PHF was also revealed to find out the bioactive compounds.

scholarly journals The Effect of Extender Particle Size on the Glass Transition Temperature of Model Epoxy Coatings

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 196 ◽  
Author(s):  
Muhammad Ahsan Bashir ◽  
Martin Gjerde Jakobsen ◽  
Vivian Beate Farstad
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Analysis ◽  
Organic Coatings ◽  
Particle Sizes ◽  
Scanning Calorimetry ◽  
Epoxy Amine ◽  
Thermosetting Epoxy

Inorganic extenders are important constituents of 2K thermosetting epoxy-amine coatings and their physical properties play an important role in the final properties of the organic coatings. The effects of extender particle size and loading (i.e., the amount of extender in component A or in the total formulation) on the glass transition temperature (Tg) of model epoxy-amine coatings were studied in this work with differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The obtained results show that the particle size and loading of feldspar particles (from 25 wt% to 70 wt%) do not influence the glass transition temperature of the model epoxy-amine coating significantly. In general, the smaller the particle size the lower the glass transition temperature of the coating but this depression in Tg seems negligible when seen relative to the change in extender particle size. Similar observations are reported for two model coatings having the same lamda (Λ) value but with silica of very different particle sizes (i.e., nanosilica and micron sized silica).

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