Hasil untuk "Organic chemistry"

V. Georgakilas, M. Otyepka, A. Bourlinos et al.

Gregory R. Fulmer, Alexander J. M. Miller, Nathaniel H. Sherden et al.

J. Wen, G. Wilkes

J. M. Jay

C. Jonah, J. W. T. Spinks, R. Woods

J. R.

F. Endres, S. Zein El Abedin

Davide Ravelli, D. Dondi, M. Fagnoni et al.

K. Kirk

C. Sanchez, Galo J. A. A. Soler-Illia, F. Ribot et al.

M. Nishio

D. Bong, T. D. Clark, J. Granja et al.

A. Carlton, C. Wiedinmyer, J. Kroll

Abstract. Recent field and laboratory evidence indicates that the oxidation of isoprene, (2-methyl-1,3-butadiene, C5H8) forms secondary organic aerosol (SOA). Global biogenic emissions of isoprene (600 Tg yr−1) are sufficiently large that the formation of SOA in even small yields results in substantial production of atmospheric particulate matter, likely having implications for air quality and climate. Here we present a review of field measurements, experimental work, and modeling studies aimed at understanding the mechanisms, yield, and atmospheric importance of isoprene-derived SOA. SOA yields depend on a number of factors, including organic aerosol loading (Mo), NOx level (RO2 chemistry), and, because of the importance of multigenerational chemistry, the degree of oxidation. These dependences are not always included in SOA modules used in atmospheric transport models, and instead most yield parameterizations rely on a single set of chamber experiments (carried out over a limited range of conditions); this may lead to very different estimates of the atmospheric importance of isoprene SOA. New yield parameterizations, based on all available laboratory data (Mo=0–50 μg m−3), are presented here, so that SOA formation may be computed as a function of Mo, NOx level, and temperature. Current research needs and future research directions are identified.

J. Hachmann, R. Olivares-Amaya, Sule Atahan-Evrenk et al.

A. Stolle, Tony Szuppa, S. Leonhardt et al.

Noor S. Sadeq, Siti Norain Harun, Gan Yian Chee et al.

Metal–Organic Frameworks (MOFs) have rapidly emerged as versatile nanoparticles system for their use in biomedical field, especially in drug delivery. Of the materials in this class, zeolitic imidazolate framework ZIF-8 has recently captured significant interest due to its tunable structure and significant potential for surface modification. It is these same features which allow ZIF-8 to act as a suitable carrier in both single agent and combination therapy. In particular, surface chemistry will be reiterated throughout the present article as significant in improving the physicochemical stability, biocompatibility and targeted drug delivery of the materials. In addition, through well-designed modification strategies ZIF-8 herein we propose to show controlled release profiles, improved colloidal stability, and improved therapeutic efficacy. This review will discuss recent advances made in the surface engineering of ZIF-8 and present salient design principles and functionalisation techniques and their usefulness in the area of drug-delivery applications.

Viktor Johánek, Mateusz Wróbel, Kateřina Knotková et al.

Abstract Oxidative dehydrogenation of propane (ODHP) is a promising alternative route for producing light olefins, especially propene. Since the discovery of the exceptional activity of h-BN and other boron-based solids, their role in ODHP has attracted strong interest but remains insufficiently understood. Here, we provide the first direct experimental evidence of volatile boron oxide (BOₓ) species under ODHP conditions, revealed by TPD–MS and supported by XPS and solid-state NMR analyses. Advanced MAS ssNMR showed preferential coordination of BOₓ to Al in SiO₂–Al₂O₃ supports. BOₓ dispersion and stability were found to be strongly support-dependent: silica-supported BOₓ facilitates sublimation of boron oxides and propane activation at lower temperatures compared to γ-Al₂O₃ or SiO₂–Al₂O₃. Despite this, all systems follow identical selectivity–conversion trends. These results highlight a mechanistic pathway where volatile boron intermediates influence catalytic performance, advancing fundamental understanding and suggesting new strategies for designing selective, energy-efficient catalysts.

Yanni Xuan, Kun Yu, Hong Tian et al.

Particle adsorbents have gained significant traction in flue gas desulfurization applications, primarily attributed to their high structural homogeneity and large specific surface area. To address the multifaceted requirements of industrial sectors regarding the structural configurations and physicochemical properties of particle adsorbents while promoting sustainable manufacturing practices, this study systematically evaluates and critically appraises contemporary advancements in particle desulfurizing agent technologies. The synthesis of these findings establishes a theoretical framework to facilitate technological innovation and industrial progress within the particle desulfurizer domain. The research systems of particle adsorbents, encompassing active components, inert carriers, preparation methodologies, and gas–solid reaction models, were comprehensively reviewed. The advantages and current limitations of these systems were then systematically summarized. Finally, the fundamental principles and research trajectories in the application fields of distinct particle adsorbent research systems were elucidated. An analysis of the developmental trends indicated that enhancing the utilization efficiency of active components and improving the cyclic stability of adsorbents remained critical engineering challenges. It is posited that the pursuit of high reaction activity, thermal stability, mechanical strength, and superior anti-aggregation/sintering performance constitutes key directions for the advancement of particle adsorbents in China’s flue gas desulfurization industry.

Ru Wu, Yue Cao, Zixuan Chen et al.

Graphene quantum dots (GQDs), as an emerging class of nascent carbon-based materials, demonstrate remarkable promise in fluorescence sensing applications. Those potentials stem from several factors, including their favorable photoluminescence (PL) characteristics, feasibility of surface functionalization, excellent biocompatibility, and low cytotoxicity. This review concentrates on the fundamental optical properties of GQDs, with specific reference to the manipulation of intrinsic characteristics both by heteroatom doping and surface/edge functionalization. These modifications permit the alteration of optical properties, thereby rendering GQDs more versatile for an array of applications. Subsequently, we then delve into the recent applications of GQDs in fluorescence sensing, encompassing both turn-off and turn-on mechanisms. Finally, it presents a systematic assessment of the current state of research on GQDs, along with discussions on challenges and prospects for expanding and improving their applications.

Wei Lai, Hu Geliang, Xu Bin et al.

Abstract As an emerging technology, organoids are promising new tools for basic and translational research in disease. Currently, the culture of organoids relies mainly on a type of unknown composition scaffold, namely Matrigel, which may pose problems in studying the effect of mechanical properties on organoids. Hydrogels, a new material with adjustable mechanical properties, can adapt to current studies. In this review, we summarized the synthesis of recent advance in developing definite hydrogel scaffolds for organoid culture and identified the critical parameters for regulating mechanical properties. In addition, classified by different mechanical properties like stiffness and viscoelasticity, we concluded the effect of mechanical properties on the development of organoids and tumor organoids. We hope this review enhances the understanding of the development of organoids by hydrogels and provides more practical approaches to investigating them.