@article { ISI:000234644600023, title = {Hydrothermal synthesis of MCM-41 using differently manufactured amorphous dioxosilicon sources}, journal = {Materials Letters}, volume = {60}, number = {7}, year = {2006}, month = {APR}, pages = {957-961}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The influence of differently manufactured amorphous dioxosilicon sources such as fumed silica (FS), spray dried precipitated silica (PSI) and flash dried precipitated silica (PS,) on the course of structural development and properties of hydrothermally prepared siliceous MCM-41 phases have been investigated. Powder XRD, N-2 adsorption/desorption and scanning electron microscopy techniques were used for sample characterization. On the basis of results obtained from time dependent study on the progressive development of MCM-41 mesophases, the reactivity trend of dioxosilicon sources observed was as: FS \> PS1 \> PS2. MCM-41 synthesized using least expensive PS2 having less surface area has exhibited thicker pore walls but poor orderness, while MCM-41 prepared from expensive FS having high surface area has thinner pore walls and was well ordered. The extent of contraction caused by calcination, magnitude of the wall thickness and structural stability were found to be dependent on manufacturing process of dioxosilicon sources. The noticeable morphological differences were also observed by variations in the type of dioxosilicon sources used in the hydrothermal synthesis MCM-41 materials. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Characterization, dioxosilicon sources, Hydrothermal synthesis, MCM-41, porosity, Structural stability}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.10.049}, author = {Gaydhankar, T. R. and Samuel, V. and Joshi, P. N.} } @article { ISI:000241686000011, title = {Novel beaded polymers from telechelic methacrylic ether esters}, journal = {Reactive \& Functional Polymers}, volume = {66}, number = {10}, year = {2006}, month = {OCT}, pages = {1087-1096}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A series of telechelic dimethacrylic ether-esters (MEE) were prepared by solventless reaction of alpha,omega-dihydroxy poly(oxytetramethylene) (polytetrahydrofuran, PTHF) with phthalic anhydride and glycidyl methacrylate (GMA). MEE was polymerized with GMA as well as GMA-ethylene dimethacrylate (EGDM) to form porous beads. The terpolymer beads were observed using optical microscopy and SEM and characterized for internal pore volume, equilibrium volume-swelling ratio and dimethyl formamide and aqueous buffer regain. The morphology of the beads was dictated by the mole fraction and molecular weight of MEE in the feed. Porosity was found to increase with increase in molecular weight of MEE. Thus, porosity as high as 49\%, 50\% and 55\% was observed with MEE of molecular weights 1580, 2580 and 3480, respectively. At a specific terpolymerization feed ratio of monomers, the terpolymers formed transform from gel like structure into a macroporous one, with increase in molecular weight of MEE. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {ether-ester dimethacrylates, macroporous, Pore size distribution, porosity, telechelics}, issn = {1381-5148}, doi = {10.1016/j.reactfunctpolym.2006.01.020}, author = {Pujari, N. S. and Trivedi, J. and Ingavle, Ganesh C. and Ponrathnam, S.} } @article { ISI:000248062700019, title = {Exhaustive analysis of frontal copolymerization of functionalized monovinyl and divinyl monomers}, journal = {Chemistry-A European Journal}, volume = {13}, number = {20}, year = {2007}, month = {APR}, pages = {5862-5872}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

A series of copolymers of 2-hydroxyethyl methacrylate (HEMA)/ glycidyl methacrylate (GMA) and ethylene dimethacrylate (EGDM) were synthesized by frontal polymerization (FP). This study was conducted to investigate the effect of crosslink density, type and concentration of initiator, the use of a complex initiator system, porogen, and diluent on the most relevant parameters of FP, such as sustainability of the front, temperature profile, front velocity, and yield. The products were also characterized for intruded pore volume, pore-size distribution, epoxy-functionality number, and surface morphology. Higher crosslink densities (CLDs) and initiator concentration produced higher front velocities, whereas no trend in front temperature was noted. A complex initiation system was effective in stabilizing and increasing the polymerization yield. Relative to suspension polymerization (SP), FP products synthesized without a solvent were microporous, whereas micro-to-macroporous products were obtained in the presence of a solvent (for HEMA-EGDM polymers). We also present, explain, and discuss the exotic patterns observed under a microscope. We observed two basic types of spatial patterns, namely, planar and nonplanar patterns. The type of planar pattern observed under scanning electron microscopy (SEM) has a spatial impulse that appears as a loop followed by regular periodic motion in the radial and axial directions. This behavior gives rise to a repeating pattern that is a few microns thick. Also, nonplanar patterns, namely, layered concentric rings and winding staircase patterns, were observed under SEM.

}, keywords = {copolymerization, patterns, Polymers, porosity}, issn = {0947-6539}, doi = {10.1002/chem.200601428}, author = {Pujari, Narahari S. and Inamdar, Satish R. and Ambekar, Jalindar D. and Kulkarni, B. D. and Ponrathnam, Surendra} } @article { ISI:000261133600029, title = {New microporous MOF material based on Zn(II)-polycarboxylate coordination polymer synthesized with the aid of 1,6-diaminohexane as template}, journal = {Microporous and Mesoporous Materials}, volume = {116}, number = {1-3}, year = {2008}, month = {DEC}, pages = {204-209}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A new microporous metal-organic framework (MOF) material ZBTEC-1 has been synthesized by designing infinite coordination polymer network formed between Zn(II) and 1,2,4,5-benzenetetracarboxylic acid (BTEC) under solvothermal conditions in the presence of 1,6-diaminohexane (DAH) as a single molecule template. Powder XRD data demonstrate that the ZBTEC-1 material has a new MOF structure. N-2 sorption studies indicated moderately good surface area (306 m(2) g(-1)) with large size micropores (average pore diameter ca. 0.7 nm) and very high pore volume (1.93 ccg(-1)). C-13 solid state MAS-NMR, FT-IR and UV-visible spectroscopic studies showed the presence of BTEC moieties in the framework. TEM and FE-SEM analysis indicated 30-60 nm diameter size microporous spherical particles for the ZBTEC-1 crystallites. This novel MOF material showed good hydrogen adsorption capacity at 77 K, indicating its potential application in hydrogen storage. (C) 2008 Elsevier Inc. All rights reserved.

}, keywords = {Coordination polymer, Metal-organic framework, Microporous material, porosity, Zinc complex}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2008.04.003}, author = {Chandra, Debraj and Kasture, Mahesh W. and Bhaumik, Asim} } @article { ISI:000349401200010, title = {Porous poly(ethylene glycol)-polyurethane hydrogels as potential biomaterials}, journal = {Polymer International}, volume = {64}, number = {3}, year = {2015}, month = {MAR}, pages = {397-404}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

We report the synthesis of porous poly(ethylene glycol)-polyurethane (PEG-PU) hydrogels using PEG-4000 as a soft segment and 4,4-methylenebis(cyclohexylisocyanate) as a hard segment. The degree of swelling in the hydrogels could be controlled by varying the amount of crosslinking agent, namely 1,2,6-hexanetriol. Structural characterization of the hydrogels was performed using solid-state C-13 NMR and Fourier transform infrared spectroscopy. Wide-angle X-ray diffraction studies revealed the existence of crystalline domains of PEG and small-angle X-ray scattering studies showed the presence of lamellar microstructures. For generating a porous structure in the hydrogels, cryogenic treatment with lyophilization was used. Scanning electron microscopy and three-dimensional micro-computed tomography imaging of the hydrogels indicated the presence of interconnected pores. The mechanical strength of the hydrogels and xerogels was measured using dynamic mechanical analysis. The observed dynamic storage moduli (E) for the equilibrium swollen and dry gels were found to be 0.15 and 4.2 MPa, respectively. Interestingly, the porous PEG-PU xerogel also showed E of 5.6 MPa indicating a similar mechanical strength upon incorporating porosity into the gel matrix. Finally, preliminary cytocompatibility studies showed the ability of cells to proliferate in the hydrogels. These gels show promise for applications as scaffolds and implants in tissue engineering. (c) 2014 Society of Chemical Industry

}, keywords = {hydrogels, permeability, poly(ethylene glycol), polyurethane, porosity}, issn = {0959-8103}, doi = {10.1002/pi.4802}, author = {Divakaran, Anumon V. and Torris, Arun A. T. and Lele, Ashish K. and Badiger, Manohar V.} } @article {43908, title = {Modular assembly of porous organic cage crystals: isoreticular quasiracemates and ternary co-crystal}, journal = {CrystEngComm}, volume = {19}, year = {2017}, month = {SEP}, chapter = {4933-4941}, abstract = {

Small changes in molecular structure and crystallisation conditions can have a profound effect on the crystal packing of molecules. Increasing the system complexity-for example, by introducing multiple components-greatly increases the number of potential outcomes. Hence, the rational design of porous cocrystals with multiple components is challenging. Here, we report a family of isoreticular quasiracemate crystalline phases for porous organic cages, FT-RCC3-R center dot CCX-S (where X = 1, 2, or 4), that were prepared in a modular and predictable fashion. By using directional intermolecular interactions between cages, we were able to prepare a rare ternary co-crystal, (CC3-S(0.5)CC4-S-0.5)center dot(CC13-S(0.5)CC3-S(0.25)CC4-S-0.25).

}, keywords = {cocrystals, Frameworks, Gas-chromatography, Halogen Bonds, Hydrogen-bonds, Molecular Cage, Nanoparticles, Pores, porosity, Separation}, issn = {1466-8033}, doi = {10.1039/c7ce00783c}, author = {Tothadi, Srinu and Little, Marc A and Hasell, Tom and Briggs, Michael E. and Chong, Samantha Y. and Liu, Ming and Cooper, Andrew I.} } @article {48314, title = {Highly interconnected porous monolithic and beaded polymers using high internal phase emulsion polymerization: tuning porous architecture through synthesis variables}, journal = {Polymer International}, volume = {72}, year = {2023}, month = {APR}, pages = {451-466}, type = {Article}, abstract = {

Open porous polymeric materials have gained popularity due to their exceptional properties and applications in tissue engineering scaffolds, drug delivery, enzyme immobilization and catalysis support. This study developed a novel two-stage approach to create networked, crosslinked poly(2-hydroxyethyl methacrylate-co-N,N{\textquoteright}-methylenebisacrylamide) HEMA-MBA beads. The first part involves producing an oil-in-water-in-oil high internal phase emulsion (HIPE). This is followed by suspension polymerization using a redox initiator pair. In this study, a mixed surfactant combination with low and high hydrophilicity-lipophilicity balance surfactants was identified and successfully utilized to prepare a stable oil-in-water-in-oil HIPE. The effect of crosslinker concentration (i.e. crosslink density), surfactant concentration and monomer-to-porogen ratio on pore architecture and surface area were successfully evaluated. In addition, a new protocol was developed to synthesize HEMA-MBA monoliths using an oil-in-water HIPE method at ambient temperature using a redox initiator pair. The effect of crosslink density and oil phase on pore architecture and surface area was evaluated. Key variables affecting the morphology of porous HEMA-MBA beads and monoliths were identified and quantified, allowing future development of porous HEMA-based polymer beads and monoliths with tunable morphologies which are suitable for numerous applications, especially in the biomedical field. (c) 2022 Society of Industrial Chemistry.

}, keywords = {HIPE polymerization, porosity, porous polymers, redox polymerization, Suspension polymerization}, issn = {0959-8103}, doi = {10.1002/pi.6489}, author = {Ponrathnam, Timothy and Behere, Isha and Ponrathnam, Surendra and Ingavle, Ganesh} }