Polypropylene (PP) samples functionalized with Maleic Anhydride (MAH) were used as interfacial coupling agents during the preparation of PP based layered silicate nanocomposites (PP-LSN). To prepare these functionalized PP samples, butyl 3-(2-furyl)propenoate (BFA) was used as coagent during the radical post-functionalization with MAH to avoid the polymer degradation. The obtained materials, differing from the functionalization degree (FD) and structure (MW and molecular weight distribution), were accurately characterized and firstly employed as polymer matrices for PP-LSN preparation to study the influence of their architecture on clay dispersion and thus on their intercalation capability. Successively, PP-LSNs were prepared by using PP as matrix and 5 phr of the above compatibilizers. Morphological, thermal, mechanical and thermo-mechanical analyses of the nanocomposites pointed out that the higher molecular weight PP-g-MAH samples allow to achieve simultaneously a good intercalation within the filler and a significant compatibilization with pristine PP chains, leading to high performances PP-LSNs.
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http://dx.doi.org/10.1166/jnn.2009.1091 | DOI Listing |
Blood Adv
January 2025
Vanderbilt University Medical Center, Nashville, Tennessee, United States.
In plasma, the zymogens factor XII (FXII) and prekallikrein reciprocally convert each other to the proteases FXIIa and plasma kallikrein (PKa). PKa cleaves high-molecular-weight kininogen (HK) to release bradykinin, which contributes to regulation of blood vessel tone and permeability. Plasma FXII is normally in a "closed" conformation that limits activation by PKa.
View Article and Find Full Text PDFWater Sci Technol
January 2025
Norwegian University of Life Sciences, Department of Building and Environmental Technology, P.O. Box 5003, 1430 Ås, Norway.
The need for stringent phosphorus removal from domestic wastewater is increasing to mitigate eutrophication, while efficient phosphate reuse is critical due to the global phosphate crisis. Combining aluminum sulfate (ALS) with high molecular weight organic polymers achieved 95-99% removal of particles, turbidity, and phosphates, reducing ALS usage by 40%. We propose mechanisms to explain the enhanced treatment efficiency.
View Article and Find Full Text PDFmSphere
January 2025
Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Coronaviruses (CoV) emerge suddenly from animal reservoirs to cause novel diseases in new hosts. Discovered in 2012, the Middle East respiratory syndrome coronavirus (MERS-CoV) is endemic in camels in the Middle East and is continually causing local outbreaks and epidemics. While all three newly emerging human CoVs from the past 20 years (SARS-CoV, SARS-CoV-2, and MERS-CoV) cause respiratory disease, each CoV has unique host interactions that drive differential pathogeneses.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Though reduction of hexavalent chromium (Cr(VI)) to Cr(III) by dissolved organic matter (DOM) is critical for the remediation of polluted soils, the effects of DOM chemodiversity and underlying mechanisms are not fully elucidated yet. Here, Cr(VI) reduction and immobilization mediated by microbial byproduct (MBP)- and humic acid (HA)-like components in (hot) water-soluble organic matter (WSOM), (H)WSOM, from four soil samples in tropical and subtropical regions of China were investigated. It demonstrates that Cr(VI) reduction capacity decreases in the order WSOM > HWSOM and MBP-enriched DOM > HA-enriched DOM due to the higher contents of low molecular weight saturated compounds and CHO molecules in the former.
View Article and Find Full Text PDFChem Sci
January 2025
Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir Prelog Weg 5 8093 Zurich Switzerland
The labile end-groups inherent to many controlled radical polymerization methodologies, including atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization, can trigger the efficient chemical recycling of polymethacrylates yielding high percentages of pristine monomer. Yet, current thermal solution ATRP and RAFT depolymerization strategies require relatively high temperatures ( 120-170 °C) to proceed, with slower depolymerization rates, and moderate yields often reported under milder reaction conditions ( lower temperatures). In this work, we seek to promote the low temperature RAFT depolymerization of polymethacrylates regulating the Z-group substitution of dithiobenzoate.
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