Characterization of Porous TiO2 Films Prepared Using PEG of Different Molecular Weight

2011 ◽  
Vol 298 ◽  
pp. 253-256
Author(s):  
Li Li Yang ◽  
Jia Wei Bai ◽  
Wen Jie Zhang

Porous TiO2 films were prepared through dip-coating on glass substrates using different molecular weight of PEG. Surface roughness increased with increasing PEG molecular weight. The film prepared with PEG400 was fairly smooth with slight roughness. The films prepared with high molecular PEG became rougher and there were some larger particles on the films. When the PEG molecular weight got higher, adsorption edge of the films tended to move toward shorter wavelength region. In the wavelength range between 350 and 450 nm, larger PEG molecules made higher film transmittance. The particles prepared using higher or lower molecular weight of PEG had less surface area than using PEG1000. The average pore sizes were 14 nm, 15 nm, 28 nm, and 52 nm, and the total pore volume were 0.12 ml/g, 0.13 ml/g, 0.08 ml/g, and 0.09 ml/g for the TiO2 powders prepared using PEG400 to PEG 6000.

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1164
Author(s):  
Angeliki Chroni ◽  
Thomas Mavromoustakos ◽  
Stergios Pispas

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.


2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Marek Nocuń ◽  
Sławomir Kwaśny

AbstractIn our investigation, V doped SiO2/TiO2 thin films were prepared on glass substrates by dip coating sol-gel technique. Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). Transmittance of the samples was characterized using UV-VIS spectrophotometry. Subsequently band-gap energy (Eg) was estimated for these films. Powders obtained from sols were characterized by FTIR spectroscopy. It was found that vanadium decreases optical band gap of SSiO2/TiO2 films.


2020 ◽  
Vol 9 (1) ◽  
pp. 1-8
Author(s):  
Agustino Agustino ◽  
Rakhmawati Farma ◽  
Erman Taer

Elektroda karbon aktif berbasis serat daun nanas (SDN) telah berhasil diproduksi dengan proses tiga langkah berikut ini, yaitu: (i) aktivasi kimia, (ii) karbonisasi, dan (iii) aktivasi fisika. Aktivasi kimia dilakukan dengan menggunakan agen pengaktif KOH dengan konsetrasi 0,3 M. Karbonisasi dilakukan dalam lingkungan gas N2 pada temperatur 600oC dan diikuti oleh aktivasi fisika pada temperatur 850oC menggunakan gas CO2 selama 2,5 jam. Luas permukaan spesifik elektroda 512,211 m2×g-1 dengan volume total pori sebesar 0,093 cm3×g–1, dan jari-jari pori rata-rata 1,199 nm. Morfologi permukaan elektroda karbon aktif menunjukkan adanya serat karbon dengan diameter serat dalam kisaran 101 - 185 nm dan memliki kandungan karbon dengan massa atomik sebesar 84,33%. Elektroda karbon aktif memiliki struktur amorf, yang ditunjukkan oleh dua puncak difraksi yang lebar pada sudut hamburan 24,64 dan 43,77o yang bersesuaian dengan bidang (002) dan (100). Kapasitansi spesifik, energi spesifik dan daya spesifik sel superkapasitor yang dihasilkan masing-masing sebesar 110 F×g-1, 15,28 Wh×kg-1 dan 36,69 W×kg-1. Pineapple leaf fiber (PALF) based activated carbon electrode has been successfully produced using three-step process, i.e. (i) chemical activation, (ii) carbonization, and (iii) physical activation. The chemical activation was carried out using KOH activating agent with a concentration of 0.3 M. The carbonization process is conducted out in N2 gas environment at 600oC and followed by physical activation at a temperature of 850oC by using CO2 gas for 2.5 h. The specific surface area of the electrode is 512.211 m2×g-1 with a total pore volume of 0.093 cm3×g-1, and average pore radius of 1.199 nm. The surface morphology of the electrode shown the carbon fibers with diameter in the range of 101 - 185 nm and carbon content with 84.33% of atomic mass. The activated carbon electrode has an amorphous structure, which is shown by two wide diffraction peaks at scattering angles of 24.64 and 43.77o which correspond to the plane (002) and (100), respectively. The specific capacitance, energy and power of the electrode are 110 F×g-1, 15.28 Wh×kg-1 and 36.69 W×kg-1, respectively.Keywords: Serat daun nanas, Kalium hidroksida, Elektroda karbon aktif, Kapasitansi spesifik, Superkapasitor 


2008 ◽  
Vol 368-372 ◽  
pp. 342-344
Author(s):  
Lin Jiang Wang ◽  
Xiang Li Xie

Porous silica was prepared by selective leaching of metakaolinite with 20 mass% HCl solution. The metakaolinite was derived from the 1:1 layered structure clay mineral kaolinite by firing at 600°C for 24 h. The characteristics of porous silica were studied. The content of Al2O3 in metakaolinite was sharply changed from 45% to less than 2% after 2 h leaching. The maximum specific surface area of the leached sample was about 350 m2/g. The average pore size is about 2 nm. The total pore volume is 0.3 ml/g. The layer structure of kaolinite and metakaolinite is responsible for forming micropores.


2011 ◽  
Vol 382 ◽  
pp. 344-347
Author(s):  
Wen Jie Zhang ◽  
Bo Yang ◽  
Hong Bo He

Porous TiO2 films were prepared through dip-coating on glass substrates using several different templates. Dip-coating process was optimized to prepare the three layered films. The film prepared with PEG1000 has the maximum activity compared with the other films using CTAB and HST. While PEG molecular weight is in the range from 400 to 6000, methyl orange degradation rate reaches its maximal value when using PEG1000. Two comparatively high activities can be found at the ratios of PEG1000:PEG400 as 3:1 and 1:2. The 1:2 ratio is the optimal one. PEG1000 seems to be more suitable of being used as a template to prepare porous TiO2 film with high photocatalytic activity. After 200 min of irradiation, 98.6 % of the initial dye can be degraded on the film prepared using 2 g of PEG1000.


2011 ◽  
Vol 106 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Ana I. Bourbon ◽  
Ana C. Pinheiro ◽  
Miguel A. Cerqueira ◽  
Cristina M.R. Rocha ◽  
Maria C. Avides ◽  
...  

2017 ◽  
Vol 380 ◽  
pp. 86-91 ◽  
Author(s):  
Won Joon Lee ◽  
Dong Sik Bae

Y2Ti2O7nanoparticles have been synthesized by co-precipitation. Y2Ti2O7was coated on a glass substrate. The average size of the synthesized Y2Ti2O7particles and thickness of the coating layer can be controlled by manipulating the relative conditions. The average size of synthesized Y2Ti2O7nanoparticles was about in the size range of 20 to 30nm with calcination temperature. The effects of synthesis parameters, such as solution pH and calcination temperature, are discussed. The synthesized Y2Ti2O7nanoparticles were coated on glass substrates by a dip coating process.


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