scholarly journals Surfactant Templated Mesoporous Hybrid Thin Films

2000 ◽  
Vol 628 ◽  
Author(s):  
Hongyou Fan ◽  
Yunfeng Lu ◽  
Roger A. Assink ◽  
Gabriel P. Lopez ◽  
C. Jeffrey Brinker
Keyword(s):  
Thin Film ◽  
Self Assembly ◽  
High Surface ◽  
Homogeneous Solution ◽  
Dip Coating ◽  
Inorganic Hybrid ◽  
Surface Areas ◽  
Hybrid Silica ◽  
Hybrid Thin Films ◽  
Coating Procedure

ABSTRACTOrganic/inorganic hybrid mesoporous films exhibiting ordered mesophases were prepared by a simple dip-coating procedure. Beginning with a homogeneous solution of tetraethoxysilane, organoalkoxysilane ((R'Si(OR)3, R' is a non-hydrolyzable functional ligand) surfactant, we relied on solvent evaporation to induce micellization and continuous self-assembly into hybrid silica-surfactant thin film mesophases. Surface acoustic wave (SAW)-based nitrogen sorption measurements indicate that the films have high surface areas and unimodal pore diameters after removal of surfactants.

scholarly journals MOCVD of Field Emission Phosphors using a Liquid Delivery System

1997 ◽  
Vol 495 ◽  
Author(s):  
T. S. Moss ◽  
B. F. Espinoza ◽  
K. V. Salazar ◽  
R. C. Dye
Keyword(s):  
Thin Film ◽  
Field Emission ◽  
Delivery System ◽  
High Surface ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray ◽  
Surface Areas ◽  
Field Emission Displays ◽  
Liquid Delivery

ABSTRACTThin film phosphors for field emission displays show the potential to overcome the life-limiting problems that traditional powders face because of their high surface areas. By depositing a fully dense thin film, the surface area can be dramatically reduced, while the electrical and thermal conductivity is increased. Metal organic chemical vapor deposition offers the ability to deposit high quality, dense films that are crystalline-as-deposited and at temperatures low enough to allow for inexpensive glass. Deposition has been produced from mixtures of Y(tmhd)3, TEOS, Tb(tmhd)3, and O2 using a liquid delivery system. Coatings were shown to be composed of Y, Si, and Tb by x-ray fluorescence, but x-ray diffraction did not show any crystallinity. Excitation using radioluminescence produced a peak in the visible green at approximately 540 nm, indicative of the excitation of Tb3+. The morphology of the deposition was smooth, with surface features on the order of one micron and below. Some limited microcracking was also observed in the morphology because of the thermal expansion mismatch.

Ultralow Fouling Surfaces from Self-Assembly of Copolymers with Sticky Biomimic Functional Groups

2018 ◽  
Vol 775 ◽  
pp. 298-304
Author(s):  
Fei Wan ◽  
Rui Pu ◽  
Chao Feng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Dip Coating ◽  
Antifouling Activity ◽  
New Strategy ◽  
Methacrylate Monomer ◽  
Fouling Release ◽  
Coating Procedure ◽  
Coated Surfaces ◽  
Surface Modified

In this work, a new strategy for preparing antifouling surfaces by a simple dip-coating procedure is reported. Copolymers containing catechol and antifouling pendant side groups were synthesized via the free radical polymerization of a catechol-containing methacrylate monomer N-(3,4-dihydroxyphenyl) ethyl methacrylamide and three kinds of antifouling monomers separately using α,α’-azobisisobutyronitrile (AIBN) as initiator. These copolymers can assemble onto variety of materials surfaces including metals, oxides, and polymers such as PTFE using catechol groups via multivalent complex bonding. The catechol groups are helpful for adhesion of the copolymers onto the surfaces, while the other side chains endow the coatings with antifouling activity. Modification on the substrates with copolymers were verified by X-ray photoelectron spectroscopy (XPS), the images of microalgaes and zoospores setting on the substrates were taken by microscope and scanning electron microscope (SEM). The copolymer-coated surfaces, especially the surface modified by copolymer with 3-sulfopropyl methacrylate potassium salt (SPMA(K)), displayed excellent antifouling activity and fouling-release properties in settlement assay with microalgaes and zoospores.

Synthesis and Characterization of Ordered Mesoporous Carbon/Silica Hybrid Thin Films

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaoxian Wang ◽  
Tiehu Li ◽  
Qilang Lin ◽  
Dawei Wang ◽  
Tingkai Zhao
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Self Assembly ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Matrix ◽  
Nanocomposite Films ◽  
Evaporation Induced Self Assembly ◽  
Hybrid Thin Films ◽  
Silica Nanocomposite

Carbon/silica nanocomposite films with a hexagonal P6mm structure were fabricated directly by the oxidation and carbonization of surfactant/silica nanocomposite films, which were obtained by a dip-coating technique through a combination of sol-gel and evaporation-induced self-assembly. The as-synthesized nanocomposite films were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy and N2 adsorption-desorption. These analyses reveal that the carbon/silica nanocomposite films, with a narrow pore size distribution of mesopores, have an ordered symmetric structure. The pore sizes of this hybrid film can be controlled within a certain range by changing the carbonization temperature. In addition, the films are composed of a continuous silica matrix and a continuous carbon coating in about 1 nm adhered well to the silica matrix. The formation of carbon coatings from surfactant acts as a framework support to prevent the pore size of the silica matrix from shrinking.

scholarly journals UiO66–NH2 AS A NEW PHOTOCATALYST FOR THE DEGRADATION OF p–XYLENE IN GASEOUS PHASE

2018 ◽  
Vol 55 (1B) ◽  
pp. 40
Author(s):  
Loc L. C.
Keyword(s):  
Thin Film ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Emitting Diode ◽  
Atmospheric Oxygen ◽  
High Surface ◽  
High Surface Area ◽  
Reaction System ◽  
Physicochemical Characteristics ◽  
Dip Coating ◽  
Total Power

Ammonia functionalized UiO66 (UiO66–NH2) in the form of thin film was synthesized by a solvothermal method combined with a dip–coating technique and determined with physicochemical characteristics by X–ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption measurements (BET), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). Also, the obtained material was assessed on the photoactivity in the degradation of p–xylene in the gas phase. Photoreaction was carried out in the micro flow reaction system with the radiation sources of a UV lamp (λ = 365 nm, the power of 8 W) and 81 pieces of light emitting diode (LED) (λ = 400–510 nm, total power of 19.2 W). The results showed that UiO66–NH2 was successfully prepared in the ball shape and featured by a high surface area of up to 576 m2/g, a band gap energy of 2.83 eV and a thermal stability of up to 673 K. Additionally, UiO66–NH2 thin film catalyst performed an efficiency of 1.27 g/gcat in the earlier 60 minutes of the photodegradation of p–xylene. The optimal treatment conditions were established with the moisture content of 8.65 mg/L and the atmospheric oxygen with the concentration of 300 mg/L.

scholarly journals Hierarchical Structures from Inorganic Nanocrystal Self-Assembly for Photoenergy Utilization

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Yun-Pei Zhu ◽  
Tie-Zhen Ren ◽  
Tian-Yi Ma ◽  
Zhong-Yong Yuan
Keyword(s):  
Self Assembly ◽  
Architectural Design ◽  
High Surface ◽  
Hierarchical Structures ◽  
Research Progress ◽  
Structural Hierarchy ◽  
Surface Areas ◽  
Nanobuilding Blocks ◽  
And Performance ◽  
Nanocrystal Assembly

Self-assembly has emerged as a powerful strategy for controlling the structure and physicochemical properties of ensembles of inorganic nanocrystals. Hierarchical structures from nanocrystal assembly show collective properties that differ from individual nanocrystals and bulk samples. Incorporation of structural hierarchy into nanostructures is of great importance as a result of enhancing mass transportation, reducing resistance to diffusion, and high surface areas for adsorption and reaction, and thus much effort has been devoted to the exploration of various novel organizing schemes through which inorganic porous structure with architectural design can be created. In this paper, the recent research progress in this field is reviewed. The general strategies for the synthesis of hierarchical structures assembled from nanobuilding blocks are elaborated. The well-defined hierarchical structures provide new opportunities for optimizing, tuning, and/or enhancing the properties and performance of these materials and have found applications in photoenergy utilization including photodegradation, photocatalytic H2production, photocatalytic CO2conversion, and sensitized solar cells, and these are discussed illustratively.

scholarly journals Enzymes@ZIF-8 Nanocomposites with Protection Nanocoating: Stability and Acid-Resistant Evaluation

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
Yuxiao Feng ◽  
Le Zhong ◽  
Muhammad Bilal ◽  
Zhilei Tan ◽  
Ying Hou ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Surface ◽  
Phosphate Buffer Solution ◽  
Acid Resistance ◽  
Initial Activity ◽  
Buffer Solution ◽  
Solution Ph ◽  
Practical Applications ◽  
Surface Areas ◽  
And Storage

Zeolitic imidazole framework-8 (ZIF-8) with tunable pore sizes and high surface areas have recently emerged as a promising support for immobilizing enzymes. However, the instability in the aqueous acidic environment and difficulty of recovery has limited their practical applications in some cases. In this study, catalase/ZIF-8 composites with a protective nanocoating were prepared by the controlled self-assembly of silanes or coordination complexes (tannic acid (TA) and Fe3+). The properties of the catalase (CAT)/ZIF-8 composites with a protective nanocoating were also determined. The recovered activity of CAT/ZIF-8 and CAT/ZIF-8 with protective nanocoating was 70% and 65%, respectively. Compared with the conventional CAT/ZIF-8 composites, CAT/ZIF-8 with protective nanocoating exhibited excellent acid resistance. For example, after treatment for 60 min in phosphate buffer solution (pH 3.0), CAT/ZIF-8 composites only maintained 20% of their initial activity (about 12 U/mg). However, CAT/ZIF-8 with a protective nanocoating could still retain about 50% of its initial activity (about 10 U/mg). Meanwhile, the thermostability and storage stability of the CAT/ZIF-8 composites was enhanced significantly due to the presence of nanocoating compared with conventional CAT/ZIF-8. More importantly, the CAT/ZIF-8 with a protective nanocoating retained 40% of its initial activity after 7 cycles, whereas CAT/ZIF-8 only retained 8% of the initial activity. The approach in this study could be an efficient strategy to prepare enzyme/ZIF-8 composites with both high acid resistance and excellent recyclability.

High temperature and water-based evaporation-induced self-assembly approach for facile and rapid synthesis of nanocrystalline mesoporous TiO2

2014 ◽  
Vol 2 (38) ◽  
pp. 15912-15920 ◽  
Author(s):  
Wei Wang ◽  
Dongthanh Nguyen ◽  
Haibo Long ◽  
Guoqiang Liu ◽  
Song Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Self Assembly ◽  
High Surface ◽  
Mesoporous Tio2 ◽  
Rapid Synthesis ◽  
Surface Areas ◽  
Water Based ◽  
Evaporation Induced Self Assembly ◽  
Large Mesopores

Through a high-temperature and water-based EISA (HW-EISA) approach, mesoporous TiO2 with high surface areas, ultra-large mesopores/pore volumes and tuneable bi-crystallinity (anatase plus rutile) can be facilely prepared in a ternary templating system (peroxotitanic acid/P123/H2O).

scholarly journals Application of TiO2 Nanoparticles in Clay Roofing Tiles as a Photocatalytic Active Material

2022 ◽  
Vol 5 (1) ◽  
pp. 90
Author(s):  
Maria Kouroutzi ◽  
Antonios Stratidakis ◽  
Marianthi Kermenidou ◽  
Spyros Karakitsios ◽  
Dimosthenis Sarigiannis
Keyword(s):  
Tio2 Nanoparticles ◽  
Active Material ◽  
Dip Coating ◽  
Morphological Characterization ◽  
Distribution Analysis ◽  
Tio2 Anatase ◽  
Surface Areas ◽  
Coating Procedure ◽  
Sem Imaging

A novel roofing tile was developed containing various types of nanoparticles of titanium dioxide (TiO2). Experiments were conducted using three types of TiO2 nanoparticles with and without polyethylene glycol (PEG). All types of newly developed nanomaterials were characterized using X-ray diffractometry. Particle size distribution analysis was performed and specific surface area was determined using the Brunauer–Emmet–Teller method. SEM imaging was used for the morphological characterization of nanoparticles. Commercial ceramic roofing tiles underwent a dip-coating procedure to obtain the desired photocatalytic surface. The TiO2 anatase samples exhibited greater surface areas of nanoparticles, thus providing potentially the highest photocatalytic efficiency.

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