THE POTENCY OF MESOPOROUS CARBON (CMK-1) AS ADSORBENT OF DYES

Proceeding ICCS-2007Dyes are group of substances used widely in industries. These substances can introduce problems in an aqueous environment. Adsorption is an effective method for lowering the concentration of such materials in the environment. This work deals with dye adsorption using mesoporous carbon (CMK-1) as the adsorbent. For comparison, activated carbon (Norit SX22) was also used as adsorbent. CMK-1 was synthesized using mesoporous silica (MCM-48) as a template and sucrose as a carbon source. Sulphuric acid was utilized as a catalyst in carbonization process. After carbonization, the silica wall was dissolved by sodium hydroxide solution in ethanol-water of 1:1. To synthesize MCM-48, sodium silicate was used as a silica source and a mixture of cationic surfactant (cetyltrimethylammonium bromide, CTAB) and neutral surfactant (Triton X-100) as template. Adsorbates used were reactive (reactive red-1, RR1), basic (Rhodamine B, RhB), and acid (Patent Blue V, PBV) dyes. The optimum contact time of dyes with CMK-1 was 120 min. The adsorption of the dyes in CMK-1 and activated carbon can be fitted to both the Langmuir and Freundlich models, although with the possible exception of RR1 in activated carbon, statistically better fits are obtained with the Langmuir model. The adsorption of the dyes using CMK-1 was considerable higher than that using Norit SX2. The amount of dyes adsorbed by CMK-1 was in the order of RR1 > RhB > PBV

FTIR AND NMR STUDIES OF ADSORBED TRITON X-114 IN MCM-41 MATERIALS

One source of water pollutions is caused by the high use of surface-active agents (surfactants) by industries\ud and households. As a consequence, it is required to remove such substances from the environment One of the\ud important and widely used methods for removal of substances from solution is adsorption. In this research, MCM-41\ud and its modification MCM41-TMCS were used to adsorb nonionic surfactant, Triton X-114. FTIR and NMR methods\ud were used to study the interaction between the surfactants and the adsorbents. MCM-41 was synthesized\ud hydrothermally at 100 oC and its modification was conducted by silylation of MCM-41 with trimethylchloro silane\ud (MCM41-TMCS). Both unmodified and modified MCM-41 can adsorb the surfactant. The amount adsorbed in the\ud unmodified material is higher than that in the modified one. The interaction of Triton X-114 with MCM-41 was\ud hydrogen bonding between the silanol groups in MCM-41 and hydroxyl groups of Triton X-114. For modified\ud samples, Triton X-114 interacted with alkylsilyl groups mostly through hydrophobic interaction. It is more likely that\ud the interaction was through C12, C13, C26 and C27 of Triton X-114

Pemanfaatan Silika Mesopori Mcm-48-nh2 sebagai Adsorben Ion Cu2+

Ion Cu2+ merupakan unsur yang berbahaya jika terkontaminasi ke dalam lingkungan. Oleh karena itu, keberadaannya dalam lingkungan perairan harus dikurangi. Adsorpsi merupakan salah satu cara untuk mengurangi kandungan ion Cu2+ dalam larutan. Adsorpsi ion Cu2+ oleh MCM-48-NH2 dipelajari dengan variasi waktu kontak, pH, dan konsentrasi dari Cu2+. Isotermal Langmuir dan Freundlich digunakan untuk mempelajari isotermal adsorpsi Cu2+ oleh MCM-48-NH2. Hasil penelitian menunjukkan bahwa adsorpsi Cu2+ oleh MCM-48-NH2 lebih sesuai dengan isotermal adsorpsi Langmuir. Nilai kapasitas adsorpsi Cu2+ oleh MCM-48-NH2 adalah 0,52 mmol g-1.Kata Kunci : Adsorpsi, MCM-48-NH2, Cu2+, isotermal Cu2+ ion is an element harmful if contaminated into the environment. Therefore, its presence in the aquatic environment must be reduced. Adsorption is one method to reduce thecontent of Cu2+ ion in solution. Adsorption of Cu2+ ion by MCM-48-NH2 was studied with variation of contact time, pH, and concentration of Cu2+ ion. Langmuir and Freundlich models were used to study the adsorption isotherm of Cu2+ by MCM-48-NH2. The result showed that adsorption of Cu2+ by MCM-48-NH2 more suitable with Langmuir models. The adsorption capacity of Cu2+ by MCM-48-NH2 was 0.52 mmol g-1

ADSORPTION OF WATER AND BENZENE VAPOUR IN MESOPOROUS MATERIALS

Makara Seri Sains 12(2) 2008Mesoporous materials have attracted the attention of many researchers due to the potential applications promised by the\ud materials. This article discusses adsorption of water and benzene vapour in mesoporous materials (mesoporous silica:\ud MCM-41, MCM-48 and their modification). MCM-41 and MCM-48 were synthesized hydrothermally at 100 oC using\ud cethyltrimethylammonium chloride or dodecyltrimethylammonium bromide for MCM-41 (C16) or MCM-41 (C12)\ud respectively and a mixture of cethyltrimethylammonium bromide and Triton X-100 for MCM-48 as templates. Their\ud modifications were conducted by silylation of MCM-41 (C16) and MCM-48 with trimethylchloro silane (MCM16-\ud TMCS and MCM48-TMCS) and t-butyldimethylchloro silane (MCM16-TBDMCS and MCM48-TBDMCS). Results\ud showed that MCM-41 and MCM-48 materials had hydrophobic features which were shown in the small amount of\ud water adsorption at low P/P0. The hydrophobicity of samples used in this study decrease in the sequence: MCM-41\ud (C16) > MCM-48 > MCM-41 (C12). The hydrophobicity increased when MCM-41 and MCM-48 were silylated with\ud TMCS or TBDMCS. All unsilylated MCM materials show higher affinity to benzene at low P/P0 than the silylated\ud samples. The results of water and benzene adsorption showed that silylated samples are promising candidates as\ud selective adsorbents for organic compounds

Amine-functionalized MCM-48 as Adsorbent of Zn2+ and Ni2+ Ions

A compound, 3-aminopropyltrimetoxy silane, has been used to modify mesoporous silica, MCM-48. The modified silica (NH2-MCM-48) was utilized to remove Zn2+ and Ni2+ ions from solutions. The mesoporous material was synthesized in the alkaline solution. Characterization of the unmodified materials was conducted by X-ray diffraction and FT-IR spectroscopy. The ions adsorbed on NH2-MCM-48 were studied at various pHs, contact times and initial ions concentrations. An Atomic Absorption Spectrophotometer (AAS) measured the ions content in the solution.. Pseudo-first-order and pseudo-second-order models performed the kinetic adsorption. The adsorption isotherm was examined by Langmuir and Freundlich isotherms. The result found that optimum contact time for the adsorption of Zn2+ ion was lower than that for Ni2+ ion. The adsorption followed the pseudo-second-order model with the adsorption rate of 4.56x10-2 g mg-1 min-1 for Zn2+ ion and 7x10-4 g mg-1 min-1 for Ni2+ ion. The optimum pH was 6 and 4 for Zn2+ and Ni2+ adsorption, respectively. The uptake of both ions from solutions by NH2-MCM-48 fixed better the Langmuir than the Freundlich model with the adsorption capacity of 0.55 and 0.43 mmol g-1, correspondingly. This research work provides valuable information on the interaction between the ions and the functional group of adsorbent

MIP-TFMAA-co-TRIM as Selective Adsorption of β-sitosterol

A functional monomer of trifluoromethylacrylic acid (TFMAA), a cross-linker of trimethylolpropane trimethacrylate (TRIM) and a template molecule of β-sitosterol have been used to produce a molecularly imprinted polymer, MIP_TFMAA-co-TRIM by a polymerization process based on non-covalent interaction between the monomer and the template. After the removal of the template, we used the product of MIP as an adsorbent of β-sitosterol and determined the adsorption capacity. The adsorption-desorption process for β-sitosterol and the selectivity test for β-sitosterol and cholesterol were also studied. High Performance Liquid Chromatography (HPLC) and UV-vis spectrophotometry were methods for measuring the amount of .materials adsorbed. Langmuir and Freundlich equations were models used to study the adsorption isotherm of the removal of β-sitosterol. The adsorption of β-sitosterol on MIP_TFMAA-co-TRIM followed the Freundlich isotherm with a capacity of 0.61 mg/g. The first and the second adsorption-desorption processes showed that the recovery percentages of β-sitosterol from MIP_TFMAA-co-TRIM were 66.36 and 40.56%, respectively. The MIP was more selective for β-sitosterol than for cholesterol

Peripheral blood RNA gene expression profiling in patients with bacterial meningitis

Objectives: The aim of present study was to find genetic pathways activated during infection with bacterial meningitis (BM) and potentially influencing the course of the infection using genome-wide RNA expression profiling combined with pathway analysis and functional annotation of the differential transcription. Methods: We analyzed 21 patients with BM hospitalized in 2008. The control group consisted of 18 healthy subjects. The RNA was extracted from whole blood, globin mRNA was depleted and gene expression profiling was performed using GeneChip Human Gene 1.0 ST Arrays which can assess the transcription of 28,869 genes. Gene expression profile data were analyzed using Bioconductor packages and Bayesian modeling. Functional annotation of the enriched gene sets was used to define the altered genetic networks. We also analyzed whether gene expression profiles depend on the clinical course and outcome. In order to verify the microarray results, the expression levels of ten functionally relevant genes with high statistical significance (CD177, IL1R2, IL18R1, IL18RAP, OLFM4, TLR5, CPA3, FCER1A, IL5RA, and IL7R) were confirmed by quantitative real-time (qRT) PCR. Results: There were 8569 genes displaying differential expression at a significance level of p < 0.05. Following False Discovery Rate (FDR) correction, a total of 5500 genes remained significant at a p-value of < 0.01. Quantitative RT-PCR confirmed the differential expression in 10 selected genes. Functional annotation and network analysis indicated that most of the genes were related to activation of humoral and cellular immune responses (enrichment score 43). Those changes were found in both adults and in children with BM compared to the healthy controls. The gene expression profiles did not significantly depend on the clinical outcome, but there was a strong influence of the specific type of pathogen underlying BM. Conclusion: This study demonstrates that there is a very strong activation of immune response at the transcriptional level during BM and that the type of pathogen influences this transcriptional activation

SINTESIS KARBON MESOPORI, CMK-1 DAN POTENSI ADSORPSINYA ATAS SURFAKTAN DI PERAIRAN

Marina Chimica Acta 5(1) 2004Adsorption of sodium dodecyl benzene sulfonate (SDBS) on mesoporous carbon, CMK-1 with a variation\ud of the contact time, the concentration of SDBS and a variation of pH has been conducted. The\ud concentration of SDBS before and after adsorption was determined by a UV spectrophotometer. Freundlich\ud and Langmuir models were used to study the adsorption capacity of SDBS by CMK-1. The Results\ud showed that the optimum contact time was 4 hours. To know the adsorption capacity of SDBS on CMK-1,\ud adsorption of SDBS at various consentrations and various pH were conducted at optimum contact time.\ud From the results, it was clear that the adsorption capacity at pH of 7 > pH of 4 > at pH of 10 and\ud adsorption followed isoterm Freundlich