Fe³⁺-bis-ethylenediamine complex bridged periodic mesoporous organosilica for the efficient removal of arsenate and chromate

Parambadath, Surendran,Mathew, Aneesh,Kim, Su Yeon,Park, Sung Soo,Ha, Chang-Sik International Union of Pure and Applied Chemistry 2018 Pure and Applied Chemistry Vol.90 No.5

<P><B>Abstract</B></P><P>The direct removal of arsenate (AsO<SUB>4</SUB><SUP>3−</SUP>) and chromate (CrO<SUB>4</SUB><SUP>2−</SUP>) from water were achieved using a Fe<SUP>3+</SUP>-bis-ethylenediamine complex-bridged periodic mesoporous organosilica with a 20% organosilane content (Fe-EDPMO-20). The bridged Fe<SUP>3+</SUP>-bis-ethylenediamine complex was introduced to the pore wall of the PMO by combining the pre-complexation and co-condensation processes. N,N′-bis[3-(triethoxysilyl)propyl]ethylenediamine (TESEN) and tetramethyl orthosilicate (TMOS) as silica precursors were used with cetyltrimethylammonium bromide (CTABr) as a surfactant under basic conditions for the preparation of highly ordered Fe-EDPMO-20. Transmission electron microscopy, X-ray diffraction, and N<SUB>2</SUB>adsorption-desorption measurements confirmed that the Fe-EDPMO-20 had an ordered hexagonal p6mm mesostructure. The material had a Brunauer-Emmett-Teller surface area of 734 m<SUP>2</SUP>g<SUP>−1</SUP>, pore diameter of 2.6 nm, and pore volume of 0.61 cm<SUP>3</SUP>g<SUP>−1</SUP>. UV-vis and X-ray photoelectron spectroscopy confirmed that Fe<SUP>3+</SUP>was embedded in the coordination site by the nitrogen atoms from ethylenediamine. The adsorption efficiencies of arsenate and chromate ions by Fe-EDPMO-20 were examined as a function of pH, stirring time, amount of adsorbent, and initial concentration of metal ion solution. The maximum adsorption for arsenate and chromate were 156 and 102 mg g<SUP>−1</SUP>within 6 and 24 h, respectively, at pH 4.</P>

A pH-responsive drug delivery system based on ethylenediamine bridged periodic mesoporous organosilica

Parambadath, S.,Mathew, A.,Jenisha Barnabas, M.,Ha, C.S. Elsevier 2015 Microporous and mesoporous materials Vol.215 No.-

Secondary amine based organic/inorganic hybrid periodic mesoporous organosilica (PMO) materials were synthesised from a bridged silsesquioxane precursor, N,N'-bis[3-(triethoxysilyl)propyl] ethylenediamine (TESEN) and tetramethyl orthosilicate (TMOS) with various amounts of TESEN and TMOS. Cetyltrimethylammonium bromide (CTABr) was used as the structure directing agent under basic conditions. The pore opening of the material was modified with N-[3-(trimethoxysilyl)propyl]aniline (TMSPA) to impart a nanovalve property under acidic conditions when co-operating with the β-cyclodextrin (β-CD) molecule. The physico-chemical properties of N,N'-bis-(propyl)ethylenediamine-bridged PMO with 15% (w/w) organo-functionality (DA-PMO-15) and the corresponding nanovalve system (GA-PMO-15) were determined by a range of spectroscopic analyses. X-ray diffraction and transmission electron microscopy showed that the DA-PMO-15 and GA-PMO-15 materials possess mesocopically ordered, hexagonal symmetry and well-defined morphologies. <SUP>29</SUP>Si magic angle spinning nuclear magnetic resonance (MAS NMR) spectral analysis revealed the silicon environment of the final material. N<SUB>2</SUB> sorption experiments showed the material has large surface area (591 m<SUP>2</SUP> g<SUP>-1</SUP>), acceptable pore diameter (3.0 nm) and affordable pore volume (0.38 m<SUP>3</SUP> g<SUP>-1</SUP>) to accommodate the guest molecules inside the pore channels. Organic functionalization was determined successfully by Fourier transform infrared and <SUP>13</SUP>C cross-polarization magic angle spinning (CP-MAS) NMR spectroscopy. Acidic drugs, such as 5-fluorouracil and ibuprofen were chosen as the cargo and the release rate from the GA-PMO-15 nanovalve at pH 4 was delayed significantly due to the gate keepers and the interaction of drug molecules with the internally functionalised N,N'-bis-(propyl)ethylenediamine molecule.

Periodic mesoporous organosilica (PMO) containing bridged succinamic acid groups as a nanocarrier for sulfamerazine, sulfadiazine and famotidine: Adsorption and release study

Parambadath, S.,Mathew, A.,Barnabas, M.J.,Rao, K.M.,Ha, C.S. Elsevier 2016 Microporous and mesoporous materials Vol.225 No.-

<P>Periodic mesoporous organosilica (PMO) with a bridged amine framework and a pendant succinamic acid group (SA-PMO-5) was synthesised using a sol gel and post modification process. The bridged amino functionality was introduced to the pore wall of the PMO (MA-PMO-5) using a silsesquioxane precursor, N,N-bis[3-(triethoxysilyl)propyl]amine (BTMSA), along with tetramethyl orthosilicate (TMOS). The succinamic acid functionality was tailored by the ring opening reaction of succinic anhydride with the bridged amine. The physico-chemical properties of SA-PMO-5 were determined by a range of spectroscopic analyses. X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that the MA-PMO-5 and SA-PMO-5 possessed mesoscopically ordered, hexagonal symmetry as well as well-defined morphologies. The N-2 sorption experiment showed the MA-PMO-5 and SA-PMO-5 had a large surface area (704 and 623 m(2) g(-1)), acceptable pore diameter (3.2 and 2.4 nm) and pore volume (0.56 and 0.47 cm(3) g(-1)) to accommodate the guest molecules inside the pore channels. Organic functionalisation was determined successfully by Fourier transform infrared spectroscopy and C-13 cross-polarisation magic angle spinning (CP-MAS) NMR spectroscopy. Si-29 MAS NMR spectral analysis revealed the silicon environment of the final material. Sulfamerazine (SMR), sulfadiazine (SDZ) and famotidine (FAMO) adsorption as well as the release properties from the MA-PMO-5 and SA-PMO-5 were investigated at pH 4 and 7.4. The high adsorption and delayed release properties exhibited by SA-PMO-5 were attributed to the strong interaction between succinamic acid functionality with the drug molecules. (C) 2015 Elsevier Inc. All rights reserved.</P>

Heterogeneous Ru(2)-NH-propyl-(1R,2S)-(+)-cis-1-amino-2-indanol as chiral catalyst for asymmetric transfer hydrogenation reaction of prochiral ketones

Surendran Parambadath,K. R. Kamble,A. P. Singh,하창식 한국고분자학회 2009 한국고분자학회 학술대회 연구논문 초록집 Vol.2009 No.10

Periodic Malodorous Organnoilica having Large Heterocyclic tri-Urea Bridgin Groups Derived from Melamine

라나,Surendran Parambadath,김일,하창식 한국고분자학회 2010 한국고분자학회 학술대회 연구논문 초록집 Vol.2010 No.4

Hydrophobically modified spherical MCM-41 as nanovalve system for controlled drug delivery

Mathew, A.,Parambadath, S.,Park, S.S.,Ha, C.S. Elsevier 2014 Microporous and mesoporous materials Vol.200 No.-

Spherical MCM-41 nanovalve having hydrophobically modified pore channels was synthesized via surfactant assisted sol-gel methodology and post modification process. The spherical MCM-41 has been tailored as a smart pH responsive drug carrier system by the insertion of N-3-(trimethoxysilyl)propyl aniline (TMSPA) at the pore opening before extracting the surfactant and further with phenyltrimethoxysilane (PTMS) to impart hydrophobicity on the inner surfaces of the pore channels. The surfactant extracted MCM-41 exhibits excellent textural properties such as very high specific surface area (1307 m<SUP>2</SUP>g<SUP>-1</SUP>), pore diameter (24 A) and pore volume (0.65 cm<SUP>3</SUP>g<SUP>-1</SUP>). The transmission electron microscope (TEM) and scanning electron microscope (SEM) images of mesosphere reflect the highly uniform and mono-dispersed spherical morphology having a particle size of 500nm. 5-Fluorouracil (5-Fu) and famotidine have been loaded into the hydrophobically modified channels followed with β-cyclodextrin (β-CD) as the gatekeeper to make the material as a pH responsive drug delivery system. The drug delivery has been carried out under in vitro condition at pH 4 and the amount of drug released from the nanovalve system was monitored by UV-Vis spectroscopy under regular intervals. The hydrophobically modified nanovalve was found to have delayed drug release of both 5-Fu and famotidine in comparison to the drug delivery from the nanovalve having unmodified pore channels synthesized from spherical MCM-41 under similar experimental conditions. The significance of functionalization as well as capping has been verified by the comparison of drug delivery behaviors among hydrophobically modified, unmodified, β-CD capped and uncapped nanocontainers.

Diffusion mediated selective adsorption of Zn²⁺ from artificial seawater by MCM-41

Mathew, A.,Parambadath, S.,Kim, S.Y.,Ha, H.M.,Ha, C.S. Elsevier 2016 Microporous and mesoporous materials Vol.229 No.-

<P>MCM-41 can play a pivotal role as a host material for adsorption applications. In this work, MCM-41 was found to be 100% selective for Zn2+ from artificial seawater containing Ni2+, Li+, Co2+, Cd2+ and Zn2+ as hetero ions. The pristine and Zn2+ ions adsorbed MCM-41 (Zn@MCM-41) were well characterized by various spectroscopic techniques. The selective Zn2+ ion adsorption property of MCM-41 remained intact irrespective of the concentration of Zn2+ ions. The adsorption property of MCM-41 was unaffected by the synthesis strategy of MCM-41. SBA-15 exhibited 85 and 15% mole selectivity for Zn2+ and Cd2+ ions, respectively, under similar experimental conditions. This highlights the unique property of MCM-41 for the selective adsorption of Zn2+ ions from artificial seawater. TEM, FTIR and XPS analysis confirmed the presence of Zn2+ ions in Zn@MCM-41. The protection using methyl group on the outer/both surfaces of MCM-41 (Me-MCM-41/MeS-MCM-41) disclosed the necessity of interaction between silica surface and metal ion for selective adsorption of Zn2+ ions. The detailed investigation of adsorption mechanism postulates that the selective adsorption of Zn2+ ions by MCM-41 was achieved only in the presence of sodium chloride, which is the major component of artificial seawater. An adsorbed amount of 12 mg g(-1) was observed for Zn2+ ions even in presence of Cd2+ ions, while both of the ions possess similar chemical characteristics. (C) 2016 Elsevier Inc. All rights reserved.</P>

Adsorption of Cr(III) ions using 2-(ureylenemethyl)pyridine functionalized MCM-41

Mathew, Aneesh,Parambadath, Surendran,Kim, Su Yeon,Park, Sung Soo,Ha, Chang-Sik Springer-Verlag 2015 Journal of porous materials Vol.22 No.3

Silver (I)- Schiff-base complex intercalated layered double hydroxide with antimicrobial activity

Barnabas, Mary Jenisha,Parambadath, Surendran,Nagappan, Saravanan,Chung, Ildoo,Ha, Chang-Sik Techno-Press 2021 Advances in nano research Vol.10 No.4

In this work, silver nitrate complexes of sulfanilamide-5-methyl-2-thiophene carboxaldehyde (SMTCA) ligand intercalated Zn/Al-layered double hydroxide [Ag-SMTCA-LDH] were synthesized for the potential application as an antimicrobial system. The SMTCA ligand was synthesized by reacting sulfanilamide and 5-methyl-2-thiophene carboxaldehyde in methanol and further complexation with silver nitrate metal ions [Ag-SMTCA]. The structural analyses of synthesized compounds confirmed an intercalation of Ag-SMTCA into Zn/Al-NO₃-LDH by flake/restacking method. SMTCA, Ag-SMTCA and Ag-SMTCA-LDH were characterized by ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, Fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). It was found that Ag-SMTCA-LDH exhibited good antimicrobial activity against both gram-positive (Bacillus subtilis, [B. subtilis], Staphylococcus aures, [S. aureus]) and gram-negative (Escherichia coli, [E. coli], Pseudomonas aeruginosa [P. aeroginosa]) bacteria as well as excellent antioxidant activity.

Melamine-Sulfonic Acid Functionalized SBA-15 for Selective Adsorption of Metal Ions from Artificial Seawater and Wastewater

Kim, Su Yeon,Parambadath, Surendran,Park, Sung Soo,Ha, Chang-Sik American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.10

<P>The silica wall surface of SBA-15 was modified with (3-chloropropyl)triethoxysilane (ClPTES) to tailor its properties for specific applications (Cl-SBA-15) after removing the surfactant by calcination. Cl-SBA-15 was also modified using melamine (Mel-SBA-15) and chlorosulfonic acid (SUP-SBA-15) by a two-step post modification process. The physico-chemical properties of SBA-15 and the organically modified materials were characterized using a range of spectroscopic and microscopic techniques and N2 sorption experiments. SUP-SBA-15 showed excellent adsorption selectivity of 95 and 89% towards Li+ ions from artificial seawater and wastewater, respectively. Rapid adsorption equilibrium was achieved for the adsorption of Li+ ions from both artificial seawater and wastewater. In addition, the selectivity of Li+ adsorption decreased with increasing temperature. The ion-exchange mechanism played the crucial role in the selective adsorption of Li+ ions in addition to the steric hindrance, charge repulsion, and chelating structure of ligand.</P>