Abstract:The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new OPEN ACCESSPolymers 2014, 6 2248 aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

In the present study, chemical-physical properties of nanofibers isolated from rubberwood (Hevea brasiliensis) and empty fruit bunches (EFB) of oil palm (Elaeis guineensis) were analyzed by microscopic, spectroscopic, thermal and X-ray diffraction methods. The isolation was achieved using chemo-mechanical processes. Microscopy study showed that the diameters of the nanofibers isolated from the EFB ranged from 5 to 40 nm while those of the nanofibers isolated from rubberwood had a wider range (10-90 nm). Fourier transform infrared spectroscopy study demonstrated that almost all the lignin and most of the hemicellulose were removed during the chemical treatments. X-ray diffraction analysis revealed that the crystallinity of the studied nanofibers increased after the chemo-mechanical isolation process. The results of thermogravimetric analysis showed that the nanofibers isolated from both sources had higher thermal stability than those of the bleached pulp and untreated fibers.

Abstract:In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. Among the many possible bio resources, biologically active products from fungi and yeast represent excellent scaffolds for this purpose. Since fungi and yeast are very effective secretors of extracellular enzymes and number of species grow fast and therefore culturing and keeping them in the laboratory are very simple. They are able to produce metal nanoparticles and nanostructure via reducing enzyme intracellularly or extracellularly. The focus of this review is the application of fungi and yeast in the green synthesis of inorganic nanoparticles. Meanwhile the domain of biosynthesized nanoparticles is somewhat novel; the innovative uses in nano medicine in different areas including the delivery of drug, cancer therapy, antibacterial, biosensors, and MRI and medical imaging are reviewed. The proposed signaling pathways of nanoparticles induced apoptosis in cancerous cells and anti-angiogenesis effects also are reviewed. In this article, we provide a short summary of the present study universally on the

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The aim of this study was to isolate cellulose nanofibers from kenaf (Hibiscus cannabinus) stem using chemo-mechanical treatments. The fiber purification method included pulping and bleaching processes whereas the mechanical treatments employed to isolate kenaf nanofibers were grinding and high pressure homogenizing. Kenaf nanofibers were found to have diameters in the range of 15-80 nm while most nanofibers have diameters within the range 15-25 nm. Fourier transform infrared spectroscopy (FTIR) showed that the chemical treatments removed lignin and most of the hemicelluloses from the fibers. The thermal characteristics of the fibers were analyzed using the technique of thermogravimetric analysis (TGA) which demonstrated that these characteristics were enhanced noticeably both for the bleached pulp and nanofibers. On the other hand, the X-ray analysis indicated that both chemical and mechanical treatments can improve the crystallinity of fibers.

a b s t r a c tThe objective of the study was to investigate the influence of heat treatment and exposure time on surface roughness, wettability, shear strength and hardness of rubberwood, Eastern redcedar and red oak samples. The anatomical structure of each species was also observed using scanning electron microscope (SEM). All specimens were exposed to two different temperature levels, namely 120°C and 190°C for 2 and 8 h. Red oak samples had the most enhanced surface quality along with less wettability characteristics followed by rubberwood and Eastern redcedar specimens as function of increased heat exposure. On the other hand, it appears that heat exposure adversely affected shear strength and hardness properties of all three types of samples. These two properties of heat treated samples had reduction values ranging from 52.7% to 69.4% and 10.8% to 33.3%, respectively as compared to those of control samples.Published by Elsevier Ltd.

The MALDI-TOF mass spectrometry (MS) and solid state CP-MAS 13C Nuclear Magnetic Resonance (NMR) spectroscopic technique were introduced to characterize Acacia mangium tannin (condensed tannins). The MALDI-TOF MS illustrated a series of peaks corresponding to oligomers of condensed tannins of up to 11 flavonoid units (3200 Da). A. mangium condensed tannins were found to consist predominantly of prorobinetinidin combined with profisetinidin and prodelphinidin. Both the MALDI-TOF mass spectra and the solid state CP-MAS 13C NMR indicated that the A. mangium tannins obtained from Kudat, had an almost completely linear structure; In addition, Lembah Beringin, consist of "angular" polymer structure; and Tawau, has included "twice-angular" polymer structures present in oligomers type of up to 7 flavonoid units. The high degree of polymerization of linear, angular type, twice-angular structures and longer oligomer (3200 Da) chains have not been observed in previous studies of condensed tannins. The spectra also indicated that A. mangium tannins are more heavily branched and have higher degree of polymerization (>7.0) compared to commercial mimosa (A. mearnsii) tannin (4.9). Because tannins are phenolic, it was expected that they can be used to replace phenol-formaldehyde (PF) adhesives.

Kenaf (Hibiscus cannabinus) from the family of Malvaceae is a valuable fibre plant native to India and Africa. Kenaf is composed of various active components including tannins, saponins, polyphenolics, alkaloids, essential oils and steroids. It has been used to treat bruises, bilious conditions, fever and puerperium. Nevertheless, the anti-cancer properties of kenaf seed oil have not yet been investigated. In this study, kenaf seed oils obtained by Sonication, Soxhlet and supercritical carbon dioxide fluid extraction (SFE) with 9 different combinations of pressure (bars) and temperature (°C) (200/40, 200/60, 200/80, 400/40, 400/60, 400/80, 600/40, 600/60 and 600/80) were investigated for the cytotoxicities. All the oils were cytotoxic towards ovarian cancer (CaOV3) and colon cancer (HT29) cell lines in a dose dependent manner as detected by using the MTT assay and trypan blue dye exclusion method. Oil from Sonication was the most cytotoxic towards CaOV3 cell line. Treated cells exhibited characteristics of apoptosis such as chromatin condensation and nuclear fragmentation. In conclusion, kenaf seed oils from the three extractions were cytotoxic towards CaOV3 cell line in a dose-dependent manner possibly via the induction of apoptosis. In considering the safety of the product, SFE technology is a better alternative extraction method that is suitable in kenaf seed oil extraction.