Chemical and Materials Sciences: Research Findings Vol. 4

Development and Characterisation of PLA-Nanofiber Scaffolds with Cinnamon Oil-Lanolin Emulsions for Antibacterial Human Skin Grafts

Wed, 18 Jun 2025 00:00:00 +0000

Tissue engineering has emerged as an innovative solution to develop alternatives to traditional grafts, particularly with scaffolds. These structures, intended for use as skin grafts, must meet specific requirements, including biocompatibility, a porous structure, mechanical properties similar to human skin, and antibacterial capabilities. The interest in tissue engineering is growing in the scientific and medical communities, as it can solve actual problems regarding donor tissues, wound healing and drug delivery systems. Nanofibers are gaining relevance in this topic thanks to their excellent mechanical properties and similarities to the human skin.

Polylactic acid (PLA) as polymer and Hexafluoro isopropanol (HFIP) as solvent, both from Sigma-Aldrich, were used in the membrane formation. This project has explored how combining the nanofibers’ membranes created of PLA, made by electrospinning, with a dissolution of lanoline and cinnamon essential oil not only imitates the human skin, as it was demonstrated in a later project, but also obtains an antibacterial character. Analytical techniques such as a spectrophotometer, an electrokinetic analyser, a scanning electron microscope, a Fourier transform infrared spectroscope, and an optical tensiometer were employed.

Results confirmed successful integration and migration of the cinnamon oil, with antibacterial efficacy achieved against specific bacterial strains, as hypothesised. Notably, scaffolds composed of seven layers exhibited migration behaviour closely aligned with theoretical expectations. Additionally, it has also been found that the scaffold presents an antibacterial character when analysing the Escherichia coli bacteria.

In conclusion, among all the analytical methods used, the drug delivery test and the FT-IR test have been the most useful in order to determine the migration of the emulsion. With the drug delivery test, it could also be determined how the migration of LAT changes depending on the number of layers used to form the scaffolds.

A Synthesis and Characterisation of Activated Carbon-incorporated Chitosan Composite for Harnessing Hexavalent Chromium Adsorption

Hunge Sudhir — Wed, 18 Jun 2025 00:00:00 +0000

Industrial effluent is a complex aqueous matrix comprising hazardous substances like phenols and toxic organics, often mixed with nutrients, suspended solids and multiple pollutants. Its constituents vary with industry, making it a significant environmental challenge requiring targeted treatment solutions. In view of their toxicity, non-biodegradability and persistent nature, their removal becomes an absolute necessity. Hexavalent chromium metal is one of the carcinogenic pollutants in the environment and is frequently present in wastewater from various industrial units. This chapter reports the characterisation and use of chitosan-coated activated carbon derived from the bark of Pongamia pinnata (CCPPAC) as a potential adsorbent for the removal of hexavalent chromium from aqueous solution. SEM analysis proved the mesoporous nature of the material under investigation. The batch experiment was carried out to study the effect of significant process parameters such as pH, contact time, adsorbent doses and initial Cr (VI) concentration. The maximum adsorption efficacy for Cr(VI) removal by CCPPAC was found at pH 4.5, 5 gm/lit of adsorbent dose and 140 min contact time. Under optimum conditions, 96% Cr (VI) was removed from aqueous solution. This investigation verifies that CCPPAC, a mesoporous material, can be successfully used as an excellent sorbent material for the removal of hexavalent chromium from contaminated water and thus can be applied in wastewater treatment. In this study, the activated carbon derived from the bark of the Pongamia pinnata tree and surface was successfully coated with chitosan and characterised employing FTIR and SEM studies. The newly developed CCPPAC high porous structure and excellent surface area.

Natural Radioactivity in the Reinforced Cement Concrete Building Materials Used in the Southern Districts of Manipur, India

B. Arunkumar Sharma, A. Ronibala Devi — Wed, 18 Jun 2025 00:00:00 +0000

This study aimed to measure the amount of natural radiation found in different building materials used in the southern parts of Manipur, India. These materials include cement, concrete, sand, and bricks, which are commonly used in Reinforced Cement Concrete (RCC) construction.

The study looked at the levels of three naturally occurring radioactive elements: Radium-226 (²²⁶Ra), Thorium-232 (²³²Th), and Potassium-40 (⁴⁰K).

Observations:

Portland cement had average radioactivity levels of 40 BqKg^-1for ²²⁶Ra, 38 BqKg^-1for ²³²Th, and 1644 BqKg^-1for ⁴⁰
Concrete had 34 BqKg^-1for ²²⁶Ra, 61 BqKg^-1for ²³²Th, and 547 BqKg^-1for ⁴⁰
Sand had 46 BqKg^-1for ²²⁶Ra, 112 BqKg^-1for ²³²Th, and 1580 BqKg^-1for ⁴⁰
Bricks had 31 BqKg^-1for ²²⁶Ra, 148 BqKg^-1for ²³²Th, and 1388 BqKg^-1for ⁴⁰

The study also discussed how this radiation might affect people. The average annual radiation dose people might receive from these materials is about 1.7 millisieverts per year (mSvy^-1), which may vary between 0.8 and 3.0 mSvy^-1.

The gamma radiation index, which helps to estimate the safety of the materials, was on average 1.0 (ranging from 0.5 to 1.9). A value higher than 1 could suggest higher radiation exposure.

Finally, the extra yearly radiation caused specifically by these building materials ranged from 0.1 to 2.3 mSvy^-1, with an average of 1.0 mSvy^-1.

Microstructure Formation Mechanism for Ca(Zr,Hf)\(O_3\) /(Zr,Hf)\(O_2\) by Rapid Solidification Process

Shunkichi Ueno — Wed, 18 Jun 2025 00:00:00 +0000

The binary phase diagram of ZrO₂-CaO includes the eutectic of the CaZrO₃ phase and the CaO-stabilised ZrO₂ phase. In this study, Ca(Zr_1-xHf_x)O₃/(Zr_1-xHf_x)O₂ (x=0, 1/3, 0.5) eutectic film was prepared by rapid solidification process using high power laser irradiation method. CaCO₃ of 99.9% purity, ZrO₂ and HfO₂ of 98% purity powders were used as starting materials. The coating process was performed in an electric furnace at 1300°C. Solidified film with fine lamellar structure was obtained. When the Zr site was substituted with Hf, the lamellar spacing increased with the amount of substitution. Separate from the solidification film prepared by laser irradiation, a rapidly solidifying sample with x=0.1 composition was prepared using an optical floating zone apparatus. The melt of the sample was free-falling onto a copper dish. No film-like rapidly solidified sample was obtained. Hf ion was homogeneously solid-soluble in both phases of CaZrO₃ and ZrO₂. This study attempted to prepare eutectic solidification coatings for CaHfO₃/HfO₂ eutectic under the same conditions as for CaZrO₃/ZrO₂ eutectic coatings. No eutectic structure was obtained.

\(Gd^{3+}\) / \(Sm^{3+}\) Co-doped Lead Alumino-borophosphate Glasses: Synthesis and Characterization

Randev Singh — Wed, 18 Jun 2025 00:00:00 +0000

A series of multicomponent (Lead, Sodium, Aluminum and Zinc) Borophosphate glasses doped with Sm³⁺ and Gd³⁺ions with molar composition xPbO - (40-0.5x)B₂O₃- (40-0.5x)P₂O₅- 9.0Na₂O - 1.0Al₂O₃- 9.6ZnO - 0.2Sm₂O₃- 0.2Gd₂O₃ (x = 10, 15, 20, 25, 30, 35) was synthesized using the conventional melt quenching technique. The amorphous nature of these glasses was confirmed with XRD studies. The density measurement was done by using Archimedes' principle with the help of a KEROY mechanical balance. The density measurements show a regular and systematic increase in density from 3.6008 g/cm³ to 4.6397 g/cm³ with an increase in PbO content in exchange for the two glass formers. The optical absorption spectra of these glasses were recorded by using a UV/visible spectrometer (Shimadzu, Japan) in the wavelength range of 200–1100 nm at normal incidence. The values of Eg for the glass samples of the series decrease with an increase in PbO content. The synthesised samples may find applications for energy converters, X-ray dosimeters, and radiation shielders/sensors.

Effect of Red Mud Reinforcement on the Corrosion Resistance of Aluminium 6061 Metal Matrix Composites in Sea Water

P.V. Krupakara, H.R. Ravikumar — Wed, 18 Jun 2025 00:00:00 +0000

Corrosion can affect the metal matrix composite in a variety of ways, which depend on its nature and the environmental conditions prevailing. The red mud content in aluminium 6061 alloy plays a significant role in the corrosion resistance of the material. A lot of research has been done on corrosion characteristics of particulate reinforced metal matrix composites, but no concrete investigation has been made on red mud particulate reinforced with aluminium alloy 6061 metal matrix composites. The present investigation aims to evaluate the corrosion properties of red mud particulate reinforced aluminium 6061 metal matrix composites. Red mud particulates reinforced varying from two to six per cent by weight in steps of two per cent under dry conditions. Composites are prepared by liquid melt metallurgy techniques using the vortex method. Castings are cut, turned and shaped into the required size to prepare the specimens for evaluation of the corrosion properties. Corrosion tests were conducted at room temperature (23⁰ °C) using the conventional weight loss method according to ASTM G69-80. The corrodent used for the tests was Arabian Sea water collected from Malpe beach, Udupi District, Karnataka. Weighed specimens dipped in seawater. Specimens were taken out at every 24 hours intervals up to 96 hours. Four specimens for each condition and time were immersed in the corrosive solutions. In all 16 specimens of matrix and composites were immersed in the corrodent. Corrosion rates were calculated using the formula 534DAT/W. In each case, the corrosion rate in seawater decreases with an increase in exposure time for matrix and metal matrix composites due to passivation induced by aluminium. Therefore, incorporating red mud particulates in Aluminium alloy 6061 enhances corrosion resistance, making it a more effective material for marine and other corrosive environments.

Electrochemically Activated Insertion of Sulphur to Organic Compounds from Heterogenous Solution at Sacrificial Copper Anode

Harpreet Kaur, Shilpa Rani — Wed, 18 Jun 2025 00:00:00 +0000

Two new thioates of copper with formula L_(-2H)S₂Cu (where L_(-2H) = 1,10-phen - 2H or 2,2'-bipy - 2H) have been synthesised by electrolysing the heterogeneous solution of sulphur and an organic compound. The process proceeds by in-situ insertion of sulphur into the organic compound (1,10-phenanthroline and 2,2'-bipyridyl), followed by preparation of the complex in a single step. Tetrabutylammonium chloride has been used as a supporting electrolyte and acetonitrile as a solvent in these systems. The resulting solution was electrolysed at a sacrificial copper anode and an inert platinum cathode by passing a current of 6 mA. The products were identified with elemental analysis data, UV-Visible spectroscopy, FT-IR spectra and mass spectral data. The present work represents a single-step, direct route for the synthesis of copper(II) thiolates.

Green Synthesis, Morphological and Magnetic Studies of Pure Nickel and Cobalt-doped Nickel Oxide/ Nickel Hydroxide (Co\(_x\)Ni\(_{1-x}\)O//Ni (OH)\(_2\)) Nano Composites

Wed, 18 Jun 2025 00:00:00 +0000

Magnetic Ni-Co Nano particles are gaining significant attention due to their unique physical, chemical, and magnetic properties. These properties have made them ideal candidates for several magnetic applications. In this study, a significant effort has been made to provide a deep analysis of the highly relevant and promising synthesis method (i.e., green synthesis by carambola fruit Juice modified oxalate method) while focusing on the possibility of modulating the morphology, particle size/ particle size distribution, and crystallinity of the final nanomaterial. These parameters have a direct influence on the magnetic performance of the Nanomaterial. The general properties and particle morphology of nickel oxide / Nickel hydroxide NPs can be modified by the introduction of impurity atoms or ions. Nano-sized nickel oxide/nickel hydroxide nanocomposites were obtained from the thermal decomposition of single molecular precursors synthesised by a modified oxalate route using Carambola fruit juice as a precipitating agent. The compositional and morphological variations were studied by introducing cobalt as an impurity ion at different w/w% fractions (0, 0.1, 0.3, 0.5, 1, 3, 5.0, 40.0, and 50.0%) into the microstructure of the nickel oxide/hydroxide. The precursors were characterised by FT─IR to identify the functional groups present in the precipitate formed, while TGA/DTG was carried out to study the decomposition profile and the decomposition temperature of the precursors. The precursors decomposed at 400 °C. PXRD characterised the decomposition products to determine the phases, and SEM/TEM to determine the morphology. The results revealed that Pure Nickel Oxide (NiO) and, Cobalt-doped Nickel Oxide/ nickel hydroxide (Co_xNi_1-xO//Ni (OH)₂) Nano composites have been synthesized and the synthesized samples have exhibited three distinct morphologies (porous face-centered cubic nano rods, rough and discontinuous (Co_xNi_1-xO/Ni(OH)₂) composite and, smooth and continuous mix spherical/cuboidal mixed morphological phase of (NiO/CoO). The morphology of the NPs varied with the introduction of the dopant atoms and with an increase in the concentration of dopant atoms in the composite. The EDS results showed that only nickel, cobalt, Oxygen, carbon, and hydrogen were present in the decomposed samples. Magnetic studies using vibrating sample magnetometry revealed superparamagnetic properties that correlated strongly with particle size, shape, and morphology. Observed values of retention (4.50 × 10⁻³ emu/g) and coercivity (65.321 Oe) were found for 0.5 w/w% corresponding to impregnated porous nanorods of Co-doped NiO, and retention (9.03 × 10⁻³ emu/g) and coercivity (64.341 Oe), for X = 50.0%, corresponding to an aggregate network of a Nano spherical/cubic CoO/NiO mixed phase. Magnetic properties within this range are known to improve the magnetic memory and hardness of the magnetic materials. Therefore, the synthesised Cobalt-doped Nickel Oxide/ nickel hydroxide (Co_xNi_1-xO//Ni (OH)₂) Nano composites have potential applications in Magnetic memories and the hardness of magnetic materials.

Doping of Poly (3,4-ethylenedioxythiophene) (PEDOT) by FeCl\(_3\) and CSA

Ashish B. Chourasia, Deepali S. Kelkar — Wed, 18 Jun 2025 00:00:00 +0000

Academic and industrial researchers have focused on developing conducting polymers that are stable in their conductive state during application, easy to process, and economical to produce. Conducting polymers, often referred to as synthetic metals, have garnered significant attention since Shirakawa and colleagues discovered that polyacetylene can achieve exceptionally high electrical conductivity. The study aims to investigate the structural, electrical, and thermal properties of the resulting material. Poly(3,4-ethylenedioxythiophene) (PEDOT) has been chemically synthesised using 3,4-ethylenedioxythiophene (EDOT) (Aldrich) as a monomer in an aqueous solution with FeCl₃ as the oxidant. Doping of PEDOT using Camphor Sulfonic Acid (CSA) and FeCl₃ was carried out separately for a 5-hour duration, and the resulting material was then subjected to various analyses. To detect structural changes after doping, infrared spectroscopic analysis, wide-angle x-ray diffraction analysis have been carried out. Elemental analysis (C, H, N, S, and O) of undoped and all doped samples was carried out using Thermofinniagn, Italy, model FLASH EA 1112 series, and ICP - Atomic Emission Spectroscopy made by Jobin Yvon, France, model JY Ultima–2 was used to detect Fe contents in all samples. PEDOT has been chemically synthesised by oxidation, coupling with FeCl₃ as an oxidation reagent, and then treated with hydrazine to de-dope the prepared polymer. For complete confirmation, FTIR spectroscopy studies were carried out. The results of thermal analysis show that after doping PEDOT with FeCl₃, the glass transition temperature (Tg) value decreases. It is observed that in the case of FeCl₃-doped PEDOT, sulfur contents decrease while Fe contents increase compared to undoped PEDOT, indicating that it is quite likely that the S of PEDOT is getting replaced by Fe after doping with FeCl₃. The utilization of FTIR analysis verified the successful synthesis of PEDOT, as well as the desired doping with FeCl₃ and CSA. The crystal structure of the samples was analyzed using XRD, revealing modifications following doping. Additionally, the XRD results allowed for the calculation of sample crystallinity, which increased after doping with FeCl₃ but decreased after doping with CSA. Using the four-probe method, electrical conductivity (σ) measurements were obtained, showing a significant increase in conductivity after doping with both FeCl₃ and CSA, with the undoped sample having a conductivity of 3.41X10-3S/cm. A plot of Log σ versus 1/T was created, revealing that the undoped PEDOT had metallic characteristics above 308 K, while both doped samples displayed semiconducting behavior in the temperature range from ambient to 383̊ K. An indigenously designed apparatus similar to Lee's method was used for measuring the thermal conductivity, which revealed that all samples exhibited comparatively small thermal conductivity values. However, these values were found to increase upon doping and with a temperature rise. The thermal conductivity of all the samples was also measured using the FOX 50 instrument, a commercially available apparatus for the measurement of thermal conductivity. The values of thermal conductivity of all the samples were found to match the laboratory-designed instrument.

Optoelectronic and Nanomechanical Properties of Sputtered Cu\(_3\)N Thin Films: A Versatile Material for Sustainable Energy Applications

Wed, 18 Jun 2025 00:00:00 +0000

The pursuit of efficient, profitable, and eco-friendly materials is one of the undisputed pillars of optoelectronic devices research from its inception to the present day. Some materials, such as copper nitride (Cu₃N), show great promise for promoting sustainable technologies. Cu₃N is a metastable semiconductor, as it decomposes into metallic copper (Cu) and nitrogen (N) when heated above 300 °C. This chapter presents the fabrication of Cu₃N by reactive radio-frequency magnetron sputtering using a pure nitrogen (N₂) environment to achieve quality Cu₃N thin films. The film-deposition process was carried out using a single-chamber sputtering system from MVSystem LLC (Golden, CO, USA). Both substrate temperature and gas working pressure are evaluated to determine their impact on the optoelectronic properties. The aim is to highlight the absorption capability and the nanomechanical properties of that nitride binary compound. Several characterisation techniques, including X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), Raman spectroscopy, scanning electron microscopy (SEM), nanoindentation, and photothermal deflection spectroscopy (PDS), are used for such purposes. The results indicate the importance of both the substrate temperature and the working pressures to achieve a close to stoichiometric Cu₃N material (Cu/N ratio ≈ 3) with the (100) plane as preferred orientation. Such stoichiometry begins to decrease as the substrate temperature increases. This demonstrates the clear influence of these sputtering deposition conditions. This fact is attributed to the nitrogen re-emission that happens at high substrate temperatures. In addition, Raman microscopy confirms the formation of the Cu-N bonds within the 628-637 cm⁻¹ range. On the other hand, both the substrate temperature and the working pressure significantly influence the film hardness and the grain size, thus affecting the elastic modulus. Optical properties reveal tunable band gap energies, refractive indexes and Urbach energies as functions of the deposition parameters. These findings underscore the potential of Cu₃N thin films in sputtering different energy applications such as photovoltaic, photodetectors and even hydrogen storage. This is mainly due to the tunable and advantageous properties of Cu₃N and its resilience against defects. It can be considered that this research may pave the way for future advances in efficient and sustainable energy technologies.