Article
Polymer Science
Jae Sang Lee, Mehrnoosh Taghavimehr, Reza Montazami, Matthew D. Green
Summary: A series of PEG-based segmented block copolymers were synthesized and their properties were controlled by varying the weight fractions of hard and soft domains. The ionenes showed good thermal stability and mechanical properties at certain weight fractions, with DABCO-based ionenes exhibiting superior elastomeric behavior and phase separation compared to aliphatic analogs.
Article
Chemistry, Analytical
Wouter C. Knol, Quincy L. de Vries, Ton Brooijmans, Till Gruendling, Bob W. J. Pirok, Ron A. H. Peters
Summary: Size-exclusion chromatography (SEC) coupled with pyrolysis-gas chromatography (Py-GC) is a powerful tool for polymer analysis. However, the long analysis times of the Py-GC step limit its wider application. Therefore, an online hyphenated SECxPy-MS/FID method was developed, removing the need for GC separation and significantly reducing the second-dimension analysis time compared to SEC-Py-GC. The developed method showed no molar mass discrimination for masses above +/- 1.3 kDa, making it applicable to most commercial polymer systems. Multiple samples, including a complex industrial sample, were successfully analyzed using this method, providing information on chemical composition heterogeneity and molar mass distribution.
ANALYTICA CHIMICA ACTA
(2023)
Article
Polymer Science
Jia Yang, Takahiro Sato
Summary: Size exclusion chromatography equipped with a multi-angle, light-scattering online detector (SEC-MALS) was used to study the influence of degrees of substitution (DS) on the radius of gyration for hydrophobically modified pullulan (PUL-OSA) in aqueous NaCl solution. Results showed that the introduction of OSA groups led to an increase in chain size, consistent with the loose flower necklace model. However, samples with higher DS values exhibited deviations from the expected values due to the presence of aggregating components with a branched architecture composed of loose flower necklaces.
Article
Chemistry, Multidisciplinary
Arulselvan Ponnudurai, Peter Schulze, Andreas Seidel-Morgenstern, Heike Lorenz
Summary: This study develops and evaluates a new acetone-water-based SEC method coupled with ESI-MS and MALLS for direct determination of absolute molar masses of organosolv lignin in ethanol-sodium sulfate-water system.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Polymer Science
Yin-Ning Zhou, Tian-Tian Wang, Zheng-Hong Luo
Summary: Accurate determination of the molar mass of polymers is crucial for polymerization kinetic investigation and precision polymer synthesis. This study proposes a distribution function-based strategy that rectifies the deviation of conventional calibration methods, leading to more accurate results. The strategy has been successfully applied to controlled chain-growth polymerizations, resulting in higher accuracy and minimal errors in molar mass determination.
Article
Polymer Science
Hamza Mahmoud Aboelanin, Jan-Hendrik Arndt, Tibor Macko, Stepan Podzimek, Robert Bruell
Summary: Characterization of the molar mass distribution of poly(ether ether ketone) (PEEK) is difficult due to its insolubility in common solvents. Sulfonated PEEK (SPEEK) was prepared by sulfonation of PEEK with concentrated H2SO4 and its presence of sulfonic acid group in PEEK matrix was confirmed. The molar mass and distribution of SPEEK were determined in different solvents using calibration with PMMA standards.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Biochemical Research Methods
Sandrine Reymond, Lyssia Gruaz, Jean-Charles Sanchez
Summary: This study aimed to improve the efficiency and protein coverage of plasma-derived extracellular vesicles (EVs) by removing highly abundant plasma proteins. Depleted EVs showed higher particle concentrations and a broader protein coverage. However, EVs from non-depleted plasma carried slightly more EV markers. This study also demonstrated the clinical feasibility of characterizing the proteome of EVs derived from small plasma volumes.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2023)
Article
Polymer Science
Pieter-Jan Voorter, Manfred Wagner, Christine Rosenauer, Jinhuo Dai, Priya Subramanian, Alasdair Mckay, Neil R. Cameron, Jasper J. Michels, Tanja Junkers
Summary: Diffusion-ordered NMR spectroscopy (DOSY) is a solvent-independent method for molecular weight calibration with low lab variability. It has been used for data calibration in different solvents and confirmed the inter-laboratory and inter-polymer consistency. It can also determine the molecular weight of polymers with added complexity.
Article
Chemistry, Applied
Tong Li, Jialun Hu, Ran Tian, Kaili Wang, Jinpeng Li, Abdul Qayum, Akhunzada Bilawal, Munkh-Amgalan Gantumur, Zhanmei Jiang, Juncai Hou
Summary: The study revealed that citric acid treatment under non-acidic conditions can promote disulfide bond formation in whey protein isolate, leading to an increase in molecular size and changes in structural characteristics.
Article
Chemistry, Analytical
Markus Matz, Carlo Botha, Timo Beskers, Manfred Wilhelm
Summary: Methods to increase sensitivity are important in research. In this study, a continuous injection method with a sinusoidal analyte concentration profile was developed to enhance sensitivity in HPLC. The proposed method was established and evaluated for SEC, and the phase angle shift was utilized for molecular weight determination.
Article
Polymer Science
Jae Sang Lee, Mehrnoosh Taghavimehr, Reza Montazami, Matthew D. Green
Summary: This study investigates the effects of soft and hard segment contents, as well as the type of hard segments (linear aliphatic and DABCO), on the properties of PTMO-based segmented ionenes. Results show that high weight fractions of soft segments induce heterogeneous crystallization and lower melting temperature. It is found that both types of PTMO ionenes form a higher degree of ionic aggregates due to strong Coulombic interactions between hard segments. DABCO-based ionenes exhibit higher degree of phase separation and long-range ordered lamellar structure compared to linear aliphatic analogs, which form random ionic domains.
Article
Polymer Science
Wei Liu, Yong-gang Liu, Xiang-ling Ji
Summary: Size exclusion chromatography (SEC), also known as gel permeation chromatography (GPC), is a liquid chromatography technique used to separate molecules based on their hydrodynamic volume in solution. It is commonly used to characterize molecular weight and distribution of polymers. Proper optimization of eluent composition and avoidance of column overloading are crucial for obtaining accurate results in SEC experiments.
ACTA POLYMERICA SINICA
(2021)
Article
Chemistry, Analytical
Jun Dai, Chengjie Ji
Summary: Although reversed-phase liquid chromatography (RPLC) is commonly used, other separation modes such as size exclusion chromatography (SEC) and ion-exchange chromatography (IEX) are crucial for characterizing protein therapeutics. This study demonstrates the power of native mass spectrometry (MS) coupled with SEC and IEX for the characterization of bevacizumab and NISTmAb, providing valuable insights into the protein therapeutics at the native state.
ANALYTICA CHIMICA ACTA
(2023)
Article
Energy & Fuels
Saroj K. Panda, Munther M. Alshammari, Abdullah A. Al-Zahrani, Dominic J. Kearney
Summary: The characterization of aromatic compounds in petroleum samples is important for the conversion of low-value aromatics to high-value petrochemicals. In this study, a size exclusion chromatographic method was applied for the characterization of aromatic compounds in high-boiling fractions from different crude oils. The compositional information obtained showed similarities in the distilled cuts, regardless of the origin of the crude oil. The method is simple, fast, and suitable for providing average compositional information.
Article
Nutrition & Dietetics
Kit-Leong Cheong, Jia-Kang Li, Saiyi Zhong
Summary: In this study, laminaran oligosaccharides (LOs) were obtained through acid hydrolysis of laminaran derived from Laminaria digitata. The purified LOs showed a main oligosaccharide structure corresponding to the connection of glucose with beta-D-Glcp-(1 -> 3)-beta-D-Glcp. LOs exhibited excellent antioxidant activities and a prebiotic effect on the growth of Bifidobacterium adolescentis and Lactobacillus plantarum. Therefore, the development of LOs as natural antioxidants and prebiotics in the functional food and pharmaceutical industries is proposed.
FRONTIERS IN NUTRITION
(2022)
