Sessile Drop Test Research Articles

Interfacial Interactions Between Inclusions Comprising TiO2 or TiN and the Mold Flux During the Casting of Titanium-Stabilized Stainless Steel

Interfacial properties play a key role in determining the solubility of solids in liquids for both low- and high-temperature processes. In this study, the interfacial interactions between inclusions comprising TiO2 or TiN and the mold flux were investigated. The results of sessile drop tests show that the wettability of the mold flux on the TiO2 substrate was better than that on the TiN substrate when the temperature was below 1503 K. However, the contact angle on the TiN substrate decreased more than that on the TiO2 substrate when the temperature was above 1503 K due to the enhancement of the interfacial reaction. The thermodynamic calculations suggest that the reactions of TiN with O2 and SiO2 resulted in a bubbling phenomenon during the TiN sessile drop test. The scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) results show that the final products of the interfacial interaction between the mold flux and the TiO2 substrate comprised perovskites, whereas those for the TiN substrate comprised perovskites and SiTi.

Investigation on surface free energy and moisture damage of asphalt mortar with fine solid waste

Recently, the application of fine solid waste (FSW) in asphalt material improves the sustainability of pavement engineering. However, the effect of FSW on asphalt materials is complicated due to the different physical and chemical properties of FSW. Most of the recent research focused on the effect of FSW on the rheological and mechanical properties of asphalt material. Nevertheless, these macroscopic mechanisms still need more illustration at the microscopic level. In this paper, flyash, diatomite and four types of bauxite residues were selected as six types of FSW, in addition limestone filler was nominated as a control group. For each type of filler, five filler-binder ratios by volume (FBv) were designed and tested. First, Scanning Electron Microscope test was conducted to evaluate the interface fusion between asphalt and filler at the micro-level. Second, Column Wicking test conducted by kerosene and filler, was used to qualitative evaluate the wettability between asphalt and filler. Moreover, the Sessile Drop test was conducted to evaluate the effect of filler type and content on the surface free energy parameters of asphalt mortar. The obtained results indicated that filler with high content of metal elements and porous structure can increase the polarity (γAB) of asphalt mortar, which is a benefit to the resistance to moisture damage of the asphalt mortar. However, the increase of FBv will decrease the spreading coefficient of asphalt mortar, which leads to an increase in potential defects and a decrease of mechanical interlocking between asphalt mortar and aggregate.

Investigation of Surface Roughness Parameter in Dissimilar Diffusion Brazing of WC-Co to AISI 4145 Steel

In this paper, the influence of surface roughness on microstructure and mechanical properties of AISI 4145 steel/WC-Co joint was investigated. Sessile drop test was conducted to evaluate the spreading behavior of Cu-Zn-Ni filler metal on the substrate with different surface roughness values. SEM micrographs were used to study the microstructure of interface and fracture surface while the mechanical properties of joint zone were compared by shear strength test. The sessile test reveals that an optimized roughness value is needed for the highest wettability. The sample with 0.36 μm surface roughness showed a minimum wetting angles of 15°/22°. The microstructure of filler metal/cemented carbide interface indicates that some defects such as micro-voids are produced when the surface of sample is too smooth. With the increase of surface roughness, the micro-voids disappeared which implies on the positive effect of roughness. However, the exceeding rise in roughness led to the further creation of micro-voids at the interface. Shear strength test also reveals that the defect-free samples show a ductile behavior while the flawed samples have the brittle failure. As a whole, it is indicated that an optimized surface roughness is required for achieving a high-quality brazed joint.

Feasibility Study of Pressure Boiled Method on Defibrillation Stalk Sweet Sorghum Fibres Waste

Today, due to environmental reasons and limited of fossil resources take many researchers to develop new and renewable materials. Bio-composites which is consisted of synthetic polymers matrix and natural fibres, is one of the alternatives to reducing its problems. Among of natural fibre that has good potential to be used as reinforcement in synthetic polymer matrices is sorghum fibre. However the hydrophilic nature of natural fibers causes it to be incompatible with synthetic polymer matrices which have hydrophobic properties and it’s need to surface modified with particular treatment. The aim of this work was conducted to study the effect of hydrothermal treatment through pressure boiled method by using distilled water in a pressurized stainless steel pan cooking for 5 minutes to defibrillation and hydrophilic properties of stalk sweet sorghum fibres. Evaluation of the experiments was characterized with Field-Emission Scanning Electron microscope (FE-SEM), Fourier Transformation Infra-Red (FTIR) Spectroscopy and sessile drop test instruments, respectively. The experiment was found that using hydrothermal treatments through pressure boiled method led to a removal of binding materials, such as a wax, hemicellulose and lignin, and enhancement the hydrophilic properties of sorghum fibres.

Effect of Y content on interface reaction and wettability between a nickel-base single crystal superalloy melt and ceramic mould

In this paper, the effect of Y content on interface reaction and wettability between a nickel-base single crystal supperalloy melt and ceramic mould were studied by means of sessile drop tests. The microstructural characterization of the alloy-ceramic interface and the elemental compositions of reaction products were performed by scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA), the phases of reaction products were identified by X-ray diffraction (XRD), and the surface analysis of reaction products was carried out by X-ray photoelectron spectroscopy (XPS). The results showed that Al and Hf in the alloy reacted with SiO2 in the ceramic mould when Y content was lower than 0.011 wt%, and the reaction products were Al2O3 and HfO2, with little change in the wetting angle. However, when Y content was higher than 0.017 wt%, Y and Al in the alloy reacted with SiO2 in the ceramic mould, and the wetting angle decreased significantly. 0.017 wt% was the critical concentration of Y content that would cause interface reactions. The reaction products of 0.017 and 0.025 wt% Y alloys were Y3Al2(AlO4)3, the reaction products of 0.1 wt% Y alloy were Y3Al5O12 and Y4Al2O9, and the reaction products of 0.5 and 1.0 wt% Y alloys were double reaction layer composed of Y2O3 and Y3Al5O12. Si generated by the interface reactions could react with O2 in the atmosphere to form SiOx during the cooling of the alloy-ceramic couples.

High-Temperature Interaction of Liquid Gd with Y2O3

The sessile drop method combined with contact heating procedure was applied for the investigation of high-temperature interaction between liquid Gd and Y2O3 substrate. Real-time behavior of Gd sample in flowing inert gas (Ar) atmosphere upon heating to and at temperature of 1362 °C was recorded using high-speed high-resolution CCD camera. The results evidenced that molten Gd wets Y2O3 substrate (the contact angle θ < 90°) immediately after melting of metal sample observed at T = 1324 °C (Tm = 1312 °C). During the first 3 min of the sessile drop test, the contact angle dropped from θ = 52° to θ = 24° and then stabilized at the final value of θf* = 33°. The solidified Gd/Y2O3 couple was subjected to structural characterization using optical microscopy, scanning electron microscopy coupled with x-ray energy-dispersive spectroscopy. The results evidenced that the wettability in the Gd/Y2O3 system has a reactive nature and the leading mechanism of the interaction between liquid Gd and Y2O3 is the dissolution of the ceramic in the liquid metal responsible for the formation of a deep crater in the substrate under the drop. Therefore, the final contact angle θf*, estimated from the side-view drop image, should be considered as an apparent value, compared to the more reliable value of θf = 70° measured on the cross section of the solidified couple.

The relationship of surface roughness and wettability of 316L stainless steel implants with plastic deformation mechanisms

The wettability of the implant plays significant role in successful tissue-implant integration and shows strong dependence on the surface topography of the material. Recent studies showed that the plastic deformation mechanisms can improve cell response, and increase surface roughness and energy. In order to understand the effect of these mechanisms on wettability, 316L stainless steel samples were subjected to tensile test and deformed up to 15% to 35% of strain levels. Atomic force microscopy (AFM) presented approximately 22-fold greater average surface roughness on the 35% deformed sample compared to undeformed one. On the other hand, sessile drop test showed contact angle decrease from 82° to 52° as the deformation increased. This finding is significant since much higher contact angle value at similar surface roughness was presented in the literature. This demonstrates that the plastic deformation mechanisms can play significant role in enhancing the surface wettability without a need for a surface treatment technique. Hence, through the activation of these mechanisms, wettability and surface energy of the implant materials could be further increased which would result with enhanced cell response and lessened post-surgical complications

Synthesis and characterization of novel foams by pyrolysis of lignin

We report the synthesis and characterization of lignin-based foams by pyrolyzing cold pressed lignin compacts at 300°C, 500°C, 700°C, and 900°C in an argon (Ar) atmosphere. Detailed thermogravimetric analysis (TGA), thermomechanical analysis (TMA), Fourier transform infrared spectroscopy (FTIR), and microstucture analysis was performed on these samples. Scanning electron microscopy (SEM) and X-ray tomography analysis showed that all the foams had cellular structure, and had a total porosity of 93.3%, 94.5%, 93.9%, and 93.4% after pyrolysis at 300°C, 500°C, 700°C, and 900°C, respectively. Comparatively, the fraction of open porosity of the total porosity increased from 89.7% at 300°C to 97.1% and 98.1% at 500°C and 700°C, respectively, and then decreased to 93.0 % at 900°C. The averaged ultimate compressive strength (UCS) of the foams fabricated at 300°C was ~0.77 MPa. It decreased to ~0.49 MPa at 500°C, after which it increased to ~0.95 MPa at 700°C and then retained similar strength at 900°C. Detailed FTIR analysis showed a decreased in intensity of peaks for all the samples fabricated at higher temperatures, which was further correlated with changes in lignin molecular structure. By analyzing TGA, TMA, FTIR, and microstructure, a novel mechanism for designing lignin-based cellular solids has been proposed in this work. The wettability study by sessile drop test showed that the foams are hydrophobic after pyrolyzing at 300°C and 500°C, after which the compacts became hydrophilic after pyrolyzing at 700°C and 900°C, respectively.

Synthesis and Characterization of Lignin-Based Polyurethane as a Potential Compatibilizer

Lignin is one of the most abundant biopolymer on earth. It has polar and non-polar side due to its hyperbranched structure, but the polarity of lignin has a higher tendency than non-polarity. Lignin has potential to be compatibilizer if the portion of non-polar can be increased. This research is focused on investigate the synthesis of lignin-based polyurethane to enhance the portion of non-polarity in lignin. Lignin-based polyurethane was prepared by reacting variation 4,4'-Methylenebis(cyclohexyl isocyanate) (HMDI) and polyethylene glycol (PEG), then lignin was added to the reaction. In this study, the structure of lignin-based polyurethane was confirmed by NMR and FTIR. NMR and FTIR showed that lignin successfully grafted. NMR, also used to investigate the variation molar mass of PEG and isocyanate contents effects to polarity of lignin-based polyurethane. The polarity of lignin-based polyurethane decrease as the composition of HMDI and molecular weight of PEG increase. This result also occurs on the sessile drop test that used to determine surface tension of lignin-based polyurethane. The thermal properties of lignin-based polyurethane also investigate using STA. Based on STA, enhancement of composition of HMDI and PEG increase thermal degradation and resistance of lignin-based polyurethane.

Damring Formation During Rotary Kiln Chromite Pre-reduction: Effects of Pulverized Carbonaceous Fuel Selection and Partial Pellet Melting

Electricity consumption is the largest cost contributing factor in the production of ferrochrome. Currently the pelletized chromite pre-reduction process (solid-state reduction of chromite) is the process option with the lowest specific electricity consumption (MWh/ton). In this process, pelletized chromite is fed into a rotary kiln at 1573 K (1300 °C), where partial pre-reduction takes place. Damring formation (material build-up) in the rotary kiln causes routine shutdowns, resulting in loss of revenue. The damring formation is possibly caused by melting of the ash of the pulverized coal used to fire the kiln and/or the partial melting of the chromite pellets. Ash fusion temperatures of twenty different samples were evaluated to assess the temperature at which the pulverized coal ash will start to contribute to damring formation. Sessile drop tests were used to assess the softening behavior of different ore types (e.g., UG2, MG, and LG metgrade), as well as softening of composite chromite pellets made from these ores. Actual damrings were also analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy. Results indicate that it is mainly the pulverized coal ash that will contribute to damring formation, and not ore or pellet softening. Multiple-linear regression was used to derive equations to predict the ash fusion temperatures of the pulverized coal ash, which can be used by ferrochrome producers to optimize pulverized coal selection.

Effect of Al and Mg Contents on Wettability and Reactivity of Molten Zn–Al–Mg Alloys on Steel Sheets Covered with MnO and SiO2 Layers

The reactive wetting behaviors of molten Zn–Al–Mg alloys on MnO- and amorphous (a-) SiO2-covered steel sheets were investigated by the sessile drop method, as a function of the Al and Mg contents in the alloys. The sessile drop tests were carried out at 460 °C and the variation in the contact angles (θc) of alloys containing 0.2–2.5 wt% Al and 0–3.0 wt% Mg was monitored for 20 s. For all the alloys, the MnO-covered steel substrate exhibited reactive wetting whereas the a-SiO2-covered steel exhibited nonreactive, nonwetting (θc > 90°) behavior. The MnO layer was rapidly removed by Al and Mg contained in the alloys. The wetting of the MnO-covered steel sheet significantly improved upon increasing the Mg content but decreased upon increasing the Al content, indicating that the surface tension of the alloy droplet is the main factor controlling its wettability. Although the reactions of Al and Mg in molten alloys with the a-SiO2 layer were found to be sluggish, the wettability of Zn–Al–Mg alloys on the a-SiO2 layer improved upon increasing the Al and Mg contents. These results suggest that the wetting of advanced high-strength steel sheets, the surface oxide layer of which consists of a mixture of MnO and SiO2, with Zn–Al–Mg alloys could be most effectively improved by increasing the Mg content of the alloys.

Evaluation on Dorsey Method in Surface Tension Measurement of Solder Liquids Containing Surfactants

With the purpose of developing a feasible approach for measuring the surface tension of solders containing surfactants, the surface tension of Sn–3Ag–0.5Cu–xP solder alloys, with various drop sizes as well as different phosphorus (P) content, was evaluated using the Dorsey method based on the sessile drop test. The results show that the accuracy of the surface tension calculations depends on both of sessile drop size and the liquid metal composition. With a proper drop size, in the range of 4.5 mm to 5.3 mm in equivalent spherical diameters, the deviation of the surface tension calculation can be limited to 1.43 mN·m−1 and 6.30 mN·m−1 for SnAgCu and SnAgCu–P, respectively. The surface tension of SnAgCu–xP solder alloys decreases quickly to a minimum value when the P content reaches 0.5 wt% and subsequently increases slowly with the P content further increasing. The formation of a P-enriched surface layer and Sn4P3 intermetallic phases is regarded to be responsible for the decreasing and subsequent increasing of surface tension, respectively.

Sustainable asphalt mixes manufactured with reclaimed asphalt and modified-lignin-stabilized bitumen emulsions

This work aims to develop asphalt mixes with 100% reclaimed asphalt pavements (RAP) as source of aggregates and bitumen emulsions stabilized by amine-functionalized lignin. To that end, reduced-temperature asphalt technologies between 80 and 130 °C were assessed. Previously, processing parameters of emulsions were evaluated by droplet size distribution and rheology measurements. Furthermore, a study combining Pendant drop and Sessile drop (on a prototype polyethylene surface) tests showed that emulsion aqueous phase containing modified lignin would be able to wet the hydrophobic surface of RAP. Manufactured asphalt mixes were characterized according to French design method for hot mixes, including gyratory compaction, rutting resistance, complex modulus and fatigue resistance tests. The results obtained showed that reduced-temperature asphalt mixes could be successfully prepared to meet French design requirements, which would further minimize impact to environment. However, mix design has required a semi-quantitative approach for estimating ‘active’ RAP binder content, by balancing the manufacturing temperature and the fresh bitumen required.

Isocyanate-Free Polyurethane Coatings and Adhesives from Mono- and Di-Saccharides.

Mostly biosourced non-isocyanate polyurethanes (NIPU) were prepared from mono- and disaccharides, namely glucose and sucrose, reacted with dimethyl carbonate and hexamethylene diamine. The main aim of this research was to show that NIPU can be prepared from mono- and disaccharides, this just being an initial exploratory work and its sole main aim. The oligomers obtained were detected by MALDI-ToF, CP-MAS 13C NMR, and FTIR spectrometries. The glucose-derived NIPU were shown to harden at a markedly lower temperature than the sucrose-derived ones and to be easier to handle and spread. The NIPU obtained were applied as wood and steel surface coatings and tested by the sessile drop test (on wood) and cross-cut test (on steel) with encouraging results. The glucose NIPU gave good surface coating results already at 103 °C, while the sucrose NIPU yielded good results only at a markedly higher temperature of hardening. The NIPU saccharide resins were also tested as thermosetting wood joint adhesives with the glucose NIPU yielding very encouraging results.

Wettability of liquid caesium iodine and boron oxide on yttria-stabilized zirconia

ABSTRACT During the Fukushima Daiichi Nuclear Power Plant accident occurred in 2011, volatile fission products (FPs) such as Cs and I had released and caused environmental contamination and public exposure, respectively. However, the release mechanism of these FPs from fuels under the accident is still not completely understood. In recent years, we have focused on the wettability of liquid FPs against solid fuels, because the interface between the fuel surface and the FPs becomes the migration pathway, which might have large influences on the release behaviour of the FPs. Here, we studied the wettability of liquid CsI and B2O3 on yttria-stabilized zirconia (YSZ) solid surface by the sessile drop test, where YSZ is a simulated material of the fuel. It was revealed that liquid CsI exhibited extremely high wettability against the YSZ surface with the contact angle of nearly zero. This high wettability may act to suppress the FPs release. Furthermore, it was confirmed that the crystal orientation and surface roughness of the YSZ solids have large influences on the wettability of liquid B2O3. The present results contribute for deep understanding of the release behaviour of the volatile FPs from fuels.

Influence of adding Ti powder in preform on microstructure and mechanical properties of Al2O3p/steel composites by squeeze casting

To improve the mechanical properties of alumina particulates reinforced steel matrix composite, Ti powder was added into the alumina preform, a 5140 steel matrix composite was fabricated by squeeze casting, and the influences of Ti powder on the microstructure, hardness and bending strength of the composite were investigated, compared with the composite without adding Ti powder. Applied Ti powder and alumina particulates were 10-25 μm and 100-180 μm in size, respectively. Both composites were successfully fabricated, however Ti powder addition increased the infiltration thickness of the composite. In the Ti contained composite, a TiC film in micron scale is formed on the surface of alumina particles, many TiC aggregates are dispersed in the steel matrix without obvious remaining Ti powder. The hardness and the three-point bending strength of the composite reach 49.5 HRC and 1 018 MPa, respectively, which are 17.9% and 52.4% higher than those of the composite in the absence of Ti addition. Fracture morphology shows that the debonding of alumina particulates is eliminated for the composite in the presence of Ti addition. Sessile drop test shows the average wetting angle between 5140 steel and that of Ti coated Al2O3 is about 82.15°, much lower than the wetting angle 150° between steel and pure Al2O3. Therefore, the increase in the mechanical properties of the composite is attributed to the improvement of Al2O3p/steel interface wetting and bonding by adding Ti powder in the preform.

Lead-free solder wettability of oxidized-aluminum enhanced by Ar-H2 plasmas for flip-chip bumping

PurposeAn investigation has been performed on the improved solder wettability of oxidized aluminum (Al) with lead-free solder (96.5Sn-3.5Ag) using Ar-H2 plasmas. The lead-free solder wettability was raised from 62.2 per cent wetting for Al oxidized in air at 250 C for 4 h to 98.4 per cent wetting of oxidized Al modified by Ar-H2 plasmas at a certain H2 flow rate. This study aims to gain insight on the surface characteristics of Al affecting the solder wettability with a liquid lead-free solder.Design/methodology/approachAr-H2 plasmas at certain H2 flow rates are intended to reduce Al oxides on the surfaces of oxidized Al substrates both by physical bombardments via Ar plasmas and chemical reductions with H2 plasmas, while Al substrates are exposed in Ar-H2 plasmas to improve the solder wettability with a liquid lead-free solder.FindingsSurface characteristics of oxidized Al substrates have been identified to play key roles for enhanced lead-free solder wettability using Ar-H2 plasmas. A decrease in polar surface free energy and an increase in dispersive surface free energy on the surfaces of oxidized Al substrates are exploited to advance the lead-free solder wettability. Decreased composition ratios of O to Al, detected by X-ray photoelectron spectroscopy (XPS) for oxidized Al substrates, are crucial for improved lead-free solder wettability.Originality/valueXPS is typically used to analyze the surface compositions of Al oxides. To provide a rapid and non-expansive method to identify the surfaces of Al substrates prior to soldering to assure lead-free solder wettability, this study proposes a measurable skill, a so-called sessile drop test method, to investigate surface free energies such as total, polar and dispersive surface free energy on the surfaces of Al substrates, to illuminate how the lead-free solder wettability of oxidized Al is improved by Ar-H2 plasmas.

Direct Measurement of Static and Dynamic Contact Angles Using a Random Micromodel Considering Geological CO2 Sequestration

The pore-level two-phase fluids flow mechanism needs to be understood for geological CO2 sequestration as a solution to mitigate anthropogenic emission of carbon dioxide. Capillary pressure at the interface of water–CO2 influences CO2 injectability, capacity, and safety of the storage system. Wettability usually measured by contact angle is always a major uncertainty source among important parameters affecting capillary pressure. The contact angle is mostly determined on a flat surface as a representative of the rock surface. However, a simple and precise method for determining in situ contact angle at pore-scale is needed to simulate fluids flow in porous media. Recent progresses in X-ray tomography technique has provided a robust way to measure in situ contact angle of rocks. However, slow imaging and complicated image processing make it impossible to measure dynamic contact angle. In the present paper, a series of static and dynamic contact angles as well as contact angles on flat surface were measured inside a micromodel with random pattern of channels under high pressure condition. Our results showed a wide range of pore-scale contact angles, implying complexity of the pore-scale contact angle even in a highly smooth and chemically homogenous glass micromodel. Receding contact angle (RCA) showed more reproducibility compared to advancing contact angle (ACA) and static contact angle (SCA) for repeating tests and during both drainage and imbibition. With decreasing pore size, RCA was increased. The hysteresis of the dynamic contact angle (ACA–RCA) was higher at pressure of one megapascal in comparison with that at eight megapascals. The CO2 bubble had higher mobility at higher depths due to lower hysteresis which is unfavorable. CO2 bubbles resting on the flat surface of the micromodel channel showed a wide range of contact angles. They were much higher than reported contact angle values observed with sessile drop or captive bubble tests on a flat plate of glass in previous reports. This implies that more precaution is required when estimating capillary pressure and leakage risk.

Hot-Dip Aluminizing on AISI F55–UNS S32760 Super Duplex Stainless Steel Properties: Effect of Thermal Treatments

The behavior of super duplex stainless steels AISI F55-UNS S32760 in hot-dip aluminizing process has been studied, investigating the influence of cold working and of different initial microstructures obtained through a preliminary thermal treatment. The microstructural features examined are the secondary austenite precipitation, the static recovery of ferrite and the thermal dissolution of austenite within ferritic matrix. The hot-dip aluminizing temperature has been optimized through sessile drop tests. The treatment has been performed at 1100 °C for 300 s, 900 s and 2700 s. A strong chemical interaction occurs, generating intermetallic compounds at the interface. Molten aluminum interacts exclusively with the ferritic phase due to its much higher diffusivity in this phase coupled with its marked ferrite-stabilizer behavior. Thus, the influence of cold working is not remarkable, since the strains are mainly allocated by austenitic phase. The diffusivity of aluminum increases due to lattice defects thermally generated and, mainly, to influence given by grain boundaries, multiplied by secondary austenite precipitation, which act as short-circuit diffusion paths. Ni and Cr contents in the ferritic matrix have an influence but not highly relevant. Then, the best starting condition of the super duplex stainless steel substrates, to obtain a thick interfacial layer, are the thermal annealing at 1080 °C for 360 s/mm after a solution thermal treatment at 1300 °C for 60 s/mm.

Electrospun polyurethane and soy protein nanofibres for wound dressing applications

In this report, a novel wound dressing material has been woven by electrospinning technique and tested for its various properties. For the nanofibre mat, a mixture of polyurethane (PU) and soy protein isolate (SPI) was electrospun in conjugation with zinc oxide nanoparticles (ZnO Nps) and ciprofloxacin hydrochloride (CipHCl) to produce fibrous mats viz. PU/SPI/ZnO and PU/SPI/CipHCl. An optimum ratio (1 : 1) of PU/SPI was used as suitable polymeric ratio in order to produce homogenous nanofibres without beads having an average diameter in the range of 300–350 nm. The electrospun nanofibre-based mats were characterised using X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis and scanning electron microscope. The mechanical properties of the nanofibrous mats were tested using universal testing machine. The wettability analysis was done using the contact angle measurement based on the sessile drop test. This study revealed that the electrospun PU/SPI-based nanofibres are non-sensitizing, non-allergic and non-toxic and that it can be used as a peculiar wound healing material.