Polymerization Of Derivatives Research Articles

Overcoming Challenges of Incorporation of Biobased Dibutyl Itaconate in (Meth)acrylic Waterborne Polymers.

Polymeric derivatives of itaconic acid are gaining interest as biobased alternatives to petroleum-based monomers due to their versatility, renewable nature, commercial availability, and cost-effectiveness. Itaconate ester monomer's challenges incorporating in (meth)acrylic waterborne polymers are the low propagation rate, unfavorable reactivity ratios, and the depropagation process. To overcome these challenges, the seeded semibatch emulsion polymerization of 100% biobased dibutyl itaconate, methyl methacrylate, and butyl acrylate was investigated at different temperatures. Consequently, 30 wt % DBI was successfully incorporated within waterborne (meth)acrylates in short reaction times (4 h), obtaining high DBI incorporation (>90%). The results demonstrate that DBI incorporation influences the instantaneous monomer conversion, polymer's microstructure, and mechanical properties. By incorporating a biobased itaconate cross-linker, kinetics and mechanical characteristics of the polymers were improved. This combined approach can be implemented without altering industrial processes, resolving the commercialization dilemma for itaconate monomers to synthesize high-performance biobased polymers for adhesive and coating industries.

Synthesis and Physicochemical Properties of Thermally Sensitive Polymeric Derivatives of N-vinylcaprolactam.

Six derivatives of poly-N-vinylcaprolactam (PNVCL) P1-P6 were synthesized via surfactant-free precipitation polymerization (SFPP) at 70 °C, with potassium persulfate (KPS) as the initiator. P5 and P6 were synthesized using the cross-linker N,N'-Methylenebisacrylamide (MBA). The conductivity was measured to monitor the polymerization process. The hydrodynamic diameters (HDs) and polydispersity indexes (PDIs) of aqueous dispersions of P1-P6 were determined using dynamic light scattering (DLS) and zeta potential (ZP) using electrophoretic mobilities. At 18 °C for P1-P6, the HDs (nm) were 428.32 ± 81.30 and PDI 0.31 ± 0.19, 528.60 ± 84.70 (PDI 0.42 ± 0,04), 425.96 ± 115.42 (PDI 0.56 ± 0.08), 440.34 ± 106.40 (PDI 0.52 ± 0.09), 198.39 ± 225.35 (PDI 0.40 ± 0.19), and 1201.52 ± 1318.05 (PDI 0.71 ± 0.30), the and ZPs were (mV) 0.90 ± 3.23, -4.46 ± 1.22, -6.44 ± 1.82, 0.22 ± 0.48, 0.18 ± 0.79, and -0.02 ± 0.39 for P1-P6, respectively. The lower critical solution temperature ranged from 27 to 29 °C. The polymers were characterized using the ATR-FTIR method. The study concluded that the physicochemical properties of the product were significantly affected by the initial reaction parameters. Polymers P1-P4 and P6 have potential for use as drug carriers for skin applications.

High-resolution 3D printable inks based on functional polymeric ionic liquids for applications in carbon dioxide valorization

This study investigates the use of epoxy-functionalized acrylate-based 3D printable ink for creating high-resolution functionalized devices, exploring the possibility to further functionalize those for chemical engineering applications. In fact, the control of the epoxy-functionalized surface enables the formation of active surfaces, and this study employs supported Ionic Liquids with catalytic properties as a proof of concept. Ionic liquids (ILs) and polymeric derivatives represent a promising path to generate multifunctional complex 3D structures, playing advanced roles in multiple applications. The fine-tuning of the functionalization methodology and formulation enhances the resolution of acrylate-based resins, allowing the production of highly detailed structures that can significantly boost catalytic efficiency. Through a comparison with commercial resins, the developed formulation demonstrates superior resolution capabilities, positioning it as an effective alternative for use in vat photopolymerization technologies. Additionally, controlling the level of functionalization and accessibility of the ILs' active sites through the control of the surface area of the reactor has led to improved process performance in terms of yield and space-time yield (STY) in the CO2 cycloaddition to epoxide reaction.

L-PTMI-co-L-PEI copolymers obtained through copolymerization of cyclic imino ethers and their chain modification: Antibacterial properties and cytotoxicity

Polymeric antimicrobial agents are intensively investigated as potential novel antibiotics. In this work we use copolymerization of 2-propyl-2-oxazine (PrOzi) and 2-methyl-2-oxazoline (MeOx) combined with hydrolysis of the polymer side chains as a tool to obtain various linear polymeric derivatives of polytrimethylenimines (L-PTMI) and polyethylenimine (L-PEI). To obtain well-defined polymers, initially we determined copolymerization rates, and subsequently, we investigated the hydrolytic rates of various repeating units, namely PrOzi, MeOx, and 2-methyl-2-oxazine (MeOzi) in both homo- and copolymers. We observed that the structure of the polymeric main chain significantly influences the rate of acidic hydrolysis. In particular, the protonated L–PEI repeating unit (r.u.) accelerates the hydrolytic cleavage of the amide bond more than the protonated L-PTMI r.u., due to the shorter distance between amine centers.The biological activity of the polymers was assessed against three model microorganisms, namely Escherichia coli, Staphylococcus aureus and Candida albicans, and benchmarked in toxicity test against human lung fibroblast cell line. The antibacterial activity of L-PTMI-co-L–PEI increases monotonically with the increasing content of PTMI r.u., indicating an additive effect of covalently bonded L-PTMI and L-PEI. The antimicrobial activity of the copolymers is almost identical to that of the tested polymer blends in the corresponding ratios.The introduction of up to 40 % of PrOzi r.u. into the polyamine structure of PTMI (PPrOzi–co-L-PTMI copolymer) does not decrease the antimicrobial activity, compared to L–PTMI. The molecule remains active, particularly against Staphylococcus aureus (MIC = 4 μg/mL). At the same time, the presence of amide r.u. reduces toxicity. The highest observable selectivity index can reach values as high as 20 (PPrOzi40%–co-L-PTMI60%).

Effect of Friction Reducers with Unreinforced PEEK and Steel Counterparts in Oil Lubrication

The increasing adoption of PEEK (polyetheretherketone) in many industrial applications has promoted intense research to optimize its lubrication along with the development of friction reducers (FRs), additives that help in reducing fuel consumption and, consequently, CO2 emissions. In this study, the effect of FRs in improving the lubrication of PEEK–steel couplings was evaluated and their mechanism studied using the Mini Traction Machine (MTM) tribometer. Different types of FRs (such as Molybdenum dithiocarbamate, glycerol monooleate, amine and polymeric derivatives) and coupling combinations (steel/steel, steel/PEEK and PEEK/steel) were considered. The oil samples were evaluated as fresh and after a rubbing time considering different operative conditions (from high to low T, fixed load and type of contact motion), and a measurement of the tribofilm was acquired. The experimental campaign showed a ranking among FRs friction-reducing behavior and, in some cases, a synergistic effect was noted between the tribofilm containing the friction modifier and the PEEK surface. Comparing the top performing FRs with reference oil showed a reduction in friction of 22%, 21% and 37%, respectively, in steel–steel, PEEK–steel and steel–PEEK couplings, while in the standard steel–steel coupling, two out of four FRs did not reduce the friction. After conditioning in the presence of PEEK, all friction-modifier additives reduced the friction effectively. This demonstrates the promising performance of PEEK, its compatibility with friction-reducing additives, and its applicability to sliding machine parts in order to improve efficiency and thus reduce CO2 emissions.

Kartogenin-loaded liposomes coated with alkylated chondroitin sulfate for cartilage repair

Cartilage loss is a common clinical problem, which leads to significant pain, dysfunction, and even disability. As a result, there is growing interest in using small, non-protein molecules to protect or repair cartilage. Kartogenin (KGN), a small hydrophobic molecule, shows chondroprotective and chondrogenic properties. In this study, we embedded KGN in liposomes, and the whole system was stabilized by covering it with n-octadecylated (at two different substitution degrees) chondroitin sulfate (CS) derivatives. We investigated the interactions of empty liposomes and KGN-loaded liposomes with both CS derivatives using various physicochemical techniques, which revealed that hydrophobically modified CSs can interact with both neutral lipid membrane and negatively charged loaded-KGN lipid membrane. The cytotoxicity and chondrogenic properties of the polysaccharides and liposome-CS formulations of KGN were analyzed towards mesenchymal stem cells (MSCs). The results showed that the alkylated CS exhibited cytotoxic properties. The higher substituted CS self-assembles into stable nanoaggregates that can form a corona on the surface of liposomes, eliminating the overall cytotoxicity of this polymer. However, all tested chondrogenic markers' expression levels are enhanced for KGN-loaded liposomes and coated by lower substituted CS. Furthermore, the undesirable hypertrophy effect for this formulation significantly decreased compared to pure polymeric derivative.

О возможности использования катионных поверхностно-активных веществ для придания текстильным материалам антимикробных свойств

The COVID-19 pandemic has demonstrated the need for improved measures to prevent infectious diseases. Combating pathogens once they have been released into the environment is complicated by their widespread distribution. It is necessary to prevent the contamination of environmental objects. One possible way to do this is to create materials that have antimicrobial action without exposure to disinfectants and thus begin to have an antimicrobial effect on microorganisms immediately upon contact. Textile materials are widely used in medical organizations and are one of the factors of pathogenic microflora spreading. In this work, the possibility of using substances from the group of cationic surfactants to impart antimicrobial properties to textile materials was considered. Substances from different classes were used – tertiary amines, quaternary ammonium compounds, polymeric guanidine derivatives. The substances were applied from aqueous solutions using a laboratory analogue of a drying and a shirring machine. An acrylate binder with thermal initiation of polymerization was used to fix the active substances to the tissues. The content of the active substances in the tissues after application was determined by high-performance liquid chromatography. Antimicrobial activity of the obtained materials was checked by the agar plate method and the area of the growth retardation zone was estimated. Tissues containing N,N-bis(3-aminopropyl)dodecylamine showed the highest activity, tissues with poly (2-hydroxypropyl dimethylammonium) chloride the lowest. Keywords: antimicrobial materials, antimicrobial textile, HAI, cationic surfactants.

Permeability of Skin-Mimicking Cell Coatings by Polymers of Complex Architecture Based on Polyoxazolines

In the scope of drug delivery, the transdermal route is desirable because it provides attainable therapeutic concentrations and has minimal systemic side effects. To make the skin a feasible route for the delivery of therapeutic agents, the biggest challenge is overcoming its natural coating. In this paper, we investigate the effect of the architectures (homopolymer vs. block copolymer vs. hybrid block–graft copolymer) of several amphiphilic polymeric derivatives of poly(2-oxazoline) on skin permeability. The block copolymers are composed of a hydrophobic poly(2-oxazoline) block and a hydrophilic PEG block. The hybrid block–graft copolymers are obtained by grafting hydrophobic side chains of polycaprolactone to a poly(2-oxazoline) backbone. We used the commercially available EpiDerm™ by MatTek, composed of human epidermal cells, as a model of human skin. Two parameters of skin permeation are reported: penetration rate and lag time. We hypothesize that the skin permeation characteristics correlate with the critical micelle concentration and particle size of the studied polymers, while both parameters are a function of the complex architectures of the presented macromolecular constructs. While homopolymer poly(2-oxazolines) show the least permeation, the block copolymers demonstrate partial permeation. The hybrid block–graft copolymers exhibited full penetration through the model skin samples.

Bioinspired Photonic Materials from Cellulose: Fabrication, Optical Analysis, and Applications.

Polysaccharides are a class of biopolymers that are widely exploited in living organisms for a diversity of applications, ranging from structural reinforcement to energy storage. Among the numerous types of polysaccharides found in the natural world, cellulose is the most abundant and widespread, as it is found in virtually all plants. Cellulose is typically organized into nanoscale crystalline fibrils within the cell wall to give structural integrity to plant tissue. However, in several species, such fibrils are organized into helicoidal nanostructures with a periodicity comparable to visible light (i.e., in the range 250-450 nm), resulting in structural coloration. As such, when taking bioinspiration as a design principle, it is clear that helicoidal cellulose architectures are a promising approach to developing sustainable photonic materials. Different forms of cellulose-derived materials have been shown to produce structural color by exploiting self-assembly processes. For example, crystalline nanoparticles of cellulose can be extracted from natural sources, such as cotton or wood, by strong acid hydrolysis. Such "cellulose nanocrystals" (CNCs) have been shown to form colloidal suspensions in water that can spontaneously self-organize into a cholesteric liquid crystal phase, mimicking the natural helicoidal architecture. Upon drying, this nanoscale ordering can be retained into the solid state, enabling the specific reflection of visible light. Using this approach, colors from across the entire visible spectrum can be produced, alongside striking visual effects such as iridescence or a metallic shine. Similarly, polymeric cellulose derivatives can also organize into a cholesteric liquid crystal. In particular, edible hydroxypropyl cellulose (HPC) is known to produce colorful mesophases at high concentrations in water (ca. 60-70 wt %). This solution state behavior allows for interesting visual effects such as mechanochromism (enabling its use in low-cost colorimetric pressure or strain sensors), while trapping the structure into the solid state enables the production of structurally colored films, particles and 3D printed objects. In this article, we summarize the state-of-the-art for CNC and HPC-based photonic materials, encompassing the underlying self-assembly processes, strategies to design their photonic response, and current approaches to translate this burgeoning green technology toward commercial application in a wide range of sectors, from packaging to cosmetics and food. This overview is supported by a summary of the analytical techniques required to characterize these photonic materials and approaches to model their optical response. Finally, we present several unresolved scientific questions and outstanding technical challenges that the wider community should seek to address to develop these sustainable photonic materials.

Features of complex formation of native and polymeric β-cyclodextrins with sulfasalazine

The work is devoted to the study of the complex formation of sulfasalazine with native and polymeric β-cyclodextrins in buffer solutions with a physiological pH value using isothermal saturation and 1H NMR methods. It was established that sulfasalazine forms two types of complexes when interacting with the cyclodextrins under consideration, but only the process of formation of inclusion complexes determines the observed increase in drug solubility, which is more pronounced in the presence of polymeric β-cyclodextrin. It was determined that complexation with β-cyclodextrin and its polymeric derivative leads to a decrease in the permeability coefficients of sulfasalazine through the model membrane, which is determined by both the stability constant of the complexes and their ability to pass through the membrane.

Unique Metal–Ligand Interplay in Directing Discrete and Polymeric Derivatives of Isomeric Azole-Carboxylate. Varying Electronic Form, C–C Coupling, and Receptor Feature

This article dealt with the ruthenium and osmium derivatives of isomeric 1H-indazole-3-carboxylic acid/2H-indazole-3-carboxylic acid (H2L1) and 1H-benzimidazole-2-carboxylic acid (H2L2) along with the π-acidic bpy (bpy = 2,2'-bipyridine) and pap (pap = 2-phenylazopyridine) co-ligands. It thus extended structurally authenticated monomeric ([(bpy)2RuII(HL1-)]ClO4 [1]ClO4, (pap)2RuII(L12-) 2, (bpy)2OsII(L12-) 3, (pap)2OsII(L12-) 4, (bpy)2RuII(L22-) 5, (bpy)2OsII(L22-) 8, and (pap)2OsII(L22-) 9) and dimeric ([(bpy)2RuII(μ-L22-)RuII(bpy)2](ClO4)2 [6](ClO4)2) complexes. It also described modified L2'2- (L2'2- = 2,2'-bisbenzimidazolate)-bridged [(pap)2RuII(μ-L2'2-)RuII(pap)2](ClO4)2 [7](ClO4)2, where L2'2- was developed selectively with the {Ru(pap)2} metal fragment via in situ intermolecular C-C coupling of the two units of decarboxylated benzimidazolate. Moreover, chemical oxidation (OsII to OsIII) of (bpy)2OsII(L12-) 3 (E0 = 0.11 V versus SCE) and (bpy)2OsII(L22-) 8 (E0 = 0.12 V versus SCE) by AgClO4 yielded unprecedented OsIII-AgI derived polymeric {[(bpy)2OsIII-L12--AgI(CH3CN)](ClO4)2}n {[10](ClO4)2}n and dimeric [(bpy)2OsIII-L22--AgI(CH3CN)](ClO4)2 [11](ClO4)2 complexes as a function of trans and cis orientations of the active N2 donor with special reference to the carboxylate O2 of L2-, respectively. Microscopic (FE-SEM, TEM-EDX, and AFM) and DLS experiments suggested a homogeneously dispersed hollow spherical shaped morphology of {[10](ClO4)2}n with an average particle size of 200-400 nm as well as its non-dissociative feature in the aprotic medium. Experimental (structure, spectroscopy, and electrochemistry) and theoretical (DFT/TD-DFT) explorations revealed a redox non-innocent feature of L2- in the present coordination situations and the selective anion sensing (X = F-, CN-, and OAc-) event of [1]ClO4 involving a free NH group at the backface of HL1-, which proceeded via the NH···X hydrogen bonding interaction.

Transdermal Delivery of Phloretin by Gallic Acid Microparticles.

Exposure to ultraviolet (UV) radiation causes harmful effects on the skin, such as inflammatory states and photoaging, which depend strictly on the form, amount, and intensity of UV radiation and the type of individual exposed. Fortunately, the skin is endowed with a number of endogenous antioxidants and enzymes crucial in its response to UV radiation damage. However, the aging process and environmental stress can deprive the epidermis of its endogenous antioxidants. Therefore, natural exogenous antioxidants may be able to reduce the severity of UV-induced skin damage and aging. Several plant foods constitute a natural source of various antioxidants. These include gallic acid and phloretin, used in this work. Specifically, polymeric microspheres, useful for the delivery of phloretin, were made from gallic acid, a molecule that has a singular chemical structure with two different functional groups, carboxylic and hydroxyl, capable of providing polymerizable derivatives after esterification. Phloretin is a dihydrochalcone that possesses many biological and pharmacological properties, such as potent antioxidant activity in free radical removal, inhibition of lipid peroxidation, and antiproliferative effects. The obtained particles were characterized by Fourier transform infrared spectroscopy. Antioxidant activity, swelling behavior, phloretin loading efficiency, and transdermal release were also evaluated. The results obtained indicate that the micrometer-sized particles effectively swell, and release the phloretin encapsulated in them within 24 h, and possess antioxidant efficacy comparable to that of free phloretin solution. Therefore, such microspheres could be a viable strategy for the transdermal release of phloretin and subsequent protection from UV-induced skin damage.

Plasma Surface Engineering of Natural and Sustainable Polymeric Derivatives and Their Potential Applications.

Recently, natural as well as synthetic polymers have been receiving significant attention as candidates to replace non-renewable materials. With the exponential developments in the world each day, the collateral damage to the environment is incessant. Increased demands for reducing pollution and energy consumption are the driving force behind the research related to surface-modified natural fibers (NFs), polymers, and various derivatives of them such as natural-fiber-reinforced polymer composites. Natural fibers have received special attention for industrial applications due to their favorable characteristics, such as low cost, abundance, light weight, and biodegradable nature. Even though NFs offer many potential applications, they still face some challenges in terms of durability, strength, and processing. Many of these have been addressed by various surface modification methodologies and compositing with polymers. Among different surface treatment strategies, low-temperature plasma (LTP) surface treatment has recently received special attention for tailoring surface properties of different materials, including NFs and synthetic polymers, without affecting any of the bulk properties of these materials. Hence, it is very important to get an overview of the latest developments in this field. The present article attempts to give an overview of different materials such as NFs, synthetic polymers, and composites. Special attention was placed on the low-temperature plasma-based surface engineering of these materials for diverse applications, which include but are not limited to environmental remediation, packaging, biomedical devices, and sensor development.

Polymerized Naphthalimide Derivatives as Remarkable Electron‐Transport Layers for Inverted Organic Solar Cells

Polymerized Naphthalimide Derivatives as Remarkable Electron‐Transport Layers for Inverted Organic Solar Cells

Metalation of 2‐Quinolyl‐Linked (Boranophosphinoyl)methane −Alkali Metal, Alkaline Earth Metal, and Ytterbium(II) Complexes of Monoanionic [CH(iPr2P−BH3)(C9H6N‐2)]− Ligand

AbstractA series of alkali and alkaline earth metal complexes, and an ytterbium(II) complex of monoanionic [CH(iPr2P−BH3)(C9H6N‐2)]− ligand (abbreviated as LQPB−) were synthesized. Lithium complexes [Li(LQPB)(TMEDA)] (2, TMEDA=Me2NCH2CH2NMe2) and [Li(LQPB)(12‐crown‐4)] (3) were prepared by lithiation of 1 with LinBu in the presence of TMEDA and 12‐crown‐4 ether, respectively. Treatment of 2 with NaOtBu and KOtBu, respectively, followed by addition of 18‐crown‐6 ether yielded monomeric sodium complex [Na(LQPB)(18‐crown‐6)] (4) and polymeric potassium derivative [K(LQPB)(18‐crown‐6)]n (5). Metalation of 1 with MgnBu2/TMEDA afforded [Mg(LQPB)2(TMEDA)] (6). Heavier group 2 complexes [Ca(LQPB)2(DME)2] (7), [Sr(LQPB)2]2 (8) and [Ba(LQPB)2(DME)] (9) were synthesized by metalation of 1 with the corresponding alkaline earth metal amide M[N(SiMe3)2]2(DME)n (M=Ca or Ba, n=2; M=Sr, n=0) in toluene under reflux conditions. Treatment of YbI2(THF)2 with potassium complex 5 led to isolation of mononuclear Yb(II) complex [Yb(LQPB)2(18‐crown‐6)] (10).

Effect of hydrochloric polyhexamethylene guanidine (PHMGH) and polyhexamethylene biguanidine (PHMBH), also in combination with plant essential oils and ZnO nanoparticles on some eukaryotic cattle and pig cells

Aim. To investigate both toxic (hemolytic), and stimulating effects of two polymeric derivatives of guani- dine, in particular, polyhexamethylene guanidine (PHMG) and polyhexamethylene biguanidine (PHMB) both in the hydrochloride form, on eukaryotic cells depending on the concentration of the preparation; to study the possibility of using wound-healing and stimulating properties of these preparations in veterinary medicine. Methods. The hemolytic activity (toxicity) of PHMGH and PHMBH preparations in the concentration of 0.1% towards cattle and pig erythrocytes was determined by titration. Primary cell cultures of fetal kidney cells of calves and piglets were used to determine the influence of PHMGH and PHMBH both alone and in combination with the following biologically active substances: essential oils of Pinus sylvestris, Eucalyptus globulus, Citrus sinensis, Monarda didyma, ZnO nanoparticles (size c. 25 nm), and electrochemically acti- vated water – anolyte (Eh = –800 mV, pH 6.5–7.0). The concentration of the cells in the nutrient medium was determined via photocolorimetry. Results. It was found that depending on the concentration, PHMGH, and PHMBH preparations can cause the lysis of erythrocytes, and stimulate cell proliferative activity, including the formation of a monolayer of kidney cells of calves and piglets They cause hemolysis of cattle erythro- cytes in the concentrations commonly used for disinfection, i.e., about 0.1 %, in the average titers of 1 : 7 for PHMGH and 1 : 2.5 for PHMBH. Therefore, PHMBH shows greater hemolytic (biocidal) activity for cattle erythrocytes than PHMGH (in ≈2.8x). The high molecular weight fraction of PHMBH (M2 ≈ 2,000–7,000 Da) demonstrated a lower (in ≈2.4x) hemolytic activity than the low molecular weight basic fraction (M1 ≈ 500–2,000 Da). The experiments on the kidney cell cultures of pigs and cattle have shown that at non-toxic concentrations (10–5 %) PHMBH can effectively stimulate (from 27 to 65 % increase) the proliferative activ- ity of eukaryotic cells and accelerate the formation of a monolayer of cells. The combinations of PHMGH with some essential oils of medicinal plants also show a good effect (from 52 to 95 % increase), and PHMBH shows a good effect with oil of pine for pig kidney cells (20 % increase) and oil of horsemint for cattle kidney cells (67 % increase). Conclusions. PHMGH and PHMBH can possibly be used in agricultural production not only as disinfectants or antiseptics, but also in wound healing. Although their toxicity is also significant to eukaryotic cells, yet they can possibly be used in veterinary medicine in low concentrations (0.005–0.5 %) for the treatment of wounds of various origin, including burns, in the composition of ointments, gels, bandages, or plasters, which we have presently in investigation.

Imidazole-Based Monomer as Functional Unit for the Specific Detection of Paraxanthine in Aqueous Environments

In the context of personalized medicine, the paraxanthine-to-caffeine ratio is an accepted standard for the optimization of the dose-response effect of many pharmaceuticals in individual patients. There is a strong drive towards the development of cheaper and portable devices for the detection of biomarkers, including paraxanthine and caffeine, which requires materials with high binding efficiency and specificity. We designed a recognition unit specific for paraxanthine which can discriminate molecules with small structural differences and can be used to increase the sensitivity of sensors. A number of functional units were screened by nuclear magnetic resonance for their ability to form specific binding interactions with paraxanthine in water and negligible interactions with its structural analogue caffeine. Imidazole was identified as the unit showing the most promising results and its two polymerizable derivatives were evaluated by isothermal titration calorimetry to identify the best monomer. The data suggested that 4-vinylimidazole was the most promising unit forming specific and strong binding interaction with paraxanthine. The calorimetry experiments allowed also the determination of the thermodynamic parameters of all interactions and the association constant values. Optimization of polymerization protocols in water, achieving high monomer conversions and chemical yields, demonstrate the suitability of the selected functional monomer for polymer preparations, targeting the detection of paraxanthine in aqueous environments.

Complementary transcriptomic and metabolomics analysis reveal the molecular mechanisms of EGCG3″Me biosynthesis in Camellia sinensis

Epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3″Me), naturally occurring in specific tea plant cultivars, is famous for its decent bioavailability and antiallergic activity. To investigate the molecular mechanisms of EGCG3″Me biosynthesis and transcriptional regulation in tea leaves, we combined multi-omics data from three tea plant cultivars (Fuding Dabaicha, FD; Mingke 1 (Jinguanyin), JGY; and Jinmudan, JMD). High-performance liquid chromatography analysis indicated that EGCG3″Me content was highest in JMD (7.78 mg/g), moderate in JGY (3.12 mg/g), and lowest in FD (0 mg/g), which was similar to the results of the non-targeted metabolic analysis. The high level of EGCG3″Me in JMD was concomitant with high levels of monomeric and polymerized catechin derivatives, but low levels of flavonols, flavones, and their glycosides, which was consistent with the expression levels of most catechin/flavonoid biosynthetic genes. Among them, the expression level of the CCoAOMT gene in the three tea plant cultivars was positively associated with the relative content of EGCG3″Me. Further verification revealed that CCoAOMT protein could directly catalyze the formation of EGCG3″Me. We further identified 38 transcription factors from transcriptome as promising regulatory candidates for regulating CCoAOMT gene expression in tea leaves. These findings provide an essential foundation for further research on the biosynthesis and transcriptional regulation of O-methylated catechins in tea leaves.

Assessment of bacterial pollution of closed water supply systems of galvanized productions

This work is devoted to assessment of the bacterial contamination of drainage systems in a galvanic production. In the course of the study, two strains of microorganisms which cause microbial contamination and lead to a decrease in the efficiency of the process equipment were isolated from water and wash sediment samples taken in the industrial water supply system of the enterprise and identified. Our study of the morphological and cultural properties of the isolated strains of bacteria has allowed them to be attributed to the genus Bacillus. As a result of a metagenomic analysis of the composition of microbial communities for the 16S rRNA gene (16S rDNA variable regions) according to the GenBank database on an ABI Prism 3730 automatic sequencer, the homology of the first strain with typical strains of the subgroup B. velezensis and B. amyloliquefaciens was established within 99.4–99.9%. When identifying the second isolated strain, the homology with B. altitudinis was 99.7%. Our study of the properties of the isolated strains has shown that they are neither pathogenic nor toxigenic. To reduce the microbial load in the technical water supply system, a series of experiments was carried out to select a biocide. Several variants of disinfectants of various groups were tested, namely: oxidizing ones (chloramine (a chlorine derivative of ammonia), hydrogen peroxide) and non-oxidizing ones (polymeric derivatives of polyhexamethylene guanidine (PHMG) produced by JSC NPK Mediana-filter and polyazolidine ammonium ionohydrate (PAG-M) produced by LLC “Constanta”). The polymeric compounds were found to be more effective than the chlorine-based disinfectants. An aqueous solution of polyhexamethylene guanidine had the best bactericidal effect on the microorganisms, therefore it was recommended to combat the existing bacterial contamination.

Polymerized Naphthalimide Derivatives as Remarkable Electron‐Transport Layers for Inverted Organic Solar Cells

Two polymerized naphthalimide derivatives, named as N-TBHOB and N-DBH, are prepared by quaternization. They exhibit excellent performance as electron-transport layers (ETLs) in inverted organic solar cells (i-OSCs). The results indicate N-TBHOB with a reticulated structure owns a superior performance on electron extraction, electron transport, thickness tolerance, and less carrier recombination compared with N-DBH with linear structure. The i-OSCs based on N-TBHOB with PTB7-Th:PC71 BM as the active layer achieve power conversion efficiencies (PCEs) of 10.72% and 10.03% under the thickness of 11 and 48nm respectively, which indicates N-TBHOB possesses better thickness tolerance than most of organic ETLs in i-OSCs. N-TBHOB also shows more competent performance than N-DBH and ZnO in nonfullerene i-OSCs for comprehensively improved Jsc , Voc , and fill factor (FF) values. Its i-OSC with PM6:Y6 blend presents a high PCE of 16.78%. The study provides an efficient strategy to prepare ETLs by combining conjugated and nonconjugated units with a reticulated structure in the backbone for high-performance i-OSCs.