Epoxy nanocomposites coatings filled with hybrid graphene oxide/halloysites (GO/HNT) based intumescent flame-retardant additives (IFR) have been fabricated and investigated in terms of flame retardancy property, thermal stability, and adhesion strength. The dispersion and interaction of the nanofillers with the matrix were characterized by transmission electron microscopy (TEM) and Fourier transform infrared (FTIR). The synergistic flame-retardant effects of ammonium polyphosphate (APP) on flame retardancy properties and thermal stability were investigated by limiting oxygen index (LOI) and thermogravimetric analysis (TGA), respectively. The result shows that the epoxy coating with hybrid GO/HNT based IFR achieve an LOI of 26 % at 1 phr of APP (EGO0.6H0.3APP1). Meanwhile, the maximum mass loss of the EGO0.6H0.3APP1 coating sample is 391.0 ° which showing an increment by 1.3 % compared with neat epoxy coating, demonstrating excellent thermal stability performance. The char residue also suggests, APP played a synergistic flame-retardant mechanism with a combination of hybrid GO/HNT. The presence of hybrid GO/HNT/IFR considerably enhances adhesion strength between the coating material and metal substrate. The EGO0.6H0.3APP1 showed the maximum LOI value, thermal stability, and adhesion strength among the studied formulations.

Posted on: 2021

Authored: Faiz Ahmad

This study investigated the effect of a distinctive design of mold to align short carbon fiber in copper matrix composite produced via metal injection molding. The mold was designed to improve the fiber orientation during flow in the core region of test samples. The composite feedstocks comprising polymeric binder and Cu powder reinforced with 0, 5 and 10 vol. % carbon fiber, prepared in Z-blade mixer, were injection molded to fabricate green samples. Green samples were debound to remove the binder and sintered in sintering furnace at 1050 ° in Argon atmosphere. Dispersion of carbon fibers was examined in composite feedstocks and TGA was used to determine the degradation temperature of binder. Uniform dispersion of carbon fibers was observed in compounded feedstocks, green and sintered samples. Fiber orientation was quantified at various locations of skin and core of the green and sintered samples. Quantification of fiber orientation showed the best value of more than 90 % of short fibers aligned in green test samples whereas sintered samples demonstrated just above 70 % of fiber alignment in the flow direction in Cu-10 %CF at section N. Overall, the results showed fiber alignment within ± 22.5 ° in both green and sintered samples without significant skin-core effect. Moreover, the calculated mechanical properties increased with an increase in alignment of carbon fiber in the Cu matrix. Conclusively, fiber alignment can be improved by controlling flow of molten feedstock during molding with potentially high mechanical properties of composite.

Posted on: December 2022

Authored: Faiz Ahmad

Graphene holds a remarkable potential as a reinforcement material for copper matrix due to its outstanding mechanical and electrical properties. However, noticeable increment in performance of graphene reinforced metal matrix composites is restricted due to inhomogeneous distribution and weak interfacial interaction between graphene reinforcement and metal matrix. Poor dispersion of graphene nanoplatelets can be attributed to absence of functional groups on graphene sheets, graphene oxide in contrast holds a large number of functional groups on its surface and edges, which make it dispersible in a wide range of matrices. In this research work, we investigate potential of graphene nanoplatelets and graphene oxide as reinforcement for copper based feedstock. During this study, two different approaches, solvent based mixing and copper grafting, have been employed as dispersion methods. A radical approach for incorporation of graphene in metal matrix is also devised, by taking benefit from functional nature of graphene oxide and anchoring copper particles on graphene oxide sheets. Successful growth of copper particles along with simultaneous reduction of graphene oxide have been observed by using scanning electron microscopy and infrared spectroscopy analysis. Copper particles as intercalation species present a viable potential to resist re-agglomeration of graphene sheets while enhancing the interfacial interaction between copper matrix and graphene at the same time. Copper graphene nanocomposite can potentially be used as a reinforcement for copper based powder injection molding feedstock.

Posted on: 2019

Authored: Faiz Ahmad

For some applications of implantable polymeric devices, material degradation and disappearance with time is necessary. In such a case, control in the polymer applications can be achieved through understanding the process of degradation. Heat effect on physical changes of polymeric materials under service condition should also not be overlooked. Poly octanediol citrate/Nano silica composite was developed and tested for glass transition (Tg) and physical degradation within the environmental factors that impact the use of the Poly octanediol citrate/Nano silica composite for medical application. Degradation correlated well with the nano silica content while the indicated low Tg value confirmed the amorphousness of the Poly octanediol citrate/Nano silica composite at 37 °C.

Posted on:2019

Authored: Faiz Ahmad

Graphene has emerged as an exceptional material for industrial usage and has widely been implemented. In this regard, the current study examines the enhanced characteristics of graphene nanoplatelets (GNP) by depositing the magnetite iron oxide (Fe3O4) on its surface. Ethylene glycol solvent was taken in Fe3O4 and GNP samples formation which were synthesized by the time parameter at various intervals. The Physicochemical characterizations were carried out by FTIR, XPS, XRD, and FESEM. It was observed that the successful grafting of iron particles on the GNP surface was achieved at a high time interval, and the results were more significant. FESEM images reveal a spherical structure on the surface of the graphene nanoplatelets in the GG 1, GG 2, and GG 4 sample. Fe3O4 has an irregular morphology with pores observed on the surface of GNP. However, the surface morphology of the graphene changes to a crinkled and rough surface.

Posted on:July 2023

Authored: Faiz Ahmad

This work aimed to study the thermal and crystalline properties of poly (1,4-phenylene sulfide)@carbon char nanocomposites. Coagulation-processed nanocomposites of polyphenylene sulfide were prepared using the synthesized mesoporous nanocarbon of coconut shells as reinforcement. The mesoporous reinforcement was synthesized using a facile carbonization method. The investigation of the properties of nanocarbon was completed using SAP, XRD, and FESEM analysis. The research was further propagated via the synthesis of nanocomposites through the addition of characterized nanofiller into poly (1,4-phenylene sulfide) at five different combinations. The coagulation method was utilized for the nanocomposite formation. The obtained nanocomposite was analyzed using FTIR, TGA, DSC, and FESEM analysis. The BET surface area and average pore volume of the bio-carbon prepared from coconut shell residue were calculated to be 1517 m2/g and 2.51 nm, respectively. The addition of nanocarbon to poly (1,4-phenylene sulfide) led to an increase in thermal stability and crystallinity up to 6% loading of the filler. The lowest glass transition temperature was achieved at 6% doping of the filler into the polymer matrix. It was established that the thermal, morphological, and crystalline properties were tailored by synthesizing their nanocomposites with the mesoporous bio-nanocarbon obtained from coconut shells. There is a decline in the glass transition temperature from 126 °C to 117 °C using 6% filler. The measured crystallinity was decreased continuously, with the mixing of the filler exhibiting the incorporation of flexibility in the polymer. So, the loading of the filler into poly (1,4-phenylene sulfide) can be optimized to enhance its thermoplastic properties for surface applications.

Posted on: April 2023

Authored: Faiz Ahmad

In this era, parts complexity, dimensional accuracy, and cost-effectiveness are one of the basic requirements of the modern industry. Most of the conventional manufacturing techniques have failed to fulfill the industry's needs. Powder injection molding (PIM) started in the early 70s, which is a combination of powder metallurgy and plastic injection molding that fulfills the gaps in conventional manufacturing techniques. In Malaysia, PIM was introduced by SIRIM Sdn Bhd Malaysia in late 2000. The latter few universities started working on PIM. Among all universities, the Advanced Functional Materials Research (AFM) group at Universiti Teknologi PETRONAS (UTP) started to work in 2008 under the direction of Prof. F. Ahmad and was decided to target various industries and their latest requirements. The work completed during the past 11 years has been published in various high-quality international journals, secure intellectual property (IP), i.e., trademarks, patents, a pre-commercialization grant from the government, one commercialization agreement, and signed a technology licensing agreement. They also worked on carbon Nanotube reinforced copper nanocomposite for thermal management and secured two patents. This project was commercialized for heat sink materials for LED Lights. The group is also working on controlling the orientation of fibers in the metal matrix to enhance thermal conductivity. Moreover, grafting graphene on metal oxide for its potential use as a radiation shielding material is one of the noble works. Currently, the group is working on the fabrication of soft magnetic material with enhanced permeability for potential use in hearing Aids, electric motors, and several other applications. Besides, bio-medical parts like a dental screw, biomedical material of 316L SS reinforced by nano Titanium and additive manufacturing by using ultra-fused BASF 316L SS parts made through FDM represent the scope of works in PIM.

Posted on: December 2022

Authored: Faiz Ahmad

Breast cancer is one of the most common cancers with high mortality, highlighting the vital need to identify new therapeutic targets. Here we report that Non-POU Domain-Containing Octamer-Binding (NONO) Protein is overexpressed in breast cancers and validated the interaction of WW domain of PIN1 with c-terminal Threonine-Proline (thr-pro) motifs of NONO. The interaction of NONO with PIN1 enhances NONO's stability by inhibiting its proteasomal degradation, and this identies PIN1 as a positive regulator of NONO to promote breast tumor development. Functionally, silencing of NONO inhibits the growth, survival, migration and invasion, epithelial-to-mesenchymal transition (EMT), and stemness of breast cancer cells in vitro. A human metastatic breast cancer cell xenograft was established in transparent zebrash (Danio rerio) embryos to study the metastasis inability of NONO silenced breast cancer cells in vivo. Biochemical analysis indicated NONO as a master regulator of the molecules associated with different hallmarks of cancer. Mechanistically, depletion of NONO promotes the expression of PDL1 cell surface protein in breast cancer cells. The identication of novel interactions of NONO with c-Jun and B-catenin proteins and activating the Akt/MAPK/B-catenin signalling suggests NONO as novel regulator of Akt/MAPK/B-catenin signalling pathways. Taken together, our results demonstrated an essential role of NONO in the tumorigenicity of breast cancer and could be a potential target for anti-cancerous drugs

Posted on: December 2022

Authored: Faiz Ahmad