Coating Technique Research Articles

Effect of Various Carbon Coating Techniques on the Electrochemical Performance of Li4Ti5O12 Synthesized by Sol-Gel Method

This study aimed to prepare spinel carbon-coated Li4Ti5O12 (LTO/C) via sol-gel reaction and applied as a high-performance lithium-ion battery anode. The LTO powder was coated using various carbon sources, super P (SP), sugar and PVDF-assisted SP. The crystal structure, morphology, conductivity and electrochemical performance of the samples were examined using X-ray diffraction (XRD), Field Emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry/Charge-discharge (CV/CD), respectively. The XRD analysis results showed that the samples contain highly crystalline spinel LTO as the main phase and rutile as impurity. The FESEM image showed that SP covers the entire LTO surface more homogenous than sugar. However, sugar carbon makes roughness on the LTO surface. FTIR spectra showed that the coating using sugar and PVDF still contain hydrocarbon element. Electrochemical performance evaluations showed that SP carbon-coated-LTO possesses higher lithium diffusion and specific capacity than pure LTO, while sugar-coated-LTO shows the lowest specific capacity. Moreover, the SP carbon-coated-LTO sample high-rate capability has improved during full cell evaluation, delivering a discharge capacity of 249, 231, 211, 194, 58, and 23 mAhg-1 at the charge or discharge current density of 0.05, 0.1, 0.5, 1, 5, and 10 C, respectively.

Polymer-Based Optical Guided-Wave Biomedical Sensing: From Principles to Applications

Polymer-based optical sensors represent a transformative advancement in biomedical diagnostics and monitoring due to their unique properties of flexibility, biocompatibility, and selective responsiveness. This review provides a comprehensive overview of polymer-based optical sensors, covering the fundamental operational principles, key insights of various polymer-based optical sensors, and the considerable impact of polymer integration on their functional capabilities. Primary attention is given to all-polymer optical fibers and polymer-coated optical fibers, emphasizing their significant role in “enabling” biomedical sensing applications. Unlike existing reviews focused on specific polymer types and optical sensor methods for biomedical use, this review highlights the substantial impact of polymers as functional materials and transducers in enhancing the performance and applicability of various biomedical optical sensing technologies. Various sensor configurations based on waveguides, luminescence, surface plasmon resonance, and diverse types of polymer optical fibers have been discussed, along with pertinent examples, in biomedical applications. This review highlights the use of biocompatible, hydrophilic, stimuli-responsive polymers and other such functional polymers that impart selectivity, sensitivity, and stability, improving interactions with biological parameters. Various fabrication techniques for polymer coatings are also explored, highlighting their advantages and disadvantages. Special emphasis is given to polymer-coated optical fiber sensors for biomedical catheters and guidewires. By synthesizing the latest research, this review aims to provide insights into polymer-based optical sensors’ current capabilities and future potential in improving diagnostic and therapeutic outcomes in the biomedical field.

Superhydrophobic Modification of Atomic Layer Deposition Antireflection Aluminum Oxide Film: A Simple Evaporative Coating Technique.

The antireflective transmittance-enhancing films have important applications in solar cells and other applications due to their self-cleaning and high light transmittance. However, obtaining high transmittance, highly durable, and superhydrophobic surfaces in a simple and easily accessible way is still a challenge. A simple evaporative coating technique has been proposed that can be used to prepare antireflective superhydrophobic aluminum oxide films using 1H,1H,2H,2H-perfluoroalkyltriethoxysilanes. The results show that the contact angle of grass-like alumina increased from 99.5° to 155°. The surface energy of grass-like alumina decreased from 17.96 to 1.93 mN/m. The maximum value of light transmittance is close to 98%, and the average transmittance is above 95%. The films have excellent ultraviolet resistance and thermal stability along with relative mechanical and chemical stability. Meanwhile, this method has an excellent capacity for shape preservation. The relationships between the evaporation temperature and time and the light transmittance and hydrophobic angle of the films were also investigated together. This approach has the potential to be extended to large-scale industrial production.

Hydrocarbon‐Based Ionomer/PTFE‐Reinforced Composite Membrane Through Multibar Coating Technique for Durable Fuel Cells

AbstractFor cost reduction and environmental‐friendly manufacturing, it is highly demanded to replace the current perfluorinated sulfonic acid‐based membrane in polymer electrolyte membrane fuel cells (PEMFCs) with inexpensive and readily available hydrocarbon‐based (HC) membranes. However, HC membranes suffer from profound dimensional changes caused by swelling and shrinking during operation, especially in automotive applications. These changes lead to severe mechanical degradation and shorten the service life of PEMFC. Herein, a multibar coating system is developed to manufacture HC/polytetrafluoroethylene (PTFE) composite membrane. This system facilitates capillary‐rise infiltration with the aid of an optimal amount of residual alcohol solvent on the PTFE. To address compatibility issues between PTFE and HC‐ionomer solutions, the effects of residual alcohol solvent on tuning the PTFE surface are investigated by controlling systemic parameters and performing diverse mechanical, optical, and electrochemical measurements. Based on its enhanced mechanical toughness (≈30.04%) and superior impregnation properties, the constructed HC/PTFE composite membrane exhibited more than seven‐fold improvement in mechanical durability under repeated accelerated wet–dry conditions compared with an unsupported pristine HC membrane while also mitigating performance loss (≈5.84%).

Improving Stability Of Sitagliptin Using Hot Melt Coating Technique

Improving Stability Of Sitagliptin Using Hot Melt Coating Technique

Prevalence of camel trypanosomosis and herders’ knowledge, attitude, and practices towards the disease in the pastoral area of southern Ethiopia

BackgroundSurra is a parasitic disease caused by Trypanosoma evansi that threatens the health and productivity of camels. Despite its significant impact on camels in Ethiopia, surra has not received as much attention as diseases in cattle and other domestic animals. The objective of the study was to estimate the prevalence of surra, identify the potential risk factors and assess the traditional knowledge, attitude and practices of camel herders towards the disease.MethodsThe study used a parasitological and participatory epidemiological (PE) approach. Between February and July 2022, a total of 335 blood samples were collected from camels across three districts and tested using the buffy coat technique. The PE investigation involved six key informant groups consisting of 8 to 12 key persons, and used a semi-structured interview and various PE tools and principles.ResultThe study found that the prevalence of surra among examined camels was 3.9% (95% CI: 2.1–6.5). The prevalence was significantly higher in camels with a poor body condition score (BCS) (OR = 9.3; 95% CI: 1.8–47.5; p = 0.008) compared with camels with a good BCS. However, district, age, sex, and ethnicity had no effect on the prevalence of surra (p > 0.05). The study also found that the packed cell volume (PCV) was significantly lower (p < 0.0001) in parasitaemic animals (18.92 ± 2.63) than in aparasitaemic animals (25.13 ± 4.56). Camels with poor BCS (22.7 ± 3.5) had a significantly (p < 0.001) lower mean PCV than camels with good BCS (26.2 ± 5.0). The PE investigation showed that all the camel herders were well aware of surra, known locally as Dhukana. The clinical symptoms, the season of high incidence, routes of transmission, impact on production, and control methods were accurately described. Moreover, this study emphasized that surra is the primary disease affecting camel health and productivity.ConclusionThe study identified a moderate prevalence of surra in the research area. To reduce surra incidence and associated losses, enhancing veterinary services and providing support for proper camel husbandry practices in the region is recommended. Additionally, future studies should consider using more sensitive and specific techniques like serological and molecular assays, as this study relied on microscopy only.

Application of x-ray energy dispersive spectroscopy to analyzing the thickness of diamond-like carbon film deposited on the surface of microparticles.

Depositing diamond-like carbon (DLC) film is considered to be more promising for surface modification of microparticles. The development of reliable and precise measurement techniques for DLC coatings on microparticles is crucial for advancing research in this field. This paper introduces a methodological approach for quantifying the thickness of the film on microparticles. The thickness of the film is obtained by establishing the quantitative relationship between the energy lost when electrons pass through the film and the thickness of the film. The proposed method allows for the estimation of film thickness by assessing solely the elemental abundance on the particle surfaces.

Bovine trypanosomosis, vector distribution and infection rate in three districts of Gamo Zone, southwestern Ethiopia

African animal trypanosomosis is one of the main obstacles to the development of livestock and agricultural output in Ethiopia. It usually results in a severe, frequently fatal sickness, and the infected animals were more weakened as the disease progress and become unfit for work. A cross sectional study design was conducted from December 2021 to April 2022 with the aim of estimating the prevalence of trypanosome infection both in Glossina spp. and cattle, and to assess apparent density of Glossina spp. A total of 298 cattle were selected and examined for trypanosome by using buffy coat technique. The overall prevalence of bovine trypanosomosis was 19.1%; and two species of trypanosomes, T. congolense and T. vivax, were identified in the study area. The prevalence of T. congolense and T. vivax were 15.8% and 2.3%, respectively. The prevalence of trypanosomosis was significantly higher in adult animals (OR = 2.7; p < 0.05) than in younger cattle and poor body condition (OR = 3.18; p < 0.05) than medium body condition animals. The mean PCV value of infected animals was 14.3% (13.3–15.4) significantly lower than the non-infected animals 18.5% (17.8–19.2). Glossina pallidipes is the only tsetse species encountered in all the study areas. In total, 2992 flies were caught of which 90.8% belong to G. pallidipes and 9.2% were other biting flies. The overall apparent density of G. pallidipes was 20.1 F/T/D and other biting flies were 2.0 F/T/D. A total of 307 live Glossina pallidipes were dissected. The overall prevalence of Glossina pallidipes infection rate was 9.1% (95% CI = 5.9–12.4). The prevalence of G. pallidipes infection was significantly higher in Kucha district (OR = 3.2, χ2 = 2.6, p < 0.05) than the other two districts, Daramalo and Arba Minch Zuria. Also it was significantly higher in flies trapped from riverine forest areas (OR = 5.5, χ2 = 2.86, p < 0.05). Therefore, to reduce the impact of trypanosomosis and Glossina, vector control and treating infected cattle with prophylactic or chemotherapeutic drugs and active community participation can play a key role.

Synthesis of ZnO/CZTS Hetero-Structure Junction by Sol–Gel Spin Coating Technique

Pertaining to the optimal band alignment of ZnO and CZTS, the heterostructure was fabricated with CZTS as the absorber layer and ZnO being the buffer layer coated on the FTO glass for photovoltaic application. Both the layers were deposited by using sol–gel spin coating technique. The results revealed the polycrystalline nature of both ZnO and CZTS films with distinct phase formations, with ZnO exhibiting prominent diffraction peaks at 31.77, 34.31, 36.20, 47.47, and 56.59° corresponding to (100), (002), (101), (102), and (110) planes, while CZTS showed diffraction peaks at (112), (220), and (312) planes. ZnO thin films demonstrated high optical transmittance (∼90%) and exhibited a wide band gap of 3.24 eV, while CZTS demonstrated a band gap of 1.44 eV. AFM images showed smooth surfaces with favorable topography for both films. Hall effect measurements indicated differences in electrical properties of the two films. Raman spectroscopy revealed vibrational energy patterns in both films. Additionally, current–voltage (I-V) characteristics revealed the electrical behavior of the ZnO/CZTS heterojunction, shedding light on its diode characteristics under both dark and illuminated conditions. With CZTS’s ideal band gap of 1.44 eV, sunlight is easily absorbed, and ZnO’s high electron mobility makes it an effective layer for electron transport. As a result, power conversion efficiency can be improved.

Enhancing Lithium‐Ion Battery Performance with Alumina‐Coated Separators: Exploring the Potential of Different Alumina Particle Sizes, Coating Techniques, and Calendering

AbstractA range of techniques for the coating of high purity alumina (HPA) on porous polypropylene battery separators has been investigated. A slurry was prepared by dispersion of the alumina powder in acetone solvent and poly (vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP) as the binder to obtain an excellent adhesion to the membrane. Doctor blade, spin coating, and electro‐spin coating techniques were utilized to coat a thin layer of HPA on the separator that was followed up with a calendering step to improve compactness, decrease thickness and enhance adhesion. Furthermore, the effect of HPA particle size, distribution, and the use of a calendering step on coating thickness, compactness, and electrochemical performance were investigated using three HPA sources. The doctor blade technique was found to give the most uniform coating with the best mechanical properties and high‐temperature resistance. The coated separators were incorporated into lithium‐ion coin cells to evaluate the rate capability and long‐term cycling performance.

Hydroxyapatite coating of TiNi shape memory alloy via Electrophoretic Deposition (EPD)

ABSTRACT In this study, hydroxyl apatite (HA) as a bio-ceramic is coated on the TiNi shape memory. In this approach, Tri-ethanolamine and butanol were used as suspensions. To set up Electrophoretic Deposition (EPD) process, voltages of 20, 30 and 40 volts were applied on the cathode for 1-5 minutes. The sintering process was done in the Ar atmosphere for two hours at 800°C. SEM and XRD were used to investigate surface morphologies and phases. Obtained results showed that higher electrical currents led to generation of thicker coatings registering 105% and 12.3% improvement for weight and thickness after 6 minutes, respectively. Moreover, Transformation of HA to other calcium phosphate phases doesn’t happen at a sintering temperature of 800°C. Moreover, a uniform, homogeneous and crackles coating can be reached in the voltage of 30 volts at low sintering temperatures. This process can be utilized an alternative technique for bioactive coatings.

Edible Coatings: A Novel Approach to Extending the Shelf Life of Fruits and Vegetables

The rapid deterioration of fruits and vegetables during pre- and post-harvest conditions leads to significant post-harvest losses, affecting both quality and shelf life. Edible coatings have emerged as an effective solution to mitigate these issues, providing a protective layer that can be safely consumed as part of the food. Recently, there has been growing interest in using herbal extracts such as lemongrass, oregano, Aloe vera, Tulsi, mint, neem, cinnamon, and clove for edible coatings due to their beneficial properties. These herbal-based coatings have been shown to prevent water loss, control the ripening process and respiration rate, delay oxidative browning, and reduce microbial growth in various fruits and vegetables, including grapes, papaya, oranges, cucumbers, tomatoes, apples, and mangoes. Research indicates that these herbal edible coatings can extend the storage time of fresh produce to 15-35 days at low temperatures, compared to the 8-10 days for uncoated produce. The use of herbal extracts in edible coatings is a promising alternative to post-harvest chemical treatments, offering an innovative approach for commercial application. Edible coatings not only extend the post-harvest life of fresh produce but also improve food appearance and safety due to their environmentally friendly nature. They can be derived from animal or vegetable sources and may consist of proteins, lipids, polysaccharides, resins, or combinations thereof. Acting as barriers to moisture and gases, these coatings reduce food deterioration and enhance safety, often incorporating antimicrobial compounds. The advantages of edible coatings include reduced packaging waste, extended shelf life, and protection from environmental effects while maintaining the transfer of oxygen, carbon dioxide, moisture, aroma, and taste. Given the high market demand for nutritious fruits and vegetables and their perishable nature, edible coatings present an effective method to address post-harvest challenges, benefiting both consumers and the environment. This review discusses the components, benefits, and application techniques of edible coatings, focusing on their potential to enhance the shelf life and quality of fresh produce.

Polymer Coating Technique Using Surface-Forming Radicals

Polymer Coating Technique Using Surface-Forming Radicals

Printing and Coating Techniques for Scalable Organic Photovoltaic Fabrication.

Within recent years, there has been an increased interest towards organic photovoltaics (OPVs), especially with their significant device performance reaching beyond 19% since 2022. With these advances in the device performance of laboratory-scaled OPVs, there has also been more attention directed towards using printing and coating methods that are compatible with large-scale fabrication. Though large-area (>100 cm2) OPVs have reached an efficiency of 15%, this is still behind that of laboratory-scale OPVs. There also needs to be more focus on determining strategies for improving the lifetime of OPVs that are suitable for scalable manufacturing, as well as methods for reducing material and manufacturing costs. In this paper, we compare several printing and coating methods that are employed to fabricate OPVs, with the main focus towards the deposition of the active layer. This includes a comparison of performances at laboratory (<1 cm2), small (1-10 cm2), medium (10-100 cm2), and large (>100 cm2) active area fabrications, encompassing devices that use scalable printing and coating methods for only the active layer, as well as "fully printed/coated" devices. The article also compares the research focus of each of the printing and coating techniques and predicts the general direction that scalable and large-scale OPVs will head towards.

Advancement in Fabrication and Characterization Techniques of Nanocomposites.

Advancements in the field of materials research have unveiled numerous unparalleled features, such as mechanical properties, clinical advances, interfacial strengthening, and porosities, providing a wide range of applications. The employment of any material begins with fabrication and characterization, demanding expertise for the effective execution of the investigation. This review encompasses the details of the working principles of some significant and frequently used fabrication and characterization techniques for various material categories, including pellets and coatings. The discussion begins with techniques for fabricating materials for various applications. A brief overview of coating synthesis methods can provide intriguing information for researchers in the field of coating fabrication. The report highlights the portrayal of morphological and physiochemical analysis techniques, followed by the estimation of the elastic modulus using nanoindentation and dynamic modulus mapping testing for the materials. Additionally, the review covers theoretical models for observing the elastic moduli of the materials. The review depicts tribological investigations of the materials, aiming to provide insight into fretting wear, pin-on-disc, and microscratch testing. The fundamentals of electrochemical characterization are presented, including the appraisal of linear polarization and potentiodynamic polarization as well as electrochemical impedance spectroscopy. Furthermore, the magnetic behavior was examined by using a vibrating sample magnetometer (VSM), and the estimation of magnetic domains in the materials was conducted through magnetic force microscopy. Thus, the report suggests that readers, especially beginners, can gain a comprehensive understanding of the extensive prospects associated with the fundamental principles of material synthesis and characterization.

Scalable slot-die coated flexible supercapacitors from upcycled PET face shields.

Upcycling Covid19 plastic waste into valuable carbonaceous materials for energy storage applications is a sustainable and green approach to minimize the burden of waste plastic on the environment. Herein, we developed a facile single step activation technique for producing activated carbon consisting of spherical flower like carbon nanosheets and amorphous porous flakes from used PET [poly(ethylene terephthalate)] face shields for supercapacitor applications. The as-obtained activated carbon exhibited a high specific surface area of 1571 m2 g-1 and pore volume of 1.64 cm3 g-1. The specific capacitance of these carbon nanostructure-coated stainless steel electrodes reached 228.2 F g-1 at 1 A g-1 current density with excellent charge transport features and good rate capability in 1 M Na2SO4 aqueous electrolyte. We explored the slot-die coating technique for large-area coatings of flexible high-performance activated carbon electrodes with special emphasis on optimizing binder concentration. Significant improvement in electrochemical performance was achieved for the electrodes with 15 wt% Nafion concentration. The flexible supercapacitors fabricated using these electrodes showed high energy and power density of 21.8 W h kg-1 and 20 600 W kg-1 respectively, and retained 96.2% of the initial capacitance after 10 000 cycles at 2 A g-1 current density. The present study provides a promising sustainable approach for upcycling PET plastic waste for large area printable supercapacitors.

Laser Induced Damage Study of Dye Doped Polystyrene Films deposited in Glass Substrate by Dip Coating Technique

In the present work, the Laser-induced Damage Morphology of Dye-doped Polystyrene films is investigated. The focus is on the Front and Rear side Damage Morphology at two different Pulse Repetition Frequencies, namely 1 pps and 20 pps. For this experiment, films were deposited on both sides of Borosilicate Glass. It was found that at 1 pps, the front side film is damaged without affecting the glass, while the modified beam propagates through the glass to damage the rear side film. Dendrimer-like microstructures are found on both the front and rear sides of the damaged spots, along with pits and craters. At 20 pps frequency, the front side film is damaged, including damage to the glass, resulting in a large crater on the front surface. The morphological features were studied using Fresnel equations. Polymeric films were fabricated using the Dip Coating Technique, and Film thickness was evaluated using the Prism Coupling technique.

Biofilm contamination in confined space stations: reduction, coexistence or an opportunity?

The prolonged human permanence in confined environments in space, such as in the case of the International Space Station, has inadvertently fostered conditions leading to uncontrolled microbial proliferation on surfaces, known as biofilm. Biofilm presence represents a challenge in critical spacecraft systems, that can lead to contamination issues and systems loss of function due to biofouling phenomena. This scenario is further complicated by microgravity that has a controversial role on biofilm growth and formation. Biocontamination can be a limiting factor in human long-term mission in outer Earth orbit and an economic and health issue on ISS. This study addresses the pressing need for effective antimicrobial strategies against such resilient biofilms in confined environments where the usage of biocidal chemical compounds is strictly controlled due to toxicity dangers. Traditional methods can be complemented by advanced antimicrobial coatings techniques. A promising approach is based on the oxygen plasma as coating platform. The technology can be potentially extended to a wide range of antibiofilm agents (e.g., peptides, bacteriophages, nanoparticles, quorum sensing disrupting agents, etc.) and substrates (e.g., metal, plastic, ceramic) showing an exceptional flexibility. An alternative vision of the biofilm challenge can be inspired by the dual nature of biofilms, addressed as “good” or “bad” depending on the specific application. Indeed, biofilm have a great potential in closed systems as small space habitat (e.g., ISS) that can be inspired by their role in “large space habitat” as planet Earth itself. The replication of such a complex biological equilibrium is an open challenge.

Laser cleaning for inorganic thermal control coatings on aluminum alloys: Microstructure evolution and mechanical properties of substrate

Thermal control coatings are crucial materials in spacecraft thermal protection systems. Investigating efficient, convenient, and environmentally friendly removal techniques for thermal control coatings is essential for their application and development. This study developed a new removal technology for thermal control coatings using nanosecond pulse laser cleaning technology. The removal effect of the thermal control coating was studied, and the microstructure evolution and mechanical properties of the substrate were analyzed. The results showed that the coating was completely removed at 5.73 and 7.00 J/cm2, while at 8.28 J/cm2, in addition to the coating, approximately 5±1.1 μm of the substrate was also removed. In the completely cleaned state, micro-melting occurred on the substrate surface, and nanostructures appeared. At 5.73 and 7.00 J/cm2, the thickness of the remelted layer is 4±0.9 μm and 5.5±0.6 μm, respectively. The grains in the remelted layer exhibit significant refinement, accompanied by the observation of numerous subgrain boundaries. Additionally, the substrate surface exhibits tensile residual stress after laser cleaning. Attributed to the influence of the remelted layer, the surface hardness and tensile properties of the substrate are slightly improved after laser cleaning compared to manual grinding.

UV Nanoimprint Lithography—Impact of Coating Techniques on Pattern Quality

In this work, three different coating techniques are compared and their applicability for ultraviolet nanoimprint lithography (UV-NIL) is investigated. As UV-NIL is considered a suitable volume manufacturing production solution for various emerging applications, it is mandatory to consider environmental aspects such as operational energy use and material consumption as well as waste management. In this paper, spin coating, spray coating, and inkjet coating are used to coat both a high refractive index resin (n = 1.9) and a filler-free resin (n = 1.5), respectively. Variable Angle Spectroscopy Ellipsometry (VASE) was used to analyze the influence of different process parameters on the resin thickness as well as to compare the refractive index achieved from each coating technology. Finally, the applicability of the different coating methods for UV-NIL was investigated by imprinting the resin layers with different test structures. For the final imprints, the resolution, the surface roughness, and the pattern fidelity over 25 imprints was assessed using AFM. Finally, a comparison of the resin consumption and the process time was performed for each coating method.