Wyniki wyszukiwania - BazTech

1

Combination of mesoporous titanium dioxide with MoS2 nanosheets for high photocatalytic activity

Karimi L.

Polish Journal of Chemical Technology

|

2017

|

Vol. 19, nr 2

56--60

EN

This study presents a facile approach for the preparation of MoS2 nanosheet decorated by porous titanium dioxide with effective photocatalytic activity. Mesoporous titanium dioxide nanostructures first synthesized by a hydrothermal process using titanium (III) chloride and then the MoS2 /TiO2 were prepared through mixing of MoS2 nanosheet with mesoporous titanium dioxide under ultrasonic irradiation. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The results showed that the nanocomposite has mesoporous structure with specific surface area of 176.4 m2 /g and pore diameter of 20 nm. The as-prepared MoS2 /TiO2 nanocomposites exhibited outstanding photocatalytic activity for dye degradation under sunlight irradiation, which could be attributed to synergistic effect between the molybdenum disulfide nanosheet and mesoporous titanium dioxide. The photocatalytic performance achieved is about 2.2 times higher than that of mesoporous TiO2 alone. It is believed that the extended light absorption ability and the large specific surface area of the 2D MoS2 nanosheets in the nanocomposite, leading to the enhanced photocatalytic degradation activity.

2

Preparation of Melt Spun Electroconductive Fine Fibres Containing Carbon Nanotubes

Mirjalili M., Karimi L.

Autex Research Journal

|

2015

|

Vol. 15, no. 2

87--92

EN

Preparation of electroconductive fine fibres containing carbon nanotubes (CNTs) by melt spinning was the main goal of the present study. In this regard, the influence of the main operating parameters such as type of polymer used (polyester, polypropylene and polyamide), type and concentration of the CNTs on conductivity, and mechanical and thermal properties of the melt spun fibres was studied. The conductivity of melt spun fibres was measured based on the method developed by Morton and Hearl. The morphologies of the CNTs–polymer composite fibres were studied by scanning electron microscopy. Thermal behaviours and mechanical properties of the CNTs–polymer composite fibres were investigated using differential scanning calorimetry and tearing tester, respectively. The results reveal that using CNTs had tangible effect on electrical, thermal and mechanical properties of the melt spun fibres. Also, polyamide had a better dispersion of CNTs and correspondingly lower surface resistivity.

3

Photocatalytic Self-cleaning Synergism Optimization of Cotton Fabric using Nano SrTiO3 and Nano TiO2

Zohoori S, Karimi L, Nazari A.

Fibres & Textiles in Eastern Europe

|

2014

|

Vol. 22, no. 2 (104)

91--95

EN

Titanium dioxide (TiO2) and Strontium titanate (SrTiO3) are well-known photocatalysts. Today, the photocatalytic activity of dyes on fabrics has attracted much attention. Therefore in this study the photocatalytic activity of nano strontium titanate mixed with nano titania was examined while being coated on cotton fabric under UV irradiation at different nano material concentrations and various pHs. The Central Composite Design (CCD) was used for different variables based on Design Expert software. The crystal size and phase of nano titania and strontium titanate were characterised by XRD. The cotton fabrics stained with two common synthesised dyes were treated under 400 W UV irradiation for 30 hours and their self-cleaning properties were investigated by reflectance spectrophotometer. SEM photos show the pervasion of nano materials. The results show that samples treated with SrTiO3 and TiO2 have higher values of ΔE* as compared with those treated with TiO2 or SrTiO3 alone.

PL

Tytanian strontu SrTiO3 i dwutlenek tytanu TiO2 są dobrze znanymi fotokatalizatorami. Obecnie fotokatalityczna aktywność barwników w materiałach tekstylnych wzbudza ogólne zainteresowanie i dlatego w przedstawionych badaniach fotokatalityczna aktywność nanocząstek SrTiO3 zmieszanych z TiO2 i naniesionych na tkaninę bawełnianą badana była przy napromieniowaniu UV przy różnym stężeniu nanocząstek i różnym pH. W badaniach stosowano program Central Composite Design i Design Expert dla różnych zmiennych. Wielkości krystalitów i faza cząstek TiO2 i SrTiO3 były charakteryzowane za pomocą XRD. Tkaniny bawełniane barwione dwoma powszechnie stosowanymi barwnikami syntetycznymi były naświetlane promieniowaniem UV o mocy 400 W przez 30 godzin a następnie były badane ich właściwości samooczyszczające przy zastosowaniu spektrofotometru refleksyjnego. Zdjęcia SEM pokazują rozłożenie nanocząstek. Wyniki badań wykazały, że próbki zawierające TiO2 i SrTiO3 mają wyższe wartości ΔE* niż próbki zawierające tylko jeden rodzaj nanocząstek.

4

Antibacterial dyeing of polyamide using turmeric as a natural dye

Mirjalili M., Karimi L

Autex Research Journal

|

2013

|

Vol. 13, no. 2

51--56

EN

Curcuma longa rhizome (turmeric) is a medicinal plant used for fabric and food coloration. In this study, polyamide (nylon 6.6) fabric was dyed with different mordants at various turmeric concentrations. The dyed fabric was evaluated for bacteriostatic activity against pathogenic strains of Gram-positive (Staphylococcus aureus) and Gramnegative (Escherichia coli) bacteria. The relationship between bacteriostatic activity and turmeric concentration was investigated. Durability of antibacterial activity to laundering is also discussed. Results indicate that the polyamide dyed with turmeric displayed excellent antibacterial activity in the presence of ferric sulfate, cupric sulfate, and potassium aluminum sulfate, and exhibited good and durable fastness properties.