Improvement Of Mechanical Properties Research Articles

Effect of the TiB2 content on the mechanical and tribological properties of TiB2/AZ91 composites fabricated by vacuum hot-press sintering process incorporating vacuum ball milling

Magnesium alloys have poor strength and wear resistance, restricting their application greatly, while Mg matrix composites can improve these deficiencies. TiB2/AZ91 composites with high TiB2 content were prepared by vacuum hot-press sintering process incorporating vacuum ball milling. The effects of TiB2 content on the microstructure, mechanical properties and tribological properties of the composites were investigated in detail. The results suggested that the TiB2 particle exhibited good bonding with the Mg matrix. With the increasing TiB2 content, the ultimate tensile strength, yield strength and elongation of TiB2/AZ91 composites firstly increased and then decreased, while the wear rate and wear surface roughness presented an opposite trend, and the hardness and coefficient of friction gradually increased. The composites with 5 wt% TiB2 obtained the maximum tensile properties (UTS: 234 MPa YS: 91 MPa EL: 7.3 %). This improvement in mechanical properties was attributed to the uniform distribution of TiB2 particles and the well bonding at the interface. The strengthening mechanisms were found to be the load transfer strengthening and the thermal mismatch strengthening. Furthermore, the composites with 15 wt% TiB2 demonstrated the lowest wear rate of 1.06×10−6 mm3/Nm and lowest wear surface roughness of 2.971 μm. This wear resistance was enhanced because of the significant increasing in hardness. The dominant wear mechanisms observed in TiB2/AZ91 composites were abrasive wear and oxidation wear.

Enhanced mechanical properties of dispersed carbide-strengthened CrFeNi-based medium entropy alloys prepared via powder metallurgy

In this study, a set of CrFeNi -based medium-entropy alloys (MEAs) with varying carbon contents were prepared by spark plasm sintering (SPS) using atomized alloy powders as raw material. The microstructures of powders and as-sintered alloys were characterized using ECCI and EBSD. The mechanical properties of as-sintered alloys were tested and the strengthening mechanical were discussed. The results showed that the microstructures of the CrFeNi gas atomized powder and sintered alloy were both single FCC phase in an equiaxed state. However, the matrix grains of powder with carbon addition were mostly dendritic, and few eutectic carbides could be observed between matrix grains. Compared with the CrFeNi MEA, the addition of 8 at. % C led to an increase in the yield strength and tensile strength from 395 MPa to 630 MPa–590 MPa and 990 MPa, respectively. Orowan strengthening and grain refinement resulting micro/nano carbides are responsible for the improvement in mechanical properties.

Improvement of Marine Biodegradability and Mechanical Properties of Poly(D-lactide) Films by Embedment of Poly(ethylene glycol)-Modified (PEGylated) Enzymes

Improvement of Marine Biodegradability and Mechanical Properties of Poly(<scp>D</scp>-lactide) Films by Embedment of Poly(ethylene glycol)-Modified (PEGylated) Enzymes

Microstructures, mechanical properties, and strengthening mechanisms of the (NbMoTa)100–xCx refractory medium-entropy alloys

Refractory high/medium-entropy alloys (RH/MEAs) are known for their outstanding performance at elevated temperatures; however, they usually exhibit poor room-temperature plasticity, which can be attributed to the non-uniform deformation that occurs at room temperature. Once cracks nucleate, they will rapidly propagate into vertical splitting cracks. Here, we introduce multiple phases including FCC and HCP phases into the NbMoTa RMEA via appropriate addition of carbon. The results show that multiple-phase synergy effectively suppresses non-uniform deformation, thereby delaying the onset of vertical splitting cracks. An optimal combination of compressive strength-plasticity is achieved by the (NbMoTa)92.5C7.5 alloy. The significant improvement in room-temperature mechanical properties can be attributed to its hierarchical microstructure: in the mesoscale, the BCC matrix is divided by eutectic structures; while at the microscale, the BCC matrix is further refined by abundant lath-like FCC precipitates. The FCC precipitates contain high-density stacking faults, acting as a dislocation source under compressive loading. The HCP phase in the eutectic microstructures, in turn, acts as a strong barrier to dislocation movement and simultaneously increases the dislocation storage capacity. These findings open a new route to tailor the microstructure and mechanical properties of RH/MEAs.

Simultaneously enhancing mechanical and anti-corrosion properties of aluminum through electrodeposition of supersaturated Al(Fe) solid solutions

The heterogeneous microstructure in bulk aluminum (Al) alloys or coatings, comprising an α-Al solid solution matrix and coarse intermetallic compounds (IMCs), poses a challenge in balancing mechanical and anti-corrosion properties. This challenge is particularly pronounced in Al alloys with high iron (Fe) content. Here, supersaturated Al(Fe) solid solutions with a single phase have been electrodeposited using imidazolium chloroaluminate ionic liquids (ILs). Ferrous chloride (FeCl2) dissolved in Lewis-acidic ILs is assumed to form Cl-bridged [Fe(AlCl4)4]2−, which, together with the well-known Al2Cl7− species, supports the reduction and deposition of Al(Fe) alloy coatings. The supersaturated Fe solutes significantly strengthens the Al matrix, with the hardness of Al(Fe, 6.6 at.%) reaching up to 3.43 GPa, surpassing that of any commercial Al alloys and other binary Al-based solid solutions. Moreover, the Al(Fe) deposits demonstrate superior anti-corrosion performance compared to pure Al. The homogeneous microstructure and extended Fe solubility within Al(Fe) solid solutions inherently contributes to a simultaneous improvements in mechanical and anti-corrosion properties. The nanograined and compact structure also benefit these properties. Accordingly, the combination of electrodeposition techniques and Al(Fe) alloys offers a promising approach for providing effective mechanical and chemical protection on metal surfaces.

Crystallization behaviors of chain extended poly (lactic acid) modified with ST‐NAB3 and its improvement for mechanical and thermal properties

AbstractThe widespread use of traditional petroleum‐based plastics is causing significant environmental pollution for example microplastics issues, due to its non‐biodegradability. Poly (lactic acid) (PLA) as a representative biodegradable polymer is a promising candidate to replace petroleum‐based plastics in some fields of disposable packaging materials and tableware. In this work, in order to improve the poor crystallization, mechanical and heat resistance performances of PLA, styrene–acrylonitrile‐glycidyl methacrylate (SAG) as a chain extender and octamethylenedicarboxylic dibenzoylhydrazide (ST‐NAB3) as a heterogeneous nucleating agent (HNA) were added simultaneously into PLA matrix. The chain‐extended PLA (CPLA) with branch structures had smaller crystal sizes and higher crystal density, compared with those of pure PLA. In addition, thanks to the nucleation effect of ST‐NAB3 and the development of “shish‐kebab”, this tendency became more pronounced in CPLA/HNA systems. It was worth mentioning that, CPLA with the ST‐NAB3 content of 1 wt% (CPLA‐1) possessed the highest crystallinity of 43.6%. Meanwhile, CPLA‐1 had the best impact strength and heat deformation temperature of 38.9 kJ/m2 and 91.3°C respectively, which had increased by 11.3 kJ/m2 and 32.4°C contrast to pure PLA. On the whole, this study proposed a simple and effective method, which provided a new possibility for PLA modification research.

Fiber-Reinforced Plywood: Increased Performance with Less Raw Material.

Fiber-reinforced plywood is a composite material that combines the natural strength and rigidity of plywood with the added durability and resilience provided by reinforcing fibers. This type of plywood is designed to offer improved characteristics over standard plywood, including enhanced strength, stiffness, resistance to impact and moisture, and environmental degradation. By integrating reinforcing fibers, such as glass, carbon, or natural fibers (like flax, bamboo, or hemp) into or onto plywood, manufacturers can create a material that is better suited for applications where traditional plywood might fall short or when a decrease in product weight or savings in wood raw material are necessary. This report reviews the current progress in fiber-reinforced plywood in the context of plywood as a construction material to better understand the potential gains in plywood applications, mechanical parameters, and material savings. It is found that a simple and cost-effective procedure of fiber reinforcement allows for substantial improvements in plywood's mechanical properties, typically to the extent of 10-40%. It is suggested that the wider adoption of fiber-reinforced plywood, especially in load- and impact-bearing applications, would greatly contribute to enhanced durability and longevity of the material while also allowing for more sustainable use of raw wood material.

Evolution of Microstructure During Stress Relieving Heat Treatment of 1S Aluminium

Aluminium and its alloys are extensively used in nuclear research reactors due to its low neutron absorption coefficient, good heat transfer properties, excellent corrosion and oxidation resistance in air and water environment combined with desirable mechanical properties along with considerable radiation stability. The thin walled tubes are normally manufactured through port hole die extrusion route and used in 'O' tempered condition. The thin tubes in 'O' tempered condition are undergone canning operation which may alter the microstructural features to some extent which may affect mechanical properties. The paper describes the extent to which microstructural and subsequently mechanical properties are altered due to the simulated canning process and further requirements of stress relieving heat treatment to restore the microstructural features and mechanical properties. The following studies are carried out with 1S aluminum tube in 'O' tempered state, simulated canning condition and stress relieved at different temperature, - hardness measurement, X ray line profile analysis for dislocation density measurement, tensile properties measurement using ring tensile testing, electron back scattered diffraction (EBSD) analysis for recrystallization fraction determination and changes in texture components. It is found that the canning operation changes dislocation density, micro-strain, coherent domain size which are well reflected in hardness and ring tensile testing. Subsequent stress relieving at 350°C for 2 hrs. leads to improvement of mechanical properties appreciably.

Improvement of Mechanical Properties of Superabsorbent Polymers by Addition of Cellulose for Flexible Batteries

Improvement of Mechanical Properties of Superabsorbent Polymers by Addition of Cellulose for Flexible Batteries

Recent advancements in chitosan-based intelligent food freshness indicators: Categorization, advantages, and applications

With an increasing emphasis on food safety and public health, there is an ongoing effort to develop reliable, non-invasive methods to assess the freshness of diverse food products. Chitosan-based food freshness indicators, leveraging properties such as biocompatibility, biodegradability, non-toxicity, and high stability, offer an innovative approach for real-time monitoring of food quality during storage and transportation. This review introduces intelligent food freshness indicators, specifically those utilizing pH-sensitive dyes like anthocyanins, curcumin, alizarin, shikonin, and betacyanin. It highlights the benefits of chitosan-based intelligent food freshness indicators, emphasizing improvements in barrier and mechanical properties, antibacterial activity, and composite film solubility. The application of these indicators in the food industry is then explored, alongside a concise overview of chitosan's limitations. The paper concludes by discussing the challenges and potential areas for future research in the development of intelligent food freshness indicators using chitosan. Thus, chitosan-based smart food preservation indicators represent an innovative approach to providing real-time data for monitoring food quality, offering valuable insights to both customers and retailers, and playing a pivotal role in advancing the food industry.

Biochar as an efficient reinforcing agent for poly(lactic acid)/poly(ε-caprolactone) biodegradable composites with high robustness and thermo-resistance

The brittleness of poly(lactic acid) (PLA) can be effectively mitigated by melt-blending it with poly(ε-caprolactone) (PCL). However, this approach compromises the vital strength and modulus of PLA, while the thermo-resistance remains low. In this regards, biochar (BC) was introduced to reinforce PLA/PCL composites as a modifier to improve mechanical and thermal performances. Herein, the effects of various contents of BC and annealing treatments were investigated on the properties of PLA/PCL composites. Interestingly, BC not only improved the mechanical properties of the composites but also reduced the semi-crystallization time by more than 70 %. Furthermore, annealing treatment increased the tensile strength and tensile modulus of the PLA/PCL/BC composites by 10.1 % and 6.3 %. Notably, Vicat softening temperatures of the composites with PLA to PCL proportions of 70:30 and 60:40 were increased to above 100°C. More importantly, the addition of BC effectively formed physical interaction with PLA, resulting in improvement in mechanical properties. Annealing treatment perfected the PLA crystal into a much more stable α-crystal form, resulting in an increase in thermal properties. This work paves an effective way to prepare PLA based biodegradable composites with high strength and thermo-resistance.

Microstructural transformation and corrosion–cavitation behavior of ultrasonic nanocrystal surface modified nickel aluminum bronze (NAB)

In this study, nickel–aluminum bronze (NAB) is optimized by ultrasonic nanocrystal surface modification (UNSM), and its surface microstructural evolution, surface hardness, electrochemical corrosion behavior, and cavitation erosion behavior are investigated. The potentiodynamic polarization curves and electrochemical impedance spectra before and after UNSM treatment of NAB are measured using a typical three-electrode system. The cavitation erosion process is simulated through the vibration of ultrasonic waves underwater, and the cavitation erosion resistance performance of various specimens is evaluated. UNSM significantly refines the coarse and heterogeneous multi-phase structure of the cast NAB, providing a relatively uniform and dispersed structure. Simultaneously, severe plastic deformation rapidly increases micro-strains on the NAB surface, which effectively improves its surface hardness from 211 to 360 Hv. After UNSM treatment, the corrosion potential increases slightly; and the passivation potential and current decrease considerably, dropping from 207 to 103 mV and from 5.23 to 2.41 mA/cm2, respectively. This is primarily because of the slowdown of selective-phase corrosion and the uniform formation of an oxide film. Additionally, UNSM parameters affect corrosion potential by regulating surface roughness. A smoother surface corresponds to a higher corrosion potential at the same load. UNSM treatment significantly improves the cavitation corrosion resistance of NAB, primarily because an increase in hardness and uniform distribution of structure effectively slows the speed of crack formation and propagation, which is a result of the synergistic improvement of mechanical and corrosion resistance properties.

Influence of the 3-Hydroxyvalerate Content on the Processability, Nucleating and Blending Ability of Poly(3-Hydroxybutyrate-co-3-hydroxyvalerate)-Based Materials.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate (P(3HB-co-3HV) copolymers are an attractive class of biopolymers whose properties can be tailored by changing the 3-hydroxyvalerate monomer (3HV) concentration, offering the possibility of counteracting problems related to high crystallinity, brittleness, and processability. However, there are few studies about the effects of 3HV content on the processability of copolymers. The present study aims to provide new insights into the effect of 3HV content on the processing step including common practices like compounding, addition of nucleation agents and/or amorphous polymers as plasticizers. P(3HB-co-3HV)-based films containing 3, 18, and 28 mol % 3HV were processed into films by extrusion and subsequent molding. The characterization results confirmed that increasing the 3HV content from 3 to 28 mol % resulted in a decrease in the melting point (from 175 to 100 °C) and an improvement in mechanical properties (i.e., elongation at break from 7 ± 1% to 120 ± 3%). The behavior of P(3HB-co-3HV) in the presence of additives was also investigated. It was shown that an increase in the 3HV content leads to better miscibility with amorphous polymers.

High tribological performance of quenched–tempered 40Cr steel treated by plasma oxynitriding

Alloy steel 40Cr was treated by plasma oxynitriding after quenching and tempering. The microstructures, mechanical properties, and tribological performances of plasma oxidized–nitrided layer at tempering temperatures of 500, 520, and 540 °C were investigated. The typical tempered sorbite structure was present when the 40Cr alloy steel was treated by quenching at 900 °C and tempering. A special structure of mixed oxide–nitride layer along with the veinlike nitride phase was formed after plasma oxynitriding. The surface hardness of the quenched–tempered 40Cr alloy steel was significantly improved. The quenched 40Cr alloy steel tempered at 520 °C exhibited the highest hardness of approximately 973 HV0.2 and the lowest wear rate of about 1.72 × 10−14 m3 N−1 m−1 than the samples tempered at 500 and 540 °C. The oxide and nitride phases inside the plasma oxidized–nitrided layer played important roles in the improvement of the surface mechanical properties and the tribological performance of the quenched–tempered alloy steel.

Stimuli-Responsive Codelivery System-Embedded Polymeric Nanofibers with Synergistic Effects of Growth Factors and Low-Intensity Pulsed Ultrasound to Enhance Osteogenesis Properties.

The present work aims to develop optimized scaffolds for bone repair by incorporating mesoporous nanoparticles into them, thereby combining bioactive factors for cell growth and preventing rapid release or loss of effectiveness. We synthesized biocompatible and biodegradable scaffolds designed for the controlled codelivery of curcumin (CUR) and recombinant human bone morphogenic protein-2 (rhBMP-2). Active agents in dendritic silica/titania mesoporous nanoparticles (DSTNs) were incorporated at different weight percentages (0, 2, 5, 7, 9, and 10 wt %) into a matrix of polycaprolactone (PCL) and polyethylene glycol (PEG) nanofibers, forming the CUR-BMP-2@DSTNs/PCL-PEG delivery system (S0, S2, S5, S7, S9, and S10, respectively, with the number showing the weight percentage). To enhance the formation process, the system was treated using low-intensity pulsed ultrasound (LIPUS). Different advanced methods were employed to assess the physical, chemical, and mechanical characteristics of the fabricated scaffolds, all confirming that incorporating the nanoparticles improves their mechanical and structural properties. Their hydrophilicity increased by approximately 25%, leading to ca. 53% enhancement in their water absorption capacity. Furthermore, we observed a sustained release of approximately 97% for CUR and 70% for BMP-2 for the S7 (scaffold with 7 wt % DSTNs) over 28 days, which was further enhanced using ultrasound. In vitro studies demonstrated accelerated scaffold biodegradation, with the highest level observed in S7 scaffolds, approximately three times higher than the control group. Moreover, the cell viability and proliferation on DSTNs-containing scaffolds increased when compared to the control group. Overall, our study presents a promising nanocomposite scaffold design with notable improvements in structural, mechanical, and biological properties compared to the control group, along with controlled and sustained drug release capabilities. This makes the scaffold a compelling candidate for advanced bone tissue engineering and regenerative therapies.

Radiation shielding properties of shotcrete containing different aggregates

In this study, the physical and mechanical properties of wet mix shotcrete produced using crushed stone aggregate (CS), ferrochrome slag aggregate (FS), and barite (B) aggregate have been investigated. Furthermore, the radiation shielding properties have been determined experimentally, theoretically, and through simulation. A control sample was produced using 50 % CS and 50 % FS. Subsequently, shotcrete groups were produced by substituting B aggregate at replacement rates of 25 %, 50 %, 75 %, and 100 % instead of FS. The mechanical properties such as density, ultrasonic pulse velocity (UPV), compressive strength, flexural strength, and splitting tensile strength of the produced spray concrete groups were investigated. Additionally, experimental radiation shielding measurements were conducted using a high-purity germanium (HPGe) detector system with emissions from four different radioactive sources (133Ba, 137Cs, 60Co, and 22Na) spanning nine different gamma energies ranging from 276.5 to 1332.5 keV. As a result of the experimental measurements, the linear attenuation coefficients (μ) of the shotcrete samples were obtained. A proportional increase in μ was determined with increasing barite content. Using the experimental mass attenuation coefficient (μ/ρ) results, half-value layer (HVL) and tenth-value layer (TVL) thicknesses, as well as mean free path (MFP) values, were calculated. An increasing B aggregate ratio did not have a significant effect on the μ/ρ value, while an increase was observed in the HVL, TVL, and MFP values. Moreover, the WinXCOM interface was employed for theoretical calculations, and the FLUKA Monte Carlo code was utilized for simulation calculations. The obtained data were compared with experimental results, revealing a good agreement between them. Based on the obtained data, it was concluded that increasing the B aggregate ratio resulted in improvement in mechanical properties compared to the control sample, and additionally, it was determined that B aggregate-added shotcrete is an effective gamma radiation shielding material.

Enhancement in mechanical properties of GFRP‐coal‐derived graphene oxide composites by addition of multiwalled carbon nanotubes and halloysite nanotubes: A comparative study

AbstractIn this study, we compare synergistic performance of two different nanofillers, namely halloysite nanotubes (HNT) clay and multiwalled carbon nanotubes (MWCNT), in conjunction with a fixed concentration (0.125 phr) of semi‐anthracite coal‐derived graphene oxide (AC‐GO) on mechanical properties improvement of EGFPs (E‐glass fiber‐based epoxy resin composites). The dispersion of AC‐GO with HNT clay (GO‐H) and AC‐GO with MWCNT (GO‐C) within epoxy matrix was achieved using sonication and homogenization. Further mixture was incorporated into mats of E‐glass fiber employing “vacuum‐assisted resin infusion molding” (VARIM). Significant enhancements (18.3% flexural strength, 14.6% tensile strength, and a slight increase of impact strength (1.8%)) were observed in EGFPs reinforced with GO‐H at 0.50 phr loading of HNT, with an AC‐GO concentration maintained at 0.125 phr. Correspondingly, optimal values for GO‐C reinforced EGFPs at 0.25 phr were 40.3%, 18.7%, and a 10.5% decrease in impact strength, respectively. Analytical techniques such as XRD, FESEM, EDX mapping, and FTIR reveal presence of relatively abundant functionalities and strong interfacial adhesion in GO‐H as well as GO‐C. The cost of HNT clay is approximately 15 times cheaper than industrial‐grade MWCNTs, therefore, these results underscore potential of GO‐H as a very economical nano‐reinforcement alternative to GO‐C for polymer nanocomposites.Highlights 0.50 phr HAGRP improves 18.3% flexural, 14.6% tensile, 1.8% impact strengths. Beyond 0.50 phr HAGRP and 0.25 phr CAGRP, mechanical properties decreased. 0.25 phr CAGRP improves 40.3% flexural, and18.7% tensile strengths. FESEM, FTIR reveal strong interfacial adhesion between nanofillers and epoxy. GO‐H has proven to be an inexpensive reinforcement for polymer nanocomposites.

W-doped concentration improved the hardness, elastic modulus, elastic anisotropy and thermodynamic properties of ZrC ultrahigh temperature ceramics

Although ZrC is a promising ultrahigh temperature ceramics due to the high melting point, high strength, high hardness and low density, the improvement of mechanical properties and thermal stability is very significance for it's ultrahigh temperature application. To improve the mechanical and thermodynamic properties of ZrC ultrahigh temperature ceramics, we apply the first-principles calculations to study the influence of W-doped concentration on the structural stability, hardness, elastic modulus, elastic anisotropy and thermodynamic properties of the cubic ZrC ceramics. The calculated results show that three W-doped ZrC are thermodynamic stability. In particular, the calculated impurity formation energy of the W-doped ZrC increases with increasing W concentration. Importantly, the calculated elastic modulus of the W-doped ZrC increases with increasing W concentration. Although the hardness of W-doped ZrC is bigger than the parent ZrC, the hardness of W-3.125 at.% is higher than the W-doped ZrC with the high concentration of W. Naturally, the high hardness and elastic modulus of the W-doped ZrC is that the metal W enhances the localized hybridization between Zr and C, which is demonstrated by the change of ZrC bond. In addition, the parent ZrC and the W-doped ZrC show excellent elastic anisotropy. Furthermore, the calculated Debye temperature of W-3.125 at.% ZrC is higher than the parent ZrC and the other W-doped ZrC. Therefore, we predict that the W-3.125 at.% ZrC shows excellent mechanical properties and better thermodynamic properties in comparison to the other W-doped ZrC ceramics.

Improvement of mechanical properties by cold plasma treatment of bonded surfaces

In nature, matter is found in solid, liquid or gaseous form. At very high temperatures, molecules can absorb an enormous amount of energy, causing them to move in a disordered way. With the absorbed energy, they can dissociate into atoms, and because of their disordered motion, these molecules or atoms can split into ions and electrons. Excessive heating of matter is therefore always accompanied by ionisation, leaving the medium electrically neutral. This ionised state is known as plasma. It is sometimes called the fourth state of matter. Plasmas are therefore mixtures of neutral and/or excited ions, electrons, atoms, radicals or demodules with an internal energy above the neutral state. Sources of plasma can be as follows: naturally occurring in the ionosphere; produced by nuclear reactions; generated by a hyperfrequency source; formed by direct heating followed by confinement in a region of space by a magnetic field; and produced by electrical discharges. Plasma is characterised by the state of its components: density, which is defined by the number of particles per unit volume; kinetic temperature; and degree of ionisation. Plasma can be thermal or out of thermal equilibrium, or 'cold plasma'. Cold plasma is formed, for example, when a gas passes through strong electric fields - electrons are dissociated from the molecules and the gas becomes electrically conductive and glows blue. The paper describes the equipment used to create cold plasma, which was used to treat different surfaces. After treatment, they were bonded with different adhesives and tested for tensile strenght. An improvement in the mechanical properties mentioned above was observed when the surfaces to be bonded were treated with cold plasma compared to surfaces bonded normally. When the impact of cold plasma treatment on elongation, or ε, is examined, it is found that for Fiber Wood samples, cold plasma treatment considerably boosts elongation, increasing it from 0.35% for untreated samples to 0.81% for samples treated with cold plasma. For samples that have been treated with cold plasma, the average value increases significantly from 0.03% to 0.63% when ArbofillFichte material is used. In addition, the application of cold plasma treatment to the surfaces results in an increase in the modulus of elasticity. For example, the modulus of elasticity doubles for Arbofill Fichte samples, going from 113.56MPa for untreated samples to 227.43MPa for cold plasma treated samples; for Fiber Wood, it increases from an average value of 789.52MPa for untreated samples to an average value of 931.62MPa for treated samples.

Effects of spironolactone on skin biophysical properties in women with acne treated with oral spironolactone.

Spironolactone (SPL) is an effective treatment for women acne, but other effects on skin biophysical properties remain to be investigated. The aim of the current study was to explore the effects of oral SPL used to treat women acne on skin biophysical properties, including hydration, transepidermal water loss (TEWL), skin surface lipid (SSL) levels, mechanical properties, color, pH, and pore size. Twenty-five Thai women with acne treated with oral SPL were followed for 6 months. Skin hydration, TEWL, SSL levels, mechanical properties, color, pH, and pore size of the forehead, chest, and inner arm were evaluated at baseline and 2, 4, and 6 months after treatment with oral SPL. Facial and upper back pore size were also assessed. Clinical outcomes were changes in these skin biophysical properties at each visit compared with baseline. Skin hydration, TEWL, SSL levels, color, pH, and pore size remained stable throughout the study. Facial skin parameters at 6 months demonstrated the following changes: hydration levels, 7.60 (95% confidence interval [CI], -59.74 to 74.94); TEWL, -2.36 (95% CI, -5.77 to 1.06); L* value, 0.51 (95% CI, -0.70 to 1.72); individual typology angle, 1.65 (95% CI -2.27 to 5.57); pH, 0.01 (95% CI -0.43 to 0.46); pore size, -0.24 (95% CI, -1.21 to 0.73); and SSL levels, 7.60 (95% CI -59.74 to 74.94). Improvement of facial mechanical properties was observed. R0 (indicating skin tightness) and R1 (indicating elasticity) showed significant decreases (-0.076 [95% CI, -0.141 to -0.010] and -0.016 [95% CI, -0.033 to -0.001]). R3 and R4 (representing tiring effects) were also improved (-0.091 [95% CI, -0.158 to -0.025] and -0.022 [95% CI, -0.044 to -0.001]). Parameters in the truncal and inner arm areas remained stable, except for skin elasticity and tiring effects, which exhibited a similar trend of improvement as the facial area. The changes were notable as early as 4 months. Oral SPL used for acne did not impair the skin barrier. Moreover, the skin mechanical properties were improved at 4 to 6 months.