Characterization Of Physical Properties Research Articles

Progress on Hybrids and Mixed Alloys of Boron Subphthalocyanines (BsubPc) and Boron Subnaphthalocyanines (BsubNc); Tuning the Electrochemical Properties Towards Organic Electronic Applications

Our research and development focus has been on the molecular design, synthetic methodology and in-depth characterization of boron subphthalocyanines (BsubPcs) and subnaphthalocyanines (BsubNcs) to apply them to organic electronic applications. BsubPcs, BsubNcs and their hybrids are macrocycles with a chelated central boron atom via nitrogen bonding, and is a p-conjugated macrocyclic material. Our focal point balances between the basic and applied chemistry, chemical engineering, their in-depth physical properties (electrochemistry included). We also do computational modelling. Once materials are developed, we merge them into organic electronics to function as light emitting, light absorbing and electronic conducting materials within organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs)/organic solar cells (OSCs). The basic electrochemical and photophysical properties, developing and evaluating the properties is critical to move onto such applications.For this presentation, I will focus on our progress on the development of hybrids and mixed alloys of BsubPcs and BsubNcs.Regarding hybrids, they are a mixture of BsubPcs and BsubNcs, and are formed via a reaction of a statistical distribution of phthalonitrile and 2,3-dicyanonaphthalene intermediates on reaction with BCl3; we have named them X-RnBsub(Pcx-Ncy); X the axial substituent, Rn the number of peripheral substitutions, Pcx being the number of 6 p-conjugated bonds, Ncy being the number of 10 p-conjugated bonds (Figure). On first study, we found that X-RnBsub(Pc1-Nc2) have low photostability. Therefore, we moved onto developing a ‘statistical’ synthetic methodology to target highest yields of X-RnBsub(Pc2-Nc1)s, and we did achieve relatively high yields. X-RnBsub(Pc2-Nc1)s therefore could be purified to enable physical characterization. Within a couple past publications, the unique absorption spectra was noted and we have confirmed its uniqueness. The X-RnBsub(Pc2-Nc1)s absorption spectra is as wide as if BsubPc and BsubNc were mixed together. This therefore has good potential to harvest a larger scope of photons from solar or to achieved FRET transfer from a host to emit via an OLED. We then did in-depth first electrochemical characterization, confirmed their electrochemical oxidation and reduction stability and also did in-depth photoluminescence characterization. Therefore, merging X-RnBsub(Pc2-Nc1)s into organic electronic devices as well as other chemistry to synthesis the hybrids is ongoing.Regarding mixed alloys, in the past as we have shown that BsubNcs ended up being a mixed alloyed composition with random bay-position halogenation, that is formed during the reaction of BCl3 with 2,3-dicyanonaphthalene at temperature, which is the process to form the BsubNcs. The random bay-position halogenation has been shown to be impactful in a positive way within OPV devices, negative within OLED devices and also has electrochemical variations and good reversibility. Ongoing, given it is random halogenation, and some of the positive outcomes, this justifies considering additional mixed alloyed compositions.We have also recently shown that mixed alloyed BsubPcs can be formed with three peripheral halogens in the alpha (a) or beta (b) positions, named as Cl-αCl3BsubPc, Cl-βCl3BsubPc, Cl-αF3BsubPc, and Cl-βF3BsubPc. The alloyed mixtures consisted of C1 and C3 isomers of trihalogenated BsubPcs. The physical properties characterization including photophysics, electrochemistry, and thermal characterization, were studied and were also positive and then were engineered into OSCs as electron donors and electrons acceptors to clarify their impact on device performance which had positivity aspects. Therefore, we moved onto developing a set of additional BsubPc mixtures. To be outlined for this presentation, we considered sets of phthalonitrile mixtures to form peripherally halogenated BsubPc mixtures during the formation of BsubPcs from these intermediates. For example, 4,5-dichlorophthalonitrile (Cl2-pn), 4,5-difluorophthalonitrile (F2-pn), tetrachlorophthalonitrile (Cl4-pn), and tetrafluorophthalonitrile (F4-pn) are commercially available compounds that were mixed together and yields a mixture of BsubPc which we named: X-Cl2nF2mBsubPc and X-Cl4nF4mBsubPc (X = Cl or F being a variant, Figure). We then did physical characterization and found positive aspects including electrochemical oxidation and reduction stability. Merging them into organic electronic devices is ongoing and might be present during this presentation time.We did also recently develop additional chemistry methodology to develop additional mixed alloyed BsubPcs. The methodology was to develop phthalonitrile intermediates that have numbers of hydrogen, chlorine and fluorine substitutions and to take them onto the formation of the BsubPc mixed alloys. This is ongoing and may have some aspects to outline during this presentation.We also do computational modelling to look into other relative impacts of the materials being developed, for example the HOMO and LUMO orbital distributions, the local ionization etc. This will also be outlined during this presentation. Figure 1

Determining of Some Engineering Properties for Harvest and Post Harvest Applications of Two Common Cultivated Hazelnuts Cultivars in Türkiye

In this study, some engineering characteristics (physical properties, colour characteristics, coefficients of static friction and mechanical behaviours) of the shelled and kernel of Çakıldak and Foşa hazelnut cultivars cultivated in Türkiye were investigated for harvest and post harvest applications. The moisture contents of Çakıldak and Foşa cultivars for shelled hazelnut 8.69-7.56% (% wet basis) and kernel hazelnut 5.37- 4.64% (% wet basis), respectively. Statistically significant (p

Copper–zinc/chitosan complex hydrogels: Rheological, degradation and biological properties

Polymer hydrogels crosslinked by therapeutic metal ions have attracted increased interest in recent years due to their unique and versatile properties. Chitosan hydrogels are widely investigated for various biomedical applications such as tissue engineering and drug delivery. Copper and zinc ions are considered as therapeutic metal ions, that have important roles in bone regeneration. The aim of this study was to investigate the physicochemical and biological properties of bimetallic–chitosan complex hydrogels with different cupric and zinc ions content. Scanning electron microscopy (SEM) revealed changes in the morphology from the microstructure with larger, tubular pores for aerogels with higher Zn content, to the sheets-like structure with long pores for samples with higher Cu content. FTIR analysis indicated the formation of bimetallic–chitosan aerogels. The obtained X-ray diffraction patterns showed a broadening of chitosan's characteristic diffraction maximum, while characterization of physical properties showed decreased swelling ability and increased shear modulus with higher Cu content. ICP-MS results showed a negligible amount of copper and zinc ions released under physiological conditions during 24 h indicating a strong physical crosslink between metal ions and chitosan chains. Furthermore, accelerated in vitro degradation showed that hydrogels maintained good stability during four weeks of lysozyme activity. The MTT assay indicated that the cytotoxicity of Cu2+–Zn2+/chitosan complexes could be adjusted by the amount of cupric ions. All results imply that Cu2+ and Zn2+ ions act as physical crosslinkers of the polymer network. Also, results are in agreement with the prediction of density functional theory (DFT) which indicated stronger chitosan–Cu tetrahedral aqua complex interactions in comparison to the chitosan–[Zn(H2O)4]2+ interactions.

Quantitative characterization of critical reservoir physical properties of tight oil charging in the third member of the Shahejie Formation in the Gaobei Slope of Nanpu Sag, Bohai Bay Basin

Unconventional petroleum occupies an important position in the world energy structure. Tight oil is an important field of unconventional oil and gas exploration and development, and the physical property condition of a tight oil reservoir is an important determinant of its commercial production. The application of different geological and engineering strategies to quantitative characterization of the aspect of hydrocarbon charge vis-à-vis reservoir physical properties is critical and essential to thoroughly understand the formation and accumulation mechanism and help in achieving the optimum producibility of tight oil resources. This study focuses on the tight oil of the third member of the Shahejie Formation (Es3) region in the Gaobei Slope of the Nanpu Sag. The upper and lower physical limits of charging were quantitatively deduced and explained characterized by a combination of geological analysis, analytical testing, and numerical simulation of force balance; the formation mechanism of the tight oil reservoir is primarily constrained by its permeability. The inversion phenomenon of oil and water in the tight oil Es3 reservoir occurs at a burial depth of 3900 m. The pore type of the reservoir is mainly primary in nature, with a positive correlation between the porosity and the permeability. The upper limit of tight oil charging is quantitatively characterized by porosity approximately equal to 10%, the corresponding permeability being 1 × 10−3 μm2. When the reservoir's physical properties exceed the upper limit of tight oil charging, the reservoir mainly develops a water layer. This is mainly caused by the boundary effect of tight reservoirs, where the pore throat radius corresponding to the critical physical property is equivalent to the boundary layer thickness of oil in the reservoir pore, making it difficult for boundary fluids to flow in the pore space at this time. On the other hand, based on comprehensive analysis of the minimum flow hole roar radius, the irreducible water saturation, and drilling result statistical methods, the lower limit of the tight oil charging in Es3 reservoir is characterized quantitatively by the porosity of about 2%–4%, wherein the pore throat radius is approximately equal to 0.04 μm. The lower limit of tight oil charging varies from one place to another, mainly attributed to factors such as interfacial tension, hydrocarbon generation dynamics, kerogen type, and basin temperature. The charging process of tight oil complies with the principle of force balance, whereas the pressure exerted the generated hydrocarbon is counterbalanced by the capillary force of the pore space.

Aromatic biomass (torch ginger) leaf-derived three-dimensional honeycomb-like carbon to enhance gravimetric supercapacitor.

Porous carbon electrode (PCE) is identified as a highly suitable electrode material for commercial application due to its production process, which is characterized by simplicity, cost-effectiveness and environmental friendliness. PCE was synthesized using torch ginger (Etlingera elatior (Jack) R.M. Smith) leaves as the base material. The leaves were treated with different concentrations of ZnCl2 , resulting in a supercapacitor cell electrode with unique honeycomb-like three-dimensional (3D) morphological pore structure. This PCE comprises nanofibers from lignin content and volatile compounds from aromatic biomass waste. From the characterization of physical properties, PCE-0.3 had an impressive amorphous porosity, wettability and 3D honeycomb-like structural morphology with a pore framework consisting of micropores and mesopores. According to the structural advantages of 3D hierarchical pores such as interconnected honeycombs, PCE-0.3 as supercapacitor electrode had a high specific capacitance of up to 285.89 F g-1 at 1 A. Furthermore, the supercapacitor exhibited high energy and power density of 21.54 Wh kg-1 and 161.13 W kg-1 , respectively, with a low internal resistance of 0.059 Ω. The results indicated that 3D porous carbon materials such as interconnected honeycombs derived from the aromatic biomass of torch ginger leaves have significant potential for the development of sustainable energy storage devices. © 2023 Society of Chemical Industry.

Engineering the Macrocyclic Donor Structures towards Deep-Blue Thermally Activated Delayed Fluorescence Emitters.

Deep-blue thermally activated delayed fluorescence (TADF) molecules present promising potential in organic light-emitting diodes (OLEDs), especially for display applications. Here, an efficient molecular engineering approach to modifying the donor or acceptor features of the D-π-A-configured TADF molecules for deep-blue emission is reported. By introducing oxygen and sulfone as a bridge unit onto the macrocyclic donor, two emitters, c-ON-MeTRZ and c-NS-MeTRZ, are synthesized and characterized, respectively. The reduced donor strength of c-ON-MeTRZ and c-NS-MeTRZ as compared to that of the model molecule c-NN-MeTRZ leads to blue-shifted emissions with high photoluminescence quantum yields (PLQYs) and retains TADF characters, while the new emitter c-NN-MePym with the most blue-shifted emission only exhibits a pure fluorescent nature because of the electron-accepting feature of pyrimidine that is insufficient for inducing the TADF property. In the presence of macrocyclic donors, these new emitters show high horizontal dipole ratios (Θ// = 85-89%), which are beneficial for improving the light out-coupling efficiency. Deep-blue TADF OLEDs incorporating c-ON-MeTRZ as an emitter doped in the mCPCN host achieves a high maximum external quantum efficiency (EQEmax) of 30.2% together with 1931 Commission Internationale de I'Eclairage (CIE) coordinates of (0.14, 0.13), while the counter device employing c-NS-MeTRZ as a dopant gives EQEmax of 15.4% and CIE coordinates of (0.14, 0.09). The EQEmax of c-ON-MeTRZ- and c-NS-MeTRZ-based devices can be significantly improved to 34.4 and 29.3%, respectively, with a polar host DPEPO, which stabilizes the charge transfer (CT) S1 state to give lower ΔEST for improving the reverse intersystem crossing process. The efficient TADF character, high PLQYs, and high anisotropic emission dipole ratios work together to render the superior electroluminescence (EL) efficiencies. Based on the detailed characterizations of physical properties, theoretical analyses, and comprehensive study on the corresponding devices, a clear structure-property-performance relationship has been successfully established to verify the effective molecular design strategy of modulating the macrocyclic donor characters for efficient deep-blue TADF emitters.

Characterization of Physical and Mechanical Properties of Rice Straw Particles and Furcraea foetida Fiber Reinforced Hybrid Composite

ABSTRACT The biodegradable characteristics and abundant availability of the fiber sources have gained the attention of various industries to produce natural fiber-based composites. As a sustainable alternative to the non-biodegradable fiber-based products, the natural composites provide a viable solution to reduce the environmental pollution caused by synthetic materials. This study developed rice straw particle (RSp) and Furcraea foetida (FF) fiber reinforced hybrid composite and investigated its physical and mechanical properties. The addition of 15 wt.% of RSp reduced the density of the test samples by 41.87% and its water absorption (WA) increased with the increase in fiber concentration. The composite with 5 wt.% and 15 wt.% of RSp showed maximum tensile strength (σt: 29.45 MPa) and modulus (σtm: 3.67 GPa), respectively. At 15 wt.% of RSp, the maximum flexural strength (σf: 43.12 MPa) and modulus (σfm: 2.09 GPa) was achieved and at 10 wt.% of RSp showed the highest impact strength (σi: 101.01 J/m). The σt (40.21%) and σf (7.76%) of the RSp reinforced composite were improved by the hybridization of FF (20 wt.%) fiber reinforcement.

Characterisation of physical properties of prepared cane from soft-cane varieties

Concerns have been raised that many sugarcane varieties in the development pipeline, particularly in the Central and Southern regions of Australia, have fiber quality classified as soft, with some soft enough to cause processing problems in the factory. The main issues have been feeding off the cane through the milling train and high bagasse moisture contents, causing subsequent combustion issues and low steam pressure at the boiler station. These cane varieties are usually designated as ‘soft-canes’, and their presence had been noted for at least 60 years. An attractive trait is their relatively high sugar yield per hectare. Some other general characteristics have been reported as often (but not always) having relatively low fiber content and being easier to prepare by the shredder, resulting in a larger number of smaller sized particles in the prepared cane. During the development of new cane varieties, Sugar Research Australia carries out tests for ‘fiber quality’. Experiments were carried out at Isis Central Mill to understand and improve the processing of existing soft-cane varieties. During the 2019 crushing season, a pilot-scale shredder was used to simulate the effect of shredder settings (speed and grid setting) that are known to affect preparation levels. Four existing soft-cane varieties (SRA1A, SRA4A, SRA11A and QN04-1643) were tested, along with Q208A that provided a reference as a middle-of-the-range variety (perceived to be neither a soft nor hard cane). The prepared cane produced was tested for fiber quality at the SRA fiber quality laboratory in Bundaberg. As measured at the factory, the preparation level and two physical properties (compression and permeability) were identified as important for the milling process. All the cane varieties responded similarly to speed and grid setting, with the soft-canes being part of a continuum, not a separate subset. The overall conclusion was that adjusting shredder speed and grid setting can control preparation and potentially address feeding problems at the milling train through improved control strategies.

Characterisation of physical and mechanical properties of seven particulate materials proposed as traction enhancers

Particulate materials are utilised in many applications to manipulate the friction between surfaces. This dataset provides the characteristics of particulates used as rail sand in the train’s wheel/rail interface (via an on-board system) to facilitate the train’s acceleration and deceleration. Seven materials are studied including Austrian rail sand, standard Great British rail sand, waste glass beads, recycled crushed glass, non-coated alumina, coated alumina, and dolomite. The main objective of this research is to provide a physical and mechanical characterisation of these granular materials in terms of their density, bulk behaviour, particle size, particle shape, hardness, reduced modulus, and mineralogical properties. In particular, three-dimensional raw and post-processed micro-computed tomography images of more than 1200 particles are shared. The results provide a detailed dataset which can be used in ongoing and future experimental and numerical investigations studying the role of particulates in the wheel/rail interface.

3D screen printing technology enables fabrication of oral drug dosage forms with freely tailorable release profiles

3D printing offers new opportunities to customize oral dosage forms of pharmaceuticals for different patient populations, improving patient safety, care, and compliance. Although several notable 3D print technologies have been developed, such as inkjet printing, powder-based printing, selective laser sintering (SLS) printing, and fused deposition modelling (FDM), among others, their capacity is often limited by the number of printing heads. 3D screen-printing (3DSP) is based on a classic flatbed screen printing that is widely used in industrial applications for technical applications. 3DSP can build up thousands of units per screen simultaneously, enabling mass customization of pharmaceuticals. Here, we use 3DSP to investigate two novel paste formulations: immediate-release (IR) and extended-release (ER) using Paracetamol (acetaminophen) as the active pharmaceutical ingredient (API). Both disk-shaped and donut-shaped tablets were fabricated using one or both pastes to design drug delivery systems (DDS) with tailored API release profiles. The size and mass of the produced tablets demonstrated high uniformity. Characterization of the tablets physical properties, such as breaking force (25–39 N) and friability (0.002–0.237%), adhering to Ph. Eur (10th edition). Finally, drug release tests with a phosphate buffer at pH 5.8 showed Paracetamol release depended on the IR- and ER paste materials and their respective compartment size of the composite DDS, which can be readily varied using 3DSP. This work further demonstrates the potential of 3DSP to manufacture complex oral dosage forms exhibiting custom release functionalities for mass production.

Biocomposite materials based on polyethylene and amphiphilic polymer-iron metal complex

Objectives. To obtain and study the properties including degradability of polymer composite materials (PCM) based on low-density polyethylene (LDPE) obtained by introducing an environmentally friendly additive comprising an oxo-decomposing additive (ODA) based on an amphiphilic polymer-iron metal complex, which accelerates the process of polymer degradation.Methods. PCMs based on LDPE and ODA were produced by processing in laboratory extruders in the form of strands, granules, and films. Thermodynamic properties were determined by differential scanning calorimetry in the temperature range 20-130 °C. In order to assess the performance characteristics (physical and mechanical properties) of the PCM, tensile strength and elongation at break were determined. The biodegradability of PCM was evaluated by Sturm's method, with the biodegradation index being determined by the amount of CO2 gas released as a result of microorganism activity, as well as composting by placing the PCMs for six months in biohumus. Changes in physical and mechanical properties and water absorption of the films during storage were evaluated. The photochemical degradability of the PCM was determined by exposing it to ultraviolet radiation for 100 h (equivalent to approximately one year of exposure of the films under natural conditions). The appearance of the composite samples following removal from the biohumus was determined using an optical microscope with ×50 magnification in transmitted and reflected light.Results. Following biodegradation by composting, the physical and mechanical properties of PCMs decrease by an average of 40.6%. This is related to the structural changes that occur in composites during storage in biohumus, i.e., the formation of a looser structure due to the development of large clusters of microorganisms that affect the formation of microcracks. It leads to the stage of fragmentation of the polyethylene matrix and indicates the progress of biological degradation of composites. In this case, the water absorption of the composite samples was 63% after 96 h of exposure. The biodegradability index determined by the Sturm method after 28 days of bubbling had changed by 82%, indicating an intensive biodegradation process. Exposure to ultraviolet radiation for 96 h resulted in the complete destruction of the PCMs, which turned into small “flakes.” This method is the most effective for the degradation of LDPE- and ODA-based PCMs.Conclusions. According to the results of the study of ODA-containing PCMs based on an amphiphilic polymer-iron metal complex, the tested filler-modifier can be recommended for the production of PCMs offering an accelerated degradation period.

Characterization and comparison of physical properties and in vitro simulated digestion of multi-component oleogels with different molecular weights prepared by the direct method

Due to the hazards of trans fatty acids and saturated fatty acids to human health, research on novel structured lipid-oleogels as lipid substitutes has attracted increasing attention. However, oleogelators of different molecular weights, oils of different properties, and adding lipophilic bioactive substances (LBAS) and/or surfactants to the system lead to differences in oleogel properties. This study characterized and compared the physical properties and in vitro simulated digestion of different multi-component oleogels of carnauba wax oleogels (CWOs), β-sitosterol/lecithin oleogels (S/LOs), and ethyl cellulose oleogels (ECOs) prepared by the direct method. Oleogel strength decreased in the order ECOs > CWOs > S/LOs and peanut oil oleogels > soybean oil oleogels. Regardless of oleogel type, resveratrol (RE) loading and surfactant addition altered the self-assembly or co-assembly behavior of oleogels, which improved their hardness, oil binding capacity (OBC), thermal stability, solid fat content (SFC), viscoelasticity, and RE loading capacity/encapsulation efficiency. The network structure of the different oleogels and the molecular properties of the oleogelators led to differences in the in vitro digestion of multi-component oleogels. Differences in oleogel processing conditions altered their degree of lipolysis and the bioavailability of RE within it. This research sets the direction toward the development of healthier fat substitutes in the future.

Determination of important biotechnical characteristics of some safflower (Carthamus tinctorius L.) cultivars

The study aimed to determine the biotechnical characteristics (physical properties, color characteristics, angle of repose, and coefficient of friction) of the seeds of safflower cultivars. Moisture contents of Asal, Balcı, and Dinçer cultivars were determined as 8.64%, 9.52%, and 8.57%, respectively. The width (4.04 mm) of the Dinçer cultivar gave higher values than other cultivars. Statistically significant (p

On characterization of physical properties for terbium (IV) oxide system via curve fitting models

The main objective of this study is to explore Terbium (IV) oxide through the use of its chemical graph. Theegree-based topological reverse indices of Terbium (IV) oxide have been related to thermodynamic assets such as heat of formation and entropy. We investigate the chemical compound Terbium (IV) oxide using its respective chemical graph and analyse its structural characteristics and physical properties using topological reverse indices by developing unique mathematical models.

Synthesis and physical properties of a new layered ferromagnet Cr1.21Te2

Single crystals of a new layered compound, ${\mathrm{Cr}}_{1.21}{\mathrm{Te}}_{2}$, were synthesized via a vapor transport method. The crystal structure and physical properties were characterized by single crystal and powder x-ray diffraction, temperature- and field-dependent magnetization, zero-field heat capacity, and angle-resolved photoemission spectroscopy. ${\mathrm{Cr}}_{1.21}{\mathrm{Te}}_{2}$, containing two Cr sites, crystalizes in a trigonal structure with a space group P-3 (No. 147). The Cr site in the interstitial layer is partially occupied. Physical property characterizations indicate that ${\mathrm{Cr}}_{1.21}{\mathrm{Te}}_{2}$ is metallic with hole pockets at the Fermi energy and undergoes a ferromagnetic phase transition at $\ensuremath{\sim}173\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. The magnetic moments align along the $c$ axis in the ferromagnetic state. Based on low-temperature magnetization, the spin stiffness constant, D, and spin excitation gap, $\mathrm{\ensuremath{\Delta}}$, were estimated according to Bloch's law to be $D=94\ifmmode\pm\else\textpm\fi{}17\phantom{\rule{0.16em}{0ex}}\mathrm{meV}\phantom{\rule{0.16em}{0ex}}{\AA{}}^{2}$ and $\mathrm{\ensuremath{\Delta}}=0.45\ifmmode\pm\else\textpm\fi{}0.33$ meV, suggesting its possible application as a low dimensional ferromagnet.

A Development and a Physical Properties Characterization of a Conductive Polymer Composite Reinforced with Metallic Particulates and Short Wire Fillers

A Development and a Physical Properties Characterization of a Conductive Polymer Composite Reinforced with Metallic Particulates and Short Wire Fillers

Mining waste and coconut fibers as an eco-friendly reinforcement for the production of concrete blocks

Using mineral and agro-industrial wastes associated with the cement matrix can add value and guarantee suitable properties for reinforced composites. This research aimed to evaluate the effect of the incorporation of quartzite and coconut fibers on masonry blocks' physical, mechanical, and thermal properties. Quartzite was evaluated replacing 0%, 25%, 50%, 75%, and 100% of the sand, whereas the coconut fibers were added in a proportion of 2.5% of the volume of gravel. Quartzite residues were analyzed regarding their granulometry, chemical composition, and pozzolanicity. The block initial formulation (control) was: 8.2% cement, 45.9% sand, and 45.9% gravel. The cement was cured at room temperature for 28days. Subsequently, the blocks were subjected to the characterization of physical, mechanical, and thermal properties. Coconut fibers presented a low percentage of extractives, with a low inhibition index (1.93%), reducing their effect on cement hardening. The increase in the content of quartzite incorporated provided a reduction in bulk density and an increase in porosity (from 11.7 to 16.0%) and water absorption after 24h (from 7.0 to 8.5%). The compressive strength was reduced from 50% with the insertion of the quartzite. The quartzite and coconut fibers reduced the concrete's thermal conductivity, providing essential reflections for the performance of the blocks in terms of thermal comfort in built environments. Further, incorporating these materials provided the potential to obtain blocks with characteristics of resistance and offering possible thermal comfort, besides contributing as an option for a destination for these mineral and agro-industrial wastes.

Study on the effect of carbon nanotubes loaded with cobalt disulfide modified multifunctional separator on Li-S battery

To solve the “deadliest” shuttle effect in Li-S battery, the design of appropriate separator become more and more important for better electrochemical performance. CoS2/CNTs composites were obtained by loading cobalt disulfide on the surface of CNTs through two-step pyrolysis. Through morphological analysis and physical property characterization, CoS2 was proved to be well loaded on CNT, and there was a good contact between the composite and PP separator. Inorganic metal sulfides in the modified layer of CoS2/CNTs can enhance the utilization of active sulfur materials through the enhanced chemical adsorption of LiPSs, which is further enhanced by the high electrical conductivity of CNTs. Moreover, the composite material can also accelerate the catalytic conversion of LiPSs, accelerate the ion diffusion rate, weaken the reaction polarization, effectively weaken the capacity decline caused by the shuttle effect, and enhance the electrochemical performance of the system.

A highly elastic absorbable monofilament suture fabricated from poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

To address the growing demand for more elastic sutures free from unwanted knot loosening, we fabricated an absorbable monofilament suture from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and subjected it to physical property characterization and performance evaluation (in vitro and in vivo degradability tests and a porcine abdominal wall suture test). As this flexible, highly stretchable, and difficult-to-untie suture exhibited additional advantages of small knot size and medium to long-term bioabsorbability, it was concluded to be a safe alternative to existing monofilament sutures, with far-reaching potential applications.

Phosphoric acid resistance PtCu/C oxygen reduction reaction electrocatalyst for HT-PEMFCs: A theoretical and experimental study

In high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs), dissociative H3PO4 in cathode will block the active sites of Pt-based electrocatalyst, which thus failure to catalyze the oxygen reduction reaction (ORR). Therefore, the electrocatalysts for the ORR in HT-PEMFCs with high resistance to H3PO4 poisoning are significantly important. Due to the similar bonding structure between HxPO43-x/O2 and Pt (Pt-O), the design of catalysts which could selectively reduce the adsorption energy of the H3PO4 is urgently needed. In this work, we screen proper H3PO4 resistance electrocatalysts through theoretical calculation based on the adsorption energy difference between HxPO43-x and O2 as an evaluation criterion. Then, we prepared a series of PtxCu catalysts based on the theoretical calculation results and further studied the structure-performance relationship of phosphoric acid-resistant catalysts through combining physical property characterization and electrochemical tests including half-cell and single-cell. The mass activity of Pt2Cu/C is 0.51 A/mgPt, exceeding the DOE's 2020 target of 0.44 A/mgPt. After add 0.1 M H3PO4 into the HClO4 electrolyte, the half-wave potential (E1/2) of Pt2Cu/C is only negatively shifted by 47 mV, much lower than 90 mV of TKK Pt/C. Furthermore, the HT-PEMFC with Pt2Cu/C in the cathode shows a peak power density of 383.4 mW/cm2, which surpasses that of TKK Pt/C for 231.0 mW/cm2. Our strategy of screening catalysts based on the adsorption energy difference study and further verified by experimental methods provides a promising strategy for the design of practical electrocatalyst in the cathode of HT-PEMFCs.