Binder Film Research Articles

Bitumen and mastic local rupture test modelling with DEM

We present some preliminary results of a national research project dealing with the wearing course damage and the tire–pavement interactions with traffic loadings, where asphalt concrete raveling test and its modelling are ongoing studies. For this, we used the Local Fracture Test (LFT) or the French acronym RULOB test, developed by Gustave Eiffel University, to analyse the fracture behaviour of bitumen and mastic. The test reproduced a film of binder placed between two aggregates under defined loading conditions. The results of the test highlighted the influence of the loading conditions on the failure scenarios encountered, and the different ageing conditions (RTFOT, RTFOT+PAV). The role of filler in the bitumen (mastic) is also investigated in the same way. The study also attempted to reproduce the experimental test using the DEM software LMGC90. The results agree with the next step of our ongoing study which is to model ravelling tests of asphalt concrete.

Impact of Binder Thin-Films on Surface Chemistry of Silicon Anodes in Lithium-Ion Batteries

The effect of polymer binder on the nature and location of solid-electrolyte interphase (SEI) formation on Si active material was investigated. Thin layers of polymeric binder (polyvinylidene fluoride and sodium carboxymethyl cellulose) were spin-coated onto polished single crystal Si wafers. The samples were cycled against a Li counter/reference electrode under various electrochemical conditions in a coin cell configuration. The electrolyte was 1 M of LiPF6 in 1:1:1 wt% EC:DEC:DMC. After cycling, the samples were extracted from the coin cell under inert conditions and X-ray photoelectron spectroscopy (XPS) was performed. Electron microscopy and atomic force microscopy indicate that the binder films are smooth and continuous across the wafer surface, and no impact on the electrochemical behavior was observed. However, notable differences were detected using XPS, which revealed both difference in SEI composition and location relative to the binder-electrolyte and binder-substrate interfaces. These observations and insights will be useful in cell designs, binder selection, and reliability estimates because the location of SEI formation may influence cyclic performance of electrodes.

Enhanced Photostability of Lead Halide Perovskite Nanocrystals with Mn3+ Incorporation.

Recently, lead halide perovskite nanocrystals (NCs) have shown great potential and have been widely studied in lighting and optoelectronic fields. However, the long-term stability of perovskite NCs under irradiation is an important challenge for their application in practice. Mn2+ dopants are mostly proposed as substitutes for the Pb site in perovskite NCs synthesized through the hot-injection method, with the aim of improving both photo- and thermal stability. In this work, we employed a facile ligand-assisted reprecipitate strategy to introduce Mn ions into perovskite lattice, and the results showed that Mn3+ instead of Mn2+, even with a very low level of incorporation of 0.18 mol % as interstitial dopant, can enhance the photostability of perovskite binder film under the ambient conditions without emission change, and the photoluminescent efficiency can retain 70% and be stable under intensive irradiation for 12 h. Besides, Mn3+ incorporation could prolong the photoluminescent decay time by passivating trap defects and modifying the distortion of the lattice, which underscores the significant potential for application as light emitters.

Effect of Pigment-Acrylic Binder Ratio on the Surface and Physical Properties of Resin Finished Leather

The current study attempts to investigate the surface phenomenon and physical characteristics of leather finished with brown pigment and different types of acrylic binders. Using the contact angle measurements of three different liquids on the above finished leathers and films, the surface energy and work of adhesion were evaluated. The pigment to acrylic binder ratio (PABR) for best adhesion of finish film on the leather surface was optimized using the contact angle goniometer. Different types of acrylic binder films were coated and their surface behaviour was studied. The crust leather was coated with different types of pigment-acrylic binder (Very Soft, Soft and Medium Soft) finish formulations. The contact angle of both the acrylic films and the PABR finished leathers were measured against Water, Dimethyl sulfoxide (DMSO) and Hexadecane (HD). According to the study’s results, the surface properties of finished leather were directly related to the degree of wetting. The PABR was found to be effective at 1:3 for very soft binder, 1:2.5 for soft, 1:2 for medium soft binders due to higher contact angle and lower surface energy values (γsv). At 1:3 and 1:2.5, the contact angle of very soft and soft binder leather was 82.62° and 83.45° and for medium soft binder it was 82.67° at 1:2 ratio. The surface energy values of optimized PABR of very soft binder (1:3) was 28.29 (mN/M), soft binder (1:2.5) was 27.50 (mN/m) and medium soft binder (1:2) was 29.27 (mN/m). The optimized PABR work of adhesion values of very soft binder, soft binder and medium soft binder was 82.15 (mJm-2), 81.11 (mJm-2), 82.09 (mJm-2). In order to correlate the observed surface properties with leather finish properties, finished leathers were tested for finish adhesion, vamp flexing value, water vapour permeability, wet and dry rub fastness. According to the water vapour permeability, soft and medium binder showed good permeation due to the uncovering of nanopores. But the adhesion, grain crack resistance and grain smoothness were higher in the case of the soft binder. Overall leather properties divulges that the pigment to binder ratio and the type of binder plays an important role in surface properties of the finished leather. This study enables us to determine the optimal PABR for effective finish properties to meet the required leather standards for various usage, as well as better utilisation of finishing chemicals.

Combined effect of acetoacetoxy - Amine interparticle crosslinking and different TG polymer phases to obtain high performance waterborne wood coatings

Two strategies to overcome the film formation dilemma of waterborne binders are combined to produce hard coatings at low temperature without the need of high amounts of coalescing agents, namely crosslinking during film formation and the mixture of soft and hard polymer phases. The crosslinking chemistry used is the one between acetoacetoxy functionalized latexes and amine functionalized ones. Crosslinked and non-crosslinked binder films are investigated by DMTA analysis to study the crosslinking degree and the degree of interdiffusion between polymeric phases in each case. TEM and AFM analysis are also used to support the results obtained by DMTA. The prepared binders are then incorporated in a pigmented coating formulation and tested for wood coating applications such as hardness development, blocking resistance, water resistance and wet adhesion. The relative effect of crosslinking and the presence of different TG phases are investigated by making a comparative study with non-crosslinked paints.

Interaction mechanism and cohesion strength of colloid structure of reclaimed asphalt modified by rubberized binder on aggregate surface

Asphalt mixture performance is attributed to morphological interlocking and physiochemical interaction between binder and aggregate. Many studies fostered the adhesion and bonding characteristics of many binders without conferring the interfacial interaction. To realistically understand the binder cohesion strength, this study investigates the impact of interfacial interaction on the binder colloid structure. An innovative experimental method was developed using the pull-off and gel permeation chromatography tests to investigate the binder/aggregate interface interaction from molecular and mechanical standpoints. The results showed success for the developed method to pursue the mechanism of the binder/aggregate interface interaction and evaluate the resulting molecular diffusion. Two mechanisms were distinguished for molecular diffusion, depending on the percentage of light components. The abundant light components can mobilize the heavy fractions, whereas binder colloids with limited light components have a molecular diffusion for light fractions only. The binder film portion near the aggregate surface has higher cohesion strength than the upper portion, where a strong correlation was proven between the decrease in the cohesion strength and the molecular diffusion due to the interfacial interaction. A robust prediction model with R2 of 0.90 was developed for the binder cohesion strength, where both the molecular composition and the molecular mobility due to interfacial interaction have significant impacts. As the accretion of heavy fractions strengthens the cohesion strength, the molecular diffusion mechanism, which mobilizes the heavy fractions toward the interface, further improves the cohesion strength of the binder film portion near the interface.

Improvement of Warm-Mix Asphalt Concrete Performance with Lignin Obtained from Bioethanol Production from Forest Biomass Waste

This study aims to assess the effect of adding lignin waste, a by-product of bioethanol production from forest biomass, to asphalt concrete to improve its performance. After adjusting the lignin content based on preliminary Marshall tests, 20% of this by-product by mass of bitumen was added to the asphalt concrete blends via the dry method. This lignin content was suitable to the temperature was decreased 40 °C compared to the usual mixing temperature, thus allowing the production of warm-mix asphalt concrete (WMA) without any other additive. Tests on a gyratory compactor assessed the workability of the studied asphalt concrete, allowing us to obtain these findings. Moreover, lignin improved moisture damage and adhesion resistance between the binder film and the aggregate particles’ surface. The behaviour at high temperatures was also enhanced, resulting in better resistance to permanent deformation. These promising laboratory results show us an opportunity to create value for this type of by-product in substituting commercial additives for asphalt concrete, such as organic wax or adhesion promoters, to allow the production of warm-mix asphalt concrete with improved properties.

Study on the effect of different environmental factors on the aging gradient of asphalt binder based on field aging test

ABSTRACT Aging of asphalt binder is a complex natural phenomenon with significant differences under the effect of different environmental factors. The accelerated aging method commonly used in the laboratory is difficult to reproduce the field aging of asphalt binder. The purpose of this study is to reveal the effect of environmental factors on the aging gradient of asphalt binder. For this reason, a layered dissolution-peeling method was developed to recycle asphalt binder films. The gradient behaviour of field-aged asphalt binder was analysed based on rheological parameters and chemical functional groups. The results showed that the layered dissolution-peeling method achieved separation of asphalt binder at 0.1 mm level. Ultraviolet light severely contributed to the distinct aging gradient of field-aged asphalt binder. The carbonyl index of field-aged asphalt binder at 0–0.32 mm was approximately 1.73 times higher than that at 0.32–0.64 mm, 1.90 times higher than that at 0.64–0.96 mm and 2.24 times higher than that at 0.96–1.28 mm. To significantly characterise the aging behaviour of asphalt binder, the film thickness in the accelerated aging simulation test should not be more than 1 mm. The findings of the study serve as a valuable reference for accurate prediction and targeted prevention for asphalt pavements.

A discrete element method to model coating layer mechanical properties with bimodal and pseudo-full particle size distributions

The mechanical properties of paper coating layers are important in converting operations such as calendering, printing, and folding. While several experimental and theoretical studies have advanced our knowledge of these systems, a particle level understanding of issues like crack-at-the-fold are lacking. A discrete element method (DEM) model is used to describe bending and tension deformations of a coating layer. The particles in the model are either bimodal distributions or pseudo-full particle size distributions of spherical particles. The impact of particle size distribution on the predicted mechanical properties of the coating layer is reported. Inputs to the model include properties of the binder film and the binder concentration. The model predicts crack formation as a function of these parameters and also calculates the modulus, the maximum stress, and the strain-to-failure. The simulation results are compared to previous experimental results. Reasonable predictions were obtained for both tensile and bending for a range of latex-starch ratios and at various binder concentrations. The influence of particle packing density on mechanical properties is reported.

Assessing the effects of sunlight and water on asphalt binder and pavement leachability related to the environment

Extensive global research conducted over 30 years explores asphalt leachability and stormwater runoff. Asphalt's widespread usage in construction materials underscores the importance of understanding its environmental consequences. This study aims to assess the influence of sunlight exposure on water quality, particularly regarding the release of hazardous organic compounds such as polycyclic aromatic compounds. We investigated the effect of concurrent versus sequential exposure to water and sunlight, and dark versus light trials utilizing thin films of asphalt binder as well as old and freshly prepared pavement cores for analysis. Initial laboratory experiments reveal significant water-soluble species when thin asphalt films are exposed to solar simulation while underwater. However, simulating environmental conditions found in roadways by exposing the asphalt binder to solar simulation followed by water immersion leads to a substantial decrease in compound formation. Leachate water from 17-year-old asphalt and 15-year-old concrete pavements exhibits complex compound compositions associated with atmospheric and/or vehicular deposition, posing challenges in deconvoluting their origins. Light and dark trials conducted on freshly prepared asphalt pavement under environmental conditions of sunlight and rain demonstrate minimal runoff variation, with semi-volatile organic compound levels resembling the background. Future investigations will focus on applying insights gained from this study to analyze larger sample sets, with an emphasis on inherent hazardous compound variations.

Forming of the structure of binder film in waterglass mixtures depending on the setting method

Forming of the structure of binder film in waterglass mixtures depending on the setting method

Proposition of a methodology for the evaluation of adhesiveness (pull-off test) of aggregate−geopolymer binder interfaces

Portland cement concrete is the most used material in civil construction, but it is a source of greenhouse gases emissions. In addition, its Interfacial Transition Zone (ITZ) is a point of weakness, which limits its performance and application, generating pathological manifestations throughout its service life, decreasing mechanical and durability properties. In this context, geopolymer concretes arise for as a potentially sustainable building material with a much reduced and denser ITZ, when compared to ordinary cement Portland concrete. However, there is a lack of methodology to evaluate the aggregate-geopolymer interface and objectively evaluate compatibility between such new binder and aggregate particles. In other materials, adhesion tests are performed to obtain parameters related to adhesiveness. Provided that context, this work aims to propose a methodology to evaluate the adhesiveness of aggregates and geopolymer binders. For this, a pull-off test based on AASHTO TP 361 (T 361: Standard method of test for determining binder bond strength by means of the binder bond strength (BBS) test, 2022) is proposed, with particular adaptation with respect to specimens’ preparation. The main proposed modifications were: (i) the application method of the binder over a wider surface; and (ii) the use of epoxy glue to attach the pull-off elements (dollies) to ensure the bonding to the geopolymer binder film. Modifications allowed to test the geopolymer adhered to the rock in order to obtain the necessary experimental results. For validation, interfaces composed of a geopolymer binder based on fly ash and steel slag glued onto two granitic rocks (biotite) were prepared and tested. For the test according to AASHTO TP 361 (2022), without the proposed modifications, the adhesion between the geopolymer binder and the equipment proved to be insufficient. Then, with the proposed modified methodology the results were more consistent, in which the specimens showed suitable adhesion for the test. Then, this work contributed to an empirical characterization of adhesiveness for aggregate-geopolymer binder interfaces, enabling adequate analyses regarding the durability, to avoid future pathologies resulting from a weak ITZ and evaluations without huge costs in time and resources.

Low-Cost and Sustainable Cross-Linked Polyvinyl Alcohol–Tartaric Acid Composite Binder for High-Performance Lithium–Sulfur Batteries

A high specific energy density in lithium–sulfur (Li-S) batteries can be achieved by constructing high-sulfur-loading electrodes. However, this electrode type leads to fast capacity decay owing to the formation of large cracks on its surface. Consequently, the optimization of polymeric binders is considered an effective strategy to decrease the volume expansion of sulfur electrodes during cycling. In this study, a three-dimensional (3D) cross-linked polymeric binder was prepared via the polymerization of polyvinyl alcohol (PVA) and tartaric acid (TA). Acetylene carbon black (C) and elemental sulfur (S) were mixed and melt-diffused to prepare a CS composite. The developed 3D cross-linked PVA-TA composite binder films exhibited improved breaking strengths and swelling degrees. Moreover, the inter/intramolecular reactions between the hydroxyl groups of the PVA and TA molecules effectively reduced expansion and suppressed lithium polysulfides (LiPSs) during cycling. The synthesized composite binder also improved the adhesion of the active material and mechanical properties, which decreased the self-discharge and overpotential polarization and increased the lithium-ion diffusion coefficient. The CS electrode (78% sulfur, 3.3–3.5 mg/cm2 sulfur loading) with PVA-TA composite binder exhibited a high initial discharge specific capacity of 537.7 mAh/g and maintained 463.99 mAh/g after 400 cycles at 1.0 C-rate with the decay rate of 0.14%. The outstanding electrochemical performance is due to the 3D cross-linked polymeric network and the excellent adsorption ability. To the best of our knowledge, a sulfur electrode with low-cost and sustainable 3D cross-linked PVA-TA composite binder with excellent electrochemical properties was used for the first time in Li-S batteries.

Evaluation and modelling of low-temperature fracture properties of asphalt binders in thin film by means of the local fracture test

ABSTRACT The experimental investigation focuses on evaluating fracture properties of asphalt binders at low temperatures through the Local Fracture Test. The test consists in subjecting a thin film of binder to controlled tensile loads, simulating the response of the material inside the pavement. The methodology adopted combines laboratory measurements and FEM simulation. The model describes the theoretical response of the sample when a crack of variable size appears, integrating linear viscoelasticity and sample geometry. Different materials are compared, based on their fracture energy determined from the force–displacement curves. A specific criterion is proposed to determine the critical fracture temperature for each binder. Outcomes showed the effectiveness of the adopted methodology in evaluating the fracture properties of investigated materials. Moreover, a high correlation between the critical temperatures derived from the Local Fracture Test and the glass transition temperatures coming from Dynamic Mechanical Analysis was found for the unmodified binders.

Effect of biorejuvenator types on microstructure, mechanistic performance, and resilient modulus prediction model of asphalt concrete containing recycled materials in Indonesia

Biorejuvenators are rejuvenating agents produced from sustainable biological raw materials. In this study, a biorejuvenator was used in recycled materials, such as reclaimed asphalt pavement (RAP), to determine its effect on the asphalt binder film thickness (ABFT) and resilient modulus (Smix) of an asphalt concrete wearing course (ACWC) mixture, which was tested at the optimum binder content (OBC). The ABFT was investigated using scanning electron microscopy and the Smix was determined from the asphalt mixture test using UMATTA at test temperatures of 20–40 °C. The asphalt mixture was prepared with RAP (0–30%), pen 60/70, aggregates, and two types of biorejuvenators, namely coconut shell bioasphalt (BioCS) and BitutechRAP (from trees). Furthermore, an Smix model was developed for each mixture type. The ABFT value obtained from the microstructural test results for each mixture corresponded with the minimum ABFT requirements for the adhesion criteria of the asphalt mixture, microstructurally demonstrating that the biorejuvenators worked well to restore the performance of 30%RAP in the ACWC mixture. Both types of biorejuvenators could activate the bitumen of the RAP (RA binder) because they could still produce Smix. The value of Smix produced from the RAP and BioCS mixture was greater than that produced from the RAP and BitutechRAP mixture. In the resulting Smix model, the influential volumetric parameters for ACWC + RAP + BioCS and ACWC + RAP + BitutechRAP were the voids in mineral aggregate and voids in asphalt, respectively. Based on the results of the microstructural, mechanistic, and Smix models, BioCS, as a local Indonesian biorejuvenator, has significant potential to rejuvenate recycled materials up to 30%.

The distribution of poly-DADMAC additive in the inkjet coating layer and its influence on the print quality

Maximizing the functionality of cationic polydiallyldimethylammonium chloride (poly-DADMAC) additive with minimal dosage in inkjet coatings can contribute to both an improvement in quality and a cost reduction. To do this, it is essential to understand how the cationic additive is distributed in the coating layer and how it affects the print quality. This study presents a three-step investigation to enhance the understanding of the distribution of poly-DADMAC, as well as its effect on inkjet print quality. First, the adsorption behavior of poly-DADMAC on silica pigments was investigated by measuring the surface charge of silica and the adsorption of the cationic additive. Second, the influence of poly-DADMAC on the printability of binder films was investigated. Finally, the effect of poly-DADMAC on the print quality of inkjet paper was examined. The addition of poly-DADMAC improved the print quality of the inkjet paper because of the improved holdout of the negatively charged colorants in the ink.

Softening of sand mixtures on a liquid-glass binder as a result of thermal-oxidative destruction of a combined carbon-containing additive. Part 1

The chemical and physical processes that occur during high-temperature heating of carbon-containing additives are studied in order to develop an effective composition, whose components destruction will lead to a violation of the integrity of the binder film and a decrease in the residual strength of liquid-glass mixtures, and hence an improvement in the knock-out of molds and cores in the conditions of obtaining castings from alloys of ferrous metals. Carboncontaining materials used in foundry production, the destruction of which proceeds in different temperature ranges, have been studied. The methods of thermogravimetric and differential thermal analyzes have been used to study the processes that tale place with materials under study when heated to temperatures comparable to the actual operating conditions of casting cores in direct contact with liquid and solidifying metal in the mold. As a result of the analysis of the considered carbon-containing materials, the temperature intervals of destruction were revealed, which made it possible to predict their effect on the structure of sodium silicate (binder) on the refractory filler and the residual strength of mixtures in order to improve the knock-out of steel castings. Obtaining high-quality casting molds and cores depends on the technological, hydraulic and mechanical characteristics of the mixture, therefore, additional studies were carried out, the results of which revealed the compliance of the determined properties of the studied samples with the requirements for molding and core sand mixtures on a liquid-glass binder.

Characterizing asphalt emissions under in-service conditions

Recent studies have suggested that asphalt related emissions at environmentally pertinent conditions are a major contributor of volatile organic compounds ubiquitous to the environment. Many variables such as temperature/viscosity of asphalt binder, solar irradiance of the asphalt binder, and geometric constraints including film thickness, the act of coating aggregate to produce Hot Mix Asphalt, and compaction into pavements influence the magnitude and composition of measured emissions. Continuous films of asphalt binder were used to determine how temperature/viscosity and film thicknesses can influence measured emissions. The magnitude of emissions scaled with the inverse of viscosity, whereas the composition of emissions varied with film thickness and age of the asphalt binder sample. Asphalt binder exposed to solar irradiance showed short term impacts on emissions in the first hours of exposure. Compacted asphalt pavements were used to simulate real world new in-service conditions. The emissions from a freshly compacted asphalt pavement were compared to a 17-year-old pavement sample collected from the field to determine how the act of compacting asphalt binder coated in aggregate influenced emissions over a 17-year period. An increase in the complexity of the system caused slowing in the total emissions profile. While lower than what was observed in the freshly compacted samples, emissions were still observed in the 17-year-old pavement. The composition of emissions indicated that smaller and more volatile compounds are capable of being released from deeper within the compacted pavement, whereas the larger and less volatile compounds tend to remain trapped. • Asphalt emission generator used to measure emissions under in-service conditions. • The effects of solar irradiation on asphalt pavement emission. • Solar irradiation of asphalt binders generates short term increases in emissions. • Effects of asphalt pavement compaction on released emissions.

Investigation of the effect of thermal-oxidative destruction of pyrocarbon on formation of structure of a binder and residual strength of sand-liquid-glass mixtures

A study of the effect of thermal-oxidative degradation of a carbon-containing additive on the formation of the binder film structure and the residual strength of sand-liquidglass mixtures after various calcination temperatures is presented. Pyrolyzed industrial carbon (pyrocarbon) of P324 grade was used as an additive. The methods of differential thermal and thermogravimetric analyzes were used to study the physical and chemical processes that occur with the investigated carbon-containing material when heated to a temperature characteristic of the heating of the surface layer of the core (molding) mixture in contact with liquid steel. This made it possible to reveal the temperature ranges of the degradation of the carbon-containing additive, which lead to a violation of the integrity of the sodium silicate film and a decrease in the residual strength of the sand-liquid-glass mixture. For a comparative analysis of the structure of silicate binder films and the residual strength of sand-liquid-glass mixtures after calcination at temperatures of 453, 673, 873, and 1073 K (180, 400, 600, and 800 °C), standard cylindrical samples from reference (quartz sand of 1K2O303 grade and liquid glass with a silicate modulus of 2.8, a density of 1490 kg/m3 as a binder) and experimental (with the introduction of pyrolytic carbon in the amount of 2 % (wt.)) mixtures have been prepared. As a result of the study, it was found that the residual strength of the studied sand-liquid-glass mixtures depends on the morphological features of the surface of the silicate binder film, expressed by the presence of carbonaceous formations (soot), pores and crystals of sodium carbonates (stress concentrators in the binder film).

Artificial intelligence-based gene expression programming (GEP) model for assessing sprayed seal performance

This research predicts residual solvent (α), which is a key component of the performance assessment for a sprayed/chip seal. In this study, conventional equations for α were assessed that showed prediction inefficiency (R 2 value as low as 0.82) under different experimental conditions. Accordingly, gene expression programming (GEP), an emerging branch in artificial intelligence, was utilised to resolve these difficulties by developing empirical models for α. The data required for model development was obtained from extensive laboratory tests conducted on bitumen-solvent binder films in this research. Model evaluation results showed an excellent degree of correspondence between predictions and experimental results (R 2 = 0.94). This is the first study to model a key component of sprayed seal performance using GEP. The model is recommended for pre-design purposes or as a tool to determine residual solvent in a sprayed seal when laboratory testing is not feasible, thereby saving time and expenditure.