Contact Angle Studies Research Articles

Silicon dioxide incorporated cellulose acetate-mixed matrix membranes for Safranin-O removal from aqueous solutions.

Nanoparticle incorporated-mixed matrix membranes are renowned for their multifaceted advantages, including improved hydrophilicity, elevated solute rejection, enhanced mechanical robustness, and augmented chemical and thermal stability. The inherent hydrophilicity of silicon dioxide (SiO2) nanoparticles, due to silanol groups (Si-OH), along with their high porosity and surface area, renders them an ideal reinforcing filler within polymer matrices, significantly strengthening structural integrity of membranes. In this work, SiO2 nanoparticles were incorporated in a cellulose acetate (CA) matrix to prepare CA/SiO2 adsorptive membranes using phase inversion method. The performance of the membranes was assessed on the removal of Safranin-O (Sf-O) from aqueous solution. The physicochemical characterization of the synthesized membranes was assessed using contact angle, XRD, FE-SEM, EDS, FTIR, TGA, and tensile strength studies. The optimization studies on novel CA/SiO2 membrane revealed that the membrane with 2.5 wt.% of SiO2 in the CA matrix was the best in terms of Sf-O removal (approximately 100% dye removal) when the operating pH, initial dye concentration, and operating pressure were 9, 50 ppm, and 1 bar respectively. It is also found that 2.5 wt.% CA/SiO2 membrane has higher water permeability than other membranes. Incorporating SiO2 nanoparticles into a polymer matrix augments the structural, mechanical, and thermal properties of the resulting membranes while also enhancing water permeability, selectivity, and dye removal efficacy.

Enhanced performance of low-dielectric siloxane-polyimide copolymers: Synthesis and properties

Low-dielectric polyimides (PI) films with outstanding overall performance are attractive for next generation microelectronic applications. Herein, a series of two different FPIs and BPIs derived from 4,4′-diaminodiphenyl ether (ODA) and two different functional dianhydrides, 4,4'-(hexafluoroisopropylidene) biphthalic anhydride (6FDA) and 4,4′-(4,4′-isopropyldiphenoxy) biphthalic anhydride (BPADA), respectively, were synthesized by a conventional two-step methodology that included thermoimidatization. Additionally, employing aminopropyl-terminated polydimethylsiloxane PDMS (molecular weight = 1000) as the source of siloxane-oxygen bonds, a series of polyimide siloxane (SiFPIs and SiBPIs) copolymers were synthesized by varying the siloxane content (ranging from 0 to 5 wt%) within the copolymer structure. The effects of siloxane bond on the thermal, solubility, water resistance, dielectric and mechanical properties of polyimide were investigated systematically. The integration of siloxane significantly enhanced the solubility of these copolymers in polar aprotic solvents (DMAC, DMF, NMP), expanding their applicability in diverse processing environments. Crucially, these copolymers exhibited remarkably low dielectric constants—2.90 for SiFPI at 3% PDMS and 2.92 for SiBPI at 4% PDMS—coupled with low loss values, positioning them as prime candidates for advanced microelectronic applications. All the composite films have high thermal stability near pure PI. The introduction of PMDS into PI can improve the elongation at break and at the same time, the composite films still remained with higher modulus and tensile strength. Extensive hydrophobicity assessments through contact angle and water absorption studies underscored the copolymers’ superior moisture resistance, a critical parameter for their potential deployment in high-performance, environmentally sensitive electronic components.

Using zero nano-valent iron/thin film composite (ZNVI/TFC) membrane for brackish water desalination and purification

This study looked at the use of synthetic Zero Nano-valent Iron (ZNVI) particles in a unique interfacial polymerization technique on a polyamide thin film PA(TF) composite membrane for the treatment and desalination of brackish wastewater. Zero nano-valent iron (ZNVI) particles were created utilizing chemical reduction technique. ZNVI/PA(TF) NCs membrane is the outcome of advancing the PA(TF) membrane by combining with different concentration of ZNVI particles into the organic phase 1,3,5-benzenetricarbonyl trichloride (TMC). ZNVI/PA(TF) NCs membranes and ZNVI particles' surface properties were examined by the use of mechanical activity, contact angle, BET, FTIR, SEM, XRD, zeta potential, TEM analysis, and EDX studies. Using a variety of salt solutions, such as NaCl, Na2SO4, MgSO4, NaHCO3, CaSO4, CaCl2, and MgCl2, the ZNVI/PA(TF) NCs membrane performance towards salt rejection, flux (at varying pressure), anti-fouling activity, and ZNVI particles stability was assessed. This work investigated the removal efficiency of four dyes: methylene blue (MB), methyl orange (MO), Congo red (CR), and malachite green oxalate (MG). The water flux of the pristine PA(TF) membrane improved from 22 to 35 L/m2.h at 15 bar, indicating a 63% flux enhancement and the NaCl rejection was improved from 88.5 to 98.6%, indicating an 11.4% rejection improvement by incorporation of 0.3 wt.% of ZNVI particles into PA(TF) matrix. The ZNVI/PA(TF) NCs membrane's separation performances were evaluated using 5000 mg/L feed solutions of various salts at 15 bar. It was discovered that the water flux and salt rejection are, respectively, 33.4, 33, 32.7, 32, 31, 30 and 29 L/m2.h for CaSO4, MgSO4, Na2SO4, NaCl, CaCl2, MgCl2, and NaHCO3, and 97.4, 97, 96.5, 96, 94, 93.2, and 92.8%. It demonstrates that the flux recovery ratio (FRR) of the ZNVI/PA(TF) NCs membrane is greater than that of pristine PA(TF) (78%), coming in at 87%. High stability and fixing of the ZNVI particles on the modified membrane surface is indicated by the low overall ZNVI particles release rate over the course of the 10-day experiment.

Effectiveness of a silane coupling agent in a resin luting cement

The objective of this study was to investigate a new silane-containing self-adhesive resin luting cement with both shear bond strength and contact angle studies to determine if silane in a resin cement would chemically bond to a lithium disilicate surface. The silane-containing cement, Panavia SA Cement Universal (Kuraray, Tokyo, Japan) was tested against a control case where a traditional silane treatment was paired with resin-luting cement, Duo-Link Universal (Bisco Inc., Schaumburg, IL, USA) with immediate shear bond strength testing on both polished and etched lithium disilicate, as well as after thermocycling. It was determined that micromechanical retention provided a substantial contribution to bond strength. However, after an aging study with 20,000 thermocycles and then storage for 6 months in 37 °C water, the silane-containing, self-adhesive resin cement significantly decreased in shear bond strength when compared to the control. From contact angle studies, while it was shown that the paste containing the silane did effectively increase hydrophobicity of the treated lithium disilicate surface, it required over 3 h contact time, which was not representative of clinical use.

Effect of silica nanoparticles on crude oil emulsions stabilized by a natural surfactant from Fenugreek Seeds and polyacrylamide for subsurface oil mobilization applications

Emulsions represent a sustainable method for subsurface resource recovery due to their superior performance in pore plugging, mobility control and interfacial tension reduction. However, the stability of emulsion plays a vital role in determining the success of field implementation. In this work, a novel formulation is reported for emulsions wherein they have been stabilized by natural surfactant extracted from fenugreek seed. In this work, two emulsion systems are reported, that is surfactant polymer and nanoparticle-surfactant-polymer emulsion. Surfactant-polymer emulsions are stabilized by natural surfactant whereas nanoparticle-surfactant-polymer emulsion are stabilized in presence of nanoparticle and natural surfactant. Both the emulsions exhibit shear thinning profile as observed from rheological studies. Nanoparticle-surfactant-polymer emulsions were found to be thermally stable than that of Surfactant-polymer emulsions as evident from microscopic and rheological studies. An increase in temperature has the unfavorable impact on surfactant-polymer emulsion as huge drop in viscosity profile was observed. The viscosity profiles of nanoparticle-surfactant-polymer emulsions were found to be best fitted by the Krieger-Dougherty model with the value of coefficient correlation R2 = 0.99. The contact angle studies showed that NSP solution can reduce the contact angle to much lower value, which is 111˚ to 30˚ whereas surfactant-polymer solution was able to reduce from 116˚ to 57˚ only. Adsorption of silica nanoparticle was also observed in presence of sandstone and decrease in 27.32 % of peak absorbance was observed in span of 20 days. Therefore, finding of the study indicates that nanoparticle-surfactant-polymer emulsions has potential to perform better than surfactant-polymer emulsions, even at elevated temperature, and can be a better and cost-effective alternative to the conventional emulsions used in oilfield applications.

Exploration of UV-induced geometrical isomer-enriched Helichrysum kraussii extract as a corrosion inhibitor for Al(111) surface in 1.0 M hydrochloric acid: An experimental and theoretical study

This study evaluated UV-radiated Helichrysum kraussii (H. kraussii) extract for its corrosion inhibition on aluminium in 1.0 M HCl. To achieve this, techniques such as Liquid chromatography-mass spectrometry (LC-MS), Fourier transform infrared spectroscopy (FTIR), Gravimetric analysis, electrochemical analysis looking at electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP), contact angle and computational studies were used. The results obtained from these techniques made it possible to conclude the performance of UV-radiated H. kraussii as a corrosion inhibitor for aluminium metal. LC-MS and FTIR proved that the exposure of extract to UV radiation caused a change in the composition of extract metabolites, demonstrated by the increase in the number of peaks in the chromatogram and the shift in the FTIR spectrum. Weight loss technique showed that the extract inhibited the corrosion of aluminium with the maximum percentage inhibition of 84.6948 % at the concentration of 1500 ppm at 30 °C. The adsorption of the inhibitor molecules on the metal surface was found to obey the Langmuir adsorption isotherm, and the activation energy values proved that the adsorption mechanism was through physisorption. Nyquist plots semi-circles were found to increase with an increase in the extract concentration, showing an increase in the inhibition efficiency. Tafel's plot showed that both anodic and cathodic corrosion were inhibited. The DFT/PBE/GGA/DNP computational investigation obtained binding energies of the inhibitors on the aluminium surface that suggest that the Al···FA interaction happens through physical adsorption.

Cellulose triacetate-based mixed matrix membranes for concurrent removal of arsenate and arsenite from groundwater

Arsenic is one of the most dangerous groundwater contaminants whose effective removal is a major challenge for environmental scientists. Herein, several cellulose triacetate-based hybrid membranes are synthesized by adding different dosages (10, 30, and 50 wt%) of chitosan or chitosan-stabilized iron nanosheets. The fabricated membranes are characterized by advanced analytical tools such as AFM, SEM, FTIR, BET, TGA, zeta potential, and XRD. The enhancement in hydrophilicity and improved antifouling are evaluated by porosity, water uptake, contact angle, permeability tests, and bovine serum albumin (BSA) studies. At neutral pH, the cellulose triacetate-chitosan 50 % (CTA-CH 50 %) removed 85.13 % As(III) and 87.20 % As(V) at 67.23 L.m−2.h−1 permeability. On the other hand, cellulose triacetate-chitosan iron nanosheets 50 % (CTA-CIN 50 %) removed 91.30 % As(III) and 84.24 % As(V) at 62.35 L.m−2.h−1 permeability. The synthesized membranes efficiently removed arsenic from real groundwater taken from different Pakistani cities. The membranes are synthesized through a low-cost and scalable method, making it convenient for industrial-level applications.

Adhesion promotion and corrosion resistance of mixed phosphonic acid monolayers on AA 2024

Mixed monolayers were used to prepare surfaces of AA 2024 with precisely controlled corrosion protective and adhesive properties. In this study, the corrosion inhibition and adhesion promotion as a function of the composition of mixed phosphonic acid monolayers on AA 2024 was investigated. Mixed monolayers were formed by competitive adsorption of n-dodecylphosphonic acid (DPA) and 12-aminododecylphosphonic acid (ADPA) from ethanolic solution. Their compositions were determined by X-ray photoelectron spectroscopy. Atomic force microscopy studies and polarization modulation infrared reflection–absorption spectroscopy as well as contact angle studies proved the formation of monolayers with varying surface chemistry. The wet-adhesion strength was tested by 90° peel tests after application of an epoxy-amine adhesive. Linear sweep voltammetry was performed to evaluate the corrosion inhibition of the monolayers, and the corrosion resistance of the metal/adhesive composite was investigated by means of its corrosive delamination behavior. The electrochemical measurements demonstrated that reducing the surface concentration of ADPA improved the corrosion inhibition of the monolayer. However, the corrosive delamination experiments revealed that the improved corrosion inhibition by the self-organized DPA is of minor importance for the corrosion behavior of the metal/adhesive composite, as the adhesive properties dominate.

Fibroblastic tissue growth on polymeric electrospun membranes: a feasibility study

In recent years the interest in synthetic scaffolds has increased significantly as an alternative to animal-derived materials, as well as the advancement of material and manufacturing engineering, has resulted in improved standardisation and reproducibility within the field. Despite these advancements, a significant amount of research on animal-derived scaffolds, whilst research on synthetic materials is lacking for the growth of non-tumourgenic breast cell lines. The main objective of this work is to manufacture biodegradable scaffolds using biocompatible materials such as PVA (Polyvinyl Alcohol), PU (Polyurethane), Ge (Gelatin) and PCL (Poly-(-caprolactone) to test human cell adhesion and investigate the optimal system that supports representative tissue organisation and that could be used as an alternative to Matrigel™. Here, human mammary fibroblasts (HMF) were used as proof of concept. The membranes were manufactured using the process of electrospinning and characterised by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (ATR-FTIR), contact angle, tensile strength, and degradation studies. The assessment of the membranes as a viable biomaterial for the growth and development of cells was studied by MTT proliferation assay, fluorescence microscopy and SEM imaging. Results demonstrate that all materials are suitable for HMF proliferation. However, from microscopy analysis, only PU and PVA membranes induced morphological organisation of HMF similar to those results obtained in the Matrigel™ control conditions. This feasibility study reveals that HMF organisation, and proliferation are affected by the properties of the scaffold. Consequently, scaffolds parameters should be adjusted and manipulated to impact cell behaviour and emulate in vivo conditions.

The potential of sonocrystallization in crystal habit modification for improving micromeritic and physicochemical properties of Dapagliflozin

Dapagliflozin propanediol monohydrate (DAPA), an antidiabetic drug owing to its needle-shaped crystals exhibits poor micromeritic and physicochemical properties. Crystal habit modification by conventional and sonocrystallization approaches was employed to improve its manufacturability. SEM analysis of sonocrystallized DAPA in acetonitrile (DAPA_SNC3) revealed a rod habit with lower aspect ratio (3.56±0.91) and narrow size distribution (span value-1.37). In case of DAPA_EH and DAPA_CS (solvent evaporation in ethanol:n-hexane, and chloroform, respectively), rod and plate-shaped crystals were obtained with aspect ratios 6.98±5.84 and 6.03±4.21, respectively. All three samples showed significantly improved powder flowability (p<0.0001) compared to DAPA. Further solid-state characterization by FTIR, TGA, DSC, and PXRD showed no polymorphic changes in recrystallized samples. The contact angle studies in water revealed wetting tendency in the following order: SONO_SNC3>SONO_EH>SONO_CS>DAPA. Polar energies of DAPA_SNC3 and DAPA_CS were significantly higher (p<0.01 & p<0.001, respectively) when compared with DAPA. The XPS studies showed increased hydrophilic elements on the surfaces of DAPA_SNC3 crystals which resulted in improved wettability. DAPA_SNC3 among all samples showed highest tensile strength at 200 MPa compression force because of its shape. DAPA_EH showed no significant improvement in IDR profile, while DAPA_CS and DAPA_SNC3 showed significantly faster IDR because of prominent polar functionality (p<0.05 and p<0.0001, respectively).

Effect of Sodium Laureth Sulfate on Contact Angles of High-Impact Polystyrene and Acrylonitrile–Butadiene–Styrene from Recycled Refrigeration Equipment

This paper investigates the effects of sodium laureth sulfate (SLES) on the wettability of the surface of the two most common recycled plastics in refrigeration equipment: HIPS (high-impact polystyrene) and ABS (acrylonitrile–butadiene–styrene). These plastics, in the form of flakes, were identified on the basis of their FTIR spectra, and then, they were subjected to a study of contact angles using the sessile droplet method. The solutions for the angle analysis included tap water with the addition of SLES. The results of this study showed that at SLES concentrations of 0.1 g/L and 0.2 g/L, the differences in the contact angles for HIPS and ABS were 10.76° and 10.10°, respectively. This research confirmed the potential of using SLES as a support for the flotation separation of plastics with similar densities and surface characteristics, such as HIPS and ABS.

Evaluation of innovative fluroapatite /silicon dioxide modified zirconia nanocomposites coated on Ti–13Nb–13Zr alloy for dental implant application

Dental implants are intended to function as a durable method for replacing missing teeth. A biocompatible dental alloy is used to achieve integration with the jawbone through Osseointegration. This creates a strong base for the implant, allowing it to withstand the mechanical forces generated during biting and chewing. Dental alloys are commonly subjected to various mouth conditions known for their intricate corrosion potential. Corrosion can weaken the structural integrity of the implant, causing issues such as implant loosening, micro-motion at the implant-bone contact, implant fracture, allergic reactions, toxicity, and possible disruption of the Osseo integration process. To improve the alloy's corrosion resistance and biocompatibility, its surface can be altered using nanocomposite materials. The materials provide a protective coating to the alloy, creating a physical barrier that effectively prevents corrosive substances from reaching the underlying bulk material. This study involves modifying the surface of the dental alloy Ti–13Nb–13Zr with Fluroapatite (FAP)/Silicon dioxide (SiO2) modified zirconia (ZrO2) nano composites. The altered surfaces are then studied in simulated body fluid and artificial saliva solutions using in vitro methods. The FAP/SiO2 modified ZrO2 nanocomposites is applied onto a Ti–13Nb–13Zr alloy utilizing Electrophoretic deposition and Dip coating techniques. The coated samples were analysis utilizing FTIR, XRD, and SEM with EDS. Corrosion analysis was carried out on coated and uncoated samples using Electrochemical methods in simulated body fluid and artificial saliva solution. The biocompatibility is assessed using MTT assay, contact angle, and immersion testing in both SBF and Artificial saliva. EIS and corrosion study results show that FAP/SiO2 modified ZrO2 nanocomposites coated Ti13Nb13Zr alloy has high polarization resistance, low corrosion rate, and good charge transfer resistance, indicating excellent corrosion resistance. The contact angle study showed that the surface-modified Ti13Nb13Zr alloy is superhydrophilic, increasing implant surface osseointegration. Cell viability measurements reveal good cell growth, while immersion investigations show calcification, leading to enhanced osseointegration between the implant and its surrounding tissues. hence, it is an excellent material for dental implants application.

Fluconazole-Loaded Ibuprofen In Situ Gel-Based Oral Spray for Oropharyngeal Candidiasis Treatment.

Oral candidiasis is a fungal infection affecting the oral mucous membrane, and this research specifically addresses on a localized treatment through fluconazole-loaded ibuprofen in situ gel-based oral spray. The low solubility of ibuprofen is advantageous for forming a gel when exposed to an aqueous phase. The 1% w/w fluconazole-loaded in situ gel oral sprays were developed utilizing various concentrations of ibuprofen in N-methyl pyrrolidone. The prepared solutions underwent evaluation for viscosity, surface tension, contact angle, water tolerance, gel formation, interface interaction, drug permeation, and antimicrobial studies. The higher amount of ibuprofen reduced the surface tension and retarded solvent exchange. The use of 50% ibuprofen as a gelling agent demonstrated prolonged drug permeation for up to 24h. The incorporation of Cremophor EL in the formulations resulted in increased drug permeation and exhibited effective inhibition against Candida albicans, Candida krusei, Candida lusitaniae, and Candida tropicalis. While the Cremophor EL-loaded formulation did not exhibit enhanced antifungal effects on agar media, its ability to facilitate the permeation of fluconazole and ibuprofen suggested potential efficacy in countering Candida invasion in the oral mucosa. Moreover, these formulations demonstrated significant thermal inhibition of protein denaturation in egg albumin, indicating anti-inflammatory properties. Consequently, the fluconazole-loaded ibuprofen in situ gel-based oral spray presents itself as a promising dosage form for oropharyngeal candidiasis treatment.

Asphaltene Adsorption on Solid Surfaces Investigated Using Quartz Crystal Microbalance with Dissipation under Flow Conditions.

Asphaltenes can cause operational challenges in petroleum production facilities and adversely affect production by adsorption on mineral surfaces and alteration of the oil wettability of reservoirs. Therefore, understanding asphaltene adsorption mechanisms and their effects is crucial to improving the efficiency of oil production and reducing costs. In this study, we focus on understanding the impact of asphaltene concentration and the depositing environment of asphaltene adsorption on solid surfaces using the quartz crystal microbalance with dissipation (QCM-D) technique. The initial and long-term kinetics of adsorption at different concentrations were examined on three different solid surfaces including silicon dioxide to represent quartz mineral, stainless steel, and gold. The frequency-dissipation data showed evidence of monolayer adsorption initially, followed by multilayer formation. At short times, the adsorbed mass increased linearly with time, suggesting that the process was kinetically controlled rather than diffusion-controlled. The results were reproducible and did not depend on convection velocity but did depend on the surface material. At later stages, the monolayer development appeared to follow the random sequential adsorption (RSA) theory. Once multilayer adsorption commenced, the rates agreed well with the two-layer model of Zhu and Gu, 1990. The impact of asphaltene adsorption on the wettability of the surface was examined using contact angle studies, which showed decreasing water wettability with an increase in the adsorbed mass. The contact angle of water after 12 h of adsorption leveled off at around 100° on all three surfaces. Contact angle measurements were also used to evaluate if brine salinity causes the wettability alteration of surfaces with the adsorbed asphaltene. The results indicate that at 3% NaCl solution, the contact angle decreased only slightly by less than 2°.

Antimicrobial fibres derived from aryl-diazonium conjugation of chitosan with Harakeke (Phormium tenax) and Hemp (Cannabis sativa) Hurd

Surface functionalisation of natural materials to develop sustainable and environmentally friendly antimicrobial fibres has received great research interest in recent years. Herein, chitosan covalent conjugation via aryl-diazonium based chemistry onto Phormium tenax fibres (PTF) and hemp hurds (HH) was investigated. PTF are fibres derived from Harakeke/New Zealand flax, an indigenous and abundant plant source of leaf fibres, which served as an important 19th century export commodity of New Zealand. HH are obtained as a by-product from the hemp (Cannabis sativa) industry and find applications as traditional construction material, animal bedding, chemical absorbent, insulation, fireboard etc. This study reports aryl-diazonium covalent attachment of chitosan and PD13 (6-O-(3-(2-(N,N-dimethylamino)ethylamino)-2-hydroxypropyl)chitosan), a chitosan derivative with improved antibacterial activity, on to PTF and HH. The modification was confirmed using FTIR, XPS, SEM and water contact angle studies. Comparison of aryl-diazonium versus the use of succinic anhydride bridging for chitosan attachment was also investigated, with the diazonium method giving improved results. The treated PTF and HH fibres had good antibacterial activity against Staphylococcus aureus and this study contributes to the development of sustainable antibacterial fibres using bio-based materials.

Interaction Studies of PVP and CTAB Capped CuO Nanorods with Aldicarb and Chlorpyrifos

Copper oxide uncapped nanorods (UC-CuO), capped with cetyltrimethylammonium bromide (CTAB-CuO), and polyvinyl pyrrolidine (PVP-CuO) were utilized for interaction study of Aldicarb (A.D.) and Chlorpyrifos (C.P.) pesticides. Electron microscopy (FE-SEM & TEM) studies confirmed the nanocrystalline structure and nanorod morphology of UC-CuO, CTAB-CuO, and PVP-CuO. The contact angle study showed the hydrophilic nature of the UC-CuO and PVP-CuO with contact angle of 51° and 57°, respectively. While CTAB-CuO exhibited hydrophobic nature with a contact angle of more than 90°. Interaction study of UC-CuO, CTAB-CuO, and PVP-CuO with A.D. and C.P was conducted using UV–vis absorption study (in the 250–400 nm region). UC-CuO showed the specific detection with A.D., while CTAB-CuO have shown with C.P. without using any bio-recognition elements. PVP-CuO did not show systematic change with both pesticides confirming the capping agent-dependent specific interaction of the pesticides.

Capillary Suction Properties of Mortar Made with Recycled Plastic Aggregates Elaborated from Waste Electrical and Electronic Equipment

It is possible to revalue the plastic fraction from WEEE using it as a recycled aggregate (RA) in cement mortars. However, this feasibility depends on elaborating a granular material via a core-shell strategy to stabilize the potential contaminants. The core is a plastic particle, and the shell is a cement, fillers, and activated carbon mixture. Due to the hydrophilic characteristics of the shell and the presence of interstitial sites generated by the use of the RA, it is necessary to study the wetting properties of these mortars. This article presents the results of capillary suction and contact angle studies of mortars made with RA having different shell compositions. The capillary suction of the latter is higher than in traditional mortars, which limits their use for structures exposed to water and environmental agents but opens the possibility of new uses in permeable concrete or for the manufacture of building components.

Mechanism for formation of porcine blood hydrogels used as additives in the mortar of traditional Chinese architectural painting

Ancient Chinese architecture drawing is a unique form of ancient Chinese art. Porcine blood hydrogels are distinctive ingredients used to prepare the composite material of the substrate layer for architecture drawing. This investigation was focused on the mechanism for porcine blood hydrogel formation. Based on the traditional Chinese recipe for the preparation of porcine blood-lime mortar, samples with different ratios of porcine blood and lime water were prepared, and the molecular-scale interactions between the lime water and proteins in the porcine blood were examined with FTIR spectroscopy, Raman spectroscopy, XRD, XPS, fluorescence spectroscopy, contact angle and rheology studies. The mechanical properties and morphological features of the samples were detected with a rheometer, universal material testing machine and SEM. The results indicated that an appropriate amount of lime water was required for gelation of the porcine blood. With the appropriate alkalinity, sufficient carboxyl groups on the fibrin chains were deprotonated, and coordination with Ca2+ ions formed enough cross-links for support networks within the structure of the porcine blood hydrogel. Complexation of deprotonated carboxyl groups on the fibrin chains with Ca2+ ions led to the formation of a hydrophobic surface due alterations of the fibrin conformation and increased the adhesive properties of the hydrogel. With the hydrogel used as an ingredient in the preparation of a substrate layer composite, it is suggested that the hydrophobic surface of the hydrogel facilitated mixing with hydrophobic tung oil during preparation of the composite material, and strong adhesion of the hydrogel increased the mechanical strength and crack resistance of the substrate layer.

Excellent Diffusive Performance of Cold-Plasma-Exposed Activated Peanut Shell Carbon as an Electrode in Al-Air Batteries

Modern energy and ecological sustainability can be accomplished in part, by using activated bio char-based electrodes made from biomass waste in energy-producing devices like metal-air batteries and fuel cells. Herein, a simple method of combining Pyrolysis graphitization with DC glow discharge plasma is used to create highly disorder carbonaceous materials incorporating surface functional groups from a readily available and inexpensive bio waste of peanut shells. The synthesized activated Peanut shell carbon material displays remarkable supercapacitance performance in 2 M KOH at elevated specific capacitances (537 Fg−1 at 10 mVs−1) and catalytic ability for the oxygen reduction response at a half-wave peak of 0.19 V. Water contact angle and dispersion studies showed a considerable improvement in the surface’s hydrophilic following plasma treatment, and FTIR and Raman spectroscopy were also used to evaluate the surface’s functional group and micro structure. In this study, a simple, affordable, and environmentally friendly method for making activated dis ordered carbon is revealed. It is then investigated as a potential electrode for supercapacitor, metal air battery, fuel cell applications.

Investigation of Orderliness of Breath Figures on Polydimethylsiloxane.

Breath figures, the self-assembled water droplet patterns formed on cold surfaces, are ideally hexagonal. A deviation from the ideal honeycomb pattern can occur due to variation of roughness of the substrate, change in vapor from water to other liquids, etc. The thermodynamics of breath figure formation is complex, and any deviation from ideality is even more difficult to understand. In the absence of a unified theory to understand such patterns and experimental difficulties in monitoring all aspects of formation of breath figures, the patterns formed are studied in terms of their orderliness by determining their Voronoi entropy. We report here the Voronoi entropy calculations of the breath figure fabricated over the smooth and constrained surfaces using polydimethylsiloxane (PDMS) of molecular weight 235 g/mol in two different environments: (a) water and (b) binary mixture of ethanol-propanol over the entire concentration range. Ordered honeycomb patterns are seen on the smooth surfaces, and disordered patterns are seen on constrained surfaces when imaged using confocal microscopy. The latter is attributed to the depinning of the triple-phase contact line, implying that the underlying constraints influence the pore morphology. Contact angle studies of water over the breath figure patterned surfaces indicate the hydrophobic nature of the patterned surfaces.