Mohammad Reza Ketabchi

Optimization of ultrasound induced emulsification on the formulation of palm-olein based nanoemulsions for the incorporation of antioxidant β-D-glucan polysaccharides.

Polysaccharides of β-D-glucan configuration have well-known antioxidant activity against reactive free radicals generated from the oxidation of metabolic processes. In this study, β-D-glucan-polysaccharides extracted from Ganoderma lucidum were incorporated in palm olein based nanoemulsions which act as carrier systems to enhance the delivery and bioactivity of these polysaccharides and could be potentially useful for skin care applications. Initially response surface statistical design (Central Composite Design--CCD) was subjected to optimize the formulation variables of oil-in-water (O/W) nanoemulsions induced by ultrasound. The optimal formulation variables as predicted by CCD resulted in considerably improving the physical characteristics of ultrasonically formulated nanoemulsions by minimizing their droplet size, polydispersity index and viscosity. Moreover, the β-D-glucan-loaded nanoemulsions exhibited good stability over 90 days under different storage conditions (4 °C and 25 °C). The studies using palm olein based β-D-glucan-loaded nanoemulsion generated using ultrasound confirm higher antioxidant activity as compared to free β-D-glucan.

Sonosynthesis of cellulose nanoparticles (CNP) from kenaf fiber: Effects of processing parameters

This study optimizes the isolation parameters of cellulose nanoparticles (CNP) from kenaf fiber using central composite design (CCD). The extraction of CNP was based on three stages (i.e. 3 factors). The independent variables (factors) were NaOH dosage, amount of NaClO2, and sonication time, while the dependent variables (response) were CNP size quality and degradation temperature. Later, size quality responses were fitted with a quadratic polynomial model and degradation point responses with a 2-factor interaction model (2FI). The quadratic model and 2FI models resulted R2 values of 0.95 and 0.79, respectively. In addition, the morphological, thermal analysis, and Fourier transform infrared (FTIR) spectroscopy indicated a progressive removal of non-cellulosic constituents. Furthermore, transmission electron microscopy (TEM) confirmed reduction in fiber diameter from ~170 μm to ~100 nm. The optimal parameters for extraction of CNP were found to be 0.2 g of NaOH/4 g of fiber at first stage, 5 ml of NaClO2/4 g of fiber at the second stage, and 20 min of sonication period during the third stage. Moreover, obtained cellulose nanoparticles were thermally more stable at higher temperature.

Mechanical and thermal properties of polylactic acid composites reinforced with cellulose nanoparticles extracted from kenaf fibre

Different approaches have been attempted to use biomass as filler for production of biodegradable polymer composites. In this study, cellulose nanoparticles (CNP) extracted from kenaf fibres were used to produce polylactic acid (PLA) based biodegradable nanocomposites. CNP concentration was varied from 1–5 wt. % and blended with PLA using Brabender twin-screw compounder. Effects of CNP loading on the mechanical, thermal and dynamic properties of PLA were investigated. Studies on the morphological properties and influence of CNP loading on the properties of CNP/PLA nanocomposite were also conducted. The results show an adequate compatibility between CNP and PLA matrix. Moreover, addition of 3 wt. % of CNP improved the PLA tensile strength by 25%.

Nanohydroxyapatite synthesis using optimized process parameters for load-bearing implant

In this study, nanohydroxyapatite (NHA) was synthesized using calcium nitrate tetrahydrate and diammonium hydrogen phosphate via the precipitation method assisted with ultrasonication. Three independent process parameters: temperature (T) (70, 80 and 90°C), ultrasonication time (t) (20, 25 and 30 min), and amplitude (A) (60, 65 and 70%) were studied and optimized using response surface methodology based on 3 factors and 5 level central composite design. The responses of the model were analysed with the help of the particle size measured from field-emission scanning electron microscopy and Brunauer–Emmett–Teller (BET). The surface area of particle was measured with BET and the thermal stability of the powder was measured using thermogravimetric analysis. Finally, with the optimized process parameters obtained from the model, the NHA powder was synthesised and validated against the predicted value. The results show a good agreement with an average error 8% between the actual and predicted values. Moreover, the thermal stability and porosity of synthesized NHA was further improved after calcination. This improvement could be due to the removal of impurities from the NHA powder after calcination as indicated by the Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy.

Sonosynthesis of Microcellulose from Kenaf Fiber: Optimization of Process Parameters

ABSTRACT Green composites using cellulose fibers as a reinforcement material provide a sustainable and renewable alternative to petroleum-based polymers. However, controlling the usage of chemicals and processing parameters to extract the cellulose could be sometimes difficult. Therefore, this study aims to optimize the conditions for extracting the microcellulose from kenaf fibers using central composite design (CCD), a statistical tool in design of experiments. Three factors and three levels were chosen for carrying out the analysis. The design was based on sodium hydroxide (NaOH) dosage, Sodium Chlorite (NaClO2) dosage and sonication time as independent variables, while dependent variables were the fiber size and degradation point. Later, size responses were fitted using quadratic polynomial model and degradation responses using 2-factor interaction model (2FI). The R2 values of 0.89 and 0.83 were obtained for the quadratic and the 2FI model, respectively. Further, surface morphology, thermal analysis, Fourier transform infrared (FTIR) spectroscopy and X-Ray diffraction (XRD) were also used for design validation. Optimal parameters for microcellulose extraction were found to be 0.15 g of NaOH at first stage, 4.6 mL of NaClO2 at second stage, and 10 min of sonication during third stage.

Reinforced Natural Rubber Nanocomposites: Next Generation Advanced Material

Undoubtedly, the advanced green composites have replaced the use of many conventional mineral based or naturally occurring single materials in wide spread industrial applications including aerospace, automotive, locomotive, chemical and biomedical industries. Specially, the reinforced natural rubber nanocomposites have drawn the attention of the research as well as industrial worlds greatly because of their superior thermal and mechanical properties without major compromise of transperancy/clarity. This chapter presents the preparation of rubber nanocomposites, characterization techniques, and the properties of the developed nanocomposites such as mechanical and thermal characteristics along with the recent applications of these nanocomposites. The rubber nanocomposite (RNC) have found their niche commercially in the tyre and sports industries providing reduced weight and energy dissipation, and enhanced air retention to the applied products.

Rubber/Nanoclay Composites: Towards Advanced Functional Materials

In the recent years, nanoclay composites have drawn the attention of the researchers as well as manufacturers greatly because of their excellent capacity to withstand thermal and mechanical stress without significant compromise of impact and/or clarity. This chapter presents the preparation of nanoclay composites, characterization techniques, and the properties of the developed composites such as mechanical and thermal characteristics along with the recent applications of these nanocomposites. The rubber nanocomposite (RNC) and clay polymer nanocomposite (CPNC) have found their niche commercially in the tyre and sports industries providing reduced weight and energy dissipation, and enhanced air retention to the applied product.

Critical Concerns on Manufacturing Processes of Natural Fibre Reinforced Polymer Composites

For the last one decade, natural fibre reinforced polymer composites have attracted a considerable attention around the globe due to their inherent performances such as biodegradability, recyclability and accessibility. A suitable manufacturing process is required to develop a promising reinforced polymer composite accordingly. It has been observed that the matrices, materials and chemical, physical, mechanical and thermal properties of both the hosting polymer and the employed natural fibres play the most important role in choosing an appropriate processing technique. Recently, valuable studies have been carried out in this field, as engineers have tried different processing methods and conditions. In this chapter and later a brief introduction to biomass materials, a comprehensive review has been done over the latest biocomposite processing techniques. Beneficial solutions and treatment methods have been addressed. Furthermore, a combination of both traditional and modern processing technique has been recommended for future studies.