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In this studies, synthesis of silver nanoparticles (Ag-NPs) on pullulan-based biofilm was achieved by microwave irradiation technique. Synthesis of Ag-NPs was achieved using pullulan as both a reducing and stabilizing agent. The effect of different microwave irradiation duration on pullulan and silver nitrate in synthesis of silver nanoparticles (Ag-NPs) was investigated. The synthesized Ag-NPs/PL were first screened and identified using surface plasmon peaks of UV–Vis spectroscopy. The research results indicated that the surface plasmon resonance peaks were observed between 400–414 nm wavelengths in UV-VIS spectroscopy studies. From Fourier-transform infrared spectroscopy (FTIR) spectra, stretching vibrations of hydroxyl (OH), carbonyl (C=O) and C=C stretches exhibits the reduction and stabilization of Ag-NPs. Further, five characteristic peaks Ag(111), Ag(200), Ag(210), Ag(220) and Ag(311) confirmed the presence of elemental silver and the crystalline structure of silver nanoparticles from X-ray Diffraction analysis. Biofilms were produced by mixing the synthesized Pulullan-Ag-NPs with polyvinyl alcohol. The AgNP/PL were applied for the antimicrobial activity against Bacillus subtilis and found to have high antibacterial activity. In addition, the clear zones of inhibition was found at 11 mm to 16 mm against Bacillus Subtillis. The experimental results demonstrated that pullulan could be used as reducing and stabilizing agent for formation of Ag-NPs.

The production of pure silver nanoparticles (Ag-NPs) with unique properties remains a challenge even today. In the present study, the synthesis of silver nanoparticles (Ag-NPs) from natural pullulan (PL) was carried out using a radiation-induced method. It is known that pullulan is regarded as a microbial polysaccharide, which renders it suitable to act as a reducing and stabilizing agent during the production of Ag-NPs. Pullulan-assisted synthesis under gamma irradiation was successfully developed to obtain Ag-NPs, which was characterized by UV-Vis, XRD, TEM, and Zeta potential analysis. Pullulan was used as a stabilizer and template for the growth of silver nanoparticles, while gamma radiation was modified to be selective to reduce silver ions. The formation of Ag-NPs was confirmed using UV–Vis spectra by showing a surface plasmon resonance (SPR) band in the region of 410–420 nm. As observed by TEM images, it can be said that by increasing the radiation dose, the particle size decreases, resulting in a mean diameter of Ag-NPs ranging from 40.97 to 3.98 nm. The XRD analysis confirmed that silver metal structures with a face-centered cubic (FCC) crystal were present, while TEM images showed a spherical shape with smooth edges. XRD also demonstrated that increasing the dose of gamma radiation increases the crystallinity at a high purity of Ag-NPs. As examined by zeta potential, the synthesized Ag-NP/PL was negatively charged with high stability. Ag-NP/PL was then analysed for antimicrobial activity against Staphylococcus aureus, and it was found that it had high antibacterial activity. It is found that the adoption of radiation doses results in a stable and green reduction process for silver nanoparticles.

The broad range of nanotechnology applications makes it an immensely developing field especially form the areas of science and technology. A facile and eco-friendly biosynthesis approach was introduced in this study. The aqueous flower extract of Clitoria ternatea (CT) is used to reduce gold ions, gold(III) chloride trihydrate (HAuCl ·3H O) to gold nanoparticles (Au-NPs). The effect of reaction time (15 min, 60 min) was changed to determine the outcome of the size of nanoparticles. CT flower extract plays an essential part in producing Au-NPs which act as a stabilizing and reducing (Au3+ to Au) agent to reduce the consumption of harmful substances during the synthesis of CT/Au-NPs. Furthermore, it also cut down the production of unnecessary side product during the reaction that can cause harm to the ecosystem and surrounding. Ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy was used for quantification of CT/Au-NPs synthesized form different parameters. An absorption UV-vis peaks of CT/Au-NPs was noticed approximately at the range of 540 nm wavelength with different concentration of HAuCl ·3H O. X-ray diffraction was used to identify the structure and purity of synthesized CT/Au-NPs. These spectrums provide a sharp peak at around 2θ = 38.44°, 44.41°, 65.03°, and 77.58° respectively. Meanwhile, it also correlated to a face-centered cubic structure with a plane of (111), (200), (220), and (311). Furthermore, high-resolution transmission electron microscopy analysis showed the formation of highly distributed CT/Au-NPs with an average diameter of about 15.53±10.12 nm to 59.43±27.62 nm and mostly spherical. This paper has been concentrated on producing simple, cost-effective, non-toxic, and environmentally friendly nanoparticles with size controlled.

This paper reported the synthesis of copper nanoparticles (Cu-NPs) via the chemical method in the presence of CuSO4.5H20 as precursor, polysaccharide as a stabilizer and ascorbic acid was acted as a reducing agent. In this study, the irradiation time was varied to evaluate the effect of time exposure with the Cu-NPs production. The analysis of samples without and with polysaccharide was characterized using ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) and Fourier-transform infrared coupled with attenuated total reflection instrument (ATR-FTIR). Based on the observation, reddish-brown colour solution demonstrated the formation of Cu-NPs and UV-Vis proved the plasmon resonance (SPR) spectra at the peak of 580 nm. The sharp peak of XRD at angle 2Ɵ gives the value of 43.69°, 50.81°, and 74.42° was attributed to Cu-NPs and the presence of polysaccharides maintained the crystallinity of Cu-NPs. FTIR results shows that the interaction peaks were occurred based on shifting of the peak to higher wavenumber. In conclusion, Cu-NPs were successfully produced by using the microwave method and be a function of time.

The synthesis of gold nanoparticles (Au-NPs) is being accomplished by the reduction of aqueous gold metal ions, gold(III) chloride trihydrate (HAuCl4.3H2O) reacted with the aqueous flower extract of Clitoria Ternatea (CT). CT flower extract plays an important role in synthesizing Au-NPs. It acts as a reducing (Au3+ to Au) and stabilizing agent that can eliminate the usage of chemicals during the production of Au-NPs. Besides that, it also reduces the production of unwanted by-products which would cause hazardous to the surroundings and environment. In this study, an absorption peak of Au-NPs is observed at the range of 540-550 nm from ultraviolet-visible spectroscopy (UV-vis) analysis. Furthermore, the diffraction peaks at 2θ = 38.44°, 44.41°, 65.03° and 77.58° respectively which correspond to face-centered cubic structure with (111), (200), (220) and (311) plane confirm the successful synthesis of Au-NPs. According to transmission electron microscopy (TEM), the majority of Au-NPs are spherical in shape and having a mean particle size distribution of 18.16 nm with a standard deviation of 4.67 nm.

Radiation induced technique was employed during the synthesis of silver nanoparticles (AgNPs) on pullulan. In this study, the Ag-NPs on pullulan by γ irradiated process is performed to reduce Ag+ ions at the ambient temperature without using excessive reducing agents or producing unwanted by-products of the reductant. Moreover, reducing agent can be uniformly distributed in the solution and AgNPs are produced in highly pure and stable form. The results from ultraviolet-visible spectroscopy (UV-vis) and XRD demonstrated that the silver nanoparticles can be synthesize using pullulan. This can be confirmed by absorption band of UV-vis spectrum at 420 nm as well as the XRD pattern at (1 1 1), (2 0 0), (2 2 0), and (3 1 1) planes of silver. In addition, the pullulan also acts as a reducing and stabilizing agent. TEM images showed formed AgNPs are spherical in shape with smooth edges. The TEM also revealed that the increasing radiation dose decreases the particle size and increase the rate of reduction. It was found that the mean diameter of silver nanoparticles was about 3.98 -14.87 nm. In addition, the size of the AgNPs is believed can be tuned by controlling the radiation doses. The γ-rays doses also provide the powerful reduction process in a harmless condition by producing a very stable silver nanoparticles.

The tensile properties of starch fiber (SF) and native starch (NS) filled polyvinyl alcohol were investigated in this study. Polyvinyl Alcohol (PVA) was blend with starch fiber as well as native starch. Prior to compounding process, PVA was plasticized with 30 phr glycerol as well as 10 phr distilled water. A solution casting method was used to prepare the SF-PPVA and NS-PPVA film sheet. Based on the tensile test results SF filled PVA recorded the highest tensile strength (20.015 MPa) as compared to NS filled PVA (12.302MPa). The tensile strength of the blends film was depending to the interfacial adhesion between matrixes in the blends. In spite of that, NS filled PVA have noted the highest elongation during the test. SF and NS played important role in affecting the blends matrix through disturbing the arrangement of continuous phase of PVA.

Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

The growing attention of starch fiber (SF) has led to the innovation of Polyvinyl Alcohol-SF (PVA-SF) blends. This blend is regarded as the biodegradable material which aims to reduce the accumulation of synthetic polymer solid waste derived from petroleum. In this study, the thermal blending characterizations of PVA-SF were investigated by differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The water resistance of the blend was also evaluated to study the polarity of the blends. The blend was prepared by plasticizing the polyvinyl alcohol with glycerol and distilled water with the addition of starch fiber. The incorporation of SF to the blends was at 10 wt% to 50 wt% composition. Based on the thermal analysis, PVA-SF blends were suitable for processing at high temperatures, which can be seen by the shifted onset degradation temperature to a higher temperature. This is because cyclic hemiacetals which were provided by SF can act to prevent the thermal attacks. Conversely, increa...

The effects of fiber content in sweet potato peel-plasticized polyvinyl alcohol blends were investigated. Plasticized Polyvinyl Alcohol (PPVA) was blended with Sweet Potato Peel (SPP). Prior to compounding process, PVA was plasticized with 30 phr glycerol as well as 10 phr distilled water. Blends of PPVA at composition of 80%, 70%, 60%, 50% and 40% of SPP were compounded using melt mixing equipment with an additional of 20 phr glycerol. A casting method was used to prepare the PPVA-SPP film sheet. Based on the tensile test results, PPVA with 80% SPP recorded the lowest tensile strength (5.385 MPa) as compared to blends which contain 40% SPP (13.612 MPa). The reduction of tensile strength with the addition of SPP was due to poor interfacial adhesion between the PVA and SPP which was proven by Scanning Electron Microscopy (SEM) analysis.

The weathering performance of rice husk-filled high-density polyethylene (RHPE) and natural wood was investigated in this study. The injection molded RHPE, in column end-cap (CECap) shapes, was exposed to both natural and accelerated weathering attacks. The durability of RHPE was compared to Kempas wood (Koompassia malaccensis) and neat polyethylene. Wood underwent the greatest losses in properties among the specimens. Four months of outdoor weathering turned the color of RHPE CECap into silvery grey. When the exposure time increased, the color of RHPE composite faded faster than neat polyethylene. The wood surface darkened and RHPE surface flaked off after being exposed to accelerated weathering conditions. Prolonged weathering exposure caused loss of impact strength of the RHPE composites. In general, RHPE is more resistible to weathering attacks as compared to Kempas wood.

The specific heat capacity (C sp) of polyvinyl alcohol (PVOH) blends with cassava starch (CSS) was studied by the differential scanning calorimetry method. Specimens of PVOH–CSS blends: PPV37 (70 mass% CSS) and PPV46 (60 mass% CSS) were prepared by a melt blending method with glycerol added as a plasticizer. The results showed that the specific heat capacity of PPV37 and PPV46 at temperatures from 330 K to 530 K increased from (2.963 to 14.995) J· g−1 · K−1 and (2.517 to 14.727) J · g−1· K−1, respectively. The specific heat capacity of PVOH–CSS depends on the amount of starch. The specific heat capacity of the specimens can be approximated by polynomial equations with a curve fitting regression > 0.992. For instance, the specific heat capacity (in J · g−1 · K−1) of PPV37 can be expressed by C sp = −17.824 + 0.063T and PPV46 by C sp = −18.047 + 0.061T, where T is the temperature (in K).

Preliminary studies of Cabomba furcata from Chini Lake, Pahang, Malaysia has shown that this plant containing bioactive phytochemical such as saponin. Unfortunately no intensive research has been conducted since saponin are believed to have medicinal benefits to the humankind and they have the potential to be commercialized in pharmaceutical field. This study was done to identify the type of saponin that are present in C. furcata. Hot extraction was performed by using methanol and HPLC - Dad with C18 column had confirmed the presence of oleanolic acid and ursolic acid in the aquatic plant.

The effects of glycerol content in modified polyvinyl alcohol-tapioca starch were investigated. A series of plasticized polyvinyl alcohol (PPVA) and TS blends were prepared. Prior to compounding process, PVA was plasticized with 15–40 phr glycerol as well as addition of calcium stearate (CaS) and phosphoric acid. Blends of PPVA at composition of 50%, 60%, 70%, 80% and 90% TS with 20 phr glycerol were compounded using twin screw extruder. Blends of PPVA-TS were then processed via injection molding to produce test specimen for mechanical testing. It was found that the addition of glycerol in the blending is compulsory in order to have a better flowability during the processing process. In spite of that, the amount of glycerol inside the blending must be in the optimum composition to ensure that the mechanical properties of the blends are not affected.