Doped Poly Methyl Methacrylate Films Research Articles

Luminescence under UV(A, B and C) and sunlight exposure of tetrakis Tb3+ carboxylate complexes doped in different polymers

New tetrakis Lanthanide(III) carboxylate-based complexes (Ln3+: Eu and Tb) were successfully synthesized via a facile one-pot method with flufenamic acid (fluf) as ligand and benzimidazole (Bzim) or 1-ethyl-3-methylimidazole (C2mim) as counterions. In addition, the Q[Tb(fluf)4] complexes (Q+: Bzim and C2mim) were doped into polymethylmethacrylate (PMMA), polystyrene (PS), polycaprolactone (PCL) and poly(9-vinylcarbazole) (PVK) polymeric matrices at a 1 % (w/w) concentration and revealed highly desirable photophysical features such as wide range excitation wavelengths for the PMMA and PCL matrices and a very uncommon emission under sunlight exposure arising from the Tb3+ ion for the PMMA material. Thus, the tetrakis compounds with general formula Q[Ln(fluf)4] were characterized by elemental and thermal analysis, ESI-MS mass spectrometry, and FTIR absorption spectroscopy. The PMMA:(1 %)Q[Tb(fluf)4] doped films revealed higher thermal stability than the complexes. The tetrakis Eu3+ complex with Bzim as counterion shows no luminescence either for room or low temperature due to a highly operative low-lying ligand to metal charge transfer (LMCT) state quenching, while the corresponding C2mim-based analogous complex reveals some weak intensity emission, showing very low intrinsic quantum yield (QEuEu) values. On the other hand, the corresponding Tb3+ compounds presented bright green emission for the solid-state complexes and, particularly, for the PMMA:(1 %)Q[Tb(fluf)4] doped films when excited at UVA, UVB, and UVC radiation. Moreover, when the doped PMMA films are exposed to sunlight radiation in an open external environment, a bright green emission arising from the 5D4 → 7F5 transition from the Tb3+ ion can be seen. In this way, these optical results suggest that the PMMA:(1 %)Q[Tb(fluf)4] luminescent photonic materials can act as versatile and efficient light-converting molecular devices (LCMDs).

Highly Emissive Luminogens in Both Solution and Aggregate States

Highly Emissive Luminogens in Both Solution and Aggregate States

Phosphonium-Based Ionic Thermally Activated Delayed Fluorescence Emitters for High-Performance Partially Solution-Processed Organic Light-Emitting Diodes

Phosphonium-Based Ionic Thermally Activated Delayed Fluorescence Emitters for High-Performance Partially Solution-Processed Organic Light-Emitting Diodes

Study of refractive index and dispersion behaviour of KMnO4 doped poly-methyl-methacrylate(PMMA)composites

This work presents the analysis of optical characteristics of KMnO4 doped PMMA films synthesized using solution cast technique. The optical absorption spectra of these films in the wavelength range from 300 to 1100 nm were recorded by the help of a UV–VIS spectrophotometer. It has been found that the band gap, effective single oscillator energy (Eo), dispersion energy (Ed), dielectric constant and refractive index for zero frequency (εo, ηo) and dielectric constant and refractive index for very high frequency (ε∞, η∞) optical mobility (µopt), angular plasma frequency (ωP) optical resistivity (ρopt) and relaxation time (τ) are predominantly dependent on type of filler and its weight percentage in the polymeric matrix. The structural analysis of the prepared sample films has been confirmed by XRD and FTIR analysis.

Optical studies of Rhodamine B doped polymethyl methacrylate (PMMA) films

In this paper the influence of fluorescent dye doping on the optical properties of polymethylmethacrylate (PMMA), in particular on the optical band gap and refractive index of PMMA host matrix is reported. Solution casting method was used to prepare the films of pure PMMA and rhodamine-B doped PMMA films containing varying levels of doping and their optical properties were evaluated. UV–Visible spectra were used to evaluate the optical parameters; uv-absorption spectra reveal absorption bands between 262 and 284 nm for pure PMMA. However, dye doped PMMA film showed absorption bands in the range between 262 and 560 nm depending upon the degree of doping of dye into the film. Optical absorption measurements showed strong modifications in optical properties as a result of doping dye guest molecules into the host PMMA matrix system. It is observed that all optical parameters such as absorption band, absorption edge, energy band gap (direct and indirect) got affected by doping of the dye. Indirect optical band gap of pure PMMA was observed as 4.72 eV but it reduced to 4.13 eV on incorporation of rhodamine-B into PMMA matrix. Studies on the metallization criterion (M) implicate better scope of electronic mobility with the increase in the dopant concentration into the film.

Surface morphology and optical limiting properties of azure B doped PMMA film

Surface morphology of azure B doped polymethyl methacrylate (PMMA) film is studied by using optical microscopy and Origin 2017 software program. The optical limiting properties for solution of azure B in the solvent chloroform and azure B doped polymethyl methacrylate (PMMA) film are reported. Measurements were performed using two continuous wave (CW) laser beams. The effects of both concentration of the sample and the wavelength of the laser used on the optical limiting properties have been investigated. The optical limiting properties of the dye solution and dye doped PMMA film are compared. A mechanism for the optical limiting is given.

Luminescence properties of 2-benzoyl-1,3-indandione based Eu3+ ternary and tetrakis complexes and their polymer films

Six new Europium (III) complexes with ternary and tetrakis structures - Eu(BID)3(PHEN), Eu(MBID)3(PHEN), [Eu(BID)4]−N+(Et)4, [Eu(MBID)4]−N+(Et)4, [Eu(BID)4]−N+(Bu)4, and [Eu(MBID)4]−N+(Bu)4 (BID – 2-benzoyl-1,3-indandionate, MBID - 2-(4-methylbenzoyl)-1,3-indandionate and PHEN – 1,10-phenantroline) are synthesized, characterized, and incorporated into poly-N-vinylcarbazole (PVK) and poly methyl methacrylate (PMMA) matrices. Complex structure shows significant effect on thermal properties and emission properties of complexes in solid-state. Used countercations (N+(Et)4 or N+(Bu)4) greatly affects complex solubility in solvents, absolute photoluminescence quantum yields and photoluminescence lifetimes in solid-state. Complexes exhibit red-light emission attributed to 5D0→7FJ (J = 0–4) transitions of Eu3+ ion with moderate to high quantum yields (0.06–0.60), bi-exponential lifetimes and pure red-light CIE chromaticity coordinates (x = 0.670; y = 0.330) in solid-state. Incorporation of synthesized complexes in PVK matrices leads to significant emission intensity and quantum yield decrease.However, doped PMMA films with synthesized complexes exhibit moderate PLQY (0.09–0.14) and longer lifetime values than in solid-state and could show potential application as polymer optical fibers or in OLED's and other devices.

Highly Efficient Deep‐Blue Electrophosphorescent Pt(II) Compounds with Non‐Distorted Flat Geometry: Tetradentate versus Macrocyclic Chelate Ligands

A new class of deep blue electrophosphorescent Pt(II) emitters have been designed and synthesized. This new class of deep blue Pt(II) emitters employ tetradentate and macrocyclic chelate chromophores to constrain the Pt(II) molecules in a non‐distorted flat geometry in both the ground state and the excited state. The new deep blue emitters do not produce excimer emission, with emission quantum efficiency as high as 95% in 10% doped PMMA (poly(methyl methacrylate) films, and excellent UV stability, compared to the corresponding bidentate Pt(II) emitters. The macrocyclic tetradentate chelate Pt(II) compounds are the first examples of fully sterically constrained deep blue Pt(II) emitters that do not display structural distortion and have a higher thermal stability and a higher emission quantum efficiency than the corresponding non‐macrocyclic tetradentate Pt(II) analogues. A computational study supports that the macrocylic Pt(II) compounds are structurally more stable than the tetradentate Pt(II) molecules. Bright and efficient deep blue electrophosphorescent devices using a macrocyclic Pt(II) emitter have been successfully fabricated with a maximum brightness of 10 680 cd m−2, maximum external quantum efficiency of 15.4% (at 490 cd m−2), and Commission Internationale de L'Eclairage (1931) coordinates (x + y) of less than or near 0.30, respectively.

Time dependent diffraction ring patterns in bromothymol blue dye doped PMMA film under irradiation with continuous wave green laser light

Diffraction ring patterns are generated in bromothymol blue (BTB) doped poly methyl methacrylate (PMMA) film with the aid of visible light from a solid state laser of Gaussian distribution. Temporal evolution of patterns i.e. the number of rings increases as time elapse is observed. Based on the experimental findings, change in refractive index (∆n) effective nonlinear refractive index (n 2) and variation of refractive index with temperature (dn/dT) have been obtained as 0.0025, 1.45 × 10−6 cm2 W−1, 1.69 × 10−5 K−1 respectively. Obtained results suggest the possibility of using BTB doped PMMA in data storage, recording and holography.

Effect of Electric Field on Nonlinear Optical Properties of Hydrazone Doped PMMA Films

We report the effect of electric field on third order nonlinear optical properties of Hydrazone (Hz) doped Polymethyl methacrylate (PMMA) films. The films were prepared by solution casting method. Poling of films was done by corona discharge. Single beam Z-scan technique with 7ns Nd: YAG laser pulses at 532nm were employed for the measurements. Third order susceptibility of films was measured with an emphasis on the applied electric field. We also demonstrated the second harmonic generation in the corona poled films.

Solution-Processed High-Efficiency Organic Phosphorescent Devices Utilizing a Blue Ir(III) Complex

We report high-efficiency blue phosphorescence organic light-emitting devices by solution process utilizing a blue Ir(III) complex [(F2ppy)2Ir(ph-imz)CN] (F2ppy = 2',6' -difluoro-2-phenyl pyridine and ph-imz = N-phenyl imidazole) blended with the host mCP (N, N'-dicarbazolyl-3,5-benzene), and the inert polymers polystyrene (PS) and polymethylmethacrylate (PMMA). The effects of the dopant confinement in the PS and PMMA matrix on the device performance are studied by field emission transmission electron microscopy (FE-TEM) and atomic force microscopy (AFM). The complex shows photoluminescence peaked at 458 nm with CIE color coordinates (0.14, 0.21) in solution and (0.14, 0.18) in doped PMMA film. The PS based device showed better device performance than the PMMA based device with a maximum luminous efficiency of (etaL) 5.11 cd/A with CIE color coordinates (0.17, 0.29) (at 10 mA/cm2) and a maximum luminance of 9765 cd/m2.

Characterization of polystyrene and doped polymethylmethacrylate thin layers

About 1 μm thick films of polystyrene (PS) and polymethylmethacrylate (PMMA) were prepared from solutions using spin-coating method. The PMMA films were doped with diphenylsulfoxide (DS) up to 45 wt%. Glass transition temperature (T g ) of doped PMMA films was determined by DSC technique and relative permittivity (e) as a function of the sample temperature was determined from capacitance measurement. The dependence of polarization (P) on electric field (E) and the temperature was measured using a standard Sawyer-Tower circuit. Spectral dependence of film refractive index was measured using a refractometer. The glass transition temperature T g of PMMA/DS composite was found to be decreasing function of the DS concentration. Relative permittivity e of unpolar PS is lower than that of polar PMMA. The PS permittivity does not depend on the sample temperature. For PMMA the permittivity is increasing function of both, DS dopant concentration and sample temperature. The dependence of the polarization on the electric field on PS film does not exhibit a hysteresis and indicate no polarization contrary to PMMA. PMMA/DS composites exhibit easier and larger polaribility and a permanent dipole moment. Resulting polarization is an increasing function of DS concentration. Refractive index of both pristine PS and PMMA decreases with increasing wave length. The refractive index of PMMA/DS composites depends on the DS concentration.

Loss characterization in rhodamine 6G doped polymer film waveguide by side illumination fluorescence

We report the position dependent tuning of fluorescence emission from rhodamine 6G doped polymethylmethacrylate film waveguide using a side illumination technique. The transmitted fluorescence as a function of the distance from the point of illumination is measured by translating the waveguide horizontally across a monochromatic light source. This technique has been utilized to characterize the optical loss in dye doped waveguides. We observe that the optical loss coefficients for shorter and longer distances of propagation through the dye doped waveguide are different. At longer distance of propagation a decrease in optical loss coefficient is observed.

Zwitterionic polymers for nonlinear optics

Good optical quality thin films could be obtained with zwitterionic polymaleimides grafted by pyridinium–phenoxide zwitterions and also with polymethylmethacrylate (PMMA) doped by the same chromophores. Zwitterionic grafted polymaleimides presented low nonlinear efficiencies. Conversely, orientation of the PMMA doped films by the corona method could easily be performed and led to efficient systems for second-harmonic generation. Orientation within the doped films and susceptibility coefficients were very stable with time. Since doped polymers readily loose their orientation generally, the stability of these zwitterionic systems must be highlighted. The efficiency of zwitterionic doped PMMA films was of the same order as that of classical guest–host systems of PMMA such as DR 1, DO 3, DCV and TCV. Illumination of zwitterionic grafted or doped polymers in the chromophore absorption band and during the corona poling led to a reversible depoling of thin films. The poling was restored when the illumination was switched off. A cycling of poling–depoling, monitored by the external light illumination, led to an enhanced polar orientation as well as to an enhanced temporal stability of the induced order, as checked by the in situ second-harmonic generation experiments. This perfectly reversible effect, accompanied by the light-induced refractive index variation of thin film, should find numerous practical applications.

Transient currents in the discharge mode in pure and malachite green doped polymethylmethacrylate films

AbstractThe transient currents in the discharge mode in polymethylmethacrylate (PMMA) and malachite green doped PMMA films measured as a function of temperature (363–383 K) and field strength (2.0 ×103‐2.0 × 104 V/cm) have been found to follow the Curie–von Schweidler law, characterized by different slopes in the short and long time regions. Various mechanisms which may be responsible for the time‐dependent transient currents of pure and malachite green doped PMMA films are discussed. The effect of doping with malachite green on the discharge current indicates the formation of molecular aggregates.

Resonant Third-Order Nonlinear Optical Properties of Hemicyanine Doped PMMA Thin Film

Abstract The resonant third-order nonlinear optical properties of hemicyanine, 3-methyl-2-(6-morpholino-1,3,5-hexatrienyl)-benzoxazolium iodide (HC) doped polymethylmethacrylate (PMMA) thin films were measured by degenerate four- wave mixing (DFWM) at 580nm with 4ps pulses. It was found that the temporal profile of DFWM signal in 0.01M HC doped PMMA film was much different from that in dilute dimethylsulfoxide solution of HC. The decay of DFWM signal in the thin film consisted of the faster component (∼10ps) in addition to the slower one (>100ps). The phase conjugate reflectivity was not proportional to the square of pump intensity and saturated even in the weak pump intensity. The effective X (3) xxxx value of the thin film was relatively large (2.8∼10−9esu) at weak pump intensity (0.03μJ/pulse).

Temperature optimisation of optical phase conjugation in dye doped polymer films

Experimental results of the temperature dependence of the nonlinear optical response of methyl red doped polymethylmethacrylate films in the range 20°C to 170°C are reported. It is found that the intensity of the phase conjugate signal resulting from degenerate four-wave mixing using pump and probe beams with parallel polarisation states increases dramatically on heating by a factor of ∼ 10, reaching a maximum at ∼ 100°C. The intensity of the phase conjugate signal for the case with crossed polarisation states of the pump and probe beams drops monotonically with increasing temperature. For both configurations the response time shortens with increasing temperature. The particular role of the polymer matrix in this temperature variation of the nonlinear optical response is discussed.

Photokinetic etching of polyethylene terephthalate films by continuous wave ultraviolet laser radiation

Continuous wave laser radiation from an argonion laser in the wavelength range 275–330 nm can be used to etch polyethylene terephthalate (PET) films with as little thermal damage as from a pulsed, ultraviolet laser (248 nm or 308 nm) provided the beam is focussed to a spot of 10–100 kW/cm2 of power density and is moved over the surface at speeds at which the transit time over its own diameter (which can be looked upon as a “pulse width”) is on the order of 10–200 μs. In contrast to results which had been obtained previously on the photokinetic etching of polyimide and doped polymethyl methacrylate films under similar conditions, the sensitivity of PET to etching is >5-fold greater than either of these polymers and increases steadily with increasing pulse width. There is lateral thermal damage as the pulse widths increase to >200 μs. The material that is removed is vaporized in part. More than 20% is probably ejected in a molten state and resolidifies at the edge of the cut. There is no acoustic report similar to that seen in ablative photodecomposition. The process appears to be largely thermal in nature.

Spontaneous current emission in solution-grown doped polymethylmethacrylate films

Measurements on spontaneous current emission (SCE) in the complex of polymethylmethacrylate and malachite green samples were made by varying electrode materials, film thickness, heating rates and concentration of malachite green. The spontaneous current is found from metal-complex-metal systems in a temperature range from 40 to 200°C. SCE thermograms from the Al-complex-Al system exhibit two transitions at 110°C and 170°C; the former goes in the negative and the latter in the positive direction. These transitions are explained on the basis of (a) the field created at the surfaces and (b) the field produced in the bulk of the material. For electrode systems (Al-complex-Ag and Al-complex-Cu) no such transition has been found.

Space ? charge ? limited conduction in NiCl2 ? doped PMMA films

The effect of weight fraction (1–4%) of NiCl2 dopant on some parameters characterising the space charge limited conduction (SCLC) in polymethylmethacrylate (PMMA) composites was investigated. The studied parameters are the concentrations of traps, trapped and free charge carriers. It was implied that NiCl2 acts as an efficient electron acceptor and this was attributed to the formation of Ni11CL42−.