Complex Binder Research Articles

Magnetically processed composite material for the production of plywood based on compacted aspen veneer (Populus tremula L.) and a complex binder with nanocrystalline cellulose

Magnetically processed composite material for the production of plywood based on compacted aspen veneer (Populus tremula L.) and a complex binder with nanocrystalline cellulose

Development of a universal atomistic cement model incorporating nanomaterials: From laboratory investigation to molecular simulation

Hydrated cement is considered one of the most complex binder systems. The development of models that suitably represent hydrated cement is still far from established due to the complexity of the hydration process, as well as the multiscale phase and different morphological properties. Therefore, this study attempts to develop a hydrated cement model using molecular-level simulation and laboratory testing. This model aimed to predict the mechanical properties of cement paste between 0.25 and 0.65 w/c ratios. In this regard, five cement paste mixtures with various w/c ratios were prepared and tested to evaluate their mechanical properties and micro-structures. Then, a novel modeling methodology using molecular dynamics (MD) simulation was carried out to develop an ingredient-based atomistic cement model. In this regard, the Dreiding force field (DFF) was used in all the simulation processes, starting from the cement clinker phases to the hydrated cement. The experimental results of cement paste mixtures revealed some useful data that was supportive of the simulations. Radial distribution function (RDF) and fractional free volume (FFV) were utilized to investigate the local atomic structure of the cement paste models. The calcium-silicate-hydrated (C–S–H) of the developed model was characterized through RDF and benchmarked to a well-known mineral analog, namely tobermorite. The developed model was computationally tested under different w/c ratios, and reliable results in terms of micro-structural matrix as well as mechanical properties were obtained. Then, the cement models incorporating different ratios of nano-silica were developed, and a good estimation of the mechanical properties was obtained. Because of the universal nature of the reported model in this research, it could be utilized to further predict the mechanical behavior and durability performance of the cement paste.

Novel-designed cobweb-like binder by “four-in-one” strategy for high performance SiO anode

The choice of binder can prodigiously affect the electrochemical performance of the silicon-based anode. Unfortunately, conventional binders with relatively weak intermolecular van der Waals forces have a weak buffering effect on the volume expansion of silicon-based anodes, which leads to electrode contact failure and substantial capacity decay during cycling. Herein, inspired by the spider web, a multifunctional cobweb-like complex binder (TA-PAA) with strong adhesion constructed of tapioca (TA) and polyacrylic acid (PAA) is designed and applied as a high efficiency binder for high capacity and long-term cycle performance SiO anode. Originating from high viscoelasticity, robust tensile, as well as mechanical strength and self-healing property (“four-in-one” effect), TA-PAA/SiO electrode accommodates volumetric stress and addresses electrode contact failure. The electrode delivers a brilliant rate performance (619.2 mA h g−1 at 5 A g−1) and long-term cycle performance (901.2 mA h g−1 over 1200 cycles at 2 A g−1).

СУЧАСНІ ПІДХОДИ КОМПЛЕКСНОЇ ПЕРЕРОБКИ ПРОМИСЛОВИХ ТЕХНОГЕННИХ ВІДХОДІВ

This article provides information on the possibility of integrated use of phosphogypsum, metal sludge and red bauxite sludge in the manufacture of construction products.
 The aggravation of the ecological and economic situation in Ukraine requires the development of new efficient technologies for processing and use of man-made industrial waste from the chemical industry. Such technologies should ensure their maximum degree of use in the manufacture of construction products. The choice of technology for the preparation, processing and use of industrial waste depends on a number of factors, namely the chemical-mineralogical and particle size distribution and method of production. Although such wastes are mostly used as aggregates, their overall use remains low. The share of their use in the manufacture of construction products is only 10 - 12%.
 It has been established that in the presence of open dumps phosphogypsum and red bauxite sludge are a source of pollution of the surrounding areas. 
 Large-scale use of phosphogypsum is hampered by its specific features: the presence in its composition of phosphoric and sulfuric acid and water-soluble harmful compounds of phosphorus and fluorine. Therefore, before using phosphogypsum, it is necessary to neutralize harmful impurities and reduce the concentration of acid residues. The most effective method of using phosphogypsum, fine powders of sludge steel SHH-15 and red bauxite sludge is the integrated use of such waste, resulting in metal-phosphate and metal-ash-phosphate binder.
 Key words: industrial waste; building materials; complex binder.

Pozzolanic efficiency of calcined clays in blended cements with a focus on early hydration

Fundamental knowledge about the reaction mechanism of calcined clays in cement and their mutual interaction is important for their assessment as supplementary cementitious materials and the resulting concrete properties. In this study, the hydration of two cements differing in alkali content and with the addition of a highly reactive, aluminium-rich metakaolin and a calcined common clay with low kaolinite content was investigated during the first 48 h. For this purpose, four established methods that describe the early hydration were used: isothermal calorimetry, thermogravimetric analysis, in situ X-ray diffraction and chemical analysis of pore solution. This as yet unique combination of methods led to greater understanding of the hydration behaviour of the complex binder (cement–calcined clay). The results showed considerable differences depending on the type of calcined clay, its chemical–mineralogical composition and fineness, especially with regards its reaction mechanism with aluminate clinker phases controlled by the composition of the pore solution. The impact of calcined clay on early clinker hydration extens far beyond well known physical effects.

Host–Guest Interlocked Complex Binder for Silicon–Graphite Composite Electrodes in Lithium Ion Batteries

AbstractMaximizing the energy density of a lithium‐ion battery cell by increasing the silicon content in the silicon–graphite (Si–Gr) composite anode is an ongoing research topic that is receiving much attention. However, the paradoxical surface characteristics of Si and Gr make it challenging to uniformly distribute the electrode components and maintain their adhesion during cycling accompanied with the immense volume change of Si. Here, an amphiphilic, tightly interlocked host–guest complex binder composed of pyrene‐conjugated poly(acrylic acid) (Py‐PAA) and a hyperbranched γ‐cyclodextrin polymer (γ CDp) is reported. The pyrene unit ofPy‐PAAnot only endows enhanced affinity to the Gr surface but also serves as a guest molecule capable of interlocking with theγ CDphost. This highly effective host–guest interaction sustains the integrity of the electrode to enable superior cycling performance and rate capability for Si–Gr electrodes with commercial‐level areal capacity. This study shows that hierarchical, multifunctional supramolecular binders of two kinds can offer improved battery performance for emerging high‐capacity electrodes consisting of components with different surface characteristics compared to conventional binders of a single kind.

Increasing calcium phosphate aqueous solubility and spontaneous supersaturation combining citrate and gluconate with perspectives for functional foods

Uptake of calcium from food depends on solubility of calcium salts in the intestines, and precipitation of calcium phosphates decreases bioaccessibility of food calcium. Citrate as a high affinity complex binder for calcium was found spontaneously to create strongly supersaturated solutions by rapid dissolution of calcium hydrogen phosphate characterized by short lag phases for precipitation. Gluconate with weaker affinity for calcium binding showed longer lag phases for precipitation from supersaturated solutions. For citrate/gluconate combinations, the highest degree of supersaturation with longest lag phases for precipitation were found by trial-and-error experiments for a citrate/gluconate ratio of 1:10 for dissolution of calcium hydrogen phosphate resulting in supersaturation factors around three and without precipitation for more than a month. The aim of the present study was to provide a physicochemical explanation of this robust supersaturation. Calcium speciation based on electrochemical calcium activity measurement identified a low [Ca2+]·[HCitr2−] product as critical for supersaturation.

THERMOSETTING BINDER FOR FIBROUS INSULATING MATERIALS

Statement of the problem. The modernization of insulation systems if engineering structures, including pipelines and industrial facilities, is aimed both at solving the general problems of energy efficiency, as well as the particular tasks of heat saving and environmental safety. In this regard, the development and use of a binder that cures at much lower temperatures and does not contain phenols is an urgent task. Results. An experiment conducted to assess the effect on adhesion to various surfaces of a complex binder, cured in the temperature range from 80 to 140 °C, allowed us to determine the optimal flow rate of the latent component and modifier, which were respectively 3.6--4.0 % and 2.6±0.1 % by weight of a binder at an optimal heat treatment temperature of 100 °C. The calculation established that when switching from heat treatment at 250 °C to heat treatment at 100 °C, direct heat costs are reduced by 60 %, and energy costs for the manufacture of mineral wool cylinders by 20--30 %. Conclusion . The possibility of using epoxy glue on latent hardeners as a binder for highly porous systems with the distribution and curing of this binder on thin mineral fibers was justified theoretically and confirmed experimentally. The characteristic parameters of the curing process were determined, the duration of which decreases with increasing temperature and the content of latent hardener.

ВИКОРИСТАННЯ АКРИЛОВОЇ КОПОЛІМЕРНОЇ ДОБАВКИ SOIL STABILIZATION PLUS ДЛЯ ПРИГОТУВАННЯ СУМІШЕЙ, ВИГОТОВЛЕНИХ ЗА ТЕХНОЛОГІЄЮ ХОЛОДНОГО РЕСАЙКЛІНГУ ТА ЩЕБЕНЕВО-ПІЩАНИХ СУМІШЕЙ У ШАРАХ ОСНОВИ ДОРОЖНЬОГО ОДЯГУ

ntroduction. Rehabilitation of public roads network requires a comprehensive recovery with strengthening of the bearing capacity of the pavement foundation. Rehabilitation of the foundation bearing capacity performed by arranging layers of road material made by cold recycling technology (hereinafter — CRRM) in accordance with [4] or by arranging a layer of crushed stone — sand mixture reinforced with cement or complex binder (hereinafter — CSSM 20) according to [13]. Purpose. The purpose of the work is to study the feasibility of using acrylic additives for the preparation of mixtures made by cold recycling technology and crushed stone-sand mixtures treated with cement in the layers of pavement foundation. Materials and methods. Experimental comparative tests of CRRM and CSSM 20 with different content of complex binder were performed. Results. Feasibility of acrylic additives use has been established (hereinafter — the additive) for the preparation of CRRM and CSSM 20 in the pavement foundation layers. Recommendations on technological parameters of preparation, transportation, laying and compaction of mentioned mixtures are given. Conclusions. Performed researches have shown that according to physical and mechanical indicators CRRM and CSSM20 meet the requirements of the current normative documents of Ukraine. The advantages of use are noted.

ABOUT MODERN POSSIBILITIES OF REUSING ROAD-BUILDING MATERIALS WHEN REPAIRING ROAD PAVEMENTS OF AN IMPROVED LIGHTWEIGHT TYPE

At present, when developing design solutions for the repair of non-rigid road pavements of an improved lightweight type, they provide for the device of a base layer using cold recycling technology or from a crushed stone-sand mixture treated with a mineral or complex binder, and two layers of asphalt concrete are laid on top. Based on the results of exploratory studies aimed at wider reuse of road building materials, it is proposed, when repairing a road surface of an improved lightweight type, instead of the top layer of a base made of asphalt concrete, arrange a layer of road material made by the technology of cold recycling ” in the mixer” using an organic binder, and the bottom layer of the base should be made of road material made by the technology of cold recycling “on the road” using a mineral or complex binder. Considering that Ukraine has insufficient experience in preparing mixtures using cold recycling technology using foamed bitumen or bitumen emulsion, the features of their manufacture are given. After milling the asphalt concrete, the bottom layer of the base is reinforced from the road material made using the cold recycling technology “on the road” using a mineral or complex binder. Layers of materials arranged according to the technology of cold recycling, due to processing with a small amount of binders, have insufficient resistance to the action of the wheels of vehicles, and therefore, on top of these layers, it is necessary to arrange a coating layer of materials that provide resistance to dynamic action. The given approach allows to obtain a reduction in the cost of pavement repair due to a decrease in energy consumption for the preparation of asphalt concrete, since the production of materials using cold recycling technologies does not provide for heating the material.

Surface engineering enables highly reversible lithium-ion storage and durable structure for advanced silicon anode

Silicon has been regarded as one of the most promising anodes for lithium-ion batteries (LIBs). However, state-of-the-art silicon-based material suffers from huge volume changes and poor conductivity. Here, we develop a surface engineering strategy to address the intrinsic defects. A dual-binder formed by cross-linking sodium alginate and chitosan is investigated and proposed. Moreover, a 3,4,9,10-perylenetetracarboxylic diimide (PDI) shell is introduced into the Si@SiO x surface. Density functional theory (DFT) calculations reveal that π-π stacking PDI with Li-ion trapping properties is compatible with an SA/CS complex (SC) binder through strong adsorption. These factors buffer the interface tension of Si@SiO x and facilitate Li-ion diffusion. The fabricated electrode shows highly reversible lithium-ion storage and long-term stability. Furthermore, a full-cell configuration with lithium nickel cobalt manganate (NCM) as the cathode demonstrates superior electrochemical properties and potential applications. Such surface engineering creates an opportunity for the fabrication of advanced silicon anodes. Surface engineering is guided by theoretical calculations π-π stacking PDI with Li-ion trapping properties are compatible with SC dual-binder Electrochemical mechanisms have been well studied Silicon-based anode materials persistently suffer from low conductivity and drastic volume expansion. In this work, Meng et al. design a surface engineering strategy consisting of a dual-binder and a coating layer with capturing lithium-ion properties. The prepared electrode shows a superior lithium-ion storage capability and long-term stability.

Composite Binder Containing Industrial By-Products (FCCCw and PSw) and Nano SiO2.

This article analyzes the integrated effect of industrial by-products (spent fluidized bed catalytic cracking catalyst waste (FCCCw) and paper sludge waste (PSw) generated in paper manufacturing) combined with nano-SiO2 (NS) on the properties of cement binder, when a certain part of the binder is replaced with the said by-products in the cement mix. Standard testing methods were used to analyze the physical and mechanical properties of cement-based materials. For structure analysis, we used X-ray diffraction (XRD), derivative thermogravimetry (DTG), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). It was found that the replacement of cement by a combined additive of FCCCw, PSw and NS is important not only for ecological reasons (abatement of CO2 emissions and recovery of waste through secondary raw materials), but also in order to enhance the properties of cement-based binders. Presumably, higher amounts of calcium silicate hydrate (CSH) and calcium alumina silicate hydrate (CASH) in the compound binder are the result of the low content of portlandite and alite in the test specimens. The specimens modified with all three additives had the highest density (~2100 kg/m3), ultrasonic pulse velocity (UPV) (~4160 m/s) and compressive strength (~105 MPa), which was ~40% higher than in the control specimens. The average pore diameter of the complex binder decreased by 21%, whereas the median pore diameter decreased by 47%.

ПЕРСПЕКТИВЫ ПРИМЕНЕНИЯ ШЛАКА МЕДЕПЛАВИЛЬНОГО ПРОИЗВОДСТВА В ДОРОЖНОМ СТРОИТЕЛЬСТВЕ

The article discusses the option of strengthening the soils of the roadbed of highways with complex binders based on granular slag of copper smelting production and air lime. The characteristics of the investigated slag, photomicrographs of its surface, as well as the chemical and phase compositions are presented. A detailed description of the X-ray diffractogram of the studied slag with the processing of the obtained reflections using the ICDD PDF-2 database is presented. Calculations of hydrolytic equilibria were carried out using the main phases found from the data of X-ray phase analysis. It was found by the calculation method that at pH = 11-12 in the lime-slag mixture decomposition of iron silicates and aluminosilicates occurs with the formation of gels of iron and aluminum hydroxides, as well as amorphous silica. On the basis of the obtained complex binder, standard samples of strengthened soil based on loam were made and tested to determine the physical and mechanical properties. The results of the experiments carried out create an opportunity for obtaining hardened soils based on a complex mineral binder with a compressive strength of up to 2.2 MPa.

Constructing crosslinked lithium polyacrylate/polyvinyl alcohol complex binder for high performance sulfur cathode in lithium-sulfur batteries

High loading sulfur cathode is a vital ingredient for the application of high-energy-density Li-S battery. However, the traditional PVDF binder with inherent defects, such as relatively weak adhesion, inferior Li+ conduction, and poor polysulfides adsorption, is not suitable for sulfur cathode, especially at high sulfur loading. Herein, the multifunctional LiPAA/PVA binder with crosslinked three-dimensional structure was proposed to substitute PVDF binder. Benefiting from the effective polysulfides adsorption and successful conduction of electron and Li+, the sulfur cathode with LiPAA/PVA binder exhibited superior rate and cycle performance. Even at high sulfur loading of 4.0 mg/cm2, the LiPAA/PVA based cathode also shows a highest areal capacity of 3.03 mA h/cm2, matching the requirement for high energy density of Li-S battery. Additionally, owing to the low price and water solubility of LiPAA and PVA, the fabrication of LiPAA/PVA based cathode could be finished through an low-cost and environmentally friendly process, demonstrating the potential of LiPAA/PVA binder to realize high loading sulfur cathode in the field of large-scale Li-S battery.

Modulating Androgen Receptor-Driven Transcription in Prostate Cancer with Selective CDK9 Inhibitors

Castration-resistant prostate cancers (CRPCs) lose sensitivity to androgen-deprivation therapies but frequently remain dependent on oncogenic transcription driven by the androgen receptor (AR) and its splice variants. To discover modulators of AR-variant activity, we used a lysate-based small-molecule microarray assay and identified KI-ARv-03 as an AR-variant complex binder that reduces AR-driven transcription and proliferation in prostate cancer cells. We deduced KI-ARv-03 to be a potent, selective inhibitor of CDK9, an important cofactor for AR, MYC, and other oncogenic transcription factors. Further optimization resulted in KB-0742, an orally bioavailable, selective CDK9 inhibitor with potent anti-tumor activity in CRPC models. In 22Rv1 cells, KB-0742 rapidly downregulates nascent transcription, preferentially depleting short half-life transcripts and AR-driven oncogenic programs. Invivo, oral administration of KB-0742 significantly reduced tumor growth in CRPC, supporting CDK9 inhibition as a promising therapeutic strategy to target AR dependence in CRPC.

Man-made soils and mining wastes as raw materials for building composites

The crucial task up to date is to find effective solutions to expand the raw material base of the construction industry by involving local natural and man-made raw materials instead of traditional expensive energy-intensive materials. An inexhaustible source of raw materials can be mining waste, such as dolomite and lime. Currently, they are large-tonnage industrial deposits that limit the area of development. The problems of strengthening man-made cohesive soils for the manufacture of wall materials, and their use as natural bases is also front and center. The optimal compositions of soil-concrete mixtures based on waste carbonate deposits are selected. The goal of this work was to design a composition of a complex binder for strengthening clay soil. The second goal of the work was to obtain masonry soil-concrete products. For this purpose, waste from the dolomite production of the Melekhovsky deposit was used. To solve the problems, authors carried out such tests as chemical analysis, mineralogical analysis, X-ray phase analysis, raster electron microscopy, compressive strength test, frost resistance test, and water resistance test. Comparing the obtained results, it is now becoming apparent that the compositions of GD-4 and GD-5 at close density values have high strength characteristics at design age. The content of dolomite waste above 30% leads to an increase in strength, the best results are achieved with a dolomite content of 34.6-45.3%, in this range also with increasing binder content, water absorption and density increase, and therefore porosity decreases. The phosphates that make up the composite increase its water resistance.

Structure Formation and Properties of Concrete Based on Organic Hydraulic Binders

The article addresses the issues of structure formation of road composite materials containing hydraulic (рortland cement) and organic (bitumen) binders. It has been determined that organic and hydraulic binders, being thermodynamically incompatible, are capable of interaction and complement each other. Structure formation processes are associated with interphase transition layers interaction mechanism and the direct formation of phase contacts with cement crystallohydrates. The interphase boundary is diffuse and is established through interphase transition layers. The emergence of interfacial layers is thermodynamically advantageous, since it contributes to a decrease in Gibbs free energy and does not contradict modern concepts of solid state physics. It was established that with cement content of about 30 % of complex bitumen-cement binder volume, there will appear (nucleate) phase contacts that will prevail in the binder structure when the cement content is more than 60 %. In the case phase contacts prevail, concrete will demonstrate significant strength at high temperatures, but low temperature and fatigue crack resistance, which will lead to their durability loss. The cement content of 30–40 % of the total complex binder can be considered optimal.

Высокопрочное вяжущее на основе жидкого стекла для бесцементного полистиролбетона

This research set out to obtain a high-strength binder based on low-energy liquid glass using silica fume produced in the Bratsk Ferroalloy Plant. The starting materials used for the development of polystyrene concrete were liquid glass obtained from silica fume using sol-gel technology, fly ash, screening from diabase crushing, ground channel quartz sand and foamed polystyrene granules. Math-ematical processing of the results was performed using the Statistica 10 software package in the mod-ule of planned experiment. According to the conducted analysis, the resulting material corresponds to the strength characteristics of concrete classes B1–B3 with an average density of 400–600 kg/m3. In comparison with polystyrene concrete based on cement, foamed polystyrene concrete based on the developed complex binder has half the shrinkage strain. This can be explained by the reduced water-absorbing capacity and hydraulic activity of the hardened binder, which ensures the stability of the block sizes during long-term operation. The results of determining the thermal conductivity show the effec-tiveness of polystyrene concrete as a heat insulator. Based on the optimized composition of the binder die, filled light concretes were obtained using foamed polystyrene boulder from recycled packaging ma-terials. Effective heat-insulating and heat-insulating structural concretes of D400–D600 density grades characterized byan increased stability of geometric dimensions were obtained.

Structural and thermal insulation products based on vegetable raw materials

The author of the article addresses the issues of obtaining insulation products based on flax shives. The article suggests a systematization method for the flax shives based materials, which takes into account the principle of obtaining construction materials based on flax processing waste on various types of binders. It is based on the literature data and the existing research. The possibility of using flax shives as a large structure-forming aggregate of concrete is determined along with the composition and properties of organic aggregate - flax shives. The article presents the optimal ratios selection of flax and binding bonfires in the preparation of granular materials. The characteristics of granulated aggregates on the basis of flax shives are given. The manufacture of cob granules was carried out in two technological ways: on a complex binder and on mineral binders with “dusting” with portland cement. The the method involving the coating of granules with a cement shell was used to produce a granulated material with higher rates of adhesion to the hardened stone of mineral binders in the concrete composition. The technological parameters of the granulation process are determined for two technological methods.

Use of polymeric additive "Nanoterrasoil" produced by Germany for stabilization of soils of military-automotive (field, forest) roads and platforms

The article concerns the decision of the actual scientific and applied task of substantiation of the necessity of preparing troop movements in a short time with the corresponding requirements, for which it is proposed to use the technology of cold recaikeling to strengthen the soil. The basis of cold recycling technology is the principle of reinforcement and stabilization of milled mixtures, which leads to changes in the properties of materials from existing layers of road clothes of different composition and turning them into a monolithic strong frost-resistant constructive layer of road clothing. Soil reinforcement / stabilization with the use of inorganic abrasive materials has been used in road construction for a long time, both in our country and abroad. When using this technology, the stabilization and strengthening of soils are shared. Soil stabilization makes it possible to improve the conditions of consolidation of local soils. This method makes it possible to arrange frost protection layers, and to increase the bearing capacity of ground soils. When strengthening soils, there is a significant increase in the physical and mechanical characteristics of local soils. This is achieved by introducing abrasive materials and impurities into the soil, and successively performing machining operations using ground blending and sealing machines.This technology allows practically to avoid penetration of moisture everywhere the layer of reinforced base of road clothing to the materials of the earth's canvas, resulting in the humidity of the working layer of the earth's canvas being always less than when using traditional rubble foundations on the drainage sandy layer.To strengthen the milling material as astringent, mineral binders (cement, lime, active or high-grade slag), organic binders (bituminous emulsions, bitumen oil road liquids, bitumen petroleum road viscous) or complex binders (mineral and organic binders)are to be used. In this paper, the feasibility of using the Nanoterrasoil (NTS) polymer stabilizer as a component of a complex binder together with cement to strengthen the milled material with the use of cold recaikeling technology was substantiated.