Feldspar Reinforced Polypropylene Composites: The Effect Of Compatibilizers, Silane Coupling Agent And Multi-Walled Carbon Nanotube On Mechanical, Thermal And Morphological Properties

Di dalam kajian ini, felspar telah dipilih sebagai bahan pengisi untuk pelbagai pembebanan pengisi iaitu 10 wt%, 20 wt%, 30 wt%, dan 40 wt% feldspar terisi komposit polipropilena telah disediakan menggunakan teknik pencampuran leburan.. Seterusnya, kepingan komposit dihasilkan menggunakan penekan panas. Ujian tensil telah dilakukan menggunakan mesin pengujian Instron. Didapati kekuatan tensil dan % pemanjangan pada takat putus berkurang manakala modulus tensil dan kekerasan meningkat dengan peningkatan pembebanan pengisi. In this research, feldspar was chosen as a filler material where different filler loading viz. 10 wt%, 20 wt%, 30 wt%, and 40 wt% feldspar filled Polypropylene (PP) composites were prepared using melt mixing technique and then the composite sheet was produced using Hot Press. Tensile test was carried out using an Instron universal testing machine where the tensile strength and elongation at break decrease but tensile modulus and hardness increase as the filler loading is increased. Compatibilizers improved the processability and compatibility of the feldspar/PP composites

Review of the Common Deposition Methods of Thin-Film Pentacene, Its Derivatives, and Their Performance

Pentacene is a well-known conjugated organic molecule with high mobility and a sensitive photo response. It is widely used in electronic devices, such as in organic thin-film transistors (OTFTs), organic light-emitting diodes (OLEDs), photodetectors, and smart sensors. With the development of flexible and wearable electronics, the deposition of good-quality pentacene films in large-scale organic electronics at the industrial level has drawn more research attention. Several methods are used to deposit pentacene thin films. The thermal evaporation technique is the most frequently used method for depositing thin films, as it has low contamination rates and a well-controlled deposition rate. Solution-processable methods such as spin coating, dip coating, and inkjet printing have also been widely studied because they enable large-scale deposition and low-cost fabrication of devices. This review summarizes the deposition principles and control parameters of each deposition method for pentacene and its derivatives. Each method is discussed in terms of experimentation and theory. Based on film quality and device performance, the review also provides a comparison of each method to provide recommendations for specific device applications

Taguchi design optimization of machining parameters on the CNC end milling process of halloysite nanotube with aluminium reinforced epoxy matrix (HNT/Al/Ep) hybrid composite

This paper introduces the application of Taguchi optimization methodology in optimizing the cutting parameters of end-milling process for machining the halloysite nanotubes (HNTs) with aluminium reinforced epoxy hybrid composite material under dry condition. The machining parameters which are chosen to be evaluated in this study are the depth of cut (d), cutting speed (S) and feed rate (f). While, the response factors to be measured are the surface roughness of the machined composite surface and the cutting force. An orthogonal array of the Taguchi method was set-up and used to analyse the effect of the milling parameters on the surface roughness and cutting force. The result from this study shows that the application of the Taguchi method can determine the best combination of machining parameters that can provide the optimal machining response conditions which are the lowest surface roughness and lowest cutting force value. For the best surface finish, A1–B3–C3 (d = 0.4 mm, S = 1500 rpm, f = 60 mmpm) is found to be the optimized combination of levels for all the three control factors from the analysis. Meanwhile, the optimized combination of levels for all the three control factors from the analysis which provides the lowest cutting force was found to be A2–B2–C2 (d = 0.6 mm, S = 1000 rpm, f = 40 mmpm)

Chitosan/poly vinyl alcohol/graphene oxide based ph-responsive composite hydrogel films: drug release, anti-microbial and cell viability studies

The composite hydrogels were produced using the solution casting method due to the non-toxic and biocompatible nature of chitosan (CS)/polyvinyl alcohol (PVA). The best composition was chosen and crosslinked with tetraethyl orthosilicate (TEOS), after which different amounts of graphene oxide (GO) were added to develop composite hydrogels. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle was used to analyze the hydrogels. The samples were also evaluated for swelling abilities in various mediums. The drug release profile was studied in phosphate-buffered saline (PBS) at a pH of 7.4. To predict the mechanism of drug release, the data were fitted into kinetic models. Finally, antibacterial activity and cell viability data were obtained. FTIR studies revealed the successful synthesis of CS/PVA hydrogels and GO/CS/PVA in hydrogel composite. SEM showed no phase separation of the polymers, whereas AFM showed a decrease in surface roughness with an increase in GO content. 100 µL of crosslinker was the critical concentration at which the sample displayed excellent swelling and preserved its structure. Both the crosslinked and composite hydrogel showed good swelling. The most acceptable mechanism of drug release is diffusion-controlled, and it obeys Fick’s law of diffusion for drug released. The best fitting of the zero-order, Hixson-Crowell and Higuchi models supported our assumption. The GO/CS/PVA hydrogel composite showed better antibacterial and cell viability behaviors. They can be better biomaterials in biomedical applications

Development of antibacterial, degradable and pH-responsive chitosan/guar gum/polyvinyl alcohol blended hydrogels for wound dressing

The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels’ crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spec-troscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker–Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R2 = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications

Electrospun nanofiber and cryogel of polyvinyl alcohol transdermal patch containing diclofenac sodium: Preparation, characterization and in vitro release studies

Transdermal drug delivery systems (TDDS) have drawn more interest from pharmaceutical scientists because they could provide steady blood levels and prevent the first-pass metabolism over a longer period. Polyvinyl alcohol (PVA) has been widely used in this application due to its biocompatibility, non-toxicity, nanofiber and hydrogel-forming ability. Despite those benefits, their morphology would easily be destroyed by continuous water absorption and contribute to burst drug release due to its hydrophilicity. The aim of this study was to prepare the diclofenac sodium (DS)-medicated dual layer PVA patch using a combination of electrospinning and cryogelation (freeze–thaw) methods to improve the physicochemical properties and drug compatibility and investigate the release of the DS-medicated dual layer PVA patch. Morphological observations using scanning electron microscopy (SEM) verified the polymer-polymer interaction between both layers, whereas Fourier transform infrared (FTIR) spectroscopy has demonstrated the compatibility of DS in PVA matrix up to 2% w/v of PVA volume. The DS loads were found amorphously distributed efficaciously in PVA matrix as no visible spectra of DS–PVA interaction were detected. The DS-medicated dual layer PVA patch with a thicker nanofiber layer (3-milliliter running volume), three freeze–thaw cycles and 2% DS loading labeled as 2%DLB 3C show the lowest swelling capacity (18.47%). The in vitro assessment using Franz diffusion cells showed that the 2%DLB 3C indicates a better sustained release of DS, with 53.26% of the DS being released after 12 h. The 2%DLB 3C owned a flux (Jss) of 0.256 mg/cm2 /h and a permeability coefficient (Kp) value of 0.020 cm/h. Thus, the results demonstrate that DS-medicated dual layer PVA patches prepared via a combination of electrospinning and cryogelation are capable of releasing drugs for up to 24 h and can serve as a drug reservoir in the skin, thereby extending the pharmacologic effects of DS

Degradation and physical properties of sugar palm starch/ sugar palm nanofibrillated cellulose bionanocomposite

This paper aims to study the degradation rate of sugar palm nanofibrillated cellulose (SPNFCs) and sugar palm starch (SPS). SPNFCs were isolated from sugar palm fiber, while SPS is extracted from sugar palm trunk. The SPNFCs were reinforced with SPS biopolymer as biodegradable reinforcement materials of different diameter/length based on the number of passes of high pressurize homogenization process (5, 10 and 15 passes represented by SPS/SPNFCs-5, SPS/SPNFCs-10, and SPS/SPNFCs-15). These SPNFCs were incorporated into SPS plasticized with glycerol and sorbitol via solution casting method. Soil burial experiment performed on SPS and SPS/SPNFCs bionanocomposites showed that SPS was degraded more rapidly by losing 85.76% of its mass in 9 days compared to 69.89% by SPS/SPNFCs-15 bionanocomposite. The high compatibility between SPNFCs nanofiber and SPS biopolymer matrices can be observed through field emission scanning electron microscopy (FE-SEM)

Development and Characterization of Cross Arm for Power Transmission Line using Natural Fiber and Polymer

Cross arms are the arm like equipment used in the power transmission line that holds the conductor with support of an insulator in a structure in power transmission line. Traditionally, transmission line structures have utilized treated lumber, steel, or concrete as a construction material. However, the difficulty in obtaining good quality timber and the shorter life span of non-quality timber wood have triggered the research to obtain alternate materials for cross arm. Hence, in this research project epoxy and thermoplastic elastomer were taken as polymer matrix and were reinforced with kenaf and oil palm fibers respectively. The percent of fibers was varied in the composite and were characterized by evaluating mechanical properties, water absorption, flammability, scanning electron micrographs (SEM) and energy dispersive X-ray (EDX). It was observed that the mechanical strength increased with increase of fiber content. However, water absorption was increased for both the composites. Fire resistance was observed for composite composed of TPE and oil palm fiber but kenaf fiber did not influence the epoxy composite in fire resistance. The SEM revealed good adherence of fiber in the matrix. Good interfacial bonding, fire resistance, suitable mechanical properties revealed that the natural fiber reinforced polymer composite can be considered as a suitable candidate for cross arm materials for power transmission lines in power generation.</p

Functionally Graded Piezoelectric Energy Harvester: A Numerical Study

The performance of linear energy harvesters is primarily confined to a very narrow operating frequency bandwidth around its natural frequency. Even a slight deviation of the excitation frequency from the fundamental frequency of the system tremendously reduces the harvester’s performance. In order to minimize this shortcoming, the presented study considers the piezoelectric energy harvester with magnets introducing non-linearity in the system. The simple harmonic balance method is used to solve the non-linearity and for computing the voltage output and power in the frequency domain. In addition, the study also incorporates the functionally graded piezoelectric materials because of their superior properties. The distance between magnets (d0) has been varied from 0.4 mm to 10 mm along with grading index (n) in the range of 0 to ∞. Finally, voltage and power across the resistance were computed. The effective harvesting frequency range for d0 = 0.4 mm and n = 1 is observed in the range of 20 Hz to 85 Hz, while it was only between 35 Hz and 65 Hz for d0 = 10 mm, yielding a 216% increase in the frequency bandwidth. Under different case studies, the peak output power varied from 2 mW (d0 = 0.4 mm and n = ∞) to 6 mW (d0 = 10 mm and n = 0)

Development of biodegradable bio-based composite for bone tissue engineering: synthesis, characterization and in vitro biocompatible evaluation

Several significant advancements in the field of bone regenerative medicine have been made in recent years. However, therapeutic options, such as bone grafts, have several drawbacks. There is a need to develop an adequate bone substitute. As a result, significant bone defects/injuries pose a severe challenge for orthopaedic and reconstructive bone tissue. We synthesized polymeric composite material from arabinoxylan (ARX), β-glucan (BG), nano-hydroxyapatite (nHAp), graphene oxide (GO), acrylic acid (AAc) through free radical polymerization and porous scaffold fabricated using the freezedrying technique. These fabricated porous scaffolds were then coated with chitosan solution to enhance their biological activities. The complex structure of BG, nHAp, GO was studied through various characterization and biological assays. The structural, morphological, wetting and mechanical analyses were determined using FT-IR, XRD, XPS, SEM/EXD, water contact angle and UTM. The swelling (aqueous and PBS media) and degradation (PBS media) observed their behavior in contact with body fluid. The biological activities were conducted against mouse pre-osteoblast cell lines. The result found that BGH3 has desirable morphological, structural with optimum swelling, degradation, and mechanical behavior. It was also found to be cytocompatible against MC3T3-E1 cell lines. The obtained results confirmed that the fabricated polymeric scaffolds would be a potential bone substitute to regenerate defective bone with different loading bearing applications for bone tissue engineering