Mechanism of Surfactant Removal from Ordered Nanocomposite Silica Thin Films by Deep-UV Light Exposure

2003 ◽  
Vol 788 ◽  
Author(s):  
Andrew M. Dattelbaum ◽  
Meri L. Amweg ◽  
Julia D. Ruiz ◽  
Laurel E. Ecke ◽  
Andrew P. Shreve ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Assembly ◽  
Uv Light ◽  
Light Exposure ◽  
Complete Removal ◽  
Combined Application ◽  
Silica Thin Films ◽  
Deep Uv ◽  
Surfactant Removal

ABSTRACTIn recent years, methods have been developed for the generation of complex ordered nanocomposite materials through organic templating of inorganic structures. One approach involves preparation of composite materials by an evaporation induced self-assembly process involving organization of organic surfactants and formation of inorganic silica from soluble precursors. Recently, we have shown that deep-UV light (185–254nm) is efficient at removing the surfactant microphase for a routine production of well-ordered mesoporous silica thin films. Here we probe the evolution of surfactant removal from nanocomposite thin film silica mesophases as a function of deep-UV exposure using a combined application of FTIR and single wavelength ellipsometry. Taken together, these data indicate that surfactant removal occurs in a step-wise fashion with the formation of oxidized intermediates prior to complete removal of the surfactant from the thin film.

scholarly journals Carbon Nano-Onions Reinforced Multilayered Thin Film System for Stimuli-Responsive Drug Release

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1208
Author(s):  
Narsimha Mamidi ◽  
Ramiro Velasco Delgadillo ◽  
Aldo Gonzáles Ortiz ◽  
Enrique Barrera
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Drug Release ◽  
Self Assembly ◽  
Critical Role ◽  
Layer By Layer ◽  
Film System ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Thin Film System

Herein, poly (N-(4-aminophenyl) methacrylamide))-carbon nano-onions (PAPMA-CNOs = f-CNOs) and anilinated-poly (ether ether ketone) (AN-PEEK) have synthesized, and AN-PEEK/f-CNOs composite thin films were primed via layer-by-layer (LbL) self-assembly for stimuli-responsive drug release. The obtained thin films exhibited pH-responsive drug release in a controlled manner; pH 4.5 = 99.2% and pH 6.5 = 59.3% of doxorubicin (DOX) release was observed over 15 days. Supramolecular π-π stacking interactions between f-CNOs and DOX played a critical role in controlling drug release from thin films. Cell viability was studied with human osteoblast cells and augmented viability was perceived. Moreover, the thin films presented 891.4 ± 8.2 MPa of the tensile strength (σult), 43.2 ± 1.1 GPa of Young’s modulus (E), and 164.5 ± 1.7 Jg−1 of toughness (K). Quantitative scrutiny revealed that the well-ordered aligned nanofibers provide critical interphase, and this could be responsible for augmented tensile properties. Nonetheless, a pH-responsive and mechanically robust biocompatible thin-film system may show potential applications in the biomedical field.

A High Performance UV Photodetector from Thin Film Diamond

1995 ◽  
Vol 416 ◽  
Author(s):  
Robert D. Mckeag ◽  
Michael D. Whitfield ◽  
Simon Sm Chan ◽  
Lisa Ys Pang ◽  
Richard B. Jackman
Keyword(s):  
Thin Film ◽  
Visible Light ◽  
Quantum Efficiency ◽  
Dark Current ◽  
External Quantum Efficiency ◽  
High Performance ◽  
Uv Light ◽  
High Sensitivity ◽  
Uv Photodetector ◽  
Deep Uv

ABSTRACTThin film diamond has been used to fabricate a photodetector which displays high sensitivity to deep UV light, with an external quantum efficiency of greater than one, a dark current of less than 0.1nA and which is near ‘blind’ to visible light.

Photoreactions in Polyalkylsilynes Induced by ArF-Laser Irradiation

1990 ◽  
Vol 204 ◽  
Author(s):  
R. R. Kunz ◽  
P. A. Bianconi ◽  
M. W. Horn ◽  
D. A. Smith ◽  
C. A. Freed
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Irradiation ◽  
Alkyl Group ◽  
Optical Components ◽  
X Ray ◽  
Oxygen Coordination ◽  
Bond Scission ◽  
Deep Uv ◽  
193 Nm

ABSTRACTPhotoreactions in polyalkylsilyne thin films induced by ArFlaser (193 nm) irradiation have been examined. Photoexcitation of the σ-conjugated Si-network at 193 nm (6.42 eV) results in Si-Si bond scission and alkyl-group desorption when irradiated in a vacuum. In addition to these processes, efficient (up to 7% quantum efficiency) insertion of oxygen into the Si backbone occurs when the irradiation is performed in air, resulting in the formation of a siloxane. Both infrared and X-ray photoelectron spectroscopies indicate a higher oxygen coordination about the Si atoms in the oxidized product than observed for linear polysilanes. This higher oxygen coordination indicates a siloxane network. The polysilynes have been demonstrated as deep UV photoresists and may have additional applications as precursors for thin film or binary optical components.

Electrochemically assisted self-assembly of mesoporous silica thin films

2007 ◽  
Vol 6 (8) ◽  
pp. 602-608 ◽  
Author(s):  
A. Walcarius ◽  
E. Sibottier ◽  
M. Etienne ◽  
J. Ghanbaja
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Silica Thin Films

scholarly journals Synthesis and Properties of Electrochemically Deposited Vertical Mesoporous Silica Thin Films

2015 ◽  
Vol 18 (3) ◽  
pp. 169-175
Author(s):  
Yuan Zhou ◽  
Qiming Liu ◽  
Ye Feng ◽  
Min Tan
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Ammonium Bromide ◽  
Silica Thin Films ◽  
Transmission Electron ◽  
Hydroxyl Ion ◽  
Mesoporous Film ◽  
Electrochemically Deposited ◽  
Cetyltrimethyl Ammonium

Electrochemical deposition was successfully used to prepare mesoporous silica thin films with highly ordered and vertically oriented pores. Tetraethyl orthosilicate was used as the inorganic silicon source and cetyltrimethyl ammonium bromide was the template. A negative potential was applied to the working electrode, which was initially immersed in collosol and then in hydroxyl at the electrode/solution interface. Hydroxyl ion served as the catalyst that promoted the polycondensation and self-assembly of the silicon precursor, as well as the formation of thin films with pores which are highly ordered and vertically oriented with respect to the panel.The pore arrangement of the mesoporous film was hexagonal, and its aperture was 2 nm to 3 nm. The verticality of the thin film pore was demonstrated through permeability and transmission electron microscopy analyses. The prepared mesoporous film possessed good optical amorphous antireflective property with ordered and vertically oriented pores.

scholarly journals Synthesis, Self-Assembly and Photoresponsive Behavior of Liquid Crystals Based on Azobenzene

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1560
Author(s):  
Yaming Wu ◽  
Yuhai Liu ◽  
Jianxiang Chen ◽  
Runmiao Yang
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Driving Force ◽  
1H Nmr Spectroscopy ◽  
Uv Light ◽  
Light Exposure ◽  
Scanning Calorimetry ◽  
Stimulus Response ◽  
Cis Isomer

A new amphiphilic surfactant (C4-Azo-C5-HDA) was formed by liquid crystals (LCs) based on azobenzene, whose structures were characterized by 1H-NMR spectroscopy. The reversible hydrogelation upon changes in temperature and light exposure was also studied. Under the irradiation of UV light, the trans-isomer of C4-Azo-C5-HDA rapidly photoisomerized to the cis-isomer, resulting in rapid disruption of the gel. The thermotropic liquid crystal behavior of the gelator was investigated via Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscopy (POM). The biocompatibility experiment of multi-stimulus response of the liquid crystal provides a potential driving force for the development of biomaterials.

SELF-ASSEMBLY FABRICATION OF GRAPHENE-BASED MATERIALS WITH OPTICAL–ELECTRONIC, TRANSIENT OPTICAL AND ELECTROCHEMICAL PROPERTIES

2012 ◽  
Vol 11 (06) ◽  
pp. 1240032 ◽  
Author(s):  
JIAYI ZHU ◽  
JUNHUI HE
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Assembly ◽  
Large Scale ◽  
Building Blocks ◽  
Precipitation Method ◽  
Hybrid Thin Film ◽  
Lbl Assembly ◽  
Metal Metal ◽  
Oppositely Charged

Directed self-assembly of nano or microsized materials as building blocks is a very exciting research topic to construct large-scale but still uniform 2D or 3D architectures. Graphene shows great potential as an advanced building block for fabricating varied graphene-based functional films or architectures together with other metal, metal oxide and semiconductor nanomaterials. In our work, we demonstrated an approach to fabrication of flexible, transparent conductive thin films via layer-by-layer (LbL) assembly of oppositely charged reduced graphene oxides (RGOs). The graphene thin films showed remarkable optical–electronic properties. Inspired by this, we further fabricated transparent conductive hybrid thin film via LbL assembly of oppositely charged RGO nanosheets and Pt nanoparticles. The graphene– Pt hybrid thin film showed transient optical property as well as appropriate conductive and wetting properties. Moreover, we demonstrated graphene wrapped- MnO2 (GW- MnO2 ) nanocomposites by self-assembly of honeycomb MnO2 nanospheres and graphene sheets via an electrostatic co-precipitation method. The hybrid materials had a good electrochemical performance.

Self-assembly of donor–acceptor semiconducting polymers in solution thin films: a molecular dynamics simulation study

2017 ◽  
Vol 5 (37) ◽  
pp. 9602-9610 ◽  
Author(s):  
Makoto Yoneya ◽  
Satoshi Matsuoka ◽  
Jun’ya Tsutsumi ◽  
Tatsuo Hasegawa
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Simulation Study ◽  
Self Assembly ◽  
Semiconducting Polymers ◽  
Dynamics Simulation ◽  
Polymer Thin Film ◽  
Donor Acceptor

The direction of π-stacking in a polymer thin film is crucially important in applications of semiconducting polymers.

Enhancement of nonlinear optical property in ZnS PVA films due to self-assembly

2015 ◽  
Vol 24 (02) ◽  
pp. 1550020 ◽  
Author(s):  
S. Mathew ◽  
Manu Vaishak ◽  
Boni Samuel ◽  
T. M. Libish ◽  
P. Radhakrishnan ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Assembly ◽  
Second Harmonic ◽  
Laser System ◽  
Laser Pulses ◽  
Saturable Absorption ◽  
Nanosecond Laser ◽  
Harmonic Intensity ◽  
Visible Luminescence

Nanostructured zinc sulfide ( ZnS ) thin films were synthesized in polyvinyl alcohol matrix by chemical bath deposition and self-assembly techniques. ZnS nanostructured thin films show second harmonic generation (SHG) under irradiation with a pico-second Nd :YAG laser system and the second harmonic intensity is higher for self-assembled nanotree like structured ZnS thin film in comparison with that from chemical bath deposited thin film. Under nanosecond laser pulses, thin films possess good saturable absorption behavior. The optical bandgap and visible luminescence also get enhanced.

Synthesis Photocatalytic TiO2/ZnO Nanocomposite and Investigation through Anatase, Wurtzite and ZnTiO3 Phases Antibacterial Behaviors

2018 ◽  
Vol 51 ◽  
pp. 69-77 ◽  
Author(s):  
Hanif Mohammadi ◽  
Mohammad Ghorbani
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Antibacterial Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Molar Ratio ◽  
Plate Count ◽  
Gel Method ◽  
Sol Gel Method ◽  
E Coli

Titanium dioxide is prepared by sol gel method from titanium tetraisopropoxide (TTIP) as precursor and likewise zinc oxide is prepared by sol gel method from zinc acetate dehydrate (ZAD) as precursor. The composite sols are prepared in three different molar ratios 90TiO2:10ZnO, 70TiO2:30ZnO and 50TiO2:50ZnO. Thin film deposition is carried out by dip coating technique. Crystal structure, surface morphology and photocatalytic activity of the prepared nanocomposite thin films are investigated. The antibacterial activity of the prepared nanocomposite thin film against E-coli ATCC 25922 bacteria is examined by placing the thin film in standard aqueous E-coli medium under UV light for 1, 2, 3 and 4 hours and then counting the bacteria with Standard Plate Count Agar (SPC) technique. The prepared thin films have shown strong antibacterial activity in the presence of UV light and by increasing the ZnO molar ratio from 10 to 50, antibacterial activity of the thin films decreases because of decreases in the anatase phase of the TiO2. In the dark conditions by increasing the molar ratio of ZnO, the antibacterial activity of the thin films increases and this phenomenon is related to increasing the zinc ions in the thin films.

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