thin film porous membranes

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Fabrication and Modification of Thin-Film Composite Hollow Fiber NF Membranes

Fabrication and Modification of Thin-Film Composite Hollow Fiber NF Membranes

A composite membrane is provided by forming a nano-thin selective dense layer on a porous substrate. The top selective layer and bottom porous substrate of the composite membrane can be modified to maximize the overall membrane performance [16, 17]. Reports show that the performance of the NF membrane is determined by the chemical structure of the thin active layer, pore size and its distribution, film thickness, and the surface charge and its morphological features [18]. Among the methods for preparing TFC membranes, interfacial polymerization (IP) is the most effective one [19-20]. The IP technique is based on a polycondensation reaction between two monomers; that is, a poly functional amine and a poly functional acid chloride. The advantage of the IP method is that the reaction is self-inhibiting via passage of a limited supply of reactants through the already formed layer [21]. Moreover, the thin layer can be optimized for a particular function by varying the monomer concentration in each solution, monomer ratios and reaction time of the interfacial polymerization [22-28].
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Exploring the potential of nanofillers for advanced thin film nanocomposite forward osmosis membranes fabrication

Exploring the potential of nanofillers for advanced thin film nanocomposite forward osmosis membranes fabrication

In both FO and PRO processes, osmotic pressure difference is the driving force. In these membranes, features o f the support layer strongly influence efficiency o f the process. Here water molecules chemically diffuse across the membrane in both FO and PRO processes. As a result, decrease in flux can be expected due to internal concentration polarization (ICP). ICP refers to dilution o f the draw solution in the porous substrate which leads to dramatic decrease in driving force across the FO membrane. It is concluded that ICP in FO process will be minimized if substrate layer has a small structural parameter, 5, (McCutcheon and Elimelech, 2006). Moreover, substrates with higher hydrophilicity show lower resistance against water passage and allow more water productivity.
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The Potential of Nanoparticles for Upgrading Thin Film Nanocomposite Membranes – A Review

The Potential of Nanoparticles for Upgrading Thin Film Nanocomposite Membranes – A Review

Over the past decade, many applications were intended for filtration by membrane technology especially the thin film composite (TFC) membranes. In advanced developments of thin film membranes, an attempt was made to spread a new generation of membranes called thin film nano composite (TFN) membranes. However, in the last generation of TFNs, an ultrathin selective film of nanoparticles is coated on the porous sub-layer with different procedures (i.e. interfacial polymerization (IP), dip coating and Plasma polymerization) which contained nanoparticles in a scale of 20-200 nm. Thin film nanocomposite membranes are the last generation of RO membranes which are known as the best appliance in the nanofiltration researches. In this realm, with the help of nanotechnology, membrane science has introduced a novel gamut in science and technology. By using new nanoparticles and nanocomposites among the structure of membranes, the TFNs were born to help the separation and purification processes. To fabricate high efficiency thin film nanocomposites, many manners, theories and additive particles are modified and chosen with regards to time and applications which can increase selectivity, permeability and porosity in addition to the reduction of fouling or improvement of salt rejection. The current review is written to seek the maze of thin film nanocomposite membranes in the past few years with the goal of clarifications of this novel method of filtration, its outlook, nanoparticles and applications which were used before and can be used in the future.
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Thin Film Composite and/or Thin Film Nanocomposite Hollow Fiber Membrane for Water Treatment, Pervaporation and Gas/Vapor Separation

Thin Film Composite and/or Thin Film Nanocomposite Hollow Fiber Membrane for Water Treatment, Pervaporation and Gas/Vapor Separation

Sukitpaneenit and Chung [42] fabricated novel membranes with a thin selective polyamide layer, which was formed by interfacial polymerization onto a porous polyethersulfone (PES) hollow fiber support (free of macrovoids). The PES support was fabricated via dual-layer co-extrusion technology. A thin film of polyamide layer on the inner surface of PES hollow fiber was formed by an interfacial polymerization (IP) between the MPD monomer in the aqueous phase and the TMC monomer in the organic phase. The surface of the TFC was modified by coating with either polydopamine or silicone rubber. The polydopamine or silicone rubber coated membranes exhibited water separation factors of up to 51 and 60, with substantial high fluxes of 6.6 and 7.5 kg m −2 h −1 , respectively, when used in pervaporation
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Low-Cost and High-Performance Electrospun Carbon Nanofiber Film Anodes

Low-Cost and High-Performance Electrospun Carbon Nanofiber Film Anodes

Carbon nanofiber thin membrane is a promising candidate material for chemical power supply because of its simple design and fast charge-transfer network. In this study, the original porous carbon nanofiber thin membrane electrode was electrospun following a simple and rapid washing process. The structural features of the porous carbon nanofiber membranes were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller analysis. The electrochemical performance of the porous carbon nanofiber membranes was investigated by electrochemical test. Results show that the as-prepared porous carbon nanofiber film possesses a highly porous surface structure and demonstrates an outstanding electrochemical performance. The film electrode exhibits a charge capacity of 948.1 mAh·g −1 under a C-rate of 0.1C (37.2 mA·g −1 ) and 208.8 mAh·g −1 after 1700 cycles under a C-rate of 5C (1860 mA·g −1 ). In the preparation of a binder- and conductive-free thin film electrode, the addition of NaCl increases the precursor viscosity, which results in a slimmer fiber and significantly improves the specific surface area by washing NaCl crystals with water. This method avoids rinsing with an acidic or basic solution and recycles the used NaCl, thereby significantly reducing the preparation cost of porous carbon fiber thin film electrode. This work demonstrates a new method of preparing high-value porous carbon fiber thin film electrodes at a low cost.
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Development of a Novel Reusable Real Time Monitoring Glucose Sensor Based on Nanostructured Conducting  Polyaniline (NSPANI)

Development of a Novel Reusable Real Time Monitoring Glucose Sensor Based on Nanostructured Conducting Polyaniline (NSPANI)

NSPANI, with different morphologies, have been synthesized using various techniques such as template synthesis, self-assembly, emulsions and interfacial po- lymerization [18-20], seeding polymerization [21] ra- pidly mixed reaction [22] and surfactant-directing meth- ods [23,24]. One of the most elegant and facile way of synthesizing NSPANI is the use of structure directing agent (SDA) which can act as a soft template. The SDA controls the polymerization in a restricted zone so that the crystal growth can take place in a definite manner. It has been observed that the nature and composition of SDA regulate the morphology, nano dimension, switch- ing properties and conductivity etc. [25]. The fabrication of nano structure using SDA into conducting polymers can improve their biocompatibility and conformation and provide porous surface morphology at the nano scale to improve enzyme immobilization for enzyme based bio- sensor applications [26,27].
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Liewald, Clemens
  

(2018):


	Microscopy and nanoscopy of organic semiconductors for structural and electronic analysis.


Dissertation, LMU München: Fakultät für Physik

Liewald, Clemens (2018): Microscopy and nanoscopy of organic semiconductors for structural and electronic analysis. Dissertation, LMU München: Fakultät für Physik

Photocurrent microscopy is used to characterize the kinetics of elec- trons and holes in organic field-effect transistors (FETs) with the hy- drogen-bonded pigment epindolidione as active layer. The method relies on electrons and holes, generated on local illumination, which are provided after exciton splitting, to probe charge trapping. In the dark, hole conduction is observed for negative gate voltage while no electron conduction is observed for positive gate voltage. However, under illumination, a fast displacement current with 60 µ s onset time and 1 ms exponential decay occurs for positive gate voltage, which can be explained by exciton splitting underneath the semitranspar- ent top contact followed by subsequent electron trapping and hole extraction. Afterward, trapped electrons hop via further trap states within the film to the insulator into interface traps (13 ms exponen- tial decay) which induce a positive threshold voltage shift in the FET transfer curves for hole transport. Photocurrent microscopy confirms that the displacement current occurs only for illumination under and near the semitransparent source/drain contacts, which act here as metal-insulator-semiconductor (MIS) diodes. For negative gate volt- age instead, the photocurrent comprises an enhanced hole current in the FET channel between the contacts. In the channel region, the detrapping of holes at the interface with the insulator ( 3 ms time constant) enhances the transistor current at low frequencies <1 kHz, whereas the displacement current between the contacts and the gate is observed only at frequencies >10 kHz . Thus, we show here that photocurrent microscopy allows to identify the kinetics of electrons and holes in traps close to the contacts and in the FET channel of pigment transistors.
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The Impact of PDDA in CNT Counter Electrode on the Conversion Efficiency of DSSC - Volume 9 Number 6 (Dec. 2018) - IJCEA

The Impact of PDDA in CNT Counter Electrode on the Conversion Efficiency of DSSC - Volume 9 Number 6 (Dec. 2018) - IJCEA

In this paper, we proposed a high catalysis CE for DSSC as a substitution for Pt. There are some methods to laminate carbon materials including Electrophoresis Deposition method (EPD), spin coating [9] or doctor-blading [14], [15]. EPD method is coating method by charging particles and has some advantages (short fabrication time, controllable thin film thickness and simple setting). It has been proved that Poly (diallyl dimethylammonium chloride) (PDDA) has ability of withdrawing electrons from CNT. [16] By using this method, we fabricated and tested CNT electrode and CNT mixed with PDDA (CNT/PDDA) electrode.
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Thin film calixresorcinarene membranes for chemical sensing

Thin film calixresorcinarene membranes for chemical sensing

polymer molecules dispersed in it. The level of mixing that occurs depends on the ratios of the components and their structure. High quality LB films have been reported for very diverse amphiphilic matrix materials, like cadmium sterate 3-octadecanoyl pyrrole [8], tetra-tert-butyl phthalocyanine [9], stearic acid [6], vanadium-tetraphenyl porphyrine [10^ and phosphorylated calixarenes [11l Extensive studies on gas/vapour sensing membranes utilising aniline based polymers have been conducted in the literature [12,13]. Part of their attractiveness stems from the ease of their synthesis, the low cost of the materials, their high environmental stability and an extensive pool of background knowledge that already exists. In line with aniline based sensing membranes POMA was chosen, representing a non-surface active polymer for the incorporation in the C[4]RA matrix. The focus lies here on the matrix for the application in sensoric membranes, not on fundamental studies regarding the polymer per se. No obvious difficulty can be seen, when it comes to replacing the POMA for any other aniline based polymer, with differing sidegroups, like for example ethoxy groups. Main factors, influencing the polymer conductance are its molecular weight and the type of dopant used. Any cited molecular weight is only the average of all the molecular weight fractions contained in the whole sample, making any direct comparison between polymer samples, originating from different synthesis methods, difficult. Recent studies have shown, that the kind of solvent used influences the conductance of the polymer. For m-cresol as a solvent secondary doping for polyaniline was reported [14,15], leading to an increase in the electrical conductivity and an altered film morphology. FTIR spectroscopy has shown that the m-cresol is not incorporated into the polymer [16], but influences the polymer structure. The changes have been attributed to conformational changes of the polyaniline chains, from the compact to an expanded coil structure [17,18]. Since no m-cresol is retained, this implies a kind of memory effect[14].
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Plasma-induced physicochemical effects on a poly(amide) thin-film composite membrane

Plasma-induced physicochemical effects on a poly(amide) thin-film composite membrane

50. Kim, S.H., S.-Y. Kwak, and T. Suzuki, Positron Annihilation Spectroscopic Evidence to Demonstrate the Flux-Enhancement Mechanism in Morphology-Controlled Thin- Film-Composite (TFC) Membrane. Environmental Science & Technology, 2005. 39(6): p. 1764-1770.

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Rare Earth Elements to identify archaeological strata in the Cocina Cave

Rare Earth Elements to identify archaeological strata in the Cocina Cave

PO-ESP-07 SPECIATION OF ORGANOMANGANESE AND INORGANIC MANGANESE IN WATER SAMPLES BY HEADSAPCE THIN-FILM MICROEXTRACTION ONTO GRAPHENE MEMBRANES Carlos Bendicho, Vanesa Romero, Isabel Cos[r]

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Análisis químicos no destructivos sobre cinco mangos de marfil de Época Ibérica

Análisis químicos no destructivos sobre cinco mangos de marfil de Época Ibérica

PO-ESP-07 SPECIATION OF ORGANOMANGANESE AND INORGANIC MANGANESE IN WATER SAMPLES BY HEADSAPCE THIN-FILM MICROEXTRACTION ONTO GRAPHENE MEMBRANES Carlos Bendicho, Vanesa Romero, Isabel Cos[r]

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Molecular transport through primary human small intestinal monolayers by culture on a collagen scaffold with a gradient of chemical cross-linking

Molecular transport through primary human small intestinal monolayers by culture on a collagen scaffold with a gradient of chemical cross-linking

The luminal surface of the small intestine is composed of a single layer of polarized columnar epithelial cells with the most prevalent cell type being enterocytes, ab- sorptive cells that transport nutrients, salt, metabolites and drugs [1]. The presence of villi lining the intestinal surface greatly increases the absorptive area, while microvilli covering the surface of the enterocytes, known as the brush border, increases the cellular surface area for transport and passive absorption [2, 3]. Proteins expressed by the epithelium facilitate the transport of drugs, metabolites, ions and amino acids [4]. The two major families of drug transporter proteins found in the small intestine are the ATP-binding cassette (ABC) superfamily and the solute carrier (SLC) superfamily, both of which mediate drug and metabolite uptake and export. ABC transporters harness energy from ATP hy- drolysis to actively transport substrates across cellular membranes, whereas SLC transporters are primarily in- volved in the passive uptake of small molecules into cells [5]. The ABC transporter family includes clinically im- portant proteins such as P-glycoprotein (P-gp), multi- drug resistance proteins (MRP1, 2, 3), and breast cancer resistance protein (BCRP) [6]. The SLC transporters par- ticipate in both absorption and secretion of anionic and cationic molecules and include proteins such as the or- ganic cation transporter 3 (OCT3) [7, 8]. Na + / K + -ATPase and gamma-glutamyl transpeptidase (GGTP) are not part of the two major superfamilies but play im- portant roles in the transport of molecules. The Na + / K + -ATPase enzyme present on the basal aspect of the epithelial cells actively exports sodium while importing potassium, both against their concentration gradient. The resulting Na + gradient drives a Na + -glucose sympor- ter on the cells’ luminal face that imports both Na + and glucose in an efficient manner [4, 9]. GGTP is a transfer- ase in the brush border that catalyzes the transfer of gamma-glutamyl functional groups from glutathione to an acceptor such as a peptide or amino acid to form glu- tamate, and in the intestine is involved in amino acid ab- sorption [10, 11]. To study the function of these various proteins, particularly for drug and nutrient transport, de- velopment of a primary, human intestinal epithelial monolayer system providing access to the luminal and basal aspects of the epithelium is a necessary tool.
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APATITE NUCLEATION OF DENSE AND POROUS CHITIN MEMBRANES

APATITE NUCLEATION OF DENSE AND POROUS CHITIN MEMBRANES

To obtain dense chitin membranes a LiCl solution of 7% was prepared in N,N- dimethylacetamide (DMAc) and used for the dissolution of polysaccharide to 1% (w/w). The solution was poured into Petri plates and conditioned under 88% relative humidity, the 37 o C for 3 days. After this period, the membranes were washed with deionized water until complete elimination of the organic solvent.

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Thermal tuning of
a thin-film optical filter based on porous silicon and liquid crystal

Thermal tuning of a thin-film optical filter based on porous silicon and liquid crystal

Spectral characteristics of an interference optical filter based on a free-standing mesoporous silicon film containing nematic liquid crystal E7 are studied experimentally. The porous structure represents two distributed Bragg reflectors divided by a quarter-wave microcavity having a resonance near 1600 nm. Optical transmission spectra of the filter are measured in the temperature range from 27°C to 80°C. For the temperatures less than 62 o C (a clearing point of the liquid crystal), we have observed continuous red shift of resonant wavelength of the microcavity in the range of 11 nm. The thermal dependence of the shift measured by us has sharply increasing slope near the clearing point. The resonant wavelength of the microcavity exhibits a slow linear decrease for the temperatures exceeding 62 o C. We have also studied the spectra of the filter under local heating of the sample by a laser. Our results demonstrate that the laser beam with the power of 100 mW provides total tuning of the microcavity.
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Wide Range RH Detection with Digital Readout: Niche Superiority in Terms of Its Exceptional Performance and Inexpensive Technology

Wide Range RH Detection with Digital Readout: Niche Superiority in Terms of Its Exceptional Performance and Inexpensive Technology

Measurement was done at ambient conditions. In order to determine the sur- face chemistry of alumina film, electrostatic repulsion of the particles, in relation to the pH value of aqueous systems was analysed. Figure 2 shows the charging behaviour at the alumina-water interface with changing pH without adding binders. The isoelectric point of prepared alumina is 8, which is characteristic feature of most metal oxide. The value indicates the concentration of nanopar- ticles and in good agreement with the literature [19] [20] [21] [22].

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Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

Liquid wettability indicating hydrophilicity and hydrophobicity properties are influenced by chemistry, sur- face charge and surface morphology. Figure 7 shows the wettability of the plasma modified surfaces was investi- gated with measurements of contact angle before and after plasma treatment. The hydrophilicity was significantly increased for all plasma treated membranes. At 10 W, the water contact angles were found to decrease, with increasing plasma duration from 60.8 ± 5.0° for the control membrane, down to 23.5 ± 9.0° after 30 min of plasma treatment. A consistent and similar trend was also found at 50 W in contact angle measurements. Water contact angles were reduced at 50 W from 32.2 ± 9.0° to 19.4° ± 9.0 for 1 to 30 min of treatment duration. Furthermore, the water contact angles were further reduced at 80 W when compared to 10 and 50 W, down to 29.4° ± 3.0 and Figure 6. Streaming potential with increasing excitation power and plasma durations: (A) 10 W, (B) 50 W and (C) 80 W.
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Electrochemical Performance of Mn Doped Co3O4 Thin Film Electrodes by Electrodeposition Method

Electrochemical Performance of Mn Doped Co3O4 Thin Film Electrodes by Electrodeposition Method

copper substrate. The obtained diffractogram indicates the presence of manganese and cobalt oxide peaks, also there is no impurity peaks are observed. It suggests that doped manganese ions have been well incorporated into the cobalt oxide lattice site without distorting the crystal symmetry. FESEM micrographs confirm the formation of porous and uniform film deposition on both substrates with nano structures. EDAX spectra of the prepared films clearly confirmed that the presence of Co, Mn atoms with increase in their elemental percentage when the deposited films is annealed. FT-IR spectra confirms the presence of all functional groups corresponding to the Manganese cobalt oxide. The MnCo 3 O 4 thin film electrode deposited on copper
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Porous NASICON Type Li3Fe2(PO4)3 Thin Film Deposited by RF Sputtering as Cathode Material for Li Ion Microbatteries

Porous NASICON Type Li3Fe2(PO4)3 Thin Film Deposited by RF Sputtering as Cathode Material for Li Ion Microbatteries

no. 040-1499). Various deposition parameters (such as target power, substrate temperature, or argon pressure) were previously investigated, and in all cases, the as- deposited thin films were amorphous. As it can be seen in Fig. 1, the annealing treatment leads to the crystallization of NASICON-type Li 3 Fe 2 (PO 4 ) 2 phases (JCPDS file no.

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Preparation of Novel Thin-Film Composite Nanofiltration Membranes for Separation of Amoxicillin

Preparation of Novel Thin-Film Composite Nanofiltration Membranes for Separation of Amoxicillin

Nanofiltration (NF) membranes, which exhibit separation characteristics in the intermediate range between reverse osmosis and ultrafiltration membranes, are gaining interest worldwide because of advantages such as low operation pressure, high permeate flux and high retention of multivalent ion salts [9-11]. NF process has been used in many applications such as wastewater reclamation [12-13], industrial water production, water softening [14-15] and the separation of compounds having different molecular weights [16-17]. Most NF membranes developed to date have a thin-film composite (TFC) structure due to key advantages compared to asymmetric membranes [18-21]. In a TFC membrane, the support layer provides an appropriate mechanical strength with low resistance to permeate flow and
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