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Di-stimuli Responsive poly(N-Isopropylacrylamide-co-Diethylaminoethylmethacrylate) Copolymer: Synthesis, Characterization and Investigation of Aqueous Dispersion Properties

Ashaduzzaman Md., Islam Shahidul Md.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 20, iss. 2

136--144

EN

We report on the synthesis, characterization and aqueous dispersion properties of well-defined double hydrophilic copolymer with pH- and thermo-responsive segments via atom transfer radical polymerization (ATRP). Poly(N-isopropylacrylamide-co-Diethylaminoethylmeth-acrylate), P(NIPAAm-co-DEAEMA), was prepared by ATRP using methyl-4-bromomethyl benzoate initiator. The product was characterized by proton-nuclear magnetic resonance (1H NMR) and attenuated total reflectance infrared (ATR-IR) spectroscopy. The multi-responsive switching between unimer and two types of micellar aggregates were characterized by temperature-dependent dynamic light scattering (DLS). Self-assembles into two types spherical aggregates in 1 mg/mL (0.0315 mM) aqueous solution, depending on solution pH and temperatures were widely investigated. The result shows two types of aggregate with large (280 nm) aggregate and variable sizes of small (17 nm, 25 nm, 45 nm) aggregates depending on temperature ranges from 26 to 40 °C at pH 4.

2

Surface initiated ATRP: Synthesis and Characterization of Functional Polymers Grafted on Modified Cellulose Beads

Ashaduzzaman Md., Ishikura K., Sakata M., Kunitake M.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 8, iss. 3

243-248

EN

Atom transfer radical polymerization (ATRP) was employed to synthesize novel polymer particles. The surface of porous polymeric cellulose beads was modified by sodium hydroxide, 2-chloromethyloxirane, ethylenediamine and 2-bromo-2-methylpropionyl bromide successively in order to activate the beads surface so that it can play an important role as an initiator for ATRP reaction. ATRP on the modified cellulose beads surface was carried out with styrene and sodium p-styrenesulphonate monomers in the presence of non aqueous and aqueous phases respectively. The polymer products on the substrate surface were characterized by elemental analysis (EA), attenuated total reflectance-infrared (ATR-IR) spectroscopy and carbon13 - nuclear magnetic resonance (13C-NMR).

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Investigation of Click Reactionat an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers

Ashaduzzaman Md., Kai S., Kunitake M.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 6

31-39

EN

Cu(I)-catalyzed Huisgen click reactions between lipophilic polymer (tri-arm azidofunctionalized polystyrene) and hydrophilic polymer (copolymer of styrene sulfonate sodium and propargyl methacrylate) were investigated and hollow capsules, consisting of composite polymer nanofilms were obtained in chloroform-water biphasic solution. Since the lipophilic polymer, or hydrophilic polymer and copper catalyst were present in the oil or aqueous phase, respectively, the cross-linking reaction proceeded only at the phase interface. The combination of lipophilic and hydrophilic polymers produced hollow capsules consisting of nanofilms with lipophilic core and hydrophilic shell.

4

Effect of Additives on Maximizing Petrol Production from Crude Oil and Investigation of Properties

Ashaduzzaman Md., Miah Yunus Md.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 6

6-16

EN

The objectives of this work were concentrated to investigate the enhancement of petrol distillate production from crude oil after treating with two additives. Attempts were also made to find out the mechanisms, those are responsible for enhancing the quantity and quality of petrol from crude oil by straight run refining process. From this study, it has been illustrated that the yield of petrol was directly proportional to the lubricating oil and inversely proportional to the bitumen asphalt content in the hydrocarbon mixture influenced by both physical and chemical reasons. The yield of petrol was increased ca. 4% (w/w) when 0.25% (w/w) additive-1 was used for blending before distillation. The physical properties of distillate petrol product were studied as well as the chemical quality was determined by TGA, 1H- NMR and GC-MS photometer.

5

Aqueous Dispersion and Temperature Induced Reversible Fluorescence Properties of 1-Pyrenecarboxaldehyde

Ashaduzzaman Md., Kunitake M.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 1

55-62

EN

The fluorescence intensities for various vibronic fine structures in the 1-pyrenecarboxaldehyde (PyCHO) fluorescence show strong environment dependence. In aqueous solvent, the distribution of dye is highly depended on its concentration labels and varies from excimer to monomeric state. UVVis Spectroscopic analysis could not able to detect dye below 10-7M concentration, whereas a New monomeric peak at 342 nm was observed after heating and cooling treatment at above the concentration. At 10-8M concentration, only monomeric distribution of 1-PyCHO reveals a strong temperature (20-50 ?C) induced reversible perturbation of the vibronic band intensities. This suggests the operation of some specific solute-solvent dipole-dipole interaction mechanism strongly influence by heating.