Artykuły w czasopismach: „PMMA thin films”

1

Nassir, Lamis Faaz, i Mohammed Hadi Shinen. "Study of Electrical Properties of PMMA/P3HT Films". NeuroQuantology 20, nr 3 (26.03.2022): 47–50. http://dx.doi.org/10.14704/nq.2022.20.3.nq22039.

Pełny tekst źródła

Streszczenie:

The influence of P3HT particles on the electrical characteristics of the polymer PMMA is investigated in this paper. The spin coating process was used to prepare samples of (PMMA-P3HT) thin films, the weight of P3HT are (0.02, 0.04 and 0.06) wt. %. The D.C. electrical conductivity of the (PMMA-P3HT) thin film is revealed by the experimental results increases with rising temperature, whereas the activation energy of the (PMMA-P3HT) thin film decreases with increasing concentrations of the(P3HT)thin films.

Style APA, Harvard, Vancouver, ISO itp.

2

Goyal, Alisha, Jyoti Rozra, Isha Saini, Pawan K. Sharma i Annu Sharma. "Refractive Index Tailoring of Poly(methylmethacrylate) Thin Films by Embedding Silver Nanoparticles". Advanced Materials Research 585 (listopad 2012): 134–38. http://dx.doi.org/10.4028/www.scientific.net/amr.585.134.

Pełny tekst źródła

Streszczenie:

Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.

Style APA, Harvard, Vancouver, ISO itp.

3

Charlot, Benoit, Sebastian Gauthier, Alexandra Garraud, Philippe Combette i Alain Giani. "PVDF/PMMA blend pyroelectric thin films". Journal of Materials Science: Materials in Electronics 22, nr 12 (5.04.2011): 1766–71. http://dx.doi.org/10.1007/s10854-011-0360-7.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

4

Bani-Salameh, Areen A., A. A. Ahmad, A. M. Alsaad, I. A. Qattan i Ihsan A. Aljarrah. "Synthesis, Optical, Chemical and Thermal Characterizations of PMMA-PS/CeO2 Nanoparticles Thin Film". Polymers 13, nr 7 (4.04.2021): 1158. http://dx.doi.org/10.3390/polym13071158.

Pełny tekst źródła

Streszczenie:

We report the synthesis of hybrid thin films based on polymethyl methacrylate) (PMMA) and polystyrene (PS) doped with 1%, 3%, 5%, and 7% of cerium dioxide nanoparticles (CeO2 NPs). The As-prepared thin films of (PMMA-PS) incorporated with CeO2 NPs are deposited on a glass substrate. The transmittance T% (λ) and reflectance R% (λ) of PMMA-PS/CeO2 NPs thin films are measured at room temperature in the spectral range (250–700) nm. High transmittance of 87% is observed in the low-energy regions. However, transmittance decreases sharply to a vanishing value in the high-energy region. In addition, as the CeO2 NPs concentration is increased, a red shift of the absorption edge is clearly observed suggesting a considerable decrease in the band gap energy of PMMA-PS/CeO2 NPs thin film. The optical constants (n and k) and related key optical and optoelectronic parameters of PMMA-PS/Ce NPs thin films are reported and interpreted. Furthermore, Tauc and Urbach models are employed to elucidate optical behavior and calculate the band gaps of the as-synthesized nanocomposite thin films. The optical band gap energy of PMMA-PS thin film is found to be 4.03 eV. Optical band gap engineering is found to be possible upon introducing CeO2 NPs into PMMA-PS polymeric thin films as demonstrated clearly by the continuous decrease of optical band gap upon increasing CeO2 content. Fourier-transform infrared spectroscopy (FTIR) analysis is conducted to identify the major vibrational modes of the nanocomposite. The peak at 541.42 cm−1 is assigned to Ce–O and indicates the incorporation of CeO2 NPs into the copolymers matrices. There were drastic changes to the width and intensity of the vibrational bands of PMMA-PS upon addition of CeO2 NPs. To examine the chemical and thermal stability, thermogravimetric (TGA) thermograms are measured. We found that (PMMA-PVA)/CeO2 NPs nanocomposite thin films are thermally stable below 110 °C. Therefore, they could be key candidate materials for a wide range of scaled multifunctional smart optical and optoelectronic devices.

Style APA, Harvard, Vancouver, ISO itp.

5

El-Nasser, H. M. "Morphology and Spectroscopic Ellipsometry of PMMA Thin Films". Applied Physics Research 9, nr 2 (16.02.2017): 5. http://dx.doi.org/10.5539/apr.v9n2p5.

Pełny tekst źródła

Streszczenie:

The morphology and optical properties of PMMA thin films deposited on silicon substrates were investigated. The spin coated films were characterized by atomic force microscopy and spectroscopic ellipsometry. Regardless that, the samples were deposited at different coating speeds, the surface structures of all PMMA thin films were consistent, and found to be relatively smooth, with a mean grain size in the range of 13-25 nm. The refractive index as well as the extinction coefficient of the films was determined using spectroscopic ellipsometry data over the wavelength range 380-750 nm. For this purpose, we used the Cauchy dispersion relation in order to represent PMMA layers, and then models were built by adding a roughness layer, which simply corrects any possible deviation from planarity. Besides, the thicknesses of all four films were calculated simultaneously based on multiple sample analysis method. By using this method, optical properties were coupled in such way that, the optical constants for all samples were assumed to be identical.

Style APA, Harvard, Vancouver, ISO itp.

6

Kadhem, Saba J. "Optical properties for TiO2 / PMMA nanocomposite thin films prepared by plasma jet". Iraqi Journal of Physics (IJP) 15, nr 35 (2.12.2018): 24–28. http://dx.doi.org/10.30723/ijp.v15i35.50.

Pełny tekst źródła

Streszczenie:

PMMA/TiO2 homogeneous thin films were deposited by using plasma jet system under normal atmospheric pressure and room temperature. PMMA/TiO2 nanocomposite thin film synthesized by plasma polymerization. Titanium oxide was mixed with Methyl Methacrylate Monomer (MMA) with specific weight ratios (1, 3 and 5 grams of TiO2 per 100 ml of MMA). Optical properties of PMMA/TiO2 nanocomposite thin films were characterized by UV-Visible absorption spectra using a double beam UV-Vis-NIR Spectrophotometer. The thin films surface morphological analysis is carried out by employing SEM. The structure analysis are achieved by X-ray diffraction. UV-Visible absorption spectra shows that the increasing the concentration of titanium oxide added to the polymer leads to shift the peak position (λmax) toward the infrared region of the electromagnetic spectrum. Also the peak width increases when the concentration of TiO2 increases. It can be controlled optical energy band gap of PMMA/TiO2 nanocomposite thin films by changing concentration of TiO2. SEM indicate a uniform distribution of titanium oxide particles in PMMA matrix. The x-ray diffraction pattern indicated that the thin films have amorphous structure.

Style APA, Harvard, Vancouver, ISO itp.

7

Alsaad, Ahmad, Abdul Raouf Al Dairy, Ahmad Ahmad, Issam A. Qattan, Shatha Al Fawares i Qais Al-Bataineh. "Synthesis and Characterization of Polymeric (PMMA-PVA) Hybrid Thin Films Doped with TiO2 Nanoparticles Using Dip-Coating Technique". Crystals 11, nr 2 (24.01.2021): 99. http://dx.doi.org/10.3390/cryst11020099.

Pełny tekst źródła

Streszczenie:

We report the synthesis of hybrid thin films based on Poly(MethylMethAcrylate) (PMMA) and Poly(VinylAlcohol) (PVA), doped with different concentrations of titanium dioxide nanoparticles (TiO2 NPs). As-prepared thin films of (PMMA-PVA) doped by TiO2 NPs (wt.% = 2%, 4%, 8%, and 16%) are deposited on glass substrate. Transmittance (T%), reflectance (R%), absorption coefficient (α), optical constants (n and k), and optical dielectric functions (ε1 and ε2) are deduced using the experimental transmittance and reflectance spectra. Furthermore, a combination of classical models such as Tauc, Urbach, Spitzer-Fan, and Drude models are applied to calculate the optical and optoelectronic parameters and the energy gaps of the prepared nanocomposite thin films. The optical bandgap energy of PMMA-PVA thin film is found to be 4.101 eV. Incorporation of TiO2 NPs into PMMA-PVA polymeric thin films leads to a decrease in the optical bandgap and thus bandgap engineering is possible. Fourier-transform infrared spectroscopy (FTIR) transmittance spectra of thin films are measured and interpreted to identify the vibrational modes. To elucidate the chemical stability, thermogravimetric (TGA) curves are measured. We found that (PMMA-PVA)/TiO2 NPs polymeric thin films are thermally stable below 110 °C enable them to be attractive for a wide range of optical and optoelectronic applications.

Style APA, Harvard, Vancouver, ISO itp.

8

Mathew, Roshan Jesus, Sarika Raj i Ravi Shankaran Dhesingh. "PMMA-based Stimuli-responsive Flexible Thin-films". Chemistry Letters 42, nr 11 (5.11.2013): 1360–62. http://dx.doi.org/10.1246/cl.130708.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

9

Najim, Manar Abd, Akram Raheem Jabur i Ali A. Hameed. "Effect of Iodine Addition on Improving the Electrical Conductivity and Activation Energy of Electrospun PMMA Thin Films". Materials Science Forum 1002 (lipiec 2020): 84–94. http://dx.doi.org/10.4028/www.scientific.net/msf.1002.84.

Pełny tekst źródła

Streszczenie:

Conductive polymer films were prepared from poly (methyl methacrylate) PMMA with (0, 0.3, 0.5, 0.7, and 0.9) wt. % of iodine, using electrospinning technique. A decrease was noticed in the polymer solution viscosity with increasing the iodine weight percentage while both surface tension and electrical conductivity of the polymer solutions were increased .The structure and morphology of the prepared films were characterized by scanning electron microscopy SEM, the average fiber diameter measured statistically from the SEM images and was equal to 800 nm for PMMA with 0.7 wt. % iodine thin film, and 400 nm for the pure PMMA thin film. The electrical conductivity was enhanced for the electrospun films with increasing iodine concentration, from (29.5518× 10-9 S/cm) for pure PMMA film to (59.3725× 10-9 S/cm) for PMMA with 0.9 wt. % of iodine additives at room temperature. Activation energy decreased from 0.4483 e.V for pure PMMA to 0.43029 e.V for PMMA with 0.9 wt. % iodine.

Style APA, Harvard, Vancouver, ISO itp.

10

Rameshkumar, C., S. Sarojini, K. Naresh i R. Subalakshmi. "Preparation and Characterization of Pristine PMMA and PVDF Thin Film using Solution Casting Process for Optoelectronic Devices". Journal of Surface Science and Technology 33, nr 1-2 (24.07.2017): 12. http://dx.doi.org/10.18311/jsst/2017/6215.

Pełny tekst źródła

Streszczenie:

The PMMA and PVDF thin films were synthesized by solution casting process. The structural, spectroscopic, and morphological attributes of both the interface and surface of the film have been investigated. The structural properties of pristine PMMA and PVDF thin film were studied by XRD. The XRD spectra showed the detailed state of order and disorder of the system. From the XRD studies amorphous nature as well as the crystallanity (semi crystalline nature) of the polymer thin film were identified. SEM showed the surface morphology of the pristine PMMA and PVDF thin film. From the SEM image the size and the porous nature of the thin film were estimated. The UV showed the absorption characteristics of PMMA and PVDF thin films. From the UV-Visible spectra, we determined the direct and indirect optical energy gap of pristine PMMA and PVDF polymer samples by Devi's and Mott formula and Tauc's Expression. To the best of our knowledge, the direct and indirect energy gap in pristine PMMA and PVDF polymer thin films have been observed for the first time as no such report was found in literature survey.

Style APA, Harvard, Vancouver, ISO itp.

11

Reddy, M. Ravindar, M. Jaipal Reddy i A. R. Subrahmanyam. "Structural, Thermal and Optical Properties of PMMA, PEO and PMMA/PEO/LiClO4 Polymer Electrolyte Blends". Material Science Research India 14, nr 2 (16.11.2017): 123–27. http://dx.doi.org/10.13005/msri/140206.

Pełny tekst źródła

Streszczenie:

This paper is a report of a study conducted on Structural, thermal and optical Properties of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films. These films were prepared using solution casting technique and characterized by X-ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). XRD analysis Observations confirmed that amorphous, crystalline and semi crystalline nature of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films the SEM micrographs suggest that the surface morphology of pure PEO changes from smooth to rough when PMMA and LiClO4 added to PEO polymer, which shows the interaction/ interface between the two polymers and polymer blend electrolyte due to cross – linking. Glass transition (Tg) and melting temperatures (Tm) of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films were confirmed by DSC analysis. FTIR spectra confirmed that complex formation and interaction among PMMA, PEO polymers and LiClO4 salt.

Style APA, Harvard, Vancouver, ISO itp.

12

B, Chandar Shekar, Sathisha S, Sulana Sundari, Sunnitha S i Sharmila C. "PREPARATION OF MESOSCOPIC STRUCTURE POLY METHYL METHACRYLATE THIN FILMS FOR AFM DATA STORAGE DEVICES." Kongunadu Research Journal 2, nr 1 (4.11.2019): 1–3. http://dx.doi.org/10.26524/krj54.

Pełny tekst źródła

Streszczenie:

Poly methyl methacrylate (PMMA) thin films were prepared by dip coating method. Benzene was used as a solvent to prepare PMMA thin films for the time periods ranging from 1 min. to 1 h. The thickness of the films deposited was measured by using an electronic thickness measuring instrument (Tesatronic-TTD-20). Fourier Transform Infrared spectrum was used to identify the above said films. X-ray diffraction spectra indicated the predominantly amorphous nature of the films. Surface morphology of the coated films studied by using scanning electron microscope (SEM) indicated the absence of any pits, cracks and pin holes in the surface. Both as grown and annealed films showed smooth and amorphous structures. The closer SEM inspection revealed the presence of self assembled mesoscopic cells. The mesoscopic structure PMMA thin films could be used as an AFM-based data storage which is promising alternative to conventional magnetic data storage because it offers great potential for considerable storage density improvements.

Style APA, Harvard, Vancouver, ISO itp.

13

Herbei, Elena Emanuela, Michael P. M. Jank, Susanne Oertel, Laurentiu Frangu i Viorica Mușat. "The Influence of Electrodes Deposition on the Interface and Dielectric Characteristics of Polymer Gate for Thin Films Transistors". Advanced Materials Research 1143 (luty 2017): 227–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1143.227.

Pełny tekst źródła

Streszczenie:

The paper presents some results on the effect of the metal electrode deposition on the electrical performance of amorphous polymthylmetacrylate (PMMA) thin films, measured in a MIM structure consisting of metal (Al)-insulator (PMMA)-metal (Ta). Aluminium (Al) electrode was deposited by physical vapor deposition method (PVD) on the top of PMMA film with the deposition rate of 5 and 10Å/s. The effect of aluminium deposition rate and post deposition annealing temperature on the morphology of the interface between Al electrode (100 or 300 nm thick) and PMMA thin film (40 or 70 nm thick) has been investigated by cross-section scanning electron microscopy (SEM). Based on SEM data, I-V characteristic measurements and dielectric constant values of insulating films, the deposition parameters of Al top-electrode was optimised. Our results showed that when the deposition of the Al electrode take place at a rate of 10 Å/s, no inter-diffusion or interfacial reaction at the interface between Al electrode and PMMA films were observed and the best delectric parameters of PMMA thin film were measured, which led to the best dielectric performance of PMMA layer in TFT configuration.

Style APA, Harvard, Vancouver, ISO itp.

14

Al-Bataineh, Qais M., A. A. Ahmad, A. M. Alsaad, I. A. Qattan, Areen A. Bani-Salameh i Ahmad D. Telfah. "Kinematics of Photoisomerization Processes of PMMA-BDK-MR Polymer Composite Thin Films". Polymers 12, nr 6 (3.06.2020): 1275. http://dx.doi.org/10.3390/polym12061275.

Pełny tekst źródła

Streszczenie:

We investigate and report on the kinematics of photoisomerization processes of polymer composite thin films based on azo dye methyl red (MR) hosted in polymethylmethacrylate (PMMA) incorporated with Benzyl dimethyl ketal (BDK) as a photo-initiator. Understanding photoisomerization mechanisms is crucial for several optical applications such as Read/Write/Erase (WRE) optical data storage media, UV light Read/Write heads, and UV light sensors. The as-prepared polymer composite thin films are characterized using UV–Vis spectroscopy. Furthermore, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) are employed to investigate the optical, chemical, and morphological properties of trans- and cis-states of PMMA-BDK-MR polymer composite thin films. The presence of the azo dye MR in the composite is essential for the efficient performance of the cis ↔ trans cycles through illumination ↔ thermal relaxation for Write/Read/Erase optical data storage and UV-light sensors. Moreover, UV–Vis and FTIR results confirm the hysteresis cycle of trans- and cis-states and that PMMA-BDK-MR thin films may be regarded as potential candidates for successful Write/Read/Erase optical data storage and UV-light sensors. In addition, the morphology of the thin film surface is investigated by SEM technique. The SEM images indicate that uncured surfaces of PMMA-BDK-MR thin films are inhomogeneous compared with the corresponding surfaces after curing. The transformation from inhomogeneous surfaces to homogeneous surfaces is attributed to the polymerization of thin films by UV curing.

Style APA, Harvard, Vancouver, ISO itp.

15

Alsaad, Ahmad M., Ahmad A. Ahmad, Issam A. Qattan, Abdul-Raouf El-Ali, Shatha A. Al Fawares i Qais M. Al-Bataineh. "Synthesis of Optically Tunable and Thermally Stable PMMA–PVA/CuO NPs Hybrid Nanocomposite Thin Films". Polymers 13, nr 11 (24.05.2021): 1715. http://dx.doi.org/10.3390/polym13111715.

Pełny tekst źródła

Streszczenie:

We report the synthesis and comprehensive characterization of polymethylmethacrylate (PMMA)/polyvinylalcohol (PVA) polymeric blend doped with different concentrations of Copper oxide (CuO) nanoparticles (NPs). The PMMA–PVA/CuO nanocomposite hybrid thin films containing wt.% = 0%, 2%, 4%, 8%, and 16% of CuO NPs are deposited on glass substrates via dip-coating technique. Key optical parameters are measured, analyzed, and interpreted. Tauc, Urbach, Spitzer–Fan, and Drude models are employed to calculate the optical bandgap energy (Eg) and the optoelectronic parameters of PMMA–PVA/CuO nanocomposites. The refractive index and Eg of undoped PMMA–PVA are found to be (1.5–1.85) and 4.101 eV, respectively. Incorporation of specific concentrations of CuO NPs into PMMA–PVA blend leads to a considerable decrease in Eg and to an increase of the refractive index. Moreover, Fourier Transform Infrared Spectroscopy (FTIR) transmittance spectra are measured and analyzed for undoped and doped polymeric thin films to pinpoint the major vibrational modes in the spectral range (500 and 4000 cm−1) as well as to elucidate the nature of chemical network bonding. Thermogravimetric analysis (TGA) is conducted under appropriate conditions to ensure the thermal stability of thin films. Doped polymeric thin films are found to be thermally stable below 105 °C. Therefore, controlled tuning of optoelectronic and thermal properties of doped polymeric thin films by introducing an appropriate concentration of inorganic fillers leads to a smart design of scaled multifunctional devices.

Style APA, Harvard, Vancouver, ISO itp.

16

Ismail, Lyly Nyl, Habibah Zulkefle, Sukreen Hana Herman i Mohamad Rusop Mahmood. "Influence of Doping Concentration on Dielectric, Optical, and Morphological Properties of PMMA Thin Films". Advances in Materials Science and Engineering 2012 (2012): 1–4. http://dx.doi.org/10.1155/2012/605673.

Pełny tekst źródła

Streszczenie:

PMMA thin films were deposited by sol gel spin coating method on ITO substrates. Toluene was used as the solvent to dissolve the PMMA powder. The PMMA concentration was varied from 30 ~ 120 mg. The dielectric properties were measured at frequency of 0 ~ 100 kHz. The dielectric permittivity was in the range of 7.3 to 7.5 which decreased as the PMMA concentration increased. The dielectric loss is in the range of 0.01 ~ –0.01. All samples show dielectric characteristics which have dielectric loss is less than 0.05. The optical properties for thin films were measured at room temperature across 200 ~ 1000 nm wavelength region. All samples are highly transparent. The energy band gaps are in the range of 3.6 eV to 3.9 eV when the PMMA concentration increased. The morphologies of the samples show that all samples are uniform and the surface roughness increased as the concentration increased. From this study, it is known that, the dielectric, optical, and morphology properties were influenced by the amount of PMMA concentration in the solution.

Style APA, Harvard, Vancouver, ISO itp.

17

Gong, Yu Mei, Ying Xin He, Jing Guo i Hong Zhang. "A Concise Route to Fabricate TiO₂ Nanoporous and Nanopillar Films Based on Block Copolymer Self-Assembly". Advanced Materials Research 774-776 (wrzesień 2013): 931–34. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.931.

Pełny tekst źródła

Streszczenie:

This study developed a concise route to fabricate TiO2 nanoporous and nanopillar films based on the self-assembly of block-copolymer thin films in periodic nanostructures. We obtained the perpendicularly oriented cylindrical domains in polystyrene-b-poly (methyl methacrylate) (PS-b-PMMA) diblock copolymer (BCP) films by thermal annealing on ITO substrate modified by a cross-linkable random copolymer, and then these films were immersed into the titanium oxide sol in acetic acid for a few hours. The acetic acid in the sol can selectively swell the PMMA component, which results in titanium oxide sol being loaded to the PMMA component selectively. Then the films were calcined at high temperature to remove the PS-b-PMMA block copolymer, and simultaneously the titanium oxide was transferred in situ to the substrate. As a result, a highly ordered array of nanoporous and nanopillar TiO2 thin film is observed on the ITO substrates depending upon the block copolymer used with PS and PMMA cylinder-forming components. In principle, it can be a general and versatile approach for fabricating functional nanoparticle arrays.

Style APA, Harvard, Vancouver, ISO itp.

18

Kim, Jung Min, Hyun Jung Her, J. H. Yoon, Jae Wan Kim, Y. J. Choi, C. J. Kang, D. Jeon i Yong Sang Kim. "Characteristics of Pentacene with Different Polymer Gate Insulators for Organic Thin-Film Transistors". Solid State Phenomena 124-126 (czerwiec 2007): 451–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.451.

Pełny tekst źródła

Streszczenie:

We investigated the characteristics of pentacene thin films of different materials for gate insulators using atomic force microscope (AFM) and x-ray diffraction (XRD). The pentacene thin films are fabricated by evaporation on different polymer substrates. We used HMDS (Hexa Methyl Di Silazane), PVA (Poly Vinyl Alcohol) and PMMA (Poly Methyl Meth Acrylate) for the polymer substrates, on which pentacene is deposited at various substrate temperatures. The case of pentacene deposited on the PMMA has the largest grain size and least trap concentration. We also fabricated pentacene TFTs with the PMMA gate insulator. Pentacene TFTs with PMMA gate insulator, shows high field-effect mobility (ｕFET= 0.03 cm2/Vs) and large on/off current ratio (>105) and small threshold voltage (Vth= -6 V).

Style APA, Harvard, Vancouver, ISO itp.

19

HERBEI, Elena Emanuela. "Dielectric PMMA Thin Layers Obtained by Spin Coating for Electronic Applications". Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science 45, nr 4 (15.12.2022): 87–91. http://dx.doi.org/10.35219/mms.2022.4.14.

Pełny tekst źródła

Streszczenie:

Thin polymeric films with dielectric properties become a very important part of today’s devices, being indispensable in industry, electrical applications and not only. Nowadays polymeric materials have attracted attention in academic and industrial research due to the miniaturization at the micro and nanoscale of different electronic devices. Polymers in general are used for their light weight, good mechanical strength, dielectric properties, and optical properties, which make them multifunctional materials.This paper presents research on polymethyl methacrylate (PMMA) thin films obtained by the sol-gel method. The optimization of thin film PMMA layers has been a problem due to the importance of using the polymer in the different electronic domains. Thin films of PMMA with different thicknesses were deposited onto glass and silicon wafers in order to measure dielectric properties. For dielectric properties, the PMMA thin layer was inserted in a metal-insulator-metal structure (MIM). In order to observe the morphology and roughness of thin film, optical microscopy, scanning electron microscopy and atomic force microscopy have proceeded.The dielectric constant (k) was calculated using the electrical capacitance formula. The I-V and C-V curves showed a dielectric behavior with a leakage current between 10-11 and 10-8 A and a constant capacitance in the bias range ± 5 V.

Style APA, Harvard, Vancouver, ISO itp.

20

Viorica, Ghisman Plescan, Viorica Musat, Ana Pimentel, Tomas R. Calmeiro, Emanuel Carlos, Liliana Baroiu, Rodrigo Martins i Elvira Fortunato. "Hybrid (Ag)ZnO/Cs/PMMA nanocomposite thin films". Journal of Alloys and Compounds 803 (wrzesień 2019): 922–33. http://dx.doi.org/10.1016/j.jallcom.2019.06.373.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

21

Fleming, George, Jenny Aveyard, Joanne L. Fothergill, Fiona McBride, Rasmita Raval i Raechelle A. D’Sa. "Effect of Polymer Demixed Nanotopographies on Bacterial Adhesion and Biofilm Formation". Polymers 11, nr 12 (21.11.2019): 1921. http://dx.doi.org/10.3390/polym11121921.

Pełny tekst źródła

Streszczenie:

As the current global threat of antimicrobial resistance (AMR) persists, developing alternatives to antibiotics that are less susceptible to resistance is becoming an urgent necessity. Recent advances in biomaterials have allowed for the development and fabrication of materials with discrete surface nanotopographies that can deter bacteria from adhering to their surface. Using binary polymer blends of polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycaprolactone (PCL) and varying their relative concentrations, PS/PCL, PS/PMMA and PCL/PMMA polymer demixed thin films were developed with nanoisland, nanoribbon and nanopit topographies. In the PS/PCL system, PS segregates to the air-polymer interface, with the lower solubility PCL preferring the substrate-polymer interface. In the PS/PMMA and PCL/PMMA systems, PMMA prefers the air-polymer interface due to its greater solubility and lower surface energy. The anti-adhesion efficacy of the demixed films were tested against Pseudomonas aeruginosa (PA14). PS/PCL and PCL/PMMA demixed films showed a significant reduction in cell counts adhered on their surfaces compared to pure polymer control films, while no reduction was observed in the counts adhered on PS/PMMA demixed films. While the specific morphology did not affect the adhesion, a relationship between bacterial cell and topographical surface feature size was apparent. If the surface feature was smaller than the cell, then an anti-adhesion effect was observed; if the surface feature was larger than the cell, then the bacteria preferred to adhere.

Style APA, Harvard, Vancouver, ISO itp.

22

Tippo, Tossapol, Chanchana Thanachayanont, Chabaiporn Junin, Seeroong Prichanont, Micheal Hietschold i Apinunt Thanachayanont. "Effect of Substrates on Preparation of Dissolved PMMA in DMF Solution Used as a Dielectric Layer in Otfts". Advanced Materials Research 802 (wrzesień 2013): 79–83. http://dx.doi.org/10.4028/www.scientific.net/amr.802.79.

Pełny tekst źródła

Streszczenie:

Dissolved Poly (methyl methacrylate) (PMMA) in Dimethylformamide solution was fabricated as thin films on different substrates, glass, poly (ethylene naphthalate) and Si wafer, using spin coating technique. The effect of different substrates on electrical performances of the PMMA films was investigated. For an acceptable organic thin-film transistor (OTFT) performance, uniform thickness with low defect density of the PMMA thin-films was required. A parallel plate capacitor structure was used to test electrical properties of the PMMA dielectric layers. Good dielectric properties were obtained on glass and PEN at film thicknesses of 95 nm. An optimal condition for the OTFT preparation was used to fabricate an OTFT with the PMMA dielectric layer on glass substrate. Measured results showed that the OTFT achieved a mobility of 0.16 cm2/V.s, a threshold voltage of -3.6 V, and on/off current ratio of 1×105.

Style APA, Harvard, Vancouver, ISO itp.

23

Chen, Jiayao, Jing Li, Lirong Xu, Wei Hong, Yuzhao Yang i Xudong Chen. "The Glass-Transition Temperature of Supported PMMA Thin Films with Hydrogen Bond/Plasmonic Interface". Polymers 11, nr 4 (2.04.2019): 601. http://dx.doi.org/10.3390/polym11040601.

Pełny tekst źródła

Streszczenie:

The interfacial effect is one of the significant factors in the glass-transition temperature (Tg) of the polymeric thin film system, competing against the free surface effect. Herein, the Tgs of poly (methyl methacrylate) (PMMA) films with different thicknesses and substrates are studied by fluorescence measurements, focusing on the influence of interfacial effects on the Tgs. The strong interaction between PMMA and quartz substrate leads to increased Tgs with the decreased thickness of the film. The plasmonic silver substrate causes enhanced fluorescence intensity near the interface, resulting in the delayed reduction of the Tgs with the increasing film thickness. Moreover, as a proof of the interface-dependent Tgs, hydrogen bonds of PMMA/quartz and molecules orientation of PMMA/silver are explored by the Raman spectroscopy, and the interfacial interaction energy is calculated by the molecular dynamics simulation. In this study, we probe the inter-relationship between the interfacial interactions arising from the different substrates and the Tg behavior of polymer thin films.

Style APA, Harvard, Vancouver, ISO itp.

24

Hafizah, N. N., Ismail Lyly Nyl, M. Z. Musa i Mohamad Rusop Mahmood. "Effect of TiO₂ Nanofiller on Nanocomposited PMMA/TiO₂ Thin Film". Advanced Materials Research 576 (październik 2012): 417–20. http://dx.doi.org/10.4028/www.scientific.net/amr.576.417.

Pełny tekst źródła

Streszczenie:

In this study, PMMA/TiO2 nanocomposite thin films were prepared by using sonication spin coating technique. The PMMA and TiO2 solution were mixed together and sonicated for 1h to confirm the homogeneity of the sample. The thin films obtained were then measured using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR). FESEM micrograph reveals that the uniformity increases with the increase of TiO2 weight percentage.

Style APA, Harvard, Vancouver, ISO itp.

25

Chuang, Chin Tun, Fa Ta Tsai, Ming Jun Kuo i Pei Chi Yu. "The Adhesion Properties of Parylene-C Thin Films". Applied Mechanics and Materials 421 (wrzesień 2013): 337–41. http://dx.doi.org/10.4028/www.scientific.net/amm.421.337.

Pełny tekst źródła

Streszczenie:

This work aims to enhance the adhesion of Parylene-C (poly-chloro-p-xylylene C) thin film on PMMA, Glass and Aluminum substrates by chemical vapor deposition, surface improvement and treatment of substrate as well as analysis of film on Glass, PMMA, Aluminum and its surface adhesion by dipping under A-174 silane solution and conducting on plasma treatment (18 W). The results show that: (1) After oxygen-plasma pretreatment, the surface roughness of the 200nm-thickness film on glass substrate specimens decreases from 18nm to 7nm. (2) After dipped in prescription solution pretreatment, the residual stress reduces from 107MPa to 64MPa on glass substrate specimens. (3) The critical load of 600nm-thickness film increases from 14.1 to 18.5mN, showing the substrate after dipped in prescription solution pretreatment can improve the adhesion of the Parylene-C thin film on flat glass substrate specimens.

Style APA, Harvard, Vancouver, ISO itp.

26

Yuwono, A. H., J. M. Xue, J. Wang, H. I. Elim, Wei Ji, Yuan Yuan Li i T. J. White. "Nonlinear Optical Behavior of Transparent Nanohybrids of Nanocrystalline TiO₂ in Poly(methyl methacrylate) Prepared by In Situ Sol-Gel Polymerization Technique". Journal of Metastable and Nanocrystalline Materials 23 (styczeń 2005): 367–70. http://dx.doi.org/10.4028/www.scientific.net/jmnm.23.367.

Pełny tekst źródła

Streszczenie:

Nanohybrid thin films consisting of nanocrystalline TiO2 particles in poly(methyl methacrylate)(PMMA) were successfully synthesized by in-situ sol-gel and polymerization assisted by spin coating. Using titanium isoproproxide (Ti-iP), methyl methacrylate (MMA) and 3-(trimethoxysily)propyl methacrylate (MSMA) as the starting materials, nanohybrids containing up to 60% Ti-iP in PMMA were realized. The resulting nanohybrid thin films coated on quartz substrates are optically transparent and demonstrate nonlinear optical behaviour, where their nonlinear absorption increases with the loading of Ti-iP in PMMA, as confirmed by Z-scan measurements. Using pump-probe technique, these thin films are shown to exhibit an ultrafast relaxation time of ~1.5 picosecond.

Style APA, Harvard, Vancouver, ISO itp.

27

Park, Sung Min, Hyung Ju Ahn, Sang Woo Kim, Jin Sam Gong i Du Yeol Ryu. "Structural Reorganization in Thin Films of High Molecular Weight Block Copolymer Self-Assembly". Advanced Materials Research 853 (grudzień 2013): 53–56. http://dx.doi.org/10.4028/www.scientific.net/amr.853.53.

Pełny tekst źródła

Streszczenie:

We demonstrate the structural reorganization of microdomain arrays toward the perpendicular orientation of lamellar morphology in high-molecular-weight PS-b-PMMA films using a combinational approach by solvent-vapor and sequential thermal annealing processes. Solvent annealing with a PMMA-selective acetone vapor induced a cylindrical morphology. However, the sequential thermal annealing of block copolymer (BCP) films led to structural reorganization to an equilibrium lamellar morphology, where the lamellar microdomains were oriented to normal to the film surface. This technique suggests an efficient route for directing orientation and structural reorganization of microdomain arrays in the thin films of high-molecular-weight BCP self-assembly.

Style APA, Harvard, Vancouver, ISO itp.

28

Jehnichen, Dieter, Doris Pospiech, Peter Friedel, Andriy Horechyy, Andreas Korwitz, Andreas Janke, Franziskus Näther, Christine M. Papadakis, Jan Perlich i Volker Neu. "Effects of nanoparticles on phase morphology in thin films of phase-separated diblock copolymers". Powder Diffraction 32, S1 (30.01.2017): S141—S150. http://dx.doi.org/10.1017/s0885715616000762.

Pełny tekst źródła

Streszczenie:

This study investigates the morphology changes in thin diblock copolymer (DiBCP) films occurring in the interaction with modified nanoparticles (NPs). Magnetite (Fe3O4) and silica (SiOx) were prepared and used. Poly(pentyl methacrylate-b-methyl methacrylate) (PPMA-b-PMMA) (70/30 mol mol−1, hcp cylinders of the PMMA phase) DiBCP were employed to prepare thin films having thicknesses to realize standing cylinders in pure DiBCP films. The investigations aimed at two topics: (1) morphology after controlled incorporation of organo-modified NP (gold, silver, Fe3O4, SiOx) and (2) additional solvent vapour annealing (SVA) with tetrahydrofuran (and chloroform for comparison). The laterally ordered morphology in thin films was examined by GISAXS and atomic force microscopy. Keeping the same type of morphology in nanocomposites, the dimensions of the periodic nanostructure altered depending on type and amount of incorporated NP. It was found that SiOx clusters enlarge the lateral distance of the PMMA cylinders, whereas metallic NPs reduce this parameter. Applying SVA improves the phase separation slightly, whereas lateral distances were kept constant or were reduced a little. Switching of domain orientation upon SVA could not be detected in the presence of NPs located at the polymer/substrate interface.

Style APA, Harvard, Vancouver, ISO itp.

29

Yoon, Jinhwan, Seung Yun Yang, Byeongdu Lee, Wonchul Joo, Kyuyoung Heo, Jin Kon Kim i Moonhor Ree. "Nondestructive quantitative synchrotron grazing incidence X-ray scattering analysis of cylindrical nanostructures in supported thin films". Journal of Applied Crystallography 40, nr 2 (12.03.2007): 305–12. http://dx.doi.org/10.1107/s0021889807000817.

Pełny tekst źródła

Streszczenie:

Nondestructive nanostructural analysis is indispensable in the development of nanomaterials and nanofabrication processes for use in nanotechnology applications. This paper demonstrates a quantitative, nondestructive analysis of nanostructured thin films supported on substrates and their templated nanopores by using grazing incidence X-ray scattering and data analysis with a derived scattering theory. The analysis disclosed that vertically oriented nanodomain cylinders had formed in 20–100 nm thick films supported on substrates, which consisted of a mixture of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PMMA homopolymer, and that the PMMA nanodomain cylinders were selectively etched out by ultraviolet light exposure and a subsequent rinse with acetic acid, resulting in a well ordered nanostructure consisting of hexagonally packed cylindrical nanopores.

Style APA, Harvard, Vancouver, ISO itp.

30

Abdullah, Nadhim A., i Fatima H. Malk. "Optical Properties of Blend of PMMA:PVDF". University of Aden Journal of Natural and Applied Sciences 25, nr 1 (22.03.2022): 189–96. http://dx.doi.org/10.47372/uajnas.2021.n1.a16.

Pełny tekst źródła

Streszczenie:

In this study, thin films of PMMA Poly (methyl methacrylate)- Polyvinylidene fluoride(PMMA-PVDF), PMMA polymer and soluble PVDF polymer were prepared at (5%)Toluene and polymeric blends in 1:1 volume ratio of polymers and in different proportions of polymers. The studied films were prepared by the Spin coating method, and the optical parameters of the thin films were measured within a range (300-900)nm and the thickness of the films were constant (223 nm). Absorbance (A), linear absorption coefficient (α), refractive index (n), extinction coefficient (K), real and imaginary dielectric constant (∈r, ∈i), and optical energy gap Eg were studied, as the best edge of optical absorption was 5% PVDF, And electronic transmission between levels was direct transmission.

Style APA, Harvard, Vancouver, ISO itp.

31

Iqbal, Saman, Muhammad Shahid Rafique, Safia Anjum, Asma Hayat i Nida Iqbal. "Impact of X-ray irradiation on PMMA thin films". Applied Surface Science 259 (październik 2012): 853–60. http://dx.doi.org/10.1016/j.apsusc.2012.07.146.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

32

Okerberg, B. C., i H. Marand. "Crystal morphologies in thin films of PEO/PMMA blends". Journal of Materials Science 42, nr 12 (15.02.2007): 4521–29. http://dx.doi.org/10.1007/s10853-006-0471-3.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

33

Turgut, Hatice, Divya Varadharajan, Nico Dingenouts i Guillaume Delaittre. "Nanostructured Thin Films of Moderately Functionalized PMMA-b -PS". Macromolecular Rapid Communications 39, nr 14 (26.06.2018): 1800231. http://dx.doi.org/10.1002/marc.201800231.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

34

Fujita, Masato, Naokazu Idota, Kimihiro Matsukawa i Yoshiyuki Sugahara. "Preparation of Oleyl Phosphate-Modified TiO2/Poly(methyl methacrylate) Hybrid Thin Films for Investigation of Their Optical Properties". Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/297197.

Pełny tekst źródła

Streszczenie:

TiO2nanoparticles (NPs) modified with oleyl phosphate were synthesized through stable Ti–O–P bonds and were utilized to prepare poly(methyl methacrylate)- (PMMA-) based hybrid thin films via theex situroute for investigation of their optical properties. After surface modification of TiO2NPs with oleyl phosphate, IR and13C CP/MAS NMR spectroscopy showed the presence of oleyl groups. The solid-state31P MAS NMR spectrum of the product revealed that the signal due to oleyl phosphate (OP) shifted upon reaction, indicating formation of covalent Ti–O–P bonds. The modified TiO2NPs could be homogeneously dispersed in toluene, and the median size was 16.1 nm, which is likely to be sufficient to suppress Rayleigh scattering effectively. The TEM images of TiO2/PMMA hybrid thin films also showed a homogeneous dispersion of TiO2NPs, and they exhibited excellent optical transparency even though the TiO2content was 20 vol%. The refractive indices of the OP-modified TiO2/PMMA hybrid thin films changed higher with increases in TiO2volume fraction, and the hybrid thin film with 20 vol% of TiO2showed the highest refractive index (n = 1.86).

Style APA, Harvard, Vancouver, ISO itp.

35

Vodišek, Nives, Andraž Šuligoj, Dorota Korte i Urška Lavrenčič Štangar. "Transparent Photocatalytic Thin Films on Flexible Polymer Substrates". Materials 11, nr 10 (11.10.2018): 1945. http://dx.doi.org/10.3390/ma11101945.

Pełny tekst źródła

Streszczenie:

Self-cleaning and/or photocatalytic films on polymer substrates have found numerous applications during the past decades. However, the common demand for high-temperature post synthesis treatment limits the application to temperature resistant substrates only. Herein, we prepared self-cleaning photocatalytic films on four thermosensitive polymeric substrates: polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), and acryl coated polyester (PES) fabric (D2) with poly(vinylidene fluoride) (PVDF) containing lacquer (D1). TiO2 was prepared via a low-temperature sol-gel process using titanium(IV) isopropoxide and zirconium(IV) butoxide as precursors with various loading levels of Zr; 0, 5, 10, and 20 mol.%, and deposited on the substrates by using a SiO2 binder in form of thin films (ca. 200 nm thick) via dip-coating. The films were characterized by SEM, hardness test, UV-Vis, photothermal beam deflection spectroscopy, and IR spectroscopy, while photocatalytic activity was measured by the fluorescence-based method of the terephthalic acid probe and wetting by contact angle measurements. Films containing 10 mol.% of Zr showed the best compromise regarding photocatalytic activity and mechanical stability while from substrates point of view PVC performed the best, followed by PMMA, D1, and D2. The beneficial role of SiO2 binder was not only guaranteeing excellent mechanical stability, but also to prevent the D1 polymer from deterioration; the latter was found to be labile to long-term solar-light exposure due to degradation of the top PVDF layer.

Style APA, Harvard, Vancouver, ISO itp.

36

Chen, Lung-Chien, Ching-Ho Tien, Zong-Liang Tseng, Yu-Shen Dong i Shengyi Yang. "Influence of All-Inorganic Halide Perovskite CsPbBr3 Quantum Dots Combined with Polymer Matrix". Materials 12, nr 6 (25.03.2019): 985. http://dx.doi.org/10.3390/ma12060985.

Pełny tekst źródła

Streszczenie:

The poor stability of CsPbX3 quantum dots (QDs-CsPbX3) under wet conditions is still considered to be a key issue. In order to overcome this problem, this study presents a high molecular weight polymer matrix (polymethylmethacrylate, PMMA) incorporated into the QDs-CsPbBr3 to improve its stability and maintain its excellent optical properties. In this study, the Cs2CO3, PbO, Tetrabutylammonium Bromide (TOAB) powder, oleic acid, and toluene solvent were uniformly mixed and purified to prepare high-quality QDs powders. Then, hexane was used as a dispersing agent for the QD powder to complete the perovskite QDs-CsPbBr3 solution. Finally, a solution with different proportions of quantum dots CsPbBr3 and PMMA was prepared and discussed. In the preparation of thin films, firstly, a thin film with the structure of glass/QD-CsPbBr3/PMMA was fabricated in a glove box using a well-developed QDs-CsPbBr3 solution by changing the ratio of CsPbBr3:PMMA. The material analysis of QDs-CsPbBr3 thin films was performed with photoluminescence (PL), transmittance, absorbance, and transmission electron microscopy (TEM). The structures and morphologies were further examined to study the effect of doped PMMA on perovskite QDs-CsPbBr3.

Style APA, Harvard, Vancouver, ISO itp.

37

Humud, Hammad R. "Effect of Ag nanoparticles on R6G laser dye hosted by PMMA polymerized by plasma jet". Iraqi Journal of Physics (IJP) 14, nr 29 (3.02.2019): 27–36. http://dx.doi.org/10.30723/ijp.v14i29.217.

Pełny tekst źródła

Streszczenie:

This work aim to prepare Ag/R6G/PMMA nanocomposite thinfilms by In-situ plasma polymerization and study the changes in theoptical properties of fluorophore due to the presence of Agnanoparticles structures in the vicinity of the R6G laser dye. Theconcentrations of R6G dye/MMA used are: 10-4M solutions wereprepared by dissolving the required quantity of the R6G dye inMMAMonomer. Then Silver nanoparticles with 50 average particlessize were mixed with MMAmonomer with concentration of 0.3, 0.5,0.7wt% to get R6G silver/MMA in liquid phase. The films weredeposited on glass substrates by dielectric barrier discharge plasmajet. The Ag/R6G/PMMA nanocomposite thin films werecharacterization by UV-Visible absorption spectra by using a doublebeam UV-Vis-NIR Spectrophotometer and fluorescenceSpectrophotometer. The thin films surface morphological analysis iscarried out by employing an AFM and SEM. the structure analysisare achieved by X-ray diffraction. The thickness of the films wasmeasured by optical interferometric method. AFM analysis showsthat the surface roughness of plasma polymerized pure PMMA thinfilms was 2.7 nm and for (10-4 R6G + 0.7wt% Ag)Ag/R6G/PMMAthin films was 4.16 nm. The SEM images were indicates that Agnanoparticles (NPs) disperse in the PMMA matrix with uniformdistribution and formed mostly spherical NPs and slightlyagglomerate. Also the silver nanoparticles with 0.7wt%concentration enhances the absorption process by 2.3 times and thefluorescence by 1.7 times. it can be conclude, that the addition of lowconcentrations of silver nanoparticles to the PMMA/ R6G matrix waschanging the optical properties of the prepared nanocomposite thinfilms.

Style APA, Harvard, Vancouver, ISO itp.

38

Tamulevičius, Sigitas, I. Prosyčevas, Asta Guobienė i J. Puišo. "Oxygen Plasma Processing of Silicon and Silica Substrates for Thin Films of Polymer Blends". Solid State Phenomena 99-100 (lipiec 2004): 175–80. http://dx.doi.org/10.4028/www.scientific.net/ssp.99-100.175.

Pełny tekst źródła

Streszczenie:

The influence of plasma processing of silica and crystalline silicon substrates on the formation of polymeric layers of PS/PMMA blends by sorption from 50 vol. % concentration toluene solutions was analyzed. The morphology dependence of PS/ PMMA blend films on the type and condition of substrate processing was studied by X-ray photoelectron spectroscopy (XPS), ellipsometry and atomic force microscopy (AFM). It was shown that reduction of carbon and oxygen components from the surface contaminants as well as the existence of a nonstoichiometric SiOx layer on the Si surface contributed to the hydrophilicity of the substrate. These processes can be used to produce thin nanostructured polymer blend films.

Style APA, Harvard, Vancouver, ISO itp.

39

Yadigarli, Aydan, Qimeng Song, Sergey I. Druzhinin i Holger Schönherr. "Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red". Beilstein Journal of Organic Chemistry 15 (25.10.2019): 2552–62. http://dx.doi.org/10.3762/bjoc.15.248.

Pełny tekst źródła

Streszczenie:

The permittivity of polymers and its spatial distribution play a crucial role in the behavior of thin films, such as those used, e.g., as sensor coatings. In an attempt to develop a conclusive approach to determine these quantities, the polarity of the model polymer poly(methyl methacrylate) (PMMA) in 600 nm thin films on a glass support was probed by the energy of the charge transfer transition in the oxazine dye Nile red (NR) at 25 °C. The absorption and fluorescence spectra of NR were observed to shift to the red with increasing solvent polarity, because of the intramolecular charge transfer character of the optical transition. New types of solvatochromic plots of emission frequency against absorption frequency and vice versa afforded the Onsager radius-free estimation of the ground and excited states dipole moment ratio. With this approach the values of these dipole moments of 11.97 D and 18.30–19.16 D, respectively, were obtained for NR. An effective local dielectric constant of 5.9–8.3 for PMMA thin films was calculated from the solvatochromic plot and the fluorescence maximum of NR observed in the PMMA films. The fluorescence band of NR in the rigid PMMA films shifted to the red by 130 cm−1 with increasing excitation wavelength from 470 to 540 nm, while in a series of liquids the position of the emission maximum of NR remained constant within same range of the excitation wavelength. It is concluded that the fluorescence spectrum of NR in PMMA undergoes inhomogeneous broadening due to different surroundings of NR molecules in the ground state and slow sub-glass transition (T g) relaxations in PMMA.

Style APA, Harvard, Vancouver, ISO itp.

40

Wu, Mei-Ling, Jing Li, Li-Jun Wan i Dong Wang. "Monolayer graphene-supported free-standing PS-b-PMMA thin film with perpendicularly orientated microdomains". RSC Adv. 4, nr 109 (2014): 63941–45. http://dx.doi.org/10.1039/c4ra12655f.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

41

Rao, S., D. Liu, P. Jaiswal, Sudip Ray i Debes Bhattacharyya. "Electrospun Nanofibre Cores Containing Graphene Oxide for Sandwich Films: Manufacturing and Analysis". Advanced Materials Research 410 (listopad 2011): 26–30. http://dx.doi.org/10.4028/www.scientific.net/amr.410.26.

Pełny tekst źródła

Streszczenie:

The motivation for the need of small-scale devices has made thin films technologically important in the recent years. They have found applications in broad fields, such as microelectronic integrated circuits, magnetic information storage systems, optical coatings and wear resistant coatings. However, the mechanical performance of these materials tends to depend on fabrication and post-processing parameters. With the intent of improving the mechanical properties of the films, a relatively novel concept of sandwich composite films has been tried in this research. Poly-methyl methacrylate (PMMA) and Graphene Oxide (GO) have been used to manufacture the sandwich films, where PMMA films have served as the facings and electrospun PMMA/GO nanofibre mat forms the sandwich core. Dimethylformamide (DMF) and Tetrahydrofuran (THF) solvents are used in suitable proportions to dissolve PMMA, and then GO is added to this solution to obtain a uniform suspension of PMMA/GO for electrospinning. The mechanical and functional properties depend on the fibre quality and their distributions in the mat, which in turn depends on the concentration of the solution. Therefore, design of experiments based on mixture analysis was used to identify the solution concentration for obtaining uniform fibre diameters and their distribution throughout the electrospun core. The analysis suggested 23% PMMA and 2% GO concentrations in the solution would give uniform fibre diameters and dispersion throughout the mat.

Style APA, Harvard, Vancouver, ISO itp.

42

Khan, Mohammad Saleem, Rahmat Gul i Mian Sayed Wahid. "Studies on thin films of PVC-PMMA blend polymer electrolytes". Journal of Polymer Engineering 33, nr 7 (1.10.2013): 633–38. http://dx.doi.org/10.1515/polyeng-2013-0028.

Pełny tekst źródła

Streszczenie:

Abstract Thin films of poly (vinyl chloride) (PVC)/poly (methyl methacrylate) (PMMA) blend polymers complexed with different concentrations of LiClO4 salt, containing ethylene carbonate (EC) as the plasticizer, were fabricated by the solution cast procedure. Ionic conductivity, thermal stability and X-ray diffraction (XRD) studies were undertaken. AC impedance measurements were done in the temperature range of 20–70°C. The highest ionic conductivity at room temperature was found to be 2.23×10-5 S cm-1 for the sample containing 15 wt% of LiClO4 salt. The XRD technique was used to investigate the structure and complex formation of solid polymer electrolytes. There was a decrease in degree of crystallinity. The amorphous nature of complexed solid polymer blend electrolyte films increased, due to the addition of LiClO4 salt. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed the effect of salt on the thermal stability of the polymer electrolytes. It was found that these polymer electrolyte systems show stability up to about 280°C. It was also found that, with increased LiClO4 salt content in complexed polymer electrolyte systems, the degradation temperature decreased.

Style APA, Harvard, Vancouver, ISO itp.

43

Liu, Yun Long, Wen Jun Wang, Juan Wang, Xue Xi Gao i Hui Li. "Second-Order Nonlinearity of Organic/Inorganic Hybrid Materials Doped with Organic Chromophore by All-Optical Poling". Advanced Materials Research 217-218 (marzec 2011): 533–38. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.533.

Pełny tekst źródła

Streszczenie:

A kind of hybrid material was synthesized via sol-gel process with PMMA and TEOS as reactants, and 4’-Iodo-4-dimethylaminoazobenzene (IDMA) as nonlinear optical organic chromophore. The second order nonlinear optical properties of hybrid material in thin films were investigated by using All-optical poling technique, and the influences of films thickness, structure and poling temperature on SHG properties were discussed. The experimental results indicated that the absorption spectrum of PMMA/SiO2/IDMA film was wider than the spectrum of PMMA/IDMA film. As a consequence of the experiment, we found that different thickness films had different SHG saturation values, there was an optimum thickness for the films. In addition, the higher the sample temperature is, the smaller the SHG intensity is. We also found that the existence of SiO2 network in the film significantly improved the azo orientation stability.

Style APA, Harvard, Vancouver, ISO itp.

44

Al-Hamdani, Ali H. "Studying the spectral properties of thin films of rhodamine (6G) dyes doped polymer (PMMA) dissolved in chloroform". Iraqi Journal of Physics (IJP) 12, nr 23 (18.02.2019): 59–64. http://dx.doi.org/10.30723/ijp.v12i23.339.

Pełny tekst źródła

Streszczenie:

In the present work, poly methyl methacrylate (PMMA) doped with Rhodamine 6G was prepared. The spectral properties (absorption and fluorescence) of the films were studied at different concentrations (1x10-5, 2x10-5, 5x10-5, 7x10-5, and 1x10-4mol/l). The investigated samples were made in the form of thin films. This was achieved by dissolving a certain weight of PMMA in a fixed volume of chloroform, composite films was with thickness (25.8μm) at room temperature. The achieved results were pointed out that absorption and fluorescence spectra have taken a wide spectral rang so when increased the concentration each peak shift toward along wavelength. The quantum efficiency of the films were calculated as follows (98%,89%,84%,83% and 76%) for the above concentrations respectively. It has been noticed that the quantum efficiency decreases as the concentrations increases.

Style APA, Harvard, Vancouver, ISO itp.

45

Govindaraj, A. K., J. B. B. Rayappan i B. G. Jeyaprakas. "Preparation and Characterization of Metal Oxide: PMMA Composite Thin Films". Journal of Applied Sciences 12, nr 16 (1.08.2012): 1766–68. http://dx.doi.org/10.3923/jas.2012.1766.1768.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

46

HERBEI, Elena Emanuela. "Dielectric Characterization of SiO2-PMMA Organic – Inorganic Hybrid Thin Films". Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science 42, nr 3 (15.12.2019): 40–45. http://dx.doi.org/10.35219/mms.2019.4.07.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

47

Sharma, Kalpana, Raveendra Melavanki, Basappa C. Yallur, Raviraj Kusanur i N. R. Patil. "Preparation and Optical Characterization of PMMA Thin Films of C1". Macromolecular Symposia 400, nr 1 (grudzień 2021): 2100150. http://dx.doi.org/10.1002/masy.202100150.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

48

Philip, Biju, Jose K. Abraham, Anupama Chandrasekhar i Vijay K. Varadan. "Carbon nanotube/PMMA composite thin films for gas-sensing applications". Smart Materials and Structures 12, nr 6 (19.11.2003): 935–39. http://dx.doi.org/10.1088/0964-1726/12/6/010.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Cao, Ti, Keith P. Johnston i S. E. Webber. "CO2-Enhanced Transport of Small Molecules in Thin PMMA Films". Macromolecules 38, nr 4 (luty 2005): 1335–40. http://dx.doi.org/10.1021/ma047953s.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

Duvenhage, M. M., O. M. Ntwaeaborwa i H. C. Swart. "Optical and Chemical Properties of Alq3:PMMA Blended Thin Films". Materials Today: Proceedings 2, nr 7 (2015): 4019–27. http://dx.doi.org/10.1016/j.matpr.2015.08.031.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „PMMA thin films”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych