Effects of Molecular Weight Distribution and Chemical Properties of Natural Organic Matter on Gold Nanoparticle Aggregation

2013 ◽  
Vol 47 (9) ◽  
pp. 4245-4254 ◽  
Author(s):  
Stacey M. Louie ◽  
Robert D. Tilton ◽  
Gregory V. Lowry
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Gold Nanoparticle ◽  
Molecular Weight Distribution ◽  
Natural Organic Matter ◽  
Weight Distribution ◽  
Chemical Properties ◽  
Nanoparticle Aggregation ◽  
Gold Nanoparticle Aggregation ◽  
And Chemical Properties

Pretreatment of natural organic matter to control biological stability

2016 ◽  
Vol 2 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Mahdi Bazri ◽  
Madjid Mohseni
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Molecular Weight Distribution ◽  
Natural Organic Matter ◽  
Weight Distribution ◽  
Biological Stability ◽  
Alum Coagulation

Impacts of UV/H2O2and alum coagulation on NOM molecular weight distribution and subsequent biostability of water were investigated.

Correlation of the Physicochemical Properties of Natural Organic Matter Samples from Different Sources to Their Effects on Gold Nanoparticle Aggregation in Monovalent Electrolyte

2015 ◽  
Vol 49 (4) ◽  
pp. 2188-2198 ◽  
Author(s):  
Stacey M. Louie ◽  
Eleanor R. Spielman-Sun ◽  
Mitchell J. Small ◽  
Robert D. Tilton ◽  
Gregory V. Lowry
Keyword(s):  
Organic Matter ◽  
Physicochemical Properties ◽  
Gold Nanoparticle ◽  
Natural Organic Matter ◽  
Nanoparticle Aggregation ◽  
Gold Nanoparticle Aggregation ◽  
Different Sources

Relationship between fluorescence characteristics and molecular weight distribution of natural dissolved organic matter in Lake Hongfeng and Lake Baihua, China

2006 ◽  
Vol 51 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Lanxiu Yue ◽  
Fengchang Wu ◽  
Congqiang Liu ◽  
Wen Li ◽  
Pingqing Fu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Fluorescence Characteristics

scholarly journals Molecular Weight Distribution of Kerogen with MALDI-TOF-MS

2020 ◽  
Author(s):  
Hyeonseok Lee ◽  
Mohammadreza Shokouhimehr ◽  
Mehdi Ostadhassan ◽  
Bo Liu ◽  
Arash Abarghani
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Organic Matter ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Rate Of Change ◽  
Molecular Structures ◽  
Thermal Maturity ◽  
Maldi Tof ◽  
Fine Grain

<p>Kerogen is an amorphous organic matter (AOM) in fine grain sediments, which produces petroleum and other byproducts when subjected to adequate pressure and temperature (deep burial conditions). Chemical characteristics of kerogen by considering its biogenic origin, depositional environment, and thermal maturity has been studied extensively with different analytical methods, though its molecular structure is still not fully known. In this study, conventional geochemical methods were used to screen bulk rock aliquots from the Bakken Shale with varying thermal maturities. Organic matter was isolated from the mineral matrix and then a mass spectrometry method was utilized to quantify molecular weight distribution (MWD) of four different kerogens at various thermal maturity levels (immature to late mature). Furthermore, to complement mass spectrometry, Fourier transform infrared (FTIR) spectroscopy was employed as a qualitative chemical and structural investigation technique. The MWD of four samples was obtained by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, and the results are correlated with the absorption indices (CH<sub>3</sub>/CH<sub>2</sub> ratio and aromaticity) calculated from the FTIR attenuated total reflectance (ATR) method. The results showed when the degree of maturity increases, the aliphatic length shortens, and the branching develops, as well as the aromatic structure becomes more abundant. Moreover, based on the MWD results, higher maturity kerogen samples would consist of larger size molecular structures, which are recognized as more developed aromatic, and aliphatic branching stretches. The combination of infrared spectroscopy (AFT-FTIR) and mass spectrometry (MALDI-TOF) provided MWD variations in kerogen samples as a function of maturity based on varying absorption indices and revealed the rate of change in molecular mass populations as a function of thermal maturity.</p>

scholarly journals Effect of Aging on the Rheological and Molecular Weight Distribution of Asphalt Binder Treated with Polyphosphoric Acid

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tao Ma ◽  
Kai Yang ◽  
Rui Li ◽  
Jiujian Shen
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Polyphosphoric Acid ◽  
Asphalt Binder ◽  
Chemical Properties ◽  
Gel Permeation Chromatography ◽  
Weight Analysis ◽  
Styrene Butadiene

Asphalt binder behaves as a viscoelastic material and its inherit performance is dominated by rheological and chemical properties. Aging of asphalt binder is a prominent distress for long-term in-service asphalt pavement. In this work, the effect of aging on base asphalt modified by polyphosphoric acid (PPA) has been investigated. For the objective, virgin asphalt binder was modified by various dosages of PPA, styrene-butadiene-styrene (SBS), and PPA/SBS compound modification. The short- and long-term aging processes were simulated by Rolling Thin-Film Oven Test (RTFOT) and Pressure Aging Vessel (PAV) procedure. Rheological property of five aged modified binders was evaluated by the Dynamic Shear Rheometer (DSR). Meanwhile, gel permeation chromatography (GPC) was conducted to measure the molecular weight distribution and dispersion coefficient during the aging process. The high-temperature stiffness of PPA polymer binders is slightly higher than that of SBS and PPA/SBS compound modified asphalts. The aging ratio and molecular weight analysis verify the lower thermal-oxidative susceptibility of PPA/SBS compound modified asphalts. This study offers an understanding for the promotion and application of PPA modifier.

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