Journal articles on the topic 'Macromolecular and materials chemistry, n.e.c'

Polysaccharides are beneficially used as drug carriers via prodrug formation and offer a mechanism for better effectiveness and delivery of the drug. The unique geometry of hydroxypropylcellulose (HPC), a polysaccharide, allows the attachment of drug molecules with a higher degree of substitution. Therefore, HPC-gemifloxacin conjugates, i.e., macromolecular prodrugs, were synthesized using acylation reagents, i.e., tosyl chloride and carbonyldiimidazole using N,N-dimethylacetamide as a solvent. The reactions were carried out at 80 °C under stirring for 24 h in inert environment. This strategy of reaction appeared efficient to obtain a high degree of drug substitution (DS = 0.42-1.34) on the polymer parent chain, as calculated by UV-visible spectrophotometry after hydrolysis of the samples. The method provides high efficacy as product yields were high (71-76%). Macromolecular prodrugs with different DS of gemifloxacin (GEM) designed were found soluble in organic solvents. The pharmacokinetic studies showed that the t1/2 and tmax values of GEM from HPC-GEM conjugate were considerably higher, which indicates improved bioavailability of the drug after conjugate formation.

We use the C/N ratio as a monitor of the delivery of key ingredients of life to nascent terrestrial worlds. Total elemental C and N contents, and their ratio, are examined for the interstellar medium, comets, chondritic meteorites, and terrestrial planets; we include an updated estimate for the bulk silicate Earth (C/N = 49.0 ± 9.3). Using a kinetic model of disk chemistry, and the sublimation/condensation temperatures of primitive molecules, we suggest that organic ices and macromolecular (refractory or carbonaceous dust) organic material are the likely initial C and N carriers. Chemical reactions in the disk can produce nebular C/N ratios of ∼1–12, comparable to those of comets and the low end estimated for planetesimals. An increase of the C/N ratio is traced between volatile-rich pristine bodies and larger volatile-depleted objects subjected to thermal/accretional metamorphism. The C/N ratios of the dominant materials accreted to terrestrial planets should therefore be higher than those seen in carbonaceous chondrites or comets. During planetary formation, we explore scenarios leading to further volatile loss and associated C/N variations owing to core formation and atmospheric escape. Key processes include relative enrichment of nitrogen in the atmosphere and preferential sequestration of carbon by the core. The high C/N bulk silicate Earth ratio therefore is best satisfied by accretion of thermally processed objects followed by large-scale atmospheric loss. These two effects must be more profound if volatile sequestration in the core is effective. The stochastic nature of these processes hints that the surface/atmospheric abundances of biosphere-essential materials will likely be variable.

In this paper, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing diblock copolymer poly[(p-hydroxybenzaldehyde methacrylate)m-b-(2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)oxy)ethyl methacrylate)n] (abbrev. poly(HAMAm-b-HEPOMAn)) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. When it was continued to react with titanium-hybridized aminopropyl-polyhedral oligomeric silsesquioxane (Ti-POSS) through a Schiff-base reaction, new grafted copolymers poly[(Ti-POSS-HAMA)m-b-HEPOMAn] (abbrev. PolyTi) were obtained. Then, they were used as macromolecular flame retardant to modify epoxy resin materials. The thermal, flame retardant and mechanical properties of the prepared EP/PolyTi composites were tested by TGA, DSC, LOI, UL-94, SEM, Raman, DMA, etc. The migration of phosphorus moiety from epoxy resin composites was analyzed by immersing the composites into ethanol/H2O solution and recording the extraction solution by UV-Vis spectroscopy. The results showed that the added PolyTi enhanced the glass transition temperature, the carbon residue, the graphitization of char, LOI, and mechanical properties of the EP/PolyTi composites when compared to pure cured EP. Furthermore, the phosphorus moieties were more likely to migrate from EP/DOPO composites than that from EP/PolyTi composites. Obviously, compared with small molecular flame retardant modified EP, the macromolecular flame retardant modified EP/PolyTi composites exhibited better thermal stability, flame retardancy, and resistance to migration.

Nanomaterials have attracted much attention over the last decades due to their very different properties compared to those of bulk equivalents, such as a large surface-to-volume ratio, the size-dependent optical, physical, and magnetic properties. A number of solution fabrication methods have been developed for the synthesis of metal and metal oxides nanoparticles, but few solid-state methods have been reported. The application of nanostructured materials to electronic solid-state devices or to high-temperature technology requires, however, adequate solid-state methods for obtaining nanostructured materials. In this review, we discuss some of the main current methods of obtaining nanomaterials in solid state, and also we summarize the obtaining of nanomaterials using a new general method in solid state. This new solid-state method to prepare metals and metallic oxides nanostructures start with the preparation of the macromolecular complexes chitosan·Xn and PS-co-4-PVP·MXn as precursors (X = anion accompanying the cationic metal, n = is the subscript, which indicates the number of anions in the formula of the metal salt and PS-co-4-PVP = poly(styrene-co-4-vinylpyridine)). Then, the solid-state pyrolysis under air and at 800 °C affords nanoparticles of M°, MxOy depending on the nature of the metal. Metallic nanoparticles are obtained for noble metals such as Au, while the respective metal oxide is obtained for transition, representative, and lanthanide metals. Size and morphology depend on the nature of the polymer as well as on the spacing of the metals within the polymeric chain. Noticeably in the case of TiO2, anatase or rutile phases can be tuned by the nature of the Ti salts coordinated in the macromolecular polymer. A mechanism for the formation of nanoparticles is outlined on the basis of TG/DSC data. Some applications such as photocatalytic degradation of methylene by different metal oxides obtained by the presented solid-state method are also described. A brief review of the main solid-state methods to prepare nanoparticles is also outlined in the introduction. Some challenges to further development of these materials and methods are finally discussed.

The notion of organic molecular materials showing metallic properties, such as electric conductivity or ferromagnetism, started several decades ago as a mere dream of some members of the chemical community. The goal was to create an assembly of organic molecules or macromolecules containing only light elements (C, H, N, O, S, etc.) and yet possessing the electron/hole mobility or spin alignment that is inherent in typical metals or their oxides and different from the isolated molecular materials. Organic molecular conductors initially were developed during the 1960s, but the first examples of organic molecular magnets took several more decades to be discovered, owing to the more subtle and complex structural and electronic aspects of these materials. The flurry of activity in this field can be traced to the widely held belief that even the most sophisticated properties can be rationally designed by a systematic modification of organic molecular structures. This motivation was further fueled by increased synthetic capabilities, especially for obtaining large organic molecules with suitable structures and topologies, and also by the spectacular progress of supramolecular chemistry for materials development witnessed in recent years. Also noteworthy is the pioneering work performed in the 1960s by several physical organic chemists who unraveled different ways of aligning spins within open-shell molecules (i.e., triplet diradicals, carbenes, etc.), working against nature's tendency to align them in an antiparallel manner. Magnetic interactions between unpaired electrons, located on the singly occupied molecular orbitals (SOMOs) of di- and polyradicals, or between the adjacent open-shell molecules in crystals, are a crucial issue in this evolving field. Thus, depending upon the symmetry, degeneracy,and topological characteristics of SOMOs and also on the mode of arrangement of the molecules in a crystal, the resulting interaction can align the neighboring spins parallel or antiparallel (see the introductory article by Miller and Epstein in this issue of MRS Bulletin).

This article studies the diversification of useful properties of polyurethane (PU) structures by the inclusion of new components. PUs containing a Schiff base in the main chain were synthesized by using N, N′-bis(salicylidene)-1,3-propanediamine as a chain extender. Novel Schiff base PUs were synthesized via a two-step polymerization starting from a Schiff base derivative diol chain extender with different molar ratios or by cross-linking with various natural raw materials. The sought after structures was confirmed by Fourier transform infrared spectra that showed the disappearance of the signals of both the hydroxyl and isocyanate groups. The thermal properties of these PUs were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The initial degradation temperatures of the obtained PUs were found to be in the range of 300–350°C. Based on the results from DMA, the rigid structure of the Schiff base from the backbone of the PUs presented a higher storage modulus, results which may be connected to the physical cross-linking process of the macromolecules. Their optical properties were determined by fluorescence spectroscopy. The incorporation of Schiff base structures into the main PU chain generates new PU structures with improved thermomechanical properties, which includes possible bioactive Schiff base moieties, widening the range of practical applications for such polymers.

В стандартных условиях проведен модельный эксперимент по влиянию сил обеднения на процесс высыхания капли взвесей невзаимодействующих частиц аэросил – полистирольный латекс. Впервые обнаружен быстропротекающий процесс фазового превращения аэросила в кристаллический SiO2 в течение десятков секунд, сопровождающийся резким изменением цвета раствора от светло-голубого до синего. Обнаружена дифракционная картина, свидетельствующая о нанокристаллической природе зародышеобразования новой фазы. Фазообразование интерпретировано как результат действия неравновесной силы обеднения в условиях гидродинамической неустойчивости высыхающей капли. REFERENCES Tret’yakov Yu. D. Self-organisation processes in the chemistry of materials. Uspekhi khimii [Russian Chemical Reviews], 2003, v. 72(8), pp. 651–679. https://doi.org/10.1070/RC2003v072n08ABEH000836 Kushnir S. E., Kazin P. E., Trusov L. A., Tret’yakov Yu. D. Self-organization of micro- and nanoparticles in ferrofl uids. Uspekhi khimii [Russian Chemical Reviews], 2012, v. 81(6), pр. 560–570. https://doi.org/10.1070/RC2012v081n06ABEH004250 Lebedev-Stepanov P. V., Kadushnikov R. M., Molchanov S. P., Ivanov A. A., Mitrokhin V. P., Vlasov K. O., Rubin N. I., Yurasik G. A., Nazarov V. G., Alfi mov M. V. Self-assembly of nanoparticles in the microvolume of colloidal solution: Physics, modeling, and experiment. Rossiiskie nanotekhnologii [Nanotechnologies in Russia], 2013, v. 8(3-4), pр. 137–162. https://doi.org/10.1134/S1995078013020110 Walker D. A., Kowalczyk B., Cruz M. O., Grzybowski B. A. Electrostatics at the nanoscale. Nanoscale, 2011, v. 3(4), pp. 1316–1344. https://doi.org/10.1039/C0NR00698J Ouyang Q., Castets V., Boissonade J., et al. Sustained patterns in chlorite–iodide reactions in a onedimensional reactor. J. Chem. Phys., 1991, v. 95(1), pp. 351–360. https://doi.org/10.1063/1.461490 Tarasevich Yu. Yu., Pravoslavnova D. M. Kachestvennyy analiz zakonomernostey vysykhaniya kapli mnogokomponentnogo rastvora na tverdoy podlozhke [Qualitative analysis of patterns of drying of a drop of a multicomponent solution on a solid substrate], Zhurnal tekhnicheskoi fi ziki [Technical Physics], 2007, vol. 77, no. 2. pp. 17–21. URL: http://journals.ioffe. ru/articles/viewPDF/9047 (in Russ.) Faigl’ F., Anger V. Kapel’nyi analiz neorganicheskikh veshchestv [Drip Analysis of Inorganic Substances]. Moscow, Mir Publ., 1976, v. 1, 390 p., v. 2, 320 p. (in Russ.) Yakhno T. A., Kazakov V. V., Sanina O. A., Sanin A. G., Yakhno V. G. Kapli biologicheskikh zhidkostey, vysykhayushchie na tverdoy podlozhke: dinamika morfologii, massy, temperatury i mekhanicheskikh svoystv [Drops of biological fluids drying on a solid substrate: dynamics of morphology, mass, temperature, and mechanical properties]. Zhurnal tekhnicheskoi fi ziki [Technical Physics], 2010, v. 80(7), pp. 17–23. URL: http://journals.ioffe.ru/articles/viewPDF/10043 (in Russ.) Alfi mov M. V., Kadushnikov R. M., Shturkin N. A., Alievskii V. M., Lebedev-Stepanov P. V. Immitatsionnoe modelirovanie protsessov samoorganizatsii nanochastits [Simulation modeling of self-organization processes of nanoparticles], Rossiiskie nanotekhnologii [Nanotechnologies in Russia], 2006, v. 1(1–2), pp. 127–133. (in Russ.) Lebedev-Stepanov P. V., Gromov S. P., Molchanov S. P., Chernyshov N. A., Batalov I. S., Sazonov S. K., Lobova N. A., Shevchenko N. N., Men’shikova A. Yu., Alfimov M. V. Controlling the self-assemblage of modifi ed colloid particle ensembles in solution microdropletsRossiiskie nanotekhnologii [Nanotechnologies in Russia], 2011, v. 6(9–10), 569–578, pp. 72–78. https://doi.org/10.1134/S1995078011050119 Andreeva L. V., Novoselova A. S., Lebedev-Stepanov P. V., Ivanov D. A., Koshkin A. V., Petrov A. N., Alfi mov M. V. Zakonomernosti kristallizatsii rastvorennykh veshchestv iz mikrokapli [Patterns of crystallization of dissolved substances from microdrops]. Zhurnal tekhnicheskoi fi ziki [Technical Physics], 2007, v. 77(2), pp. 22–30. URL: http://journals.ioffe.ru/articles/view-PDF/9048 (in Russ.) Barash L. Yu. Marangoni convection in an evaporating droplet: Analytical and numerical descriptions. International Journal of Heat and Mass Transfer, 2016, v. 102, pp. 445–454. https://doi.org/10.1016/j.ijh eatmasstransfer.2016.06.042 al Bityutskaya L. A., Zhukalin D. A., Tuchin A. V., Frolov A. A., Buslov V. A. Thermal dissipative structures in the case of carbon nanotubes aggregation in drying drops. Kondensirovannye sredy i mezhfaznye granitsy [Condensed Matter and Interphase], 2014, v. 16(4), pp. 425–430. URL: https://journals.vsu.ru/kcmf/ article/view/856/937 (in Russ.) Asakura S., Oosawa F. Interaction between particles suspended in solutions of macromolecules. Polymer Science Part A: General Papers, 1958, v. 33(126), pp. 183–192. https://doi.org/10.1002/pol.1958.1203312618 Minton A. P. How can biochemical reactions within cells differ from those in test tubes? Journal of Cell Science, 2015, v. 119(14), pp. 2863–2869. https://doi.org/10.1242/jcs.03063 Chebotareva N. A., Kurganov B. I., Livanova N. B. Biochemical effects of molecular crowding. Biohimija [Biochemistry], 2004, v. 69(11), pp. 1239–1251. https://doi.org/10.1007/s10541-005-0070-y Bishop K. J., Wilmer C. E., Soh S., Grzybowski B. A. Nanoscale forces and their uses in self-assembly. Small, 2009, v. 5(14), p. 1600–1630. https://doi.org/10.1002/smll.200900358 Minton A. P. The infl uence of macromolecular crowding and macromolecular confi nement on biochemical reactions in physiological media. Journal of Biological Chemistry, v. 276(14), pp. 10577–10580. https://doi.org/10.1074/jbc.r100005200 Huber F., Strehle D., Schnauss J., Kas J. Formation of regularly spaced networks as a general feature of actin bundle condensation by entropic forces. New J. Physics, 2015, v. 17(4), p. 043029. https://doi.org/10.1088/1367-2630/17/4/043029 Jiang H., Wada H., Yoshinaga N., Sano M. Manipulation of colloids by a nonequilibrium depletion force in a temperature gradient. Physical Review Letters, 2009, v. 102(20), p. 208301. https://doi.org/10.1103/physrevlett.102.208301 Deng H., Li G., Liu H. Assembling of three-dimensional crystals by optical depletion force induced by a single focused laser beam. Optics Express, 2012, v. 20(9), p. 9616. https://doi.org/10.1364/oe.20.009616 Wulfert R., Seiferta U., Speck T. Nonequilibrium depletion interactions in active microrheology. Soft Matter, 2017, v. 13(48), p. 9093–9102. https://doi.org/10.1039/c7sm01737e Dolgih I. I., Bitutskaya L. A. Entropy driven aggregation of CNT in a drying drop on hydrophilic and hydrophobic substrate. Kondensirovannye sredy i mezhfaznye granitsy [Condensed Matter and Interphase], 2018, v. 20(4), p. 664–668. https://doi.org/10.17308/kcmf.2018.20/635

Temperature and light are two of the most crucial factors for microalgae production. Variations in these factors alter their growth kinetics, macromolecular composition and physiological properties, including cell membrane permeability and fluidity. The variations define the adaptation mechanisms adopted by the microalgae to withstand changes in these environmental factors. In the Qatar desert the temperature varies widely, typically between 10° and 45 °C There are also wide variations in light intensity, with values of over 1500 μmolhν.m−2s−1 in summer. A study of the effects of these thermal and light fluctuations is therefore essential for large-scale outdoor production systems, especially during the summer when temperature and light fluctuations are at their highest. The aim of this work is to study the impact of temperature and light intensity variations as encountered in summer period on the Nannochloropsis QU130 strain, which was selected for its suitability for outdoor cultivation in the harsh conditions of the Qatar desert. It was carried out using lab-scale photobioreactors enabling simulation of both constant and dynamic temperature and light regimes. Biomass productivity, cell morphology and biochemical compositions were examined first in constant conditions, then in typical outdoor cultivation conditions to elucidate the adjustments in cell function in respect of fluctuations. The dynamic light and temperature were shown to have interactive effects. The application of temperature cycles under constant light led to a 13.6% increase in biomass productivity, while a 45% decrease was observed under light and temperature regimes due to the combined stress. In all cases, the results proved that N. sp. QU130 has a high level of adaptation to the wide fluctuations in light and temperature stress. This was shown through its ability to easily change its physiology (cell size) and metabolic process in response to different cultivation conditions.

Purpose This paper aims to a newly designed photoresponsive four-armed graft copolymer was synthesised and characterised. The synthesised polymer contains photochemical group and a greater part of the cross-linkable functional group which is not affected by short wavelength when subject to under ultraviolet (UV) irradiation in film status. Design/methodology/approach The four-armed macroinitiator was prepared by reacting diethanol amine with poly [methyl-2-chloro-4-{7-(chloroacetyl) oxy]-2-oxo-2H-chromen-4-yl}-2-methylbutanoate] and acylating the product with chloroacetyl chloride. A grafting reaction with n-butyl methacrylate was carried out in the presence of the four-armed macroinitiator and the catalyst CuBr/2, 2′-bipyridyne at 90°C. All of the synthesised polymers were structurally characterised by Fourier transform infrared spectroscopy (FT-IR) and Hydrogen-1 Nuclear Magnetic Resonance (1H-NMR) spectra. Gel permeation chromatography was used to obtain the molecular weights of polymer. Findings 1H-NMR, FT-IR and ultraviolet-visible (UV-Vis) spectroscopy demonstrated that the four-armed macroinitiator and the graft copolymer was successfully synthesised. The end-functionalised poly(methyl methacrylate) with 7-hydroxyl-4-chloromethyl coumarin was irradiated at the wavelength larger than 300 nm to create the cyclobutane ring in between the 7-hydroxyl-4-chloro methyl coumarin unities. To characterise the polymer and show the transformation of coumarin unities into photodimers, 1H-NMR, FT-IR and UV-Vis spectroscopy were used. Research limitations/implications Graft copolymer containing coumarin has involves photocrosslinkable functional group, in which reactive functional group has attracted great interest from both industrial and academic fields. Their synthesis provides the opportunity for a compatible modification of the graft copolymer structure to develop adapted macromolecules for a range of end practices. Practical implications A photoresponsive graft copolymer can have a role in an active area of polymer chemistry research due to its uses in the areas of photolithography, liquid crystal, non-linear optical materials, laser dyes, fluorescence materials and future microelectronics. Originality/value Graft copolymers containing a photocrosslinkable functional group, and a star polymer may be prepared using the method described in this paper and then used in technological applications. The method discussed here also allows photoinduced reversible self-healing in solid polymers.

Artikel review ini memberikan informasi tentang aplikasi polianilina (PANI) dan kompositnya sebagai sensor gas berbahaya khususnya amonia (NH3). Kajian yang dibahas pada artikel ini meliputi sifat gas NH3, material komposit, kinerja sensor, serta limit deteksi. Tinjauan sensor gas amonia berbasis polimer konduktif polianilina secara menyeluruh diambil dari referensi sepuluh tahun terakhir. Sebagai contoh, komposit polianilina dengan turunan karbon seperti reduced Graphene Oxide (rGO) dan Carbon Nanotube menunjukkan limit deteksi hingga 46 ppb dengan waktu pemulihan hanya 75 detik. Selain itu, komposit PANI dengan logam seperti Ag, Sr dan sebagainya, menunjukkan limit deteksi yang lebih besar yaitu 1 ppm, namun terdapat keunggulan dimana waktu pemulihan hanya 4 deti. Oleh sebab itu, polimer konduktif polianilina menjadi material yang sangat menjanjikan untuk mendeteksi keberadaan gas NH3. Terakhir, mekanisme penginderaan gas amonia terhadap material PANI juga dibahas pada tulisan ini. Referensi: [1] M. Insausti, R. Timmis, R. Kinnersley, and M. C. Rufino, “Advances in sensing ammonia from agricultural sources,” Science of the Total Environment, vol. 706. 2020. doi: 10.1016/j.scitotenv.2019.135124. [2] H. Shen et al., “Intense Warming Will Significantly Increase Cropland Ammonia Volatilization Threatening Food Security and Ecosystem Health,” One Earth, vol. 3, no. 1, 2020, doi: 10.1016/j.oneear.2020.06.015. [3] W. Wu, B. Wei, G. Li, L. Chen, J. Wang, and J. Ma, “Study on ammonia gas high temperature corrosion coupled erosion wear characteristics of circulating fluidized bed boiler,” Engineering Failure Analysis, vol. 132, p. 105896, 2022, doi: https://doi.org/10.1016/j.engfailanal.2021.105896. [4] X. Huang et al., “Reduced graphene oxide–polyaniline hybrid: Preparation, characterization and its applications for ammonia gas sensing,” Journal of Materials Chemistry, vol. 22, no. 42, pp. 22488–22495, 2012, doi: 10.1039/C2JM34340A. [5] T. Jiang, P. Wan, Z. Ren, and S. Yan, “Anisotropic Polyaniline/SWCNT Composite Films Prepared by in Situ Electropolymerization on Highly Oriented Polyethylene for High-Efficiency Ammonia Sensor,” ACS Applied Materials & Interfaces, vol. 11, no. 41, pp. 38169–38176, Oct. 2019, doi: 10.1021/acsami.9b13336. [6] H. Bai and G. Shi, “Gas sensors based on conducting polymers,” Sensors, vol. 7, no. 3. 2007. doi: 10.3390/s7030267. [7] D. Kwak, Y. Lei, and R. Maric, “Ammonia gas sensors: A comprehensive review,” Talanta, vol. 204. 2019. doi: 10.1016/j.talanta.2019.06.034. [8] M. Eising, C. E. Cava, R. V. Salvatierra, A. J. G. Zarbin, and L. S. Roman, “Doping effect on self-assembled films of polyaniline and carbon nanotube applied as ammonia gas sensor,” Sensors and Actuators, B: Chemical, vol. 245, pp. 25–33, 2017, doi: 10.1016/j.snb.2017.01.132. [9] M. P. Diana, W. S. Roekmijati, and W. U. Suyud, “Why it is often underestimated: Historical Study of Ammonia Gas Exposure Impacts towards Human Health,” in E3S Web of Conferences, 2018, vol. 73. doi: 10.1051/e3sconf/20187306003. [10] R. T. Xu et al., “Half-Century Ammonia Emissions From Agricultural Systems in Southern Asia: Magnitude, Spatiotemporal Patterns, and Implications for Human Health,” GeoHealth, vol. 2, no. 1, 2018, doi: 10.1002/2017GH000098. [11] S. A. Akbar, A. Mardhiah, N. Saidi, and D. Lelifajri, “The effect of graphite composition on polyaniline film performance for formalin gas sensor,” Bulletin of the Chemical Society of Ethiopia, vol. 34, no. 3, 2021, doi: 10.4314/bcse.v34i3.14. [12] X. Wang, L. Gong, D. Zhang, X. Fan, Y. Jin, and L. Guo, “Room temperature ammonia gas sensor based on polyaniline/copper ferrite binary nanocomposites,” Sensors and Actuators B: Chemical, vol. 322, p. 128615, 2020, doi: https://doi.org/10.1016/j.snb.2020.128615. [13] L. Wang et al., “Enhanced Sensitivity and Stability of Room-Temperature NH3 Sensors Using Core–Shell CeO2 Nanoparticles@Cross-linked PANI with p–n Heterojunctions,” ACS Applied Materials &Interfaces, vol. 6, no. 16, pp. 14131–14140, Aug. 2014, doi: 10.1021/am503286h. [14] Y. Guo et al., “Hierarchical graphene–polyaniline nanocomposite films for high-performance flexible electronic gas sensors,” Nanoscale, vol. 8, no. 23, pp. 12073–12080, 2016, doi: 10.1039/C6NR02540D. [15] M. Eising, C. E. Cava, R. V. Salvatierra, A. J. G. Zarbin, and L. S. Roman, “Doping effect on self-assembled films of polyaniline and carbon nanotube applied as ammonia gas sensor,” Sensors and Actuators B: Chemical, vol. 245, pp. 25–33, 2017, doi: https://doi.org/10.1016/j.snb.2017.01.132. [16] S. Bai et al., “Transparent conducting films of hierarchically nanostructured polyaniline networks on flexible substrates for high-performance gas sensors,” Small, vol. 11, no. 3, 2015, doi: 10.1002/smll.201401865. [17] Z. Wu et al., “Enhanced sensitivity of ammonia sensor using graphene/polyaniline nanocomposite,” Sensors and Actuators, B: Chemical, vol. 178, 2013, doi: 10.1016/j.snb.2013.01.014. [18] N. R. Tanguy, B. Wiltshire, M. Arjmand, M. H. Zarifi, and N. Yan, “Highly Sensitive and Contactless Ammonia Detection Based on Nanocomposites of Phosphate-Functionalized Reduced Graphene Oxide/Polyaniline Immobilized on Microstrip Resonators,” ACS Applied Materials and Interfaces, vol. 12, no. 8, 2020, doi: 10.1021/acsami.9b21063. [19] D. Maity and R. T. R. Kumar, “Polyaniline Anchored MWCNTs on Fabric for High Performance Wearable Ammonia Sensor,” ACS Sensors, vol. 3, no. 9, 2018, doi: 10.1021/acssensors.8b00589. [20] J. Ma et al., “Multi-walled carbon nanotubes/polyaniline on the ethylenediamine modified polyethylene terephthalate fibers for a flexible room temperature ammonia gas sensor with high responses,” Sensors and Actuators, B: Chemical, vol. 334, May 2021, doi: 10.1016/j.snb.2021.129677. [21] A. Javadian-Saraf, E. Hosseini, B. D. Wiltshire, M. H. Zarifi, and M. Arjmand, “Graphene oxide/polyaniline-based microwave split-ring resonator: A versatile platform towards ammonia sensing,” Journal of Hazardous Materials, vol. 418, Sep. 2021, doi: 10.1016/j.jhazmat.2021.126283. [22] A. Liu et al., “The gas sensor utilizing polyaniline/ MoS2 nanosheets/ SnO2 nanotubes for the room temperature detection of ammonia,” Sensors and Actuators, B: Chemical, vol. 332, Apr. 2021, doi: 10.1016/j.snb.2021.129444. [23] Q. Feng, H. Zhang, Y. Shi, X. Yu, and G. Lan, “Preparation and gas sensing properties of PANI/SnO2 hybrid material,” Polymers, vol. 13, no. 9, May 2021, doi: 10.3390/polym13091360. [24] S. Benhouhou, A. Mekki, M. Ayat, and N. Gabouze, “Facile Preparation of PANI-Sr Composite Flexible Thin Film for Ammonia Sensing at Very Low Concentration,” Macromolecular Research, vol. 29, no. 4, pp. 267–279, Apr. 2021, doi: 10.1007/s13233-021-9034-3. [25] X. Wang et al., “In situ polymerized polyaniline/MXene (V2C) as building blocks of supercapacitor and ammonia sensor self-powered by electromagnetic-triboelectric hybrid generator,” Nano Energy, vol. 88, Oct. 2021, doi: 10.1016/j.nanoen.2021.106242. [26] J. Chang et al., “Polyaniline-Reduced Graphene Oxide Nanosheets for Room Temperature NH3Detection,” ACS Applied Nano Materials, vol. 4, no. 5, pp. 5263–5272, May 2021, doi: 10.1021/acsanm.1c00633. [27] S. Matindoust, A. Farzi, M. Baghaei Nejad, M. H. Shahrokh Abadi, Z. Zou, and L. R. Zheng, “Ammonia gas sensor based on flexible polyaniline films for rapid detection of spoilage in protein-rich foods,” Journal of Materials Science: Materials in Electronics, vol. 28, no. 11, 2017, doi: 10.1007/s10854-017-6471-z. [28] J. Cai, C. Zhang, A. Khan, C. Liang, and W. di Li, “Highly transparent and flexible polyaniline mesh sensor for chemiresistive sensing of ammonia gas,” RSC Advances, vol. 8, no. 10, pp. 5312–5320, 2018, doi: 10.1039/c7ra13516e. [29] T. Syrový et al., “Gravure-printed ammonia sensor based on organic polyaniline colloids,” Sensors and Actuators, B: Chemical, vol. 225, pp. 510–516, Mar. 2016, doi: 10.1016/j.snb.2015.11.062.

Целью настоящей работы является исследование физического базиса межфазной адгезии в системе полимер – углеродные нанотрубки. Эта цель реализуется на примере нанокомпозитов полипропилен/углеродные нанотрубки (нановолокна) в рамках фрактального анализа.В силу своей высокой степени анизотропии и низкой поперечной жесткости углеродные нанотрубки (нановолокна) формируют в полимерной матрице нанокомпозита кольцеобразные формирования, структурно аналогичные макромолекулярным клубкам разветвленных полимеров. Это обстоятельство позволяет моделировать структуру нанокомпозитов полимер/углеродные нанотрубки (нановолокна) как полимерный раствор, используя для этой цели методы фрактальной физической химии. При таком подходе предполагается, что роль макромолекулярных клубков играют кольцеобразные формирования углеродных нанотрубок, а роль растворителя – полимерная матрица.Предложенная модель позволяет выполнить структурный анализ уровня межфазных взаимодействий полимерная матрица-нанонаполнитель или уровня межфазной адгезии. Обнаружено, что большая часть контактов между углеродными нанотрубками и полимерной матрицей, которые определяют указанный уровень, формируются внутри кольцеобразных формирований. В рамках фрактального анализа показано, что снижение радиуса кольцеобразных формирований или их компактизация приводит к росту фрактальной размерности, что затрудняет доступ матричного полимера в их внутренние части. Следствием этого эффекта является уменьшение числа контактов полимер-нанонаполнитель и значительное снижение уровня межфазной адгезии. Альтернативно этотэффект может быть описан как следствие компактизации кольцеобразных формирований, выраженной ростом их плотности. Показана прямая взаимосвязь показателя межфазной адгезии (безразмерного параметра ba) как с числом контактов полимер-углеродные нанотрубки, так и с объемом кольцеобразных формирований, доступным для проникновения полимера в их внутренние области. Количественный анализ продемонстрировал, что доля контактов, формирующихся на поверхности кольцеобразных формирований углеродных нанотрубок (нановолокон) составляеттолько ~ 7–10 %. Предложенная модель позволяет получить взаимосвязь между структурой нанонаполнителя в полимерной матрице и уровнем межфазной адгезии для нанокомпозитов этого класса. С практической точки зрения результаты позволяют определить структуру углеродных нанотрубок (нановолокон), необходимую для достижения наибольшего уровня межфазной адгезии. ЛИТЕРАТУРА 1. Mikitaev A. K., Kozlov G. V., Zaikov G. E. Polymer Nanocomposites: Variety of structural forms and applications. New York: Nova Science Publishers, Inc., 2008. 319 p.2. Kozlov G. V., Dolbin I. V. Transfer of mechanical stress from polymer matrix to nanofi ller in dispersionfilled nanocomposites. Inorganic Mater.: Appl. Res. 2019;10(1): 226–230. DOI: https://doi.org/10.1134/s20751133190101673. Dolbin I. V., Karnet Yu. N., Kozlov G. V., Vlasov A. N. Mechanism of growth of interfacial regionsin polymer/carbon nanotube nanocomposites. Composites: Mechanics, Computations, Applications: AnIntern. J. 2018;10(3): 213 220. DOI: https://doi.org/10.1615/CompMechComputApplIntJ.20180292344. Kozlov G. V., Dolbin I. V. The effect of uniaxial extrusion of the degree of reinforcement of nanocompositespolyvinyl chloride/boron nitride. Inorganic Mater.: Appl. Res. 2019;10(3): 642–646. DOI: https://doi.org/10.1134/S20751133190301835. Moniruzzaman M., Winey K. I. Polymer nanocomposites containing carbon nanotubes. Macromolecules.2006;39(16): 5194–5206. DOI: https://doi.org/10.1021/ma060733p6. Thostenson E. T., Li C., Chou T.-W. Nanocomposites in contex. Composites Sci. Techn. 2005;65(2):491–516. DOI: https://doi.org/10.1016/j.compscitech.2004.11.0037. Kozlov G. V., Dolbin I. V. The description of elastic modulus of nanocomposites polyurethane/graphenewithin the framework of modifi ed blends rule. Materials Physics and Mechanics. 2018;40(2): 152–157.DOI: https://doi.org/10.18720/MPM.4022018_38. Козлов Г. В., Долбин И. В. Фрактальная модель переноса механического напряжения в наноком-позитах полиуретан / углеродные нанотрубки. Письма о материалах. 2018;8(1): 77–80. DOI: https://doi.org/10.22226/2410-3535-2018-1-77-809. Kozlov G. V., Dolbin I. V., Koifman O. I. A fractal model of reinforcement of carbon polymer–nanotubecomposites with ultralow concentrations of nanofi ller. Doklady Physics. 2019;64(5): 225–228. DOI: https://doi.org/10.1134/S102833581905002110. Козлов Г. В., Долбин И. В. Структурная модель эффективности ковалентной функционализации углеродных нанотрубок. Известия высших учебных заведений, Серия Химия и химическая технология. 2019;62(10): 118–123. DOI: https://doi.org/10.6060/ivkkt.20196210.596211. Schaefer D. W., Justice R. S. How nano are nanocomposites? Macromolecules. 2007;40(24):8501–8517. DOI : https://doi.org/10.1021/ma070356w12. Atlukhanova L. B., Kozlov G. V., Dolbin I. V. Structural model of frictional processes for polymer/carbon nanotube nanocomposites. Journal of Friction and Wear. 2019;40(5). 475–479. DOI: https://doi.org/10.3103/S106836661905002713. Yanovsky Yu. G., Kozlov G. V., Zhirikova Z. M., Aloev V. Z., Karnet Yu. N. Special features of the structureof carbon nanotubes in polymer composite media. Nanomechanics. Sci. Technol.: An Intern. J. 2012;3(2).99–124. DOI: https://doi.org/10.1615/NanomechanicsSciTechnolIntJ.v3.i2.1014. Козлов Г. В., Долбин И. В. Влияние взаимодействий нанонаполнителя на степень усилениянанокомпозитов полимер/углеродные нанотрубки. Нано- и микросистемная техника. 2018;20(5):259–266. DOI: https://doi.org/10.17587/nmst.20.259-26615. Kozlov G. V., Dolbin I. V. Interrelation between elastic moduli of fi ller and polymethyl methacrylatecarbonnanotube nanocomposites. Glass Physics and Chemistry. 2019;45(4): 277–280. DOI: https://doi.org/10.1134/S108765961904006016. Kozlov G.V., Dolbin I.V., Zaikov G.E. The Fractal Physical Chemistry of Polymer Solutions and Melts. Toronto, New Jersey: Apple Academic Press, 2014; 316 p.17. Bridge B. Theoretical modeling of the critical volume fraction for percolation conductivity of fi breloadedconductive polymer composites. J. Mater. Sci. Lett. 1989;8(2): 102–103. DOI: https://doi.org/10.1007/BF0072026518. Kozlov G. V., Zaikov G. E. Structure of the Polymer Amorphous State. Utrecht, Boston: Brill AcademicPublishers; 2004. 465 p.19. Puertolas J. A., Castro M., Morris J. A., Rios R., Anson-Casaos A. Tribological and mechanical propertiesof grapheme nanoplatelet/PEEK composites. Carbon. 2019;141(1): 107–122. DOI: https://doi.org/10.1016/j.carbon.2018.09.03620. Zhang M., Zhang W., Jiang N., Futaba D. N., Xu M. A general strategy for optimizing compositeproperties by evaluating the interfacial surface area of dispersed carbon nanotubes by fractal dimension.Carbon. 2019;154(2): 457–465. DOI: https://doi.org/10.1016/j.carbon.2019.08.01721. Kozlov G. V., Dolbin I. V. Effect of a nanofi ller structure on the degree of reinforcement of polymer–carbon nanotube nanocomposites with the use of a percolation model. Journal of Applied Mechanicsand Technical Physics. 2018;59(4): 765–769. DOI: https://doi.org/10.1134/S002189441804025922. Kozlov G. V., Dolbin I. V. Structural interpretation of variation in properties of polymer/carbonnanotube nanocomposites near the nanofi ller percolation threshold. Technical Physics. 2019;64(10): 1501–1505. DOI: https://doi.org//10.1134/S106378421910012823. Kozlov G. V., Zaikov G. E. The structural stabilization of polymers: Fractal Models. Leiden, Boston:Brill Academic Publishers; 2006. 345 p.24. Kozlov G. V., Dolbin I. V. Modeling of carbon nanotubes as macromolecular coils. Melt viscosity.High Temperature. 2018;56(5): 830–832. DOI: https://doi.org/10.1134/S0018151X18050176. 25. Kozlov G. V., Dolbin I. V. Viscosity of a melt of polymer/carbon nanotube nanocomposites. An analogywith a polymer solution. High Temperature. 2019;57(3): 441–443. DOI: https://doi.org/10.1134/S0018151X1903008826. Kozlov G. V., Dolbin I. V. The simulation of carbon nanotubes as macromolecular coils: Interfacialadhesion. Materials Physics and Mechanics. 2017;32(2): 103–107. DOI: https://doi.org/10.18720/MPM.3222017-127. Kozlov G. V., Dolbin I. V. Fractal model of the nanofi ller structure affecting the degree of reinforcementof polyurethane–carbon nanotube nanocomposites. Journal of Applied Mechanics and Technical Physics.2018;59(3): 508–510. DOI: https://doi.org/10.1134/S002189441803015X28. Dolbin I. V., Kozlov G. V. Structural version of Ostwald-de Waele equation: Fractal treatment. FluidDynamics. 2019;54(2): 288–292. DOI: https://doi.org/10.1134/S001546281901005129. Atlukhanova L. B., Kozlov G. V., Dolbin I. V. The correlation between the nanofi ller structure and theproperties of polymer nanocomposites: fractal model. Inorganic Mater.: Appl. Res. 2020;11(1): 188–191. DOI:https://doi.org/10.1134/S207511332001004930. Kozlov G. V., Yanovskii Yu. G., Zaikov G. E. Structure and properties of particulate-fi lled polymercomposites: the fractal analysis. New York: Nova Science Publishers, Inc.; 2010. 282 p.31. Shaffer M. S. P., Windle A. H. Analogies between polymer solutions and carbon nanotube despersions.Macromolecules. 1999;32(2): 6864–6866. DOI: https://doi.org/10.1021/ma990095t32. Yi Y. B., Berhan L., Sastry A. M. Statistical geometry of random fi brous networks revisited: waviness,dimensionality and percolation. Journal of Applied Physics. 2004;96(7): 1318–1327. DOI: https://doi.org/10.1063/1.176324033. Berhan L., Sastry A. M. Modeling percolation in high-aspect-ratio fi ber systems. I. Soft-core versushard-core models. Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. 2007;75(23):041120. DOI: https://doi.org/10.1103/PhysRevE.75.04112034. Shi D.-L., Feng X.-Q., Huang Y.Y., Hwang K.-C., Gao H. The effect of nanotube waviness andagglomeration on the elastic property of carbon nanotube-reinforced composites. Journal of EngineeringMaterials and Technology, Transactions of the ASME. 2004;126(2): 250–257. DOI : https://doi.org/10.1115/1.175118235. Lau K.-T., Lu M., Liao K. Improved mechanical properties of coiled carbon nanotubes reinforced epoxynanocomposites. Composites. Part A. 2006;37(6): 1837–1840. DOI : https://doi.org/10.1016/j.compositesa.2005.09.01936. Martone A., Faiella G., Antonucci V., Giordano M., Zarrelli M. The effect of the aspect ratioof carbon nanotubes of their effective reinforcementmodulus in an epoxy matrix. Composites Sci. Techn.2011;71(8): 1117–1123. DOI: https://doi.org/10.1016/j.compscitechn.2011.04.00237. Shao L. H., Luo R. Y., Bai S. L., Wang J. Prediction of effective moduli of carbon nanotube – reinforcedcomposites with waviness and debonding. Composite Struct. 2009;87(3): 274–281. DOI: https://doi.org/10.1016/j.compstruct.2008.02.01138. Omidi M., Hossein Kokni D. T., Milani A. S., Seethaller R. J., Arasten R. Prediction of the mechanicalcharacteristics of multi-walled carbon nanotube/epoxy composites using a new form of the rule of mixtures.Carbon. 2010;48(11): 3218–3228. DOI: https://doi.org/10.1016/j.carbon.2010.05.00739. Shady E., Gowayed Y. Effect of nanotube geometry on the elastic properties of nanocomposites.Composites Sci. Techn. 2010;70(10): 1476–1481. DOI: https://doi.org/10.1016/j.compscitech.2010.04.027

Macromolecular motors from model materials of ectotherm muscles work as electro-chemo-mechanical and thermo-mechanical transducers harvesting, above 35 °C, up to 60% of the reaction energy from the thermal environment saving chemical energy.

Abstract Thermoresponsive diblock copolymers (DCs) were prepared by two-stage reversible addition-fragmentation chain transfer/macromolecular design by interchange of xanthate (RAFT/MADIX) polymerization of N-vinylcaprolactam and N-vinylimidazole (VI). The poly(N-vinylcaprolactam) (PVCL) blocks were first synthesized and used as macro-chain transfer agent in VI polymerization. The temperature behavior of PVCL and DCs in aqueous media has been studied by static and dynamic light scattering. It has been shown that the phase separation temperature of both PVCLs and DCs depends on the length of the PVCL chain and the composition of aqueous solvent. The temperature range above the PVCL θ temperature and below the cloud point is characterized by the conformational rearrangements leading to the formation of mesoglobules. The study of catalytic activity of DCs in the hydrolysis reaction of p-nitrophenyl propionate has shown that their activity substantially increases in this transitional temperature region owing to the formation of highly developed hydrophilic–hydrophobic interfaces inside the mesoglobules.

A new ionic liquid with intrinsic basic, ligand, and solvent properties is developed for efficient and selective Pd-catalyzed asymmetric C–C, C–O, and C–N cross-coupling reactions under mild conditions.

Spectral characterization of N,N′-Bis(2,4-dihydroxobenzylidene)1,2-diaminobenzene (DHDA) complexes with chosen f- and d-metal ions are described. Physico-chemical properties of a series of complexes were studied in methanol solution using UV-VIS, IR and fluorescence spectroscopy. It was found that the excitation and fluorescence spectra of DHDA in water and methanol after being exposed to ultraviolet radiation, show very obvious photochromism. The formation of 1 : 1 complexes between4,4′,4″,4‴-(porphine-5,10,15,20-tetrayl)-tetrakis benzoic acid, (TCPPH2) and La(III), Eu(III) and Yb(III) in methanolic solution, with the use of the spectrophotometric and spectrofluorimetric methods. The conditional stability constants of the complexes were studied by monitoring the spectral changes of energy and intensity of Q bands of the porphyrin.

Crosslinking of hydroxypropyl methyl cellulose (HPMC) and acrylic acid (AAc) was carried out at various compositions to develop a high-solid matrix with variable glass transition properties. The matrix was synthesized by the copolymerisation of two monomers, AAc and N,N′-methylenebisacrylamide (MBA) and their grafting onto HMPC. Potassium persulfate (K2S2O8) was used to initiate the free radical polymerization reaction and tetramethylethylenediamine (TEMED) to accelerate radical polymerisation. Structural properties of the network were investigated with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), modulated differential scanning calorimetry (MDSC), small-deformation dynamic oscillation in-shear, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show the formation of a cohesive macromolecular entity that is highly amorphous. There is a considerable manipulation of the rheological and calorimetric glass transition temperatures as a function of the amount of added acrylic acid, which is followed upon heating by an extensive rubbery plateau. Complementary TGA work demonstrates that the initial composition of all the HPMC-AAc networks is maintained up to 200 °C, an outcome that bodes well for applications of targeted bioactive compound delivery.

Thermoresponsive poly((N,N-dimethyl acrylamide)-co-(N-isopropyl acrylamide)) (P(DMA-co-NIPAM)) copolymers were synthesized via reversible addition−fragmentation chain transfer (RAFT) polymerization. The monomer reactivity ratios were determined by the Kelen–Tüdős method to be rNIPAM = 0.83 and rDMA = 1.10. The thermoresponsive properties of these copo-lymers with varying molecular weights were characterized by visual turbidimetry and dynamic light scattering (DLS). The copolymers showed a lower critical solution temperature (LCST) in water with a dependence on the molar fraction of DMA in the copolymer. Chaotropic and kosmotropic salt anions of the Hofmeister series, known to affect the LCST of thermoresponsive polymers, were used as additives in the aqueous copolymer solutions and their influence on the LCST was demonstrated. Further on, in order to investigate the thermoresponsive behavior of P(DMA-co-NIPAM) in a confined state, P(DMA-co-NIPAM)-b-PS diblock copolymers were prepared via polymerization induced self-assembly (PISA) through surfactant-free RAFT mediated emulsion polymerization of styrene using P(DMA-co-NIPAM) as the macromolecular chain transfer agent (mCTA) of the polymerization. As confirmed by cryogenic transmission electron microscopy (cryoTEM), this approach yielded stabilized spherical micelles in aqueous dispersions where the PS block formed the hydrophobic core and the P(DMA-co-NIPAM) block formed the hydrophilic corona of the spherical micelle. The temperature-dependent behavior of the LCST-type diblock copolymers was further studied by examining the collapse of the P(DMA-co-NIPAM) minor block of the P(DMA-co-NIPAM)-b-PS diblock copolymers as a function of temperature in aqueous solution. The nanospheres were found to be thermosensitive by changing their hydrodynamic radii almost linearly as a function of temperature between 25 °C and 45 °C. The addition of kosmotropic salt anions, as a potentially useful tuning feature of micellar assemblies, was found to increase the hydrodynamic radius of the micelles and resulted in a faster collapse of the micelle corona upon heating.

The substitution of isoelectronic B–N units for C–C units in aromatic hydrocarbons produces novel heterocycles with structural similarities to the all-carbon frameworks, but with fundamentally altered electronic properties and chemistry. Since the pioneering work of Dewar some 50 years ago, the relationship between B–N and C–C and the wealth of parent all-carbon aromatics has captured the imagination of organic, inorganic, materials, and computational chemists alike, particularly in recent years. New applications in biological chemistry, new materials, and novel ligands for transition-metal complexes have emerged from these studies. This review is aimed at surveying activity in the area in the past couple of decades. Its organization is based on ring size and type of the all-carbon or heterocyclic subunit that the B–N analog is derived from. Structural aspects pertaining to the retention of aromaticity are emphasized, along with delineation of significant differences in physical properties of the B–N compound as compared to the C–C parent.Key words: boron-nitrogen heterocycles, aromaticity, organic materials, main-group chemistry.

Vanadium-doped molybdenum carbides encapsulated in nitrogen-doped carbon exhibit significantly enhanced catalytic efficiency for both the oxidative C–N coupling of amines and C–C bond couplings of alcohols and ketones.

An efficient method for the synthesis of 8-acylated quinoline N-oxides from the reaction of quinoline N-oxides with α-diketonesviaC–C bond cleavage was developed. A variety of quinoline N-oxides and α-diketones with different groups was well tolerated in this system.

Macromolecular antioxidant due to its low physical loss, high thermal stability, and good compatibility has been considered to be a promising candidate to inhibit polymer aging. In this study, thermo-oxidative aging resistance and antioxidative mechanism of a macromolecular hindered phenol antioxidant, namely, polyhydroxylated polybutadiene containing thioether binding 2, 2′-thiobis (4-methyl-6-tert-butylphenol) (PHPBT-b-TPH) for natural rubber (NR) vulcanizate was studied in detail by oxidation induction time and accelerated thermal aging tests. The results showed that the antioxidative efficiency of PHPBT-b-TPH was very high. When the amount of PHPBT-b-TPH was only 1 phr, the NR vulcanizate could exhibit excellent thermo-oxidative aging resistance, obviously higher than that of NR vulcanizate with low-molecular-weight antioxidant TPH. After aged at 100°C for 168 h, the retentions of tensile strength and elongation at break of NR vulcanizate with PHPBT-b-TPH were 43.6% and 58.6%, respectively. However, those of NR vulcanizate with TPH were 35.6% and 54.5%. In addition, it was found that both thioether and urethane groups in PHPBT-b-TPH had antioxidative ability and had synergistic effect with hindered phenol. Through our findings, new strategy to design and synthesize the macromolecular antioxidant with multi-antioxidative groups for rubber materials and other polymer materials could be developed.

ABSTRACT A chemo-mechanical model has been developed for predicting the long-term mechanical behavior of EPDM rubbers in a harsh thermal oxidative environment. Schematically, this model is composed of two complementary levels: The “chemical level” calculates the degradation kinetics of the macromolecular network that is introduced into the “mechanical level” to deduce the corresponding mechanical behavior in tension. The “chemical level” is derived from a realistic mechanistic scheme composed of 19 elementary reactions describing the thermal oxidation of EPDM chains, their stabilization against oxidation by commercial antioxidants but also by sulfide bridges, and the maturation and reversion of the macromolecular network. The different rate constants and chemical yields have been determined from a heavy thermal aging campaign in air between 70 and 170 °C on four distinct EPDM formulations: additive free gum, unstabilized and stabilized sulfur vulcanized gum, and industrial material. This “chemical level” has been used as an inverse resolution method for simulating accurately the consequences of thermal aging at the molecular (concentration changes in antioxidants, carbonyl products, double bonds, and sulfide bridges), macromolecular (concentration changes in chain scissions and cross-link nodes), and macroscopic scales (weight changes). Finally, it gives access to the concentration changes in elastically active chains from which are deduced the corresponding changes in average molar mass MC between two consecutive cross-link nodes. The “mechanical level” is derived from a modified version of the statistical theory of rubber elasticity, called the phantom network theory. It relates the elastic and fracture properties to MC if considering the macromolecular network perfect, and gives access to the lifetime of the EPDM rubber based on a relevant structural or mechanical end-of-life criterion. A few examples of simulations are given to demonstrate the reliability of the chemo-mechanical model.

Abstract This study is about the synthesis of N,N′-bis(4-chlorophenyl)thiourea N,N-dimethylformamide (C16H17Cl2N3OS) compound. Single crystals of the compound were obtained by slow evaporation of N,N′-bis(4-chlorophenyl)thiourea (C13H10Cl2N2S) in N,N-dimethylformamide (C3H7NO; DMF) through recrystallization under mild condition. Important classical N–H⋯O links the two molecules together. Results revealed that C16H17Cl2N3OS crystallized in the monoclinic space group P21/c with the respective cell parameters of a = 92,360 (4) Å, b = 7.2232 (3) Å, 25.2555 (11) Å, β = 91.376 (3), α = γ = 90°, V = 1684.40 (12) Å3, T = 119.94 (13) K and Z = 4 and Z′ = 1.

Boron-containing π-conjugated materials are archetypical candidates for a variety of molecular scale applications. The incorporation of boron into the π-conjugated frameworks significantly modifies the nature of the parent π-conjugated systems. Several novel boron-bridged π-conjugated materials with intriguing structural, photo-physical and electrochemical properties have been reported over the last few years. In this paper, we review the properties and multi-dimensional applications of the boron-bridged fused-ring π-conjugated systems. We critically highlight the properties of π-conjugated N^C-chelate organoboron materials. This is followed by a discussion on the potential applications of the new materials in opto-electronics (O-E) and other areas. Finally, attempts will be made to predict the future direction/outlook for this class of materials.

This article provides the review of the medical use of pH- and temperature-sensitive polymer hydrogels. Such polymers are characterised by their thermal and pH sensitivity in aqueous solutions at the functioning temperature of living organisms and can react to the slightest changes in environmental conditions. Due to these properties, they are called stimuli-sensitive polymers. This response to an external stimulus occurs due to the amphiphilicity (diphilicity) of these (co)polymers. The term hydrogels includes several concepts of macrogels and microgels. Microgels, unlike macrogels, are polymer particles dispersed in a liquid and are nano- or micro-objects. The review presents studies reflecting the main methods of obtainingsuch polymeric materials, including precipitation polymerisation, as the main, simplest, and most accessible method for mini-emulsion polymerisation, microfluidics, and layer-by-layer adsorption of polyelectrolytes. Such systems will undoubtedly be promising for use in biotechnology and medicine due to the fact that they are liquid-swollen particles capable of binding and carrying various low to high molecular weight substances. It is also important that slight heating and cooling or a slight change in the pH of the medium shifts the system from a homogeneous to a heterogeneous state and vice versa. This providesthe opportunity to use these polymers as a means of targeted drug delivery, thereby reducing the negative effect of toxic substances used for treatment on the entire body and directing the action to a specific point. In addition, such polymers can be used to create smart coatings of implanted materials, as well as an artificial matrix for cell and tissue regeneration, contributing to a significant increase in the survival rate and regeneration rate of cells and tissues. References 1. Gisser K. R. C., Geselbracht M. J., Cappellari A.,Hunsberger L., Ellis A. B., Perepezko J., et al. Nickeltitaniummemory metal: A "Smart" material exhibitinga solid-state phase change and superelasticity. Journalof Chemical Education. 1994;71(4): 334. DOI: https://doi.org/10.1021/ed071p3342. Erman B., Flory P.J.. Critical phenomena andtransitions in swollen polymer networks and in linearmacromolecules. Macromolecules. 1986;19(9): 2342–2353. DOI: https://doi.org/10.1021/ma00163a0033. Tanaka T., Fillmore D., Sun S.-T., Nishio I.,Swislow G., Shah A. Phase transitions in ionic gels.Physical Review Letters. 1980;45(20): 1636–1639. DOI:https://doi.org/10.1103/physrevlett.45.16364. Polymer Gels. DeRossi D., Kajiwara K., Osada Y.,Yamauchi A. (eds.). Boston, MA: Springer US; 1991.354 p. DOI: https://doi.org/10.1007/978-1-4684-5892‑35. Ilmain F., Tanaka T., Kokufuta E. Volumetransition in a gel driven by hydrogen bonding. Nature.1991;349(6308): 400–401. DOI: https://doi.org/10.1038/349400a06. Kuhn W., Hargitay B., Katchalsky A., EisenbergH. Reversible dilation and contraction by changing thestate of ionization of high-polymer acid networks.Nature. 1950;165(4196): 514–516. DOI: https://doi.org/10.1038/165514a07. Steinberg I. Z., Oplatka A., Katchalsky A.Mechanochemical engines. Nature. 1966;210(5036):568-571. DOI: https://doi.org/10.1038/210568a08. Tian H., Tang Z., Zhuang X., Chen X., Jing X.Biodegradable synthetic polymers: Preparation,functionalization and biomedical application. Progressin Polymer Science. 2012;37(2): 237–280. DOI: https://doi.org/10.1016/j.progpolymsci.2011.06.0049. Gonçalves C., Pereira P., Gama M. Self-Assembledhydrogel nanoparticles for drug delivery applications.Materials. 2010;3(2): 1420–1460. DOI: https://doi.org/10.3390/ma302142010. Pangburn T. O., Petersen M. A., Waybrant B.,Adil M. M., Kokkoli E. Peptide- and Aptamer-functionalizednanovectors for targeted delivery of therapeutics.Journal of Biomechanical Engineering. 2009;131(7):074005. DOI: https://doi.org/10.1115/1.316076311. Caldorera-Moore M. E., Liechty W. B., PeppasN. A. Responsive theranostic systems: integrationof diagnostic imaging agents and responsive controlledrelease drug delivery carriers. Accounts of ChemicalResearch. 2011;44(10): 1061–1070. DOI: https://doi.org/10.1021/ar200177712. Das M., Sanson N., Fava D., Kumacheva E.Microgels loaded with gold nanorods: photothermallytriggered volume transitions under physiologicalconditions†’. Langmuir. 2007;23(1): 196–201. DOI:https://doi.org/10.1021/la061596s13. Oh J. K., Lee D. I., Park J. M. Biopolymer-basedmicrogels/nanogels for drug delivery applications.Progress in Polymer Science. 2009;34(12): 1261–1282.DOI: https://doi.org/10.1016/j.progpolymsci.2009.08.00114. Oh J. K., Drumright R., Siegwart D. J.,Matyjaszewski K. The development of microgels/nanogels for drug delivery applications. Progress inPolymer Science. 2008;33(4): 448–477. DOI: https://doi.org/10.1016/j.progpolymsci.2008.01.00215. Talelli M., Hennink W. E. Thermosensitivepolymeric micelles for targeted drug delivery.Nanomedicine. 2011;6(7): 1245–1255. DOI: https://doi.org/10.2217/nnm.11.9116. Bromberg L., Temchenko M., Hatton T. A. Smartmicrogel studies. Polyelectrolyte and drug-absorbingproperties of microgels from polyether-modifiedpoly(acrylic acid). Langmuir. 2003;19(21): 8675–8684.DOI: https://doi.org/10.1021/la030187i17. Vinogradov S. V. Polymeric nanogel formulationsof nucleoside analogs. Expert Opinion on Drug Delivery.2007;4(1): 5–17. DOI: https://doi.org/10.1517/17425247.4.1.518. Vinogradov S. V. Colloidal microgels in drugdelivery applications. Current Pharmaceutical Design.2006;12(36): 4703–4712. DOI: https://doi.org/10.2174/13816120677902625419. Kabanov A. V., Vinogradov S. V. Nanogels aspharmaceutical carriers: finite networks of infinitecapabilities. Angewandte Chemie International Edition.2009;48(30): 5418–5429. DOI: https://doi.org/10.1002/anie.20090044120. Lee E. S., Gao Z., Bae Y. H. Recent progress intumor pH targeting nanotechnology. Journal ofControlled Release. 2008;132(3): 164–170. DOI: https://doi.org/10.1016/j.jconrel.2008.05.00321. Dong H., Mantha V., Matyjaszewski K.Thermally responsive PM(EO)2MA magnetic microgelsvia activators generated by electron transfer atomtransfer radical polymerization in miniemulsion.Chemistry of Materials. 2009;21(17): 3965–3972. DOI:https://doi.org/10.1021/cm901143e22. Nayak S., Lyon L. A. Soft nanotechnology withsoft nanoparticles. Angewandte Chemie InternationalEdition. 2005;44(47): 7686–7708. DOI: https://doi.org/10.1002/anie.20050132123. Hennink W. E., van Nostrum C. F. Novelcrosslinking methods to design hydrogels. AdvancedDrug Delivery Reviews. 2012;64: 223–236. DOI: https://doi.org/10.1016/j.addr.2012.09.00924. Motornov M., Roiter Y., Tokarev I., Minko S.Stimuli-responsive nanoparticles, nanogels and capsulesfor integrated multifunctional intelligent systems.Progress in Polymer Science. 2010;35(1-2): 174–211. DOI:https://doi.org/10.1016/j.progpolymsci.2009.10.00425. Saunders B. R., Laajam N., Daly E., Teow S.,Hu X., Stepto R. Microgels: From responsive polymercolloids to biomaterials. Advances in Colloid andInterface Science. 2009;147-148: 251–262. DOI: https://doi.org/10.1016/j.cis.2008.08.00826. Landfester K. Miniemulsion polymerizationand the structure of polymer and hybrid nanoparticles.chemInform. 2009;40(33). DOI: https://doi.org/10.1002/chin.20093327927. Seo M., Nie Z., Xu S., Mok M., Lewis P.C.,Graham R., et al. Continuous microfluidic reactors forpolymer particles. Langmuir. 2005;21(25): 11614–11622. DOI: https://doi.org/10.1021/la050519e28. Nie Z., Li W., Seo M., Xu S., Kumacheva E. Janusand ternary particles generated by microfluidicsynthesis: design, synthesis, and self-assembly. Journalof the American Chemical Society. 2006;128(29): 9408–9412. DOI: https://doi.org/10.1021/ja060882n29. Seiffert S., Thiele J., Abate A. R., Weitz D. A.Smart microgel capsules from macromolecularprecursors. Journal of the American Chemical Society.2010;132(18): 6606–6609. DOI: https://doi.org/10.1021/ja102156h30. Rossow T., Heyman J. A., Ehrlicher A. J.,Langhoff A., Weitz D. A., Haag R., et al. Controlledsynthesis of cell-Laden Microgels by Radical-FreeGelation in Droplet Microfluidics. Journal of theAmerican Chemical Society. 2012;134(10): 4983–4989.DOI: https://doi.org/10.1021/ja300460p31. Perry J. L., Herlihy K. P., Napier M. E.,DeSimone J. M. PRINT: A novel platform toward shapeand size specific nanoparticle theranostics. Accountsof Chemical Research. 2011;44(10): 990–998. DOI:https://doi.org/10.1021/ar200031532. Caruso F., Sukhorukov G. Coated Colloids:Preparation, characterization, assembly and utilization.In: Decher G., Schlenoff J. B., editors. MultilayerThin Films. Weinheim, FRG: Wiley-VCH Verlag GmbH& Co. KGaA; 2002. p. 331-362.33. Sauzedde F., Elaïssari A., Pichot C. Hydrophilicmagnetic polymer latexes. 2. Encapsulation ofadsorbed iron oxide nanoparticles. Colloid & PolymerScience. 1999;277(11): 1041–1050. DOI: https://doi.org/10.1007/s00396005048834. Sauzedde F., Elaïssari A., Pichot C. Hydrophilicmagnetic polymer latexes. 1. Adsorption of magneticiron oxide nanoparticles onto various cationic latexes.Colloid & Polymer Science. 1999;277(9): 846–855. DOI:https://doi.org/10.1007/s00396005046135. Pich A., Richtering W. Microgels by PrecipitationPolymerization: Synthesis, Characterization, andFunctionalization. In: Pich A., Richtering W. (eds.)Chemical Design of Responsive Microgels. SpringerHeidelberg Dordrecht London New York; 2011. p. 1–37.DOI: https://doi.org/10.1007/978-3-642-16379-136. Yamada N., Okano T., Sakai H., Karikusa F.,Sawasaki Y., Sakurai Y. Thermo-responsive polymericsurfaces; control of attachment and detachment ofcultured cells. Die Makromolekulare Chemie, RapidCommunications. 1990;11(11): 571–576. DOI: https://doi.org/10.1002/marc.1990.03011110937. Kushida A., Yamato M., Konno C., Kikuchi A.,Sakurai Y., Okano T. Decrease in culture temperaturereleases monolayer endothelial cell sheets togetherwith deposited fibronectin matrix from temperatureresponsiveculture surfaces. Journal of BiomedicalMaterials Research. 1999;45(4): 355–362. DOI: https://doi.org/10.1002/(sici)1097-4636(19990615)45:4<355::aid-jbm10>3.0.co;2-738. Sekine H., Shimizu T., Dobashi I., Matsuura K.,Hagiwara N., Takahashi M., et al. Cardiac cell sheettransplantation improves damaged heart function viasuperior cell survival in comparison with dissociatedcell injection. Tissue Engineering Part A. 2011;17(23-24): 2973–2980. DOI: https://doi.org/10.1089/ten.tea.2010.065939. Nishida K., Yamato M., Hayashida Y.,Watanabe K., Yamamoto K., Adachi E., et al. Corneal reconstruction with tissue-engineered cell sheetscomposed of autologous oral mucosal epithelium. TheNew England Journal of Medicine. 2004;351(12): 1187–1196. DOI: https://doi.org/10.1056/nejmoa04045540. Kanzaki M., Yamato M., Yang J., Sekine H.,Kohno C., Takagi R., et al. Dynamic sealing of lungair leaks by the transplantation of tissue engineeredcell sheets. Biomaterials. 2007;28(29): 4294–4302.DOI: https://doi.org/10.1016/j.biomaterials.2007.06.00941. Iwata T., Yamato M., Tsuchioka H., Takagi R.,Mukobata S., Washio K., et al. Periodontal regenerationwith multi-layered periodontal ligament-derived cellsheets in a canine model. Biomaterials. 2009;30(14):2716–2723. DOI: https://doi.org/10.1016/j.biomaterials.2009.01.03242. Sawa Y., Miyagawa S., Sakaguchi T., Fujita T.,Matsuyama A., Saito A., et al. Tissue engineeredmyoblast sheets improved cardiac function sufficientlyto discontinue LVAS in a patient with DCM: report ofa case. Surgery Today. 2012;42(2): 181–184. DOI:https://doi.org/10.1007/s00595-011-0106-443. Ohki T., Yamato M., Ota M., Takagi R.,Murakami D., Kondo M., et al. Prevention of esophagealstricture after endoscopic submucosal dissection usingtissue-engineered cell sheets. Gastroenterology.2012;143(3): 582–588. DOI: https://doi.org/10.1053/j.gastro.2012.04.05044. Ebihara G., Sato M., Yamato M., Mitani G.,Kutsuna T., Nagai T., et al. Cartilage repair intransplanted scaffold-free chondrocyte sheets usinga minipig model. Biomaterials. 2012;33(15): 3846–3851. DOI: https://doi.org/10.1016/j.biomaterials.2012.01.05645. Sato M., Yamato M., Hamahashi K., Okano T.,Mochida J. Articular cartilage regeneration using cellsheet technology. The Anatomical Record. 2014;297(1):36–43. DOI: https://doi.org/10.1002/ar.2282946. Kuramoto G., Takagi S., Ishitani K., Shimizu T.,Okano T., Matsui H. Preventive effect of oral mucosalepithelial cell sheets on intrauterine adhesions. HumanReproduction. 2014;30(2): 406–416. DOI: https://doi.org/10.1093/humrep/deu32647. Yamamoto K., Yamato M., Morino T.,Sugiyama H., Takagi R., Yaguchi Y., et al. Middle earmucosal regeneration by tissue-engineered cell sheettransplantation. NPJ Regenerative Medicine. 2017;2(1):6. DOI: https://doi.org/10.1038/s41536-017-0010-748. Gan D., Lyon L. A. Synthesis and Proteinadsorption resistance of PEG-modified poly(Nisopropylacrylamide) core/shell microgels.Macromolecules. 2002;35(26): 9634–9639. DOI: https://doi.org/10.1021/ma021186k49. Veronese F. M., Mero A. The impact ofPEGylation on biological therapies. BioDrugs.2008;22(5): 315–329. DOI: https://doi.org/10.2165/00063030-200822050-0000450. Sahay G., Alakhova D. Y., Kabanov A. V.Endocytosis of nanomedicines. Journal of ControlledRelease. 2010;145(3): 182–195. DOI: https://doi.org/10.1016/j.jconrel.2010.01.03651. Nolan C. M., Reyes C. D., Debord J. D.,García A. J., Lyon L. A. Phase transition behavior,protein adsorption, and cell adhesion resistance ofpoly(ethylene glycol) cross-linked microgel particles.Biomacromolecules. 2005;6(4): 2032–2039. DOI:https://doi.org/10.1021/bm050008752. Scott E. A., Nichols M. D., Cordova L. H., GeorgeB. J., Jun Y.-S., Elbert D. L. Protein adsorption and celladhesion on nanoscale bioactive coatings formed frompoly(ethylene glycol) and albumin microgels.Biomaterials. 2008;29(34): 4481–4493. DOI: https://doi.org/10.1016/j.biomaterials.2008.08.00353. South A. B., Whitmire R. E., García A. J.,Lyon L. A. Centrifugal deposition of microgels for therapid assembly of nonfouling thin films. ACS AppliedMaterials & Interfaces. 2009;1(12): 2747–2754. DOI:https://doi.org/10.1021/am900543554. Wang Q., Uzunoglu E., Wu Y., Libera M. Selfassembledpoly(ethylene glycol)-co-acrylic acidmicrogels to inhibit bacterial colonization of syntheticsurfaces. ACS Applied Materials & Interfaces. 2012;4(5):2498–2506. DOI: https://doi.org/10.1021/am300197m55. Wang Q., Libera M. Microgel-modified surfacesenhance short-term osteoblast response. Colloids andSurfaces B: Biointerfaces. 2014;118: 202–209. DOI:https://doi.org/10.1016/j.colsurfb.2014.04.00256. Tsai H.-Y., Vats K., Yates M. Z., Benoit D. S. W.Two-dimensional patterns of poly(N-isopropylacrylamide)microgels to spatially control fibroblastadhesion and temperature-responsive detachment.Langmuir. 2013;29(39): 12183–12193. DOI: https://doi.org/10.1021/la400971g57. Lynch I. , Miller I. , Gallagher W. M. ,Dawson K. A. Novel method to prepare morphologicallyrich polymeric surfaces for biomedical applicationsvia phase separation and arrest of microgel particles.The Journal of Physical Chemistry B. 2006;110(30):14581–14589. DOI: https://doi.org/10.1021/jp061166a58. Li Y., Chen P., Wang Y., Yan S., Feng X., Du W.,et al. Rapid assembly of heterogeneous 3D cellmicroenvironments in a microgel array. AdvancedMaterials. 2016;28(18): 3543–3548. DOI: https://doi.org/10.1002/adma.20160024759. Bridges A. W., Singh N., Burns K. L., BabenseeJ. E., Andrew Lyon L., García A. J. Reduced acuteinflammatory responses to microgel conformalcoatings. Biomaterials. 2008;29(35): 4605–4615. DOI:https://doi.org/10.1016/j.biomaterials.2008.08.01560. Bridges A. W., Whitmire R. E., Singh N.,Templeman K. L., Babensee J. E., Lyon L. A., et al.Chronic inflammatory responses to microgel-basedimplant coatings. Journal of Biomedical Materials Research Part A. 2010;94A(1): 252–258. DOI: https://doi.org/10.1002/jbm.a.3266961. Gutowski S. M., Templeman K. L., South A. B.,Gaulding J. C., Shoemaker J. T., LaPlaca M. C., et al.Host response to microgel coatings on neuralelectrodes implanted in the brain. Journal of BiomedicalMaterials Research Part A. 2014;102(5): 1486–1499.DOI: https://doi.org/10.1002/jbm.a.3479962. da Silva R. M. P., Mano J. F., Reis R. L. Smartthermoresponsive coatings and surfaces for tissueengineering: switching cell-material boundaries.Trends in Biotechnology. 2007;25(12): 577–583. DOI:https://doi.org/10.1016/j.tibtech.2007.08.01463. Schmidt S., Zeiser M., Hellweg T., Duschl C.,Fery A., Möhwald H. Adhesion and mechanicalproperties of PNIPAM microgel films and theirpotential use as switchable cell culture substrates.Advanced Functional Materials. 2010;20(19): 3235–3243. DOI: https://doi.org/10.1002/adfm.20100073064. Uhlig K., Wegener T., He J., Zeiser M., BookholdJ., Dewald I., et al. Patterned thermoresponsivemicrogel coatings for noninvasive processing ofadherent cells. Biomacromolecules. 2016;17(3): 1110–1116. DOI: https://doi.org/10.1021/acs.biomac.5b01728