Статьи журнала - Нанотехнологии в строительстве: научный интернет-журнал
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Интернет-портал Nano- NewsNet (www.nano newsnet.ru) и электронное из да ние «Нанотехнологии в стро ительстве: научный Интернет- журнал» (www.nanobuild.ru) 29-30 сентября 2010 г. совместно проведут II Международную научно- практическую online-конференцию «Применение нанотехнологий в строительстве».
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III Всероссийская конференция по бетону и железобетону
Статья научная
Российская академия наук, Российская инженерная академия, Научно-исследовательский центр «Строительство», Национальный исследовательский университет «МГСУ», РААСН и другие организации при поддержке Минстроя России и Минобрнауки наметили проведение 12—16 мая 2014 года III Всероссийской (международной) конференции по бетону и железобетону. По уровню технических и экономических показателей железобетон является основным конструкционным материалом современности, лидируя в общей структуре мирового производства строительной продукции. Мировой объем применения бетона и железобетона ежегодно превышает 4 миллиарда кубометров, что составляет в стоимостном выражении более 300 миллиардов долларов. Железобетон, несомненно, сохранит свою лидирующую роль в строительстве и в ХХ! веке.
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Статья
Научный Интернет-журнал «Нанотехнологии в строительстве» (www.nanobuild.ru) совместно с Интернет-порталом NanoNewsNet (www.nanonewsnet.ru) провели III Международную научно-практическую online-конференцию «Применение нанотехнологий в строительстве». В меропри- ятии приняли участие ведущие российские и зарубежные ученые, специалисты вузов, научно-исследовательских институтов и нанотехнологических центров, учреждений и предприятий, фирм-производителей продукции наноиндустрии.
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Интернет-портал NanoNewsNet (www.nanonewsnet.ru) и электронное издание «Нанотехнологии в строительстве: научный Интернет-журнал» (www.nanobuild.ru) совместно провели IV Международную научно-практическую online-конференцию «Применение нанотехнологий в строительстве». В ней приняли участие ведущие ученые и специалисты Российской академии наук, Российской инженерной академии, Российской академии архитектуры и строительных наук, РОСНАНО, Научнотехнического центра прикладных нанотехнологий (г. Санкт-Петербург), Международной инженерной академии, Международного союза экспертов и лабораторий по испытанию строительных материалов, систем и конструкций (РИЛЕМ), руководители и специалисты организаций и предприятий, ученые, преподаватели вузов, сотрудники НИИ и научных центров из различных регионов России, стран ближнего и дальнего зарубежья.
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Статья научная
Metal nanocrystals exhibit unique properties due to their high surface-to-volume ratio and have great potential for applications in the fields of electronics, magnetics, optics and catalysis. However, their high specific surface area leads to easy coarsening in operation, which may greatly degrade their performances, especially when they are exposed to various chemical environments or at high temperatures. Therefore, the direct visualization of nanocrystals' structural evolution when they are coarsening is crucial to gain insight into the mechanism and develop more effective means to improve the size stability of nanocrystals. In this work, we investigated the structural evolution of Pt nanocrystals with sizes of ~ 4 nm on SiNx film in both oxidizing and reducing atmospheres at a moderate temperature (300оС) in the aberration-corrected environmental transmission electron microscopy (ETEM). The sizes of nanocrystals remain almost unchanged when annealed in the oxygen atmosphere with volatile PtOx formation on the surface, hindering nanocrystals sintering and leading to Pt loss. On the other hand, obvious coarsening of nanocrystals resulting from Ostwald-ripening and nanocrystal migration and coalescence was observed in the reducing atmosphere. Our findings reveal the dynamic structural evolution of nanocrystals in different atmospheres and provide possible ways to improve the size stability of nanocrystals.
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Статья научная
Various chemical additives are used for polyvinyl chloride (PVC) processing. Plasticization is one of the ways to improve the physical and mechanical PVC materials properties and simplify processing of polymer into the corresponding products. Today certain requirements to PVC-based compositions for environmental compatibility and manufacturability are increasing. Therefore, there is a need to develop new modern plasticizers and enlarge the assortment of them. This paper presents the results of research devoted to the compatibility of a new plasticizer, octylphenoxypropyl phthalate with PVC, with and without addition of pentae-rythritol ester of butyric acid. The PVC plasticizers compatibility was evaluated by the critical PVC dissolution temperature in the plasticizer and Shore A du-rometer hardness change in comparison with the industrial plasticizer dioctyl phthalate. The plasticizer influence on the flow temperature and the glass transition temperature has also been studied. It was marked that the studied octylphenoxypropyl phthalate as a plasticizer with the addition of pentaerythritol ester of butyric acid possesses sufficiently high plasticizing ability and it is well combined with PVC.
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Investigation of the rheological properties of PVC compositions containing phthalate plasticizers
Статья научная
Polymer materials based on polyvinyl chloride (PVC) are processed in the form of multitudinous compositions. One of the main indicators in the processing of polymer compositions is manufacturability. It is known that in the processing of polyvinyl chloride compositions manufacturability is estimated by rheology of melts. The determine polymer processability the melt flow index (MFI) is the most widespread and almost universally used value. The melt flow index of the polymer material is the mass of polymer in grams extruded through the capillary at a certain temperature and pressure overfall in 10 minutes. It allows us to take decisions on the necessary conditions of processing the polymer composition and to determine the temperature limits of converting. In fact, PVC compositions are characterized by high viscosity and various chemical additives. For example, plasticizers are used to improve the processing conditions. This research studied how oxyalkylated alcohol phthalates developed by the authors influence on the MFI polymer. The results show that the synthesized esters, in a greater degree respect to the industrial plasticizer di- octylphthalate (DOP), increase the fluidity of the melt of the PVC composition and reduce its processing temperature thus improving the effectiveness of the plastic production.
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Methodological bases of innovative training for specialists in area of nanotechnologies
Статья научная
The performance of innovative training system aimed at highly intellectual specialists in the area of nanotechnologies for Kazakhstan's economy demands establishment and development of nanotechnological market in the country, teaching of innovative engineering combined with consistent research, integration of trained specialists with latest technologies and sciences at the international level. Methodological aspects of training competitive specialists for nanotechnological field are specific. The paper presents methodological principles of innovative training of specialists for science-intensive industry that were realized according to grant given by the Ministry of Education and Science of the Republic of Kazakhstan.
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Nanocomposite organomineral hybrid materials. Part II
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The paper addresses the issues of alkoxide method of sol-gel synthesis and non-hydrolytic method of sol-gel synthesis and colloidal method of sol-gel synthesis. The authors also consider an alternative approach based on the use of soluble silicates as precursors in the sol-gel technology, of nanocomposites. It was shown that nanocomposites can be produced through aerogels. The paper also analyzes the mixing technologies of nanocomposites preparation. It has been demonstrated the possibility to change the types of nano-phase which is used for obtaining nanocomposites in different approaches. Various models of packaging spherical, fibrous and layered nanoparticles, introduced into the structure of the nanocomposite, in the preparation thereof were examined.
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Nanocomposite organomineral hybrid materials. Part iii
Статья научная
The paper addresses the issues of alkoxide method of sol-gel synthesis and non-hydrolytic method of sol-gel synthesis and colloidal method of sol-gel synthesis. The authors also consider an alternative approach based on the use of soluble silicates as precursors in the sol-gel technology, of nanocomposites. It was shown that nanocomposites can be produced through aerogels. The paper also analyzes the mixing technologies of nanocomposites preparation. It has been demonstrated the possibility to change the types of nano-phase which is used for obtaining nanocomposites in different approaches. Various models of packaging spherical, fibrous and layered nanoparticles, introduced into the structure of the nanocomposite, in the preparation thereof were examined.
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Nanotechnology in construction: state of the art and future trends
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The construction industry has long been regarded asenergy-intensive and high pollution industry. The emergence of nanotechnology provides an ideal solution for the construction industry to energy saving and consumption reduction. The introduction of nanotechnology has greatly promoted the development of new green building materials and brought huge economic and social benefits. This paper applies bibliometric analysis to review the nanotechnology-construction research collected by Web of Science database during 2000-2020, and further visualize their literature characteristics. At the global level, the number of literatures on nanotechnology-construction research has been on the rise in 2000-2019, although it has experienced a small decline in individual years. At the national level, the United States has become the global leader in nanotechnology-construction research with 63 articles, far more than other countries. Considering the income gap, developed countries play an indispensable role in the global nanotechnology-construction research system, while the role of developing countries is relatively weak. We found that the existing nanotechnology-construction research mainly focused on the fields of chemistry and materials science. According to the frequency of keywords, the research focus of nanotechnology-construction research mainly focused on the development and application of new building materials. It is concluded that with the extensive attention of researchers, the future research on nanotechnology-construction will continue to appear and increase at increasing rate.
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New plasticizers for PVC-compositions in construction
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The work is devoted to the analysis and development of effective types of plasticizers for a wide range of finishing (linoleum) and insulating building materials (insulation tape, cable plastic) with improved mechanical and technical characteristics. In connection with the growth of consumption of finishing and insulating materials, the development of new formulations of PVC compositions for construction with the use of new plasticizers is not only an urgent task, but also within the framework of construction it allows solving the problems of effective quality control of a finished PVC composition. This paper presents the results of the tests of octylphenoxyethylphtalates as a new chemical additivies for plasticizing PVC in the formulation of the upper and middle layers of linoleum, adhesive film and cable compound О-40 rec. ОМ-40 (black). It is noted, that obtained samples of adhesive tape with their main characteristics (tensile strength at break, extension coefficient, shatter point, thermostability) correspond to technical specification (TS) 2245-001-002033122003. Obtained samples of plasticate were analyzed according to GOST 5960-72 rev. 1-9 (PVC plasticate for isolation and protective covers of wires and cables), by main characteristics (specific insulation resistance, tensile strength at break, breaking elongation, shatter point) are not inferior to commercial prototypes, and such characteristics as «Weight loss at 160оС» and «Water absorption» are significantly lower. It is noted that, in case of using octylphenoxyethyl phtalates, obtained samples of films of upper and middle layers of linoleum analyzed according to norms of STI 00203312-100-2006 have a higher melt flow rate. In addition, films obtained through introduction of suggested plasticizers possess a low value of extractability by gasoline and oils.
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New polyvinylchloride plasticizers
Статья научная
One of the main large-capacity polymers of modern chemical industry is polyvinylchloride (PVC). Polyvinylchloride is characterized by many useful engineering properties - chemical firmness in different environments, good electric properties, etc. It explains immensely various use of materials on the basis of PVC in different engineering industries. It is cable, building, light industries, mechanical engineering and automotive industry where PVC is widely applied. One of the reasons why PVC production is dramatically growing is that there is no yet other polymer which could be subjected to such various modifying as it is done with PVC. However under normal temperature this polymer is fragile and isn't elastic that limits the field of its application. Rapid growth of production of polyvinylchloride is explained by its ability to modify properties, due to introduction of special additives when processing. Introduction of plasticizers - mostlly esters of organic and inorganic acids - into PVC allows significant changing properties of polymer. Plasticizers facilitate process of receiving polymeric composition, increase flexibility and elasticity of the final polymeric product due to internal modification of polymeric molecule. This paper presents the results of research on production methods, physicochemical and mechanical properties of new chemical additives of polyvinylchloride - plasticizers based on oxyalkylated alcohols. It also describes the optimal conditions for the compounds synthesis and the results of experiments performed with these compounds as additives in PVC film compositions. It is noted that composition obtained by introducing developed plasticizers into PVC compositions meet the requirements of the existing standards, and their oil and petrol resistance exceed standard samples.
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Production of PVC-films with specific properties
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When developing polymeric materials with specified properties special compounds such as fungicides are used alongside traditional chemical additives (plasticizers). Usage of fungicides are determined by negative influence of mold fungi, bacteria and other microorganisms on polyvinyl chloride (PVC) material. The present work focuses on the possibility to implement octylphenoxypropyl phthalates (OPOPP), proposed as plasticizers, and derivatives of 3-mercapto-1,2,4-triazinon-5, proposed as fungicides, in PVC films. The first additive was produced by esterification of phthalic anhydride by oxypropylated phenols and 2-ethylhexanol, the second additive - by cyclocondensation of alpha-keto acids with thiosemicarbazide. Having analyzed the results of experiments the authors found out that compositions obtained with the use of new additives - octylphenoxypropyl phthalates and derivatives of 3-mercapto-1,2,4-triazinone-5, acquire high performance properties that leads to increased service life. At the same time such important characteristics as strain at elongation, ultimate tensile stress, thermostability and funginertness are enhanced.
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Статья научная
Utilizing the unique properties of CNTs and CNFs to enhance the mechanical and fracture properties of cement based materials and develop smart cementitious nanocomposites can be a challenge in terms of developing scalable manufacturing methods. Scaling up the manufacturing size of CNT and CNF reinforced cement based materials and produce multifunctional concrete that exhibits exceptional strength, stiffness and toughness and multifunctionality requires optimization of dispersion procedure. The effectiveness of successfully using CNTs and CNFs in concrete depends on the fiber count, the volume fraction of sand and coarse aggregates. In this work, we present the flexural strength and stiffness, fracture toughness and brittleness of nanomodified pastes and mortars reinforced at amount of 0.08 and 0.1 wt% and an investigation on the optimization of the fiber count proportioning of concrete. The addition of a very low amount, 0.1 wt%, of both CNTs and CNFs, increases approximately 1.5 times the flexural strength and the Young`s modulus of concrete nanocomposites. The nanomodified concrete also exhibits 60% higher energy absorption capability.
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