Adsorption of heavy metal ions on surface of functionalized oil palm empty fruit bunch fibers: single and binary systems

The functionalization of surface charges on oil palm empty fruit bunch (EFB) fibers was modified by grafted carboxylic acid and polymer amine groups. Single and binary adsorption of Cu(II), Ni(II), Mo(VI) and As(V) were investigated by competitiveness in the adsorbents. The mechanism of each metal ion was deliberately studied on kinetics-diffusion (intraparticle diffusion) and isotherm adsorption models (Langmuir and Freundlich). Competitiveness of metal ions was found in the selectivity of Cu(II) > Ni(II) and Mo(VI) > As(V) in the binary solution. The regeneration of adsorbents was performed up to five cycles of an adsorption/desorption process and the reduction of adsorption performance was less than 14.5%. Therefore, this promises low-cost adsorbents for metal ion uptake, showing potential for removal and recovery in industrial wastewater treatment

Sintesis dan pencirian poli(etilena glikol) bermetoksi-ko-poli(β-amino ester) yang dibentuk daripada heksilamina linear dan siklik sebagai misel polimer

Poli(etilena glikol) bermetoksi-ko-poli(β-amino ester) (MPEG-PbAE) telah disintesis dengan menggunakan poli(etilena glikol) bermetoksi yang mempunyai kumpulan hujung berfungsi akrilat (MPEG-ac), 1,6-heksanadiol diakrilat, heksilamina linear (A) dan heksilamina siklik (B) sebagai bahan reaktan. Kopolimer MPEG-PbAE A dan B dijangka akan membentuk misel dengan MPEG berfungsi sebagai bahagian luar yang hidrofilik dan PbAE yang mempunyai kumpulan heksil berfungsi sebagai bahagian dalam yang hidrofobik. MPEG-ac selepas diubah suai dan kopolimer MPEG-PbAE A dan B selepas disintesis telah dicirikan. Spektroskopi inframerah transformasi Fourier (FT-IR) dan spektroskopi resonans magnet nukleus jenis proton (1H-NMR) telah mengesahkan pengubahsuaian kumpulan hujung hidroksil di MPEG kepada kumpulan hujung akrilat. Didapati kopolimer A adalah lebih sesuai digunakan sebagai pembawa ubat berdasarkan perbandingan antara kopolimer A daripada heksilamina linear dan kopolimer B daripada heksilamina siklik. Kromatografi penelapan gel (GPC) menunjukkan bahawa nombor-purata berat molekul, Mn kopolimer A adalah 11216 dengan indeks kepoliserakan (PDI) 1.1925. Kepekatan misel kritikal (CMC) kopolimer A dalam larutan akueus pH7.4 adalah 84.6 mg/L. Purata saiz misel yang diperoleh daripada analisis penyerakan cahaya dinamik (DLS) adalah 26.25±0.149 nm

Combination of gamma irradiation and sodium carbonate pretreatment on oil palm Empty Fruit Bunch (EFB) for high acidic hydrolysis yield

Oil palm empty fruit bunch (EFB) fibres were pretreated by gamma irradiation followed by sodium carbonate (Na2CO3) before the acid hydrolysis process to produce reducing sugars using diluted sulphuric acid (H2SO4). In this study, EFB fibres were irradiated at different doses, i.e. 0, 100 and 200 kGy. Meanwhile, the gamma irradiated sample were then subjected to Na2CO3 pretreatment with 0 and 5% total titratable alkali (TTA). The effect of the pretreatment using gamma irradiation and Na2CO3 on the physical and chemical properties of the EFB fibres and the yield of the reducing sugar obtained from the acid hydrolysis process was investigated. The obtained results showed that the content of holocellulose was increased significantly with the increase of irradiation doses combined with Na2CO3 pretreatment, whereas lignin content of the EFB was decreased. The gamma irradiation and Na2CO3 pretreatment resulted in structure breakage and removal of silica of EFB fibres which can be due to the swelling of the fibres. A synergistic effect between gamma irradiation and Na2CO3 was observed, in which the yield of reducing sugars was increased by combining the gamma irradiation and Na2CO3 pretreatment

Cytosine Palladium Complex Supported on Ordered Mesoporous Silica as Highly Efficient and Reusable Nanocatalyst for One-Pot Oxidative Esterification of Aldehydes

The synthesis of esters is one of the most fundamental and significant subjects in organic chemistry and chemical industry because they are used in high-value products such as cosmetics, biofuel, pharmaceuticals, surfactants, and food ingredients. In this study, an efficient, economic, sustainable, and green protocol for oxidative esterification reaction has been developed. A one-pot direct transformation of aliphatic, aromatic, and unsaturated aldehydes into esters in the presence of oxygen has been carried out over mesoporous organosilica-supported palladium nanocatalyst (Pd-Cyt@SBA-15) under ambient conditions. Pd-Cyt@SBA-15 efficiently catalyzed selectively large-scale conversion of aldehydes into esters in high yields and large turnover numbers (TON = 98,000). Pd-Cyt@SBA-15 nanocatalyst demonstrated excellent reusability and stability and could be recycled up to ten times without loss of significant reactivity. ICP-AES analysis showed that no leaching of active palladium species occurred during the recycling process of the heterogeneous Pd-Cyt@SBA-15 nanocatalyst

Microstructure of brushite crystals prepared via high internal phase emulsion

For the first time, various microstructures of calcium phosphates were successfully synthesized using a high internal phase emulsion process. The crystals were possessed in the brushite crystalline phase. The morphology of the crystals was influenced by the variables related to the emulsion process route, which consisted of flakes, dendrites and particulates structures

Inorganic Nanostructures Decorated Graphene

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Direct production of biodiesel from high-acid value Jatropha oil with solid acid catalyst derived from lignin

<p>Abstract</p> <p>Background</p> <p>Solid acid catalyst was prepared from Kraft lignin by chemical activation with phosphoric acid, pyrolysis and sulfuric acid. This catalyst had high acid density as characterized by scanning electron microscope (SEM), energy-dispersive x-ray spectrometry (EDX) and Brunauer, Emmett, and Teller (BET) method analyses. It was further used to catalyze the esterification of oleic acid and one-step conversion of non-pretreated <it>Jatropha </it>oil to biodiesel. The effects of catalyst loading, reaction temperature and oil-to-methanol molar ratio, on the catalytic activity of the esterification were investigated.</p> <p>Results</p> <p>The highest catalytic activity was achieved with a 96.1% esterification rate, and the catalyst can be reused three times with little deactivation under optimized conditions. Biodiesel production from <it>Jatropha </it>oil was studied under such conditions. It was found that 96.3% biodiesel yield from non-pretreated <it>Jatropha </it>oil with high-acid value (12.7 mg KOH/g) could be achieved.</p> <p>Conclusions</p> <p>The catalyst can be easily separated for reuse. This single-step process could be a potential route for biodiesel production from high-acid value oil by simplifying the procedure and reducing costs.</p

Exposure to sexually explicit media in early adolescence is related to risky sexual behavior in emerging adulthood

[[abstract]]BACKGROUND: Sexually explicit media exposure during early adolescence has been found to be associated with risky sexual behavior. However, previous study suffered from methodological issue, such as selection bias. Furthermore, little is known about the effect of multi-modality sexually explicit media exposure on risky sexual behavior, and how this relationship can be applied to non-western societies. OBJECTIVES: This study aimed to improve upon previous studies by using instrumental variable estimation. In addition, this study also included multi-modality of sexually explicit media and three risky sexual behavior measure from a sample of Taiwanese adolescents. METHODS: Participants were recruited from a prospective longitudinal study (Taiwan Youth Project). All were in 7th grade (mean age = 13.3) when the study was initiated in 2000. Sexually explicit media exposure, including ever-exposure and number of modalities exposed to, was measured in wave 2 (8th grade). Risky sexual behavior was measured in waves 8 (mean age = 20.3) and 10 (mean age = 24.3). A two-stage least squares regression was employed, with pubertal timing as the instrumental variable. RESULTS: About 50% of participants had been exposed to sexual media content by 8th grade, from an average of one modality. Sexually explicit media exposure predicted early sexual debut, unsafe sex, and multiple sexual partners (all: p < .05). Furthermore, exposure to more media modalities increased the likelihood of risky sexual behaviors. However, only the effect on early sexual debut was gender invariant. CONCLUSIONS: Exposure to sexually explicit media in early adolescence had a substantive relationship with risky sexual behavior in the emerging adulthood. Knowledge of this causal like effect provides a basis for building better preventive programs in early adolescence. One prominent way is early education on media literacy, and physicians themselves may need to be familiar with such content to initiate it.[[notice]]補正完

Isolation and fractionation of cellulose nanocrystals from kenaf core

In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4 wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO2) in acetate buffer. The bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H2SO4). The size distribution of the CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of 55 min have length around 40 to 370 nm