Secondary Binder Research Articles

High-Area-Capacity Cathode by Ultralong Carbon Nanotubes for Secondary Binder-Assisted Dry Coating Technology.

Thick electrodes with high mass loading and increased content of active materials are critical for achieving higher energy density in contemporary lithium-ion batteries (LIBs). Nonetheless, producing thick electrodes through the commonly used slurry coating technology remains a formidable challenge. In this study, we have addressed this challenge by developing a dry electrode technology by using ultralong multiwalled carbon nanotubes (MWCNT) as a conductive additive and secondary binder. The mixing process of electrode compositions and the fibrillation process of the polytetrafluoroethylene (PTFE) binder were optimized. The resulting LiCoO2 (LCO) electrode exhibited a remarkable mass loading of 48 mg cm-2 and an active material content of 95 wt %. Notably, the thick LCO electrode demonstrated a superior mechanical strength and electrochemical performance. After 100 cycles at a current density of 1/3 C, the electrode still exhibited a capacity retention of 91% of its initial capacity. This dry electrode technology provides a practicable and scalable approach to the powder-to-film LIB electrode manufacturing process.

A new method for manufacturing anode supported solid oxide fuel cells with AFL

In this study, two new methods are proposed for manufacturing anode-supported tubular SOFCs (solid oxide fuel cells) with AFL (anode functional layer). The anode supports are manufactured via thermoplastic extrusion. PEG is used as a secondary binder in the anode tubes and it is selectively removed by water debinding and sweat debinding methods and an AFL layer is obtained with different microstructure and porosity. The Sweat debinding method is suggested as a new method for forming an alternative layer with a different microstructure than the main body of the anode support. Full cells are produced from the altered anode supports. The peak power densities of the cells are measured as 0.38 W/cm2 for Sweat Debound cells, while it is 0.29 W/cm2 for the Water Debound cells.

Sustainable Hybrid Lime Mortars for Historic Building Conservation: Incorporating Wood Biomass Ash as a Low-Carbon Secondary Binder

Renewables-based power grid expansion has increased the use of wood biomass as a low-carbon fuel, resulting in the generation of predominantly inorganic wood biomass ash (WBA) as waste during biomass combustion. The conservation of historically valuable, damaged, and energy-inefficient buildings can help downsize carbon emissions and energy consumption, while promoting the use of alternative repair materials, including unavailing materials such as WBA, and implementing zero-waste measures. This study aims to underscore the importance of a proactive approach in managing WBA and its application in artificial hydraulic lime (AHL) mortars. Hybrid lime mortars were prepared by combining natural hydraulic lime (NHL) as the primary binder with fly wood biomass ash (WBA) as the secondary substitute, using different mass ratios of NHL to WBA (100:0, 80:20, and 70:30). The experimental framework encompassed interconnected analytical steps, ranging from binder analysis to paste and mortar preparation. The chemical and mineralogical composition, physical properties, and reactivity of WBA were evaluated to determine the appropriate proportion of WBA for low-carbon AHL binder formulation. Prior to mortar mixing, the water demand, setting time, and soundness of the AHL pastes were assessed. The effects of each AHL binder blend on the mechanical properties of the AHL mortars were analyzed based on compressive and flexural strength measurements after 28 days of curing under different CO2 and moisture conditions (CO2~400 ppm at 70% RH and 95% RH; CO2~30,000 ppm at 60% RH). Additionally, changes in the porous structure were studied. Notwithstanding the greatly prolonged setting time, the results indicate that the mechanical properties of AHL mortars can be enhanced by the addition of WBA in a moderate ratio, empowering the development of environmentally friendly lime mortars suitable for conservation purposes.

Effect of binder strengthening using micro-silica on mechanical and absorption characteristics of HPC reinforced with reclaimed jute fibres

The incorporation of dispersed fibres in the binder matrix is proven to be beneficial to the tensile performance of high-performance concrete (HPC). However, the insertion of new/virgin fibres in the ‘concrete matrix’ significantly adds to the final cost and embodied carbon of HPC. Therefore, the environment-friendly design of fibre-reinforced HPC remains the main challenge. In this study, the influence of different volume fractions (Vol.) of ‘jute fibre’ (JF) was examined on the engineering performance of HPC. The effect of micro-silica/silica fume (SF) inclusion as a secondary binder was also analysed on the performance of JF-reinforced HPC. To investigate the mechanical performance of designed mixes, compression, flexure, and splitting-tensile tests were conducted at 28 and 91 days. Non-destructive durability performance indicators, such as ‘water-absorption (WA)’, ‘rapid chloride-ion permeability (RCIP)’, ‘electrical-resistivity (ER)’, and ‘ultrasonic-pulse velocity (UPV)’ were also examined. It was found that the utilisation ratio/efficiency of JF addition improved with the ageing of samples. Moreover, the inclusion of SF proved to be beneficial in the strength gain due to JF addition. The combined use of 0.3% vol. of JF and SF improved the ‘compressive strength (CS)’ by 26–30%. The inclusion of 0.3% vol. of JF improved the ‘splitting-tensile strength (STS)’ of plain HPC by 43% and 23% with and without the SF inclusion, respectively. The JF incorporation showed a minor decrease in the imperviousness of HPC. SF incorporation helped minimise the damaging effect of JF incorporation on the ER, WA resistance, and UPV value of HPC. Owing to the addition of SF, the WA capacity of JF-reinforced mixes was decreased by up to 30% at 28 days and up to 50% at 91 days. While the RCIP values of JF-reinforced mixes were dropped by 40–60% (depending on the JF content) owing to the superior pozzolanic and filler effect of SF.

Improving the performance of recycled aggregate concrete using nylon waste fibers

The use of coarse recycled aggregates (CRA) as the replacement for natural aggregates is an eco-friendly solution to alleviate the extraction of natural resources and the harmful effects of demolition wastes on the environment. However, the mechanical and durability characteristics of CRA concrete are generally inferior compared to ordinary concrete. The performance of CRA concrete can be supplemented using different fibers and secondary binder materials. This study encourages the idea of using recycled nylon fiber (RNF) to upgrade the ductility of high-performance concrete (HPC) made with CRA. For this purpose, the effect of RNF on HPC properties was explored. RNF was introduced in HPC at four different volume fractions i.e., 0.1 %, 0.25 %, 0.5 % and 1 %. The experiments showed that RNF is generally harmful to the compressive strength and density of HPC. However, at 0.1 % volume, RNF showed a nominally positive effect on compressive strength. RNF addition was highly useful in enhancing the splitting tensile strength and crack resistance of HPC. The tensile strength loss of HPC due to 50 % and 100 % CRA incorporation can also be balanced using 0.25–0.5 % RNF. Water absorption and chloride permeability of HPC were marginally reduced at the incorporation of 0.1–0.25 % RNF. The recommended dosage of RNF is 0.25 %, considering the maximum tensile strength and low permeability of HPC. Owing to the addition of 0.5 % RNF, a CRA-based HPC can attain tensile strength higher than ordinary HPC. Thus, for tensile-loading applications, CRA-RNF-based HPC provides a ductile, and eco-friendly alternative to an ordinary plain HPC.

Pollen collected by stingless bees Tetragonula laeviceps (Smith, 1857) (Hymenoptera: Apidae: Meliponini) from Central Sulawesi

The diversity of pollinating insects is used as conservation management. Pollen is gametophyte from male which can give characteristics to its offspring. The pollen carried by bees can be used as an identification of feed favored by bees. This study aims to identity pollen derived from the legs of stingless bees based on the color morphological characteristics of the pollen. The methods include color identification of pollen collected by stingless bees, pollen extraction, acetolysis, and pollen identification. Pollen with the same species at the study site has a color that is not much different. Stingless bees take pollen based on the size and distance of the plant to the hive. Smell and color as a secondary binder for stingless bees. Different plant pollen species can also be influenced by the protein requirements of each stingless bee colony. It can recognize the presence of flowering plants aroud the hive. The size of pollen can affect the bees in taking plant pollen.

RESEARCH OF THE UNIFORMITY OF THE COMPOSITION OF A CERAMIC PRODUCT DURING IMPREGNATION WITH A BINDER

In the production of aircraft parts by precision casting in ceramic molds, the key parameters are the uniformity of the composition and strength of ceramic molds associated with the technology of their manufacture. The technologically optimal strength of ceramics can be achieved using the technology of re-impregnation of a ceramic product with a binder, but in this case problems arise with the isotropy of the mechanical properties of the products. The paper presents the results of research and development of methods for regulating the uniformity of impregnation of ceramic samples with a secondary binder.

Effects of key factors on the compressive strength of metakaolin and limestone powder-based alkali-activated concrete mixtures: An experimental and statistical study

The present study aimed at utilizing locally available metakaolin (MK) and limestone powder (LSP) as base binders for developing alkali-activated concrete. Ordinary Portland cement (OPC) was used as a secondary binder. Specimens with different primary binder (MK or LSP), its content (70%, 85%, or 100%), activator type (NaOH- or KOH-based), and activator composition (sodium silicate/hydroxide ratio: 1, 2.5, or 4) were prepared, and tested for compressive strength. The obtained strength data were statistically analyzed using ANOVA and response surface methods (RSM) to explore the effects of the studied variables. Test results showed that all the considered parameters had significant effects on the tested properties where the effect of the primary binder content was more pronounced than the alkaline composition. Two mixtures (70% MK with sodium silicate/KOH ratio of 2.5 and 70% LSP with sodium silicate/KOH ratio of 4.0) showed more than 20 MPa strength, which can be categorized as structural concrete. While all the remaining mixtures exhibited less than 20 MPa strength. These can find non-structural applications such as backfill, footpath slab, or controlled low strength materials (CLSM).

Synthesis of bio-polymer based composite binder for utilization of industrial coke dust waste

In the present investigation, a novel composite binder which aids in forming coke briquettes from industrial waste coke dust were synthesized in one pot setup. The composite binder enables efficient utilization of the coke fines by their reformulation into coke briquettes. The novel binder has been characterized by scanning electron microscopy, Fourier transform infrared spectrophotometry, X-ray diffraction, X-ray photonic spectroscopy and nuclear magnetic resonance spectrometry to understand the grafting efficiency and bentonite as filler incorporation. The composite binder with a secondary filler (bentonite) and a secondary binder (ordinary Portland cement) was mixed in definite proportion to obtain the compound binder. The coke briquette was made from coke fines and compound binder in a fixed ratio confers to high thermal stability with improved cold compressive strength. The high-temperature study indicates that the characteristics of coke briquette resemble that of coke used in submerged arc furnaces for ferroalloy production.

Effect of Extracted Microcrystalline Cellulose from Dracaenea arborea Stem on Aceclophenac Tablet Formulation

Micro crystalline cellulose (MCC) is a major derivative from the bio composite of natural materials such as D. arborea plant stem. It could be useful as a secondary binder and disintegrant in tablet formulation especially following direct compression technique anticipating it to provide high level of disintegration at low use level and utilizing dual mechanisms of wicking and swelling. Tablets of aceclofenac a BCS class II and non steroidal anti inflammatory drug (NSAID) which potently inhibits the cyclo oxygenase enzyme (COX-2) involved in prostaglandin synthesis was formulated by direct compression using MCC from D. arborea stem. Qualitative assessment of the plant extract was carried out and the presence of cellulose confirmed by the appearance of violet – blue coloration while the physicochemical and physicotechnical properties were comparatively evaluated with reference to avicel and corn starch. Three batches of aceclofenac tablets involving Batch A (D. arborea MCC), Batch B (Corn starch) and Batch C (Corn starch and D. arborea MCC in a 1:1 ratio), were implcated in the formulation. Physicochemical study of the MCC reveals a pH of 7.8, mean swelling index 1.14±0.05 ml and hydration capacity of 3.60±0.15 g while the pH of corn starch is 3.90 with swelling and hydration capacity at 5.09±0.03 ml and 8.26±0.01 g respectively. Quality control evaluation of resulting tablet was investigated and the wetting time of batch A tablets was 1.50, batch B 2.30 and batch C 1.80 with percentage moisture content (%) of 60.5, 56.56 and 57.8 and disintegration time (minutes) of 0.22±0.07, 0.35±0.051 and 1.60±0.286 respectively. The drug release profile of batch A, reveals an initial burst release within 10 minutes followed by gradual release while batch C had consistent drug release which was maintained although faster than that of batch A after 10 minutes but batch B had the least drug release rate.

Impact of broken brick on the properties of a cladding composite material based on a secondary polymer binder

Impact of broken brick on the properties of a cladding composite material based on a secondary polymer binder

Effect of carboxymethyl cellulose on the flow behavior of lithium-ion battery anode slurries and the electrical as well as mechanical properties of corresponding dry layers

We present a holistic view on the role of polymeric binders in waterborne LiB anodes, including preparation and processing of wet slurries as well as microstructure, electrical conductivity and mechanical integrity of dry electrode layers. We focus on carboxymethyl cellulose (CMC), with respect to technical application the influence of soft, nano-particulate styrene–butadiene rubber (SBR) as secondary binder is also addressed. We discuss the influence of CMC concentration, molecular weight (Mw) and degree of substitution (DS) on flow behavior of anode slurries. Rheological data are not only relevant for processing, here we use them to characterize the adsorption of CMC on active material particles and dispersion of these particles in the slurry at technically relevant concentrations. The fraction of CMC adsorbed onto graphite particles increases with increasing Mw and decreasing DS. Electrical conductivity increases with Mw, i.e. with decreasing free polymer deteriorating conductive carbon black pathways. CMC does not contribute to the adhesion of electrode layers, irrespective of Mw or DS, technically feasible adhesion is inferred by SBR. Cohesive strength of anode layers, determined here for the first time under well-defined mechanical load, increases with increasing Mw and decreasing DS, i.e. with increasing fraction of adsorbed CMC and corresponding improved particle dispersion. Strong cohesion and high electrical conductivity are correlated to an alignment of graphite particles as revealed by electron microscopy, presumably enabled by higher particle mobility in well-dispersed slurries. Accordingly, targeted choice of CMC is a valuable means to control processing, electrical conductivity and mechanical strength of LiB electrodes.

Morphology, microstructure, and phase states in selective laser sintered lithium ion battery cathodes

• Bulk LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) is made by binder-free selective laser sintering. • Single-track morphology is used to refine processing and produce 3D samples. • Three-dimensional (3D) samples are porous with micron sized grains. • 3D samples exhibit both layered (R-3 m) and rock salt (Fm-3 m) structures. Fabrication of high-energy cathode materials with complex geometries is necessary to enable high-power density in next-generation lithium ion batteries (LIBs). Ceramic three-dimensional (3D) printing techniques are one possible avenue to achieve high performance. Current ceramic 3D-printing methods often suspend the electrochemically active cathode powder in binders that require substantial rheological development to enable printability and secondary binder removal processes to ensure degradation does not occur during electrochemical cycling. In this study, the need for binder additives is circumvented by employing the laser-based 3D-printing technique, selective laser sintering (SLS), for direct fabrication of 3D lithium nickel cobalt aluminum oxide (NCA) cathodes. Thermal stress and part distortion are mitigated by using in-situ substrate heating while operating the 1.07 μm fiber laser in q-switched continuous mode. A parametric single-track study is performed to refine the process parameters for the layer-by-layer selective laser sintering of bulk 3D NCA samples. These bulk 3D samples are porous with 2−3 μm grains and exhibit a dual phase state, including the layered structure (with symmetry R-3 m) and rock salt structure (Fm-3 m). The retention of the electrochemically active layered structure in these samples is promising for the development of binder-free, 3D-printed cathodes for LIBs with enhanced power density.

Effects of shrinkage-reducing admixtures on autogenous shrinkage in alkali-activated materials

This paper deals with possible solutions of chemical and autogenous shrinkage of alkali-activated blast furnace slag (AAS). Shrinkage is the main reason why AAS is not used in practice. One of the solutions how to reduce the shrinkage is the utilization of special chemical admixtures. In concrete technology, the use of chemical compounds based on hydrocarbon alcohols is well known, however the efficiency in AAS is still very poorly elucidated. Therefore, isopropanol was used in this study. The main aim of the work was to recognize and study the relations between chemical processes in the early stages of hydration. The effect of isopropanol on alkali activation was determined by calorimetric measurements and compared with the initial and final setting time of binder. It was found out that the presence of isopropanol additive had only insignificant effect on the setting time. On the other hand, the results indicated that an increasing amount of isopropanol deaccelerates the hydration process which was represented by smaller amount of primary CSH gel formation and delayed time of secondary binder phase formation.

The use of fine waste material for the future of sustainable construction

The article presents data regarding scale of current production of cement and its future of sustainable construction. In the time of sustainability and Union Directives which rightly impose the reduction of emission of greenhouse gases the solution has been proposed that may in some extent contribute to reducing the cement consumption by using properly prepared recycling binder as its substitute. Some results of own research have been presented, connected with the possibility of using the waste material in form of properly processed cement grout as a partial substitute of cement in the cement composites. Due to high content of contaminants in the industrial secondary binder, which might interfere with the uniformity of results, it has been decided to obtain the recycling binder in the laboratory conditions. The secondary mineral material has been obtained in the process of multi-stage disintegration of prepared laboratory samples, made from cement grouts. The prepared material has been analysed for content of dust fraction and pozzolana activity. The obtained results have revealed that in assumed conditions of recycling binder processing it may be successfully used as cement substitute in the cement composites.

Effect of two different rubbers as secondary binders on the friction and wear characteristics of non-asbestos organic (NAO) brake friction materials

Binder provides structural integrity by holding all ingredients in the composition of a brake friction material. The modified binders have played a major role in improving the frictional performance and thermal resistance of the friction material. The present research work evaluates the influence of secondary binders (Nitrile Butadiene rubber (NBR) and Styrene Butadiene rubber (SBR)) on the tribological performance of the friction material using a full-scale inertia brake dynamometer as per JASO C406 standard. Three brake pads were developed by varying the type and composition of secondary rubber binder (5%NBR, 5%SBR and 2.5%NBR + 2.5%SBR) with rest of the ingredients kept unaltered. It was found that the quantity of SBR rubber powder present as secondary binder improved dry and wet recovery. Friction coefficient (μ) exhibited better stability during the fade with the inclusion of both the rubber powders. The friction material with the inclusion of both the NBR and SBR rubber powders exhibited overall better performance than compared to the inclusion of only one secondary binder rubber in the composition. The worn-out surface of the developed friction materials and the counter discs were characterised using FESEM.

Beneficiation of Oil Shale Processing Waste: Secondary Binder Phases in Alkali Activated Composites

Oil shales are low calorific fuels leaving upon processing large amounts of solid waste with limited secondary use, mostly because of low self-cementitious properties. In this paper, alkali activation of the waste remaining after shale oil retorting in solid-heat-carrier plants was investigated to improve the cementitious properties of this waste. The formation of secondary silicate binder phases was studied in samples activated with NaOH, Na-silicate and modified Na-silicate solutions. In mixtures with Na-silicate activator highest uniaxial compressive strength and formation of a calcium-aluminium-silicate-hydrate gel was observed and characterized according to 29Si MAS-NMR and ATR-FTIR spectra as mainly consisting of polymeric silicate middle groups (Q2), and Al substituted Q3 and Q4 species indicative of geopolymerisation. NaOH activation was not sufficient to fully dissolve the amorphous phase present in the source material and only chain silicate structures with minimal crosslinkage were formed. The results indicate that the solid-heat-carrier ash from shale oil retorting exhibits geopolymeric properties on activation with Na-silicate based activators and that, with optimisation of mixing and curing conditions, provides chemically stable composite that can be used for waste stabilization or low strength construction applications.

Cold In-Place Recycling Characterization for Single-Component or Multiple-Component Binder Systems

AbstractCold in-place recycling (CIR) is a pavement rehabilitation technique that has been used for decades. During this time, single-component binder (SCB) systems have governed the market. Single-component binders are defined as those with one binder or two if the secondary binder dosage is 1% or less (e.g., 3% asphalt emulsion with 1% hydrated lime). In contrast, this paper investigates multiple-component binder (MCB) systems (e.g., 2.5% emulsion with 2% portland cement). This paper’s objective is threefold: (1) present a universal CIR design framework applicable to any cementitious and/or bituminous material; (2) demonstrate MCB sustainability advantages; and (3) conduct an extensive SCB and MCB characterization. Universal design framework components include specimen preparation, curing, and testing protocols. Nine binder combinations were tested for wheel tracking, permeability, modulus, strength, and cracking response. Cement SCBs yielded low cracking resistance, high rutting resistance, and favorab...

Molding Properties of Inconel 718 Feedstocks Used in Low-Pressure Powder Injection Molding

The impact of binders and temperature on the rheological properties of feedstocks used in low-pressure powder injection molding was investigated. Experiments were conducted on different feedstock formulations obtained by mixing Inconel 718 powder with wax-based binder systems. The shear rate sensitivity index and the activation energy were used to study the degree of dependence of shear rate and temperature on the viscosity of the feedstocks. The injection performance of feedstocks was then evaluated using an analytical moldability model. The results indicated that the viscosity profiles of feedstocks depend significantly on the binder constituents, and the secondary binder constituents play an important role in the rheological behavior (pseudoplastic or near-Newtonian) exhibited by the feedstock formulations. Viscosity values as low as 0.06 to 2.9 Pa·s were measured at high shear rates and high temperatures. The results indicate that a feedstock containing a surfactant agent exhibits the best moldability characteristics.

Experimental Studies of Submicron Polycrystalline Diamond without Binder under High Pressure and Temperature

This paper aims to study the sintering process and mechanical properties of submicron polycrystalline diamond (SMPD) without any secondary phases and binder materials under pressure of 7-8 GPa and 1400 °C-1800 °C, using the bi-layer assembly and the conventional assembly methods. The as prepared samples were characterized by X-ray diffraction, scanning electron microscope, and Vickers indenter hardness tests. Well sintered specimen was obtained under the condition of 8 GPa and 1600 °C using the bi-layer assembly method, and an indentation test demonstrated a Vickers hardness of 52 GPa. The graphitization of diamond was found to be an important factor determining the hardness of samples sintered using the bi-layer assembly.