scholarly journals A Surfactant Directed Microcrystalline Cellulose/Polyaniline Composite with Enhanced Electrochemical Properties

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2470 ◽  
Author(s):  
Mahnaz Abdi ◽  
Paridah Md Tahir ◽  
Rawaida Liyana ◽  
Ramin Javahershenas
Keyword(s):  
Microcrystalline Cellulose ◽  
Electrostatic Interactions ◽  
Pure Pani ◽  
Morphological Properties ◽  
Soft Template ◽  
Cyclic Voltammograms ◽  
Current Response ◽  
Chemical Polymerization ◽  
Sensor Applications ◽  
Peak Broadening

In this study a cationic surfactant, cetyltrimethylammonium bromide (CTAB), was used as a soft template for in situ chemical polymerization of aniline on the surface of microcrystalline cellulose (MCC). The morphology of the wire-like and porous nanostructure of the resulting composite was highly dependent on the MCC and CTAB concentrations. The effect of the MCC and CTAB concentrations on the electrochemical and morphological properties of the polyaniline (PAni) nanocomposite was studied. Cyclic voltammograms of modified PAni/MCC/CTAB electrode displayed a high current response and the effect of scan rate on the current response confirmed a diffusion controlled process on the surface of the electrode that makes it suitable for sensor applications. The overlapping characteristic peaks of pure PAni and MCC caused peak broadening at 3263 cm−1 in the IR spectra of PAni/MCC/CTAB nanocomposite that revealed the interaction between NH of PAni and OH group of MCC via electrostatic interactions. The addition of MCC to PAni through chemical polymerization decreased the thermal stability of composite compared to pure PAni. Lower crystallinity was observed in the XRD diffractogram, with 2 theta values of 22.8, 16.5, and 34.6 for PAni/MCC, confirming the formation of PAni on the MCC surface.

scholarly journals Cholesterol Levels Affect the Performance of AuNPs-Decorated Thermo-Sensitive Liposomes as Nanocarriers for Controlled Doxorubicin Delivery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 973
Author(s):  
Mónica C. García ◽  
Nabila Naitlho ◽  
José Manuel Calderón-Montaño ◽  
Estrella Drago ◽  
Manuela Rueda ◽  
...  
Keyword(s):  
Drug Release ◽  
Cancer Cells ◽  
Electrostatic Interactions ◽  
Drug Loading ◽  
Gradient Methods ◽  
Spherical Shape ◽  
Morphological Properties ◽  
Ovarian Cancer Cells ◽  
Cholesterol Levels ◽  
L1 And L2

Stimulus-responsive liposomes (L) for triggering drug release to the target site are particularly useful in cancer therapy. This research was focused on the evaluation of the effects of cholesterol levels in the performance of gold nanoparticles (AuNPs)-functionalized L for controlled doxorubicin (D) delivery. Their interfacial and morphological properties, drug release behavior against temperature changes and cytotoxic activity against breast and ovarian cancer cells were studied. Langmuir isotherms were performed to identify the most stable combination of lipid components. Two mole fractions of cholesterol (3.35 mol% and 40 mol%, L1 and L2 series, respectively) were evaluated. Thin-film hydration and transmembrane pH-gradient methods were used for preparing the L and for D loading, respectively. The cationic surface of L allowed the anchoring of negatively charged AuNPs by electrostatic interactions, even inducing a shift in the zeta potential of the L2 series. L exhibited nanometric sizes and spherical shape. The higher the proportion of cholesterol, the higher the drug loading. D was released in a controlled manner by diffusion-controlled mechanisms, and the proportions of cholesterol and temperature of release media influenced its release profiles. D-encapsulated L preserved its antiproliferative activity against cancer cells. The developed liposomal formulations exhibit promising properties for cancer treatment and potential for hyperthermia therapy.

scholarly journals MnO2@Reduced Graphene Oxide Nanocomposite-Based Electrochemical Sensor for the Simultaneous Determination of Trace Cd(II), Zn(II) and Cu(II) in Water Samples

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 517
Author(s):  
Siyamthanda Hope Mnyipika ◽  
Tshimangadzo Saddam Munonde ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Heavy Metals ◽  
Electrochemical Sensor ◽  
Simultaneous Determination ◽  
Rapid Detection ◽  
Electrochemical Sensors ◽  
Simultaneous Detection ◽  
Cyclic Voltammograms ◽  
Current Response ◽  
Mno2 Nanoparticles

The rapid detection of trace metals is one of the most important aspect in achieving environmental monitoring and protection. Electrochemical sensors remain a key solution for rapid detection of heavy metals in environmental water matrices. This paper reports the fabrication of an electrochemical sensor obtained by the simultaneous electrodeposition of MnO2 nanoparticles and RGO nanosheets on the surface of a glassy carbon electrode. The successful electrodeposition was confirmed by the enhanced current response on the cyclic voltammograms. The XRD, HR-SEM/EDX, TEM, FTIR, and BET characterization confirmed the successful synthesis of MnO2 nanoparticles, RGO nanosheets, and MnO2@RGO nanocomposite. The electrochemical studies results revealed that MnO2@RGO@GCE nanocomposite considerably improved the current response on the detection of Zn(II), Cd(II) and Cu(II) ions in surface water. These remarkable improvements were due to the interaction between MnO2 nanomaterials and RGO nanosheets. Moreover, the modified sensor electrode portrayed high sensitivity, reproducibility, and stability on the simultaneous determination of Zn(II), Cd(II), and Cu(II) ions. The detection limits of (S/N = 3) ranged from 0.002–0.015 μg L−1 for the simultaneous detection of Zn(II), Cd(II), and Cu(II) ions. The results show that MnO2@RGO nanocomposite can be successfully used for the early detection of heavy metals with higher sensitivity in water sample analysis.

A study of the mechanical, thermal and morphological properties of microcrystalline cellulose particles prepared from cotton slivers using different acid concentrations

Cellulose ◽  
2009 ◽  
Vol 16 (5) ◽  
pp. 783-793 ◽  
Author(s):  
Kunal Das ◽  
Dipa Ray ◽  
N. R. Bandyopadhyay ◽  
Tony Ghosh ◽  
Amar K. Mohanty ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Morphological Properties

Morphology and Properties of Polyoxymethylene/Polypropylene/Microcrystalline Cellulose Composites

2017 ◽  
Vol 751 ◽  
pp. 264-269
Author(s):  
Nipawan Yasumlee ◽  
Sirirat Wacharawichanant
Keyword(s):  
Thermal Stability ◽  
Microcrystalline Cellulose ◽  
Decomposition Temperature ◽  
Sem Analysis ◽  
Morphological Properties ◽  
Melt Mixing ◽  
Cellulose Composites ◽  
The Difference ◽  
Pp Blends ◽  
Internal Mixer

The effects of microcrystalline cellulose (MCC) on mechanical, thermal and morphological properties of polyoxymethylene (POM)/polypropylene (PP) blends at different compositions were investigated. The blends and composites were prepared by melt mixing using an internal mixer at 200°C. Scanning electron microscopy (SEM) analysis revealed phase separation between POM and PP phases due to the difference in polarity of POM and PP. When adding the MCC in the blends the morphology slightly changed due to the weak interaction between MCC and polymer phases. Incorporation of MCC at 5 phr could improve Young’s modulus of POM/PP blends. The storage modulus of the blends was improved after adding MCC 5 phr due to reinforcing effect of the MCC. The thermal properties found that the addition of MCC had no effect on the melting temperature of the blends. The blends exhibited higher decomposition temperature than pure POM. The blends showed the decomposition temperatures increased when increasing amount of PP content, which were higher than pure POM. Therefore, it may be inferred that the addition of PP could enhance the thermal stability of the POM/PP blends, but the addition of MCC did not improve the thermal stability.

An Investigation of Molecular Interactions between Zinc Phthalocyanine Thin Film and Various Oxidizing Gases for Sensor Applications

2011 ◽  
Vol 403-408 ◽  
pp. 48-51 ◽  
Author(s):  
Rawat Jaisutti ◽  
Tanakorn Osotchan
Keyword(s):  
Thin Film ◽  
Step Height ◽  
Zinc Phthalocyanine ◽  
Current Response ◽  
Sensor Applications ◽  
Measuring Period ◽  
Gas Molecules ◽  
Response Current ◽  
Different Response ◽  
So2 Concentration

Molecular interaction between zinc phthalocyanine (ZnPc) thin films and various oxidizing gas molecules was examined by measuring sensor response of chemiresistor structures. The different response types can be obtained from the interactions to gas molecules of nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO). For NO2 interaction, the response current of thermal evaporated ZnPc thin film with metal inter-digitaged pattern electrodes was proportionally increase to the concentration of NO2 gas. For measurement cycle, the NO2 gas at desired concentration was flowed into the measuring chamber for 20 minutes then the nitrogen gas was flowed for 20 minutes to recovering the interaction. The current response exhibited the step up and down during this measuring cycle and the heights of response step were proportional to the NO2 concentration. For SO2 measuring cycle, the response step increased at the beginning cycle then the response of ZnPc thin film seemed to be saturate and remained the same response step height even increasing the SO2 concentration. It was found that if the SO2 concentration was maintained at the same value for each measuring period, the response current was increase for the first few cycles after that the response step height decreased and became almost constant at lower value after passing more than ten measuring cycles. However this phenomenon can recover if the ZnPc surface was leaved in air for a few days. Therefore the interaction between ZnPc and SO2 molecules can modify the ZnPc surface and change the gas response. With the same measurement setup, it cannot found any significant change in the response current of the ZnPc film under the CO gas exposure up to concentration of 250 ppm. This result indicated that no interaction between ZnPc and CO molecules can be observed and these different responses on various gas molecules can demonstrate the selectivity of using ZnPc as a gas sensor.

scholarly journals Effect of 6 MeV electron Irradiation on Nano-Cu 2 ZnSnS 4

2021 ◽  
Author(s):  
Sneha Pravin Kandare ◽  
V. N. Bhoraskar ◽  
A. B . Phatangare ◽  
Rekha Rao ◽  
Mala Rao ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Electron Irradiation ◽  
Nano Particles ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Sem Images ◽  
X Ray ◽  
Pristine Sample ◽  
Peak Broadening

Abstract Microwave synthesized nano sized Cu2ZnSnS4 (CZTS) powder was irradiated with 6 MeV electrons, to investigate stability under radiation. The structural, optical, vibrational and morphological properties were explored using X-ray diffraction, UV-Visible spectroscopy, Raman spectroscopy and Scanning Electron Microscope (SEM).The irradiated sample shows significant change in properties when compared to the pristine sample. X ray peak broadening analysis has been used to estimate the crystallite size and lattice strain. Raman spectroscopy analysis confirms the transition of ordered kesterite to disordered kesterite phase after electron irradiation at electron fluence of 4 x1015 e-/cm2. CZTS nano-particles having hierarchical flower like morphology starts agglomerating after electron irradiation as observed from SEM images. The sample did not amorphize upto the highest fluence 4 x 1015 e-/cm2 employed in this study.

scholarly journals Photocatalytic Hydrogen Production Under Near-UV Using Pd-Doped Mesoporous TiO2 and Ethanol as Organic Scavenger

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 33 ◽  
Author(s):  
Bianca Rusinque ◽  
Salvador Escobedo ◽  
Hugo de Lasa
Keyword(s):  
Hydrogen Production ◽  
Uv Light ◽  
Sol Gel ◽  
Chemical Reactor ◽  
Morphological Properties ◽  
Soft Template ◽  
Quantum Yields ◽  
Metal Doped ◽  
The University ◽  
Energy Balances

Photocatalysis can be used advantageously for hydrogen production using a light source (near-UV light), a noble metal-doped semiconductor and an organic scavenger (2.0 v/v% ethanol). With this end, palladium was doped on TiO2 photocatalysts at different metal loadings (0.25 to 5.00 wt%). Photocatalysts were synthetized using a sol-gel method enhancing morphological properties with a soft template precursor. Experiments were carried out in the Photo-CREC Water II reactor system developed at CREC-UWO (Chemical Reactor Engineering Centre- The University of Western Ontario) Canada. This novel unit offers hydrogen storage and symmetrical irradiation allowing precise irradiation measurements for macroscopic energy balances. Hydrogen production rates followed in all cases a zero-order reaction, with quantum yields as high as 30.8%.

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