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We demonstrate a facile efficient way to fabricate activated carbon nanosheets (ACNSs) consisting of hierarchical porous carbon materials. Simply heating banana leaves with K2 CO3 produce ACNSs having a unique combination of macro-, meso- and micropores with a high specific surface area of ∼1459 m2 g-1 . The effects of different electrolytes on the electrochemical supercapacitor performance and stability of the ACNSs are tested using a two-electrode system. The specific capacitance (Csp ) values are 55, 114, and 190 F g-1 in aqueous 0.5 M sodium sulfate, organic 1 M tetraethylammonium tetrafluoroborate in acetonitrile, and pure ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6 ]) electrolytes, respectively. The ACNSs also shows the largest potential window of 3.0 V, the highest specific energy (59 Wh kg-1 ) and specific power (750 W kg-1 ) in [BMIM][PF6 ]. A mini-prototype device is prepared to demonstrate the practicality of the ACNSs.

A new chemical method is developed for the preparation of a unique one-dimensional (1D) Sn(IV) hydroxide nanofluid. The 1D-Sn(IV) hydroxide nanowires of ca. 600 nm in length and ca. 25 nm in width yield transparent glass type flakes when the nanofluid is dried in air. The stability of the system, keeping it safe from sedimentation even after a year, is believed to rely on its high zeta-potential of ca. 55 mV (± 2.5 mV). We extensively investigate the thermal conductivity and viscosity of the system in order to evaluate its nanofluidic merits, resulting in thermal conductivity exceeding 1 W m−1 K−1. The nanofluid is further investigated for nonlinear optics (NLO) applications, revealing a reversible switching from positive Z-scan (convex lens) to negative Z-scan (concave lens) of the nonlinear phase when the laser power is tuned from 500 to 1000 μW.

Abstract: The poor solubility, lack of targetability, quick renal clearance, and degradability of many therapeutic and imaging agents strongly limit their applications inside the human body. Amphiphilic copolymers having self-assembling properties can form core-shell structures called micelles, a promising nanocarrier for hydrophobic drugs, plasmid DNA, oligonucleotides, small interfering RNAs (siRNAs), and imaging agents. Fabrication of micelles loaded with different pharmaceutical agents provides numerous advantages, including therapeutic efficacy, diagnostic sensitivity, and controlled release to the desired tissues. Moreover, their smaller particle size (10-100 nm) and modified surfaces with different functional groups (such as ligands) help them to accumulate easily in the target location, enhancing cellular uptake and reducing unwanted side effects. Furthermore, the release of the encapsulated agents may also be triggered from stimuli-sensitive micelles under different physiological conditions or by an external stimulus. In this review article, we discuss the recent advancements in formulating and targeting of different natural and synthetic micelles, including block copolymer micelles, cationic micelles, and dendrimers-, polysaccharide- and protein-based micelles for the delivery of different therapeutic and diagnostic agents. Finally, their applications, outcomes, and future perspectives have been summarized.

1D hematite (alpha-Fe2O3) nanorods were synthesized in the presence of rice starch solution. The size of the nanorods was about 250 nm and 50 nm in length and diameter, respectively. The synthesized nanorods possessed a single alpha-Fe2O3 phase without any impurities and crystal defects. The obtained hematite nanorods were employed as an adsorbent for lead (II) removal. The isotherms and kinetic studies indicated that our material would be a potential candidate for heavy metal adsorption and removal.

Herein, we report the fabrication of highly oxidized silver oxide/silver/tin(IV) oxide (HOSBTO or Ag3+-enriched AgO/Ag/SnO2) nanocomposite under a robust oxidative environment created with the use of concentrated nitric acid. Tin(IV) hydroxide nanofluid is added to the reaction mixture as a stabilizer for the Ag3+-enriched silver oxide in the nanocomposite. The formation of Ag nanoparticles in this nanocomposite originates from the decomposition of silver oxides during calcination at 600 °C. For comparison, poorly oxidized silver oxide/silver/tin(IV) oxide (POSBTO with formula AgO/Ag/SnO2) nanocomposite has also been prepared by following the same synthetic procedures, except for the use of concentrated nitric acid. Finally, we studied in detail the anti-pathogenic capabilities of both nanocomposites against four hazardous pathogens, including pathogenic fish bacterium (Stenotrophomonas maltophilia stain EP10), oomycete (Phytophthora cactorum strain P-25), and two different strains of pathogenic strawberry fungus, BRSP08 and BRSP09 (Collectotrichum siamense). The bioassays reveal that the as-prepared HOSBTO and POSBTO nanocomposites exhibit significant inhibitory activities against the tested pathogenic bacterium, oomycete, and fungus in a dose-dependent manner. However, the degree of dose-dependent effectiveness of the two nanocomposites against each pathogen largely varies.

A new chelating resin was synthesized by modification of Amberlite XAD-4 resin with 1,8-diaminonaphthalene through an azo linkage ( N N ). The synthesized resin was characterized by scanning electron microscope, Fourier transform infrared spectroscope, elemental analysis and thermogravimetric analysis. It was applied to preconcentrate and separate Cu(II), Cd(II) and Pb(II) ions, which were determined subsequently by graphite furnace atomic absorption spectrometry. Various physico-chemical parameters that influence the quantitative preconcentration and recovery of the metals were optimized by both static and dynamic techniques. Among them, optimum pH was in the range 6–7. 2.0 M HNO 3 was selected as eluent. Optimum flow rates of sample and the eluent were found to be 2 and 4 mL min −1 , respectively. Preconcentration factors were 220 for Cu(II) and Cd(II) and 240 for Pb(II), sorption half times ( t 1/2 ) were 5 min for Cu(II) and Cd(II) and 6 min for Pb(II), respectively. The Langmuir, Freundlich and Temkin adsorption isotherms were also studied in detail. The procedure was validated by analysis of a certified reference material (A-11, powder milk). The new method was employed to estimate the metal ion concentrations quantitatively from dairy cow’s milk collected from dairy farm, Savar, Dhaka, Bangladesh.

Dyes are priority pollutants, commonly found at significant concentrations in textile effluents. The presence of dyes stuffs in wastewater can cause severe problems to aquatic life and human beings. Therefore, the removal of dyes from wastewater is important in order to minimize their hazardous effects on the environment. One way of removing dyes is to use nanosized manganese oxides (MnOs). To date, there has been much work reported on the use of nanosized MnOs as sorbents for dyestuffs. They are promising sorbents for commercial use due to their amorphous nature, high specific surface areas (SSA), mesoporous structure, and low to the moderate point of zero charge (pHPZC). This review summarizes the toxicity and recent advances for removing dyes from wastewater using nanosized MnO sorbents. The article also describes the various experimental parameters necessary for adsorption optimization, such as adsorption time, pH, initial dye concentration, amount of sorbent and temperature. Adsorption mechanisms investigated by various modeling approaches are also discussed. In particular, it was observed that much work has been reported on the use of birnessite and its composites for dye removal. There are many papers reporting on the use of MnO in batch mode dye removal, but very few that report on the use of MnO in continuous column removal systems. Therefore, there is still a considerable need for further research to develop effective and economical large scale MnO column systems for commercial use.

The comparative study has been designed to estimate serum magnesium (Mg) and potassium (K) in patients with acute myocardial infarction (AMI) and chronic ischemic heart disease (CIHD). A total 61 subjects were selected and were divided as group-I (30 subjects of AMI) and group-II (31 subjects of CIHD). Laboratory investigations were done for estimation of serum glucose and serum creatinine to exclude the diabetes mellitus and renal disease. Serum Mg was estimated by atomic absorption spectrophotometer and serum K by ion selective electrode. This study showed that Mg and K level in serum is significantly lower in patients with AMI than that of CIHD subjects. Findings of the study suggested that significantly reduced serum level of Mg and K persists in AMI than those of CIHD, which may be the cause of further cardiac complications. So it may be recommended for estimation and supplementation of Mg and K in both the cases of AMI and CIHD patients for better management. DOI: http://dx.doi.org/10.3329/jdnmch.v17i1.12190 J. Dhaka National Med. Coll. Hos. 2011; 17 (01): 33-36

The multi-component oxide (Al0.88Fe0.67Zn0.28O3)) surface (abbreviated as MCOS) was prepared to optimize the effectiveness of the elimination of As (III) from aqueous solution. The oxide surface was synthe-sized by co-precipitation method using corresponding metal carbonates. It was characterized by XRD, TGA and DSC. The surface morphology of MCOS was observed in SEM and the elemental analysis was accomplished by EDX. The composition of Al2O3, Fe2O3 & ZnO was 23.6, 39.9 and 20.6 wt% respectively in XRF analysis. The specific surface area was found 389.85 m2 g-1. Batch experiments were performed to remove As (III) from aqueous solution considering various parameters such as effect of pH, contact time, initial arsenic concentration, temperature and sor-bent dosage. The maximum sorption capacity of the surface was almost steady from pH 4 to pH 9. Kinetic study shows that As (III) sorption is following second order rate equation with the rate constant of 80×10-2 g mg-1 min-1 at room temperature and this rate was increased with increasing temperature which indicates the sorption was endothermic process. The free energy change, ΔGo was negative which proves that the sorption was spontaneous and thermodynamically favorable. Sorption isotherm was interpreted by Langmuir equation and the maximum sorption capacity of oxide monolayer was 13×10-2 mg g-1.

A mixed oxide of cobalt (Co) and nickel (Ni) with an approximate composition of Co 0.4 Ni 0.4 O 0.2 was prepared chemically by precipitating from the corresponding metal carbonates and heating the mixture of carbonates at 650 °C under ambient atmosphere. The mixed (Co–Ni) oxide thus prepared was characterized by IR, SEM and XRD methods. The composition of the mixed metal oxide was obtained by EDX analysis. The surface behavior of the Co–Ni mixed oxide matrix was tested by adsorption studies and pH pzc measurement. The Co–Ni mixed oxide matrix behaves as a charged adsorbent at the pH media higher and lower than its pH pzc value (9.50) and thus found to be capable of anchoring the oppositely charged species onto its surface. Removal of cationic and anionic dyestuffs, viz ., methylene blue (MB) and procion red (PR), respectively, was attempted using the mixed oxide surface as adsorbent. Although both the dyes can be removed by the mixed oxide, the extent of PR removal (∼70%) seems to be much higher than that of MB (∼20%) demonstrating the superior performance of the Co–Ni mixed oxide for its use as adsorbent in removing the anionic PR dyestuff from water.

A “two-phase protocol” is proposed to prepare gold electrode with controlled surface and crystallographic properties. Gold nanoparticles were first electrodeposited onto a glassy carbon (GC) electrode. Next, gold particles were allowed to be deposited by a colloidal chemical seeding process onto the previously electrodeposited gold nanoparticles on the GC electrode and thus Au-over-Au electrodes were fabricated. It was found that the surface area, crystallographic orientation and the surface morphology of the prepared electrodes can be controlled by adding acid or additive (I − ) to the seeding media. An electrode ensemble with surface area of as high as 7.5 × 10 −3 cm 2 and ca . 60% Au(1 1 1) facet was fabricated by maintaining the seeding medium at pH 2.15. The application of the prepared electrode was demonstrated briefly in the electrochemical detection of arsenic(III) in water.

A composite based on organic copolymer and inorganic oxide, polyaniline/poly o-toluidine/silica (PANI/POT/SiO2), has been synthesized successfully by a simple electrochemical method. The composite film was found to be deposited on a Pt substrate by sweeping the potential between −0.2 and +1.0 V versus a saturated calomel electrode with a scan rate of 100 mV/s. The polymeric composite film thus obtained was characterized by scanning electron microscopy, infrared spectroscopy, conductance measurement, and cyclic voltammetry techniques. Incorporation of silica in the copolymer results a clear difference in surface morphology compared with the bulk homo- and copolymers. Further evidence of silica in the composite was achieved by infrared spectral analysis. Indeed, a chemical analysis of the composite matrix showed a content of as high as 25% SiO2 in the composite thus prepared. Based on the results of cyclic voltammetric analysis, the composite electrode as prepared was found to show good electrochemical stability even at high positive potentials. It also exhibited excellent electroactivity even after incorporation of silica in the matrix. The electroactive composite film was thus examined as electrode modifier to study the redox behavior of ferrous/ferric (Fe2+/Fe3+) and hydroquinone/benzoquinone (H2Q/Q) couples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

We report the successful measurement of the specific surface area of chemically synthesized and treated polyaniline (PANI) and its composite PANI/silica (SiO2). PANI was synthesized chemically from an aqueous solution of aniline and hydrochloric acid (HCl) in the presence of an oxidant, ammonium peroxydisulfate [(NH4)2S2O8]. In the synthesis of PANI/SiO2, SiO2 was incorporated from its colloidal solution contained in the solution for the polymerization of PANI. PANI and PANI/SiO2 thus synthesized were pretreated with double-distilled water (pH = 6.95), aqueous HCl (pH = 1.09), and aqueous ammonia (pH = 10.15) solutions to control their pH levels. Surface morphologies of the treated PANI and PANI/SiO2 matrices were investigated with scanning electron microscopy. The successful incorporation of SiO2 into the PANI/SiO2 composite was confirmed by the characteristic infrared absorption band at 1096 cm−1. The adsorption of methylene blue, which was found to follow the Langmuir isotherm, onto the prepared materials was probed to estimate the real surface area. The base-treated PANI matrix showed a higher surface area than the acidic and neutral ones. The incorporation of SiO2 into the PANI matrix yielded a larger surface area. However, the treated PANI/SiO2 showed the same trend as the treated PANI matrices. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

This article discusses the results for the development of a nanogold-particle/polyaniline-modified glassy carbon electrode for the detection of arsenic(III) in water. A thin polyaniline film was electropolymerized onto a glassy carbon electrode. The gold nanoparticle was then deposited onto the polyaniline-coated glassy carbon electrode via potential step electrolysis from 1.1 to 0 V versus Ag/AgCl/NaCl (saturated) for 45 s from a 0.5M H2SO4 solution containing 0.1 mM NaAuCl4 in the absence and presence of a 0.1 mM KI additive. The surface of the modified electrode was examined with scanning electron microscopy. Cyclic and anodic stripping voltammetry of arsenic(III) was performed on the modified electrode. The thus modified nanogold-particle/polyaniline-modified glassy carbon electrode prepared in the presence of the I− (KI) additive showed a high sensitivity in detecting arsenic(III) in water, and with stripping voltammetry, a limit of detection of 0.4 ppb arsenic was obtained, which is much lower than the arsenic guideline limit of the World Health Organization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1306–1311, 2007

Polyaniline (PANI), polythiophene (PT) and polypyrrole (PPy) films were electrochemically synthesized under centrifugal acceleration ranging 1–300g. The polymerization rate of the studied monomers was found to be affected by the applied gravitational force. The polymers thus synthesized with and without centrifugation also exhibited clear differences in their physical and chemical properties. In addition, morphological structure of the polymer films was also affected by the centrifugal field. The effect of the force exerted on the working electrode was found to be anisotropic. A mechanism for the electrochemical deposition of the polymers under centrifugal force has also been proposed.

Chemically synthesized conducting polyaniline (PANI) was investigated as adsorbent for its possible application in the removal of organic dyes, such as methylene blue (MB) and procion red (PR) from their aqueous solution. PANI adsorbent behaves as a charged surface upon post-synthesis treatment of the polymer with acid and base. The adsorbent thus treated shows a high selectivity for the removal of dyes in the adsorption process. The Langmuir adsorption isotherm was used to represent the experimental adsorption data. The cationic dye, MB can be preferentially removed by the base-treated PANI while the anionic dye, PR is predominately removed by the acid-treated one. These observations were further evidenced from the measurements of molar conductance and pH of the dye solutions employed for adsorption. The finding can be explained considering the electrostatic nature of adsorption coupled with the morphology of the PANI surface thus treated. Copyright © 2004 John Wiley & Sons, Ltd.

The effects of ultrasonication on the chemical polymerization of aniline leading to the formation of conducting polyaniline colloids were examined. The formation rate of the colloids was significantly increased under ultrasonication. Furthermore, it was also observed that the morphological structure of the colloids thus prepared was greatly affected by the sonication. The polyaniline colloids were further characterized by a range of techniques including electric resistance meter, gel permeation chromatography, FT-IR and cyclic voltammetry. It is noteworthy that the application of ultrasound to the polymerization resulted in a marked increase in the doping level, which reflected to the high electroconductivity of polyaniline colloids.

Work function measurements indicate that electrochemically synthesized poly(3-methyl thiophene) films exhibit p- and n-type conducting natures when doped anodically and cathodically with anions and cations, respectively. This has been further confirmed by the conductivity measurements together with the current-voltage measurements with and without illumination for the doped polymer films sandwiched between dissimilar metals.

Mn 3 O 4 nanoparticles with diameter ca. 10 nm were synthesized by the forced hydrolysis of Mn(II) acetate at 80 °C. The X-ray diffraction (XRD), Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques were employed to study structural features and chemical composition of the nanoparticles. The unique oxidative activity of the Mn 3 O 4 nanoparticles was demonstrated in the polymerization and dye degradation reactions. On adding Mn 3 O 4 suspension to an acidic solution of aniline, yielded immediately green sediment of polyaniline (PANI). The organic dyes, viz ., methylene blue (MB) and procion red (PR) were found to be completely decolorized from their aqueous solution on treating the dyes with Mn 3 O 4 suspension in acidic media. The Mn 3 O 4 nanoparticles also showed a clear antibacterial activity against the Vibrio cholerae , Shigella sp ., Salmonella sp ., and Escherichi coli bacteria that cause cholera, dysentery, typhoid, and diarrhea diseases, respectively.

Electrochemically synthesized films of poly(3-methyl thiophene) have been oxidized and reduced at controlled potentials in an acetonitrile solution of tetramethylammonium hexafluorophosphate. The polymer films thus treated are found to exhibit p- and n-type semiconductance based on the measurements of absorption spectra, work functions and conductivities together with the current-voltage measurements with and without illumination for the polymer films sandwiched between dissimilar metals.

An organic p-n homojunction has been successfully constructed in a single strip of poly(3-methylthiophene) (PMT) film by electrochemical cation doping on one side and photosensitized anion doping on the other side. The rectifying effect observed with the Al/(cation:anion)-doped PMT/Au cell provides evidence for the formation of a p-n homojunction in the PMT film since both Al/cation-doped PMT/Al and Au/anion-doped PMT/Au cells exhibit ohmic behavior. The formation of p-n homojunction can be inferred from measured work functions of the electrochemically cation-doped PMT, photochemically anion-doped PMT, Al and Au films. The p-n homojunction cell yields a short-circuit photocurrent of 0.16 µ A· cm-2, an open-circuit photovoltage of 0.23 V and a fill factor of 0.30. These voltaic and photovoltaic properties are found to be superior to those of the polymer diode based on a p-n junction made by pressure contact of the p-doped PMT film with the n-doped PMT film.

Tuberculosis (TB) is a prevalent systemic bacterial infection caused by Mycobacterium tuberculosis. In this article we are reporting a patient with bilateral pleural effusion and left sided neck swelling. Histopathologyof thc neck swelling diagnosed the case as tubcrculous lymphadcnopathy. Thorough investigation revealed no evidence of primary tuberculosis elsewhere, the patient improved dramatically within one month of `4 drugs combination of anti-tubercular therapy. The patient was asked to continue treatment till the prescribed period. There are limited global reports on the coexistence of tubercular lymphadenitis and pleural effusion and possibly this is the first case study from Bangladesh. DOI: http://dx.doi.org/10.3329/akmmcj.v3i1.10112 AKMMCJ 2012; 3(1): 31-33