Optical properties of pure and doped poly(vinyl chloride) (PVC) films, prepared by using casting technique, with different nanosize zinc oxide (ZnO) concentrations (1–20) wt% have been studied. Parameters such as extinction coefficient, refractive index, real and imaginary parts, Urbach energy, optical conductivity, infinitely high frequency dielectric constant, and average refractive index were studied by using the absorbance and transmittance measurement from computerized UV-visible spectrophotometer (Shimadzu UV-1601 PC) in the spectral range 200–800 nm. This study reveals that the optical properties of PVC are affected by the doping of ZnO where the absorption increases and transmission decreases as ZnO concentration increases. The extinction coefficient, refractive index, real and imaginary parts, infinitely high frequency dielectric constant, and average refractive index values were found to increase with increasing impurity percentage. The Urbach energy values are found to be decreasing with increasing ZnO concentration. The optical conductivity increased with photon energy after being doped and with the increase of ZnO concentration.

Spray drying is a widely utilized method in the pharmaceutical, food, and chemical industries for producing powdered products. However, a recurring challenge in this process is the persistent issue of surface stickiness, which diminishes product quality and operational efficiency. This paper examines the current trend of surface stickiness in spray drying and explores physicochemical approaches to mitigate fouling and enhance overall productivity. The stickiness is often attributed to the formation of lumps on drying chamber surfaces, adversely affecting the final product’s characteristics. The paper reviews existing literature on the causes and consequences of surface stickiness, emphasizing the need for innovative strategies to address this challenge. Promising solutions are emerging in the form of physicochemical approaches, involving the modification of drying chamber materials, applying different operational approaches, optimization of process parameters, and the introduction of drying aids. Researchers aim to alter the surface properties of drying chamber components, minimizing particle and wall deposition to prevent surface stickiness. The present review also delves into the impact of various physicochemical factors on spray drying performance, including temperature, airflow dynamics, and formulation composition. Understanding these factors is crucial for developing effective strategies to reduce fouling and enhance overall productivity in spray drying processes. This review sheds light on the prevalent issue of spray drying surface stickiness and underscores the significance of physicochemical approaches in overcoming this challenge. By addressing stickiness issues through innovative strategies, researchers and industry professionals can improve the efficiency and reliability of spray drying processes, ultimately elevating the quality of powdered products in pharmaceutical, food, and chemical manufacturing.

Presently, plant oils which contain high percentage of linoleic acid 1 are perceived to be a viable alternative to mineral oil for biolubricant applications due to their biodegradability and technical properties. In order to get biodegradable lubricant, triester derivatives compounds (1–5) were synthesized and characterized. The processes involved were monoepoxidation of linoleic acid 2, oxirane ring opening 3, esterification 4 and acylation 5. The structures of the products were confirmed by FTIR, ¹H and ¹³C-NMR and LC-MS. The results that showed lowest temperature properties were obtained for triester 5, with a pour point value (PP) of -73°C, highest onset temperature (260°C) and lowest volatility at 0.30%. Viscosity index (VI) increased for the ester’s synthetic compounds (2, 3, 4, 5), while the PP decreased. This behavior is the result of the increase of the chain length of the branching agents. Triester based linoleic acid has improved properties such as low-temperature and tribological properties. These results will make it feasible for plant oil to be used for biolubricants, fuels in chain saws, transmission oil and brake fluid.

Clinacanthus nutansis widely grown in tropical Asia and locally known “belalai gajah” or Sabah snake grass. It has been used as a natural product to treat skin rashes, snake bites, lesion caused by herpes, diabetes, fever, and cancer. Therefore, the objectives of this research are to determine the maximum yield and time of exhaustive flavonoids extraction using Peleg’s model and to evaluate potential of antiproliferative activity on human lung cancer cell (A549). The extraction process was carried out on fresh and dried leaves at 28 to 30°C with liquid-to-solid ratio of 10 mL/g for 72 hrs. The extracts were collected intermittently analysed using mathematical Peleg’s model and RP-HPLC. The highest amount of flavonoids was used to evaluate the inhibitory concentration (IC₅₀) via 2D cell culture of A549. Based on the results obtained, the predicted maximum extract density was observed at 29.20 ± 14.54 hrs of extraction (texhaustive). However, the exhaustive time of extraction to acquire maximum flavonoids content exhibited approximately 10 hrs earlier. Therefore, 18 hrs of extraction time was chosen to acquire high content of flavonoids. The best antiproliferative effect (IC₅₀) on A549 cell line was observed at 138.82 ± 0.60 µg/mL. In conclusion, the flavonoids content inClinacanthus nutanswater extract possesses potential antiproliferative properties against A549, suggesting an alternative approach for cancer treatment.