Diels–Alder cycloaddition and RAFT chain end functionality::an elegant route to fullerene end-capped polymers with control over molecular mass and architecture

Fullerene C60 functionalised polymers (FFPs) have found numerous applications from photovoltaic devices to materials for photodynamic therapy. Polymer end-capping is one way to fabricate FFPs since it provides enhanced control over the macromolecular architecture and composition. This paper reports, for the first time, a facile, metal catalyst-free approach to FFPs where polymers, generated by reversible-addition fragmentation chain transfer (RAFT) polymerisation, were coupled to a fullerene derivative through chain-end functionality, provided by the chain transfer agent without further modification. Two routes to a fullerene derivative were compared – based on the Prato reaction and Diels–Alder cycloaddition. The Diels–Alder route exclusively yielded the mono-addition product, whereas the Prato route resulted in a mixture of mono- and diadducts which required further separation. This elegant combination of well-defined RAFT polymerisation and precise Diels–Alder addition allowed one to obtain fullerene end-capped polymers within a wide range of molecular masses (from 5000 to 50 000 g mol−1)

Design, synthesis and RAFT polymerisation of a quinoline-based monomer for use in metal-binding composite microfibres

Metal-binding polymer fibres have attracted major attention for diverse applications in membranes for metal sequestration from waste waters, non-woven wound dressings, matrices for photocatalysis, and many more. This paper reports the design and synthesis of an 8-hydroxyquinoline-based zinc-binding styrenic monomer, QuiBoc. Its subsequent polymerisation by reversible addition–fragmentation chain transfer (RAFT) yielded well-defined polymers, PQuiBoc, of controllable molar masses (6 and 12 kg mol−1) with low dispersities (Đ, Mw/Mn < 1.3). Protected (PQuiBoc) and deprotected (PQuiOH) derivatives of the polymer exhibited a high zinc-binding capacity, as determined by semi-quantitative SEM/EDXA analyses, allowing the electrospinning of microfibres from a PQuiBoc/polystyrene (PS) blend without the need for removal of the protecting group. Simple “dip-coating” of the fibrous mats into ZnO suspensions showed that PQuiBoc/PS microfibres with only 20% PQuiBoc content had almost three-fold higher loadings of ZnO (29%) in comparison to neat PS microfibres (11%)

Determination of Coenzyme A and Acetyl-Coenzyme A in Biological samples Using HPLC with UV Detection

Coenzyme A (CoA) and acetyl-coenzyme A (acetyl-CoA) play essential roles in cell energy metabolism. Dysregulation of the biosynthesis and functioning of both compounds may contribute to various pathological conditions. We describe here a simple and sensitive HPLC-UV based method for simultaneous determination of CoA and acetyl-CoA in a variety of biological samples, including cells in culture, mouse cortex, and rat plasma, liver, kidney, and brain tissues. The limits of detection for CoA and acetyl-CoA are \u3e10-fold lower than those obtained by previously described HPLC procedures, with coefficients of variatio

Модифікований алгоритм автоматичного керування температурою в електричній печі опору для термообробки металу

The purpose is to improve the quality of heat treatment of metal in electric resistance furnaces by improving automatic temperature control in the furnace. The main quality criteria of the automatic control system is the minimization of the metal heating time without exceeding the permissible over-regulation of the transient process at the output of the control system. Research methodology. Provided that the research tasks are solved, the method of computational experiments using specialized computer programs for modeling transient processes in automatic control systems is taken as a basis. When calculating the temperature regulator in the furnace, methods of modern automatic control theory were used. The requirements for the control process and the specifics of the operation of the control object are taken into account. Theoretical research methods (systems analysis and synthesis) were used to study the automatic control system. The research was conducted on the basis of computational experiments using analytical and computerized methods of synthesis of automatic control systems. Evaluation of the effectiveness of the automatic control process was carried out using the methods of mathematical statistics