Superhydrophilic modification of APA‐TFC membrane surface by grafting QACs and salicylaldehyde units with PEG chains as the spacers

Thin film composite (TFC) membrane, which consists of polyamide (PA) active film rests on porous support layer, has been the major type of reverse osmosis (RO) membrane since its development by Cadotte in the 1970s, and has been remarkably used to produce clean water for human consumption and domestic utilization. In the past 30 years, different approaches have been exploited to produce the TFC membrane with high water flux, excellent salt rejection, and better chlorine/fouling resistance. In this brief review, we classify the techniques that have been utilized to improve the RO-TFC membrane properties into four categories: (1) Using alternative monomers to prepare the active layer; (2) modification of membrane surface; (3) optimization of polymerization reactions; and (4) incorporation of nanoparticles (NPs) into the membrane PA layer. This review can provide insights to guide future research and further propel the RO TFN membrane.

Download Full-text

Direct filtration procedure to attain antibacterial TFC membrane: A facile developing route of membrane surface properties and fouling resistance

Chemical Engineering Research and Design ◽

10.1016/j.cherd.2019.07.003 ◽

2019 ◽

Vol 149 ◽

pp. 158-168 ◽

Cited By ~ 4

Author(s):

Atefe Soleymani Lashkenrai ◽

Mahsa Najafi ◽

Majid Peyravi ◽

Mohsen Jahanshahi ◽

Mohammad Taghi Hamed Mosavian ◽

...

Keyword(s):

Surface Properties ◽

Membrane Surface ◽

Fouling Resistance ◽

Direct Filtration ◽

Tfc Membrane

Download Full-text

Densely grafting quaternary ammonium cation and salicylaldehyde on the APA-TFC membrane surface for enhancing chlorine resistance and anti-biofouling properties

Desalination and Water Treatment ◽

10.1080/19443994.2015.1081834 ◽

2015 ◽

Vol 57 (35) ◽

pp. 16384-16394 ◽

Cited By ~ 1

Author(s):

Tianlin Zhang ◽

Xiadan Yue ◽

Caiyian Zhu ◽

Huimin Ma ◽

Yabo Liu ◽

...

Keyword(s):

Quaternary Ammonium ◽

Membrane Surface ◽

Ammonium Cation ◽

Tfc Membrane

Download Full-text

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082509 ◽

1978 ◽

Vol 36 (2) ◽

pp. 328-329

Author(s):

Hideo Hayashi ◽

Yoshikazu Hirai ◽

John T. Penniston

Keyword(s):

Conformational Changes ◽

Human Erythrocyte ◽

Shape Change ◽

Membrane Surface ◽

Slight Modification ◽

Active Role ◽

Main Role ◽

Bank Blood ◽

Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

Download Full-text

Role of PKC isozymes in water transport in toad urinary bladder

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085812 ◽

1991 ◽

Vol 49 ◽

pp. 302-303

Author(s):

A.J. Mia ◽

L.X. Oakford ◽

T. Yorio

Keyword(s):

Urinary Bladder ◽

Apical Membrane ◽

Membrane Surface ◽

Protein A ◽

Cell Types ◽

Leukemic Cells ◽

Toad Urinary Bladder ◽

Pkc Isozymes ◽

Antibody Labeling

Protein kinase C (PKC) isozymes, when activated, are translocated to particulate membrane fractions for transport to the apical membrane surface in a variety of cell types. Evidence of PKC translocation was demonstrated in human megakaryoblastic leukemic cells, and in cardiac myocytes and fibroblasts, using FTTC immunofluorescent antibody labeling techniques. Recently, we reported immunogold localizations of PKC subtypes I and II in toad urinary bladder epithelia, following 60 min stimulation with Mezerein (MZ), a PKC activator, or antidiuretic hormone (ADH). Localization of isozyme subtypes I and n was carried out in separate grids using specific monoclonal antibodies with subsequent labeling with 20nm protein A-gold probes. Each PKC subtype was found to be distributed singularly and in discrete isolated patches in the cytosol as well as in the apical membrane domains. To determine if the PKC isozymes co-localized within the cell, a double immunogold labeling technique using single grids was utilized.

Download Full-text

SEM/FESEM imaging of lamellar structures in melt extruded polyethylene films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130341 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1142-1143

Author(s):

R.T. Chen ◽

M.G. Jamieson ◽

R. Callahan

Keyword(s):

Imaging Techniques ◽

Membrane Surface ◽

High Stress ◽

Extrusion Direction ◽

Polymeric Membranes ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Crystalline Polymers ◽

Lamellar Structures ◽

Resolution Imaging

“Row lamellar” structures have previously been observed when highly crystalline polymers are melt-extruded and recrystallized under high stress. With annealing to perfect the stacked lamellar superstructure and subsequent stretching in the machine (extrusion) direction, slit-like micropores form between the stacked lamellae. This process has been adopted to produce polymeric membranes on a commercial scale with controlled microporous structures. In order to produce the desired pore morphology, row lamellar structures must be established in the membrane precursors, i.e., as-extruded and annealed polymer films or hollow fibers. Due to the lack of pronounced surface topography, the lamellar structures have typically been investigated by replica-TEM, an indirect and time consuming procedure. Recently, with the availability of high resolution imaging techniques such as scanning tunneling microscopy (STM) and field emission scanning electron microscopy (FESEM), the microporous structures on the membrane surface as well as lamellar structures in the precursors can be directly examined.The materials investigated are Celgard® polyethylene (PE) flat sheet membranes and their film precursors, both as-extruded and annealed, made at different extrusion rates (E.R.).

Download Full-text

Ultrastructural identification of three types of sensory setae on copepod antennae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141159 ◽

1995 ◽

Vol 53 ◽

pp. 956-957

Author(s):

T. M. Weatherby ◽

P.H. Lenz

Keyword(s):

Phase Locking ◽

Membrane Surface ◽

Reaction Times ◽

High Sensitivity ◽

Structural Features ◽

Calanoid Copepods ◽

Marine Food Webs ◽

Dendritic Membrane ◽

Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Download Full-text

Highly proton conductive membranes based on carboxylated cellulose nanofibres and their performance in proton exchange membrane fuel cells

10.26434/chemrxiv.7851461.v3 ◽

2019 ◽

Author(s):

Valentina Guccini ◽

Annika Carlson ◽

Shun Yu ◽

Göran Lindbergh ◽

Rakel Wreland Lindström ◽

...

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Surface Charge ◽

Proton Exchange Membrane ◽

Membrane Surface ◽

Proton Exchange ◽

Membrane Thickness ◽

Fuel Cell Performance ◽

Cellulose Nanofibres ◽

Exchange Membrane

The performance of thin carboxylated cellulose nanofiber-based (CNF) membranes as proton exchange membranes in fuel cells has been measured in-situ as a function of CNF surface charge density (600 and 1550 µmol g-1), counterion (H+or Na+), membrane thickness and fuel cell relative humidity (RH 55 to 95 %). The structural evolution of the membranes as a function of RH as measured by Small Angle X-ray scattering shows that water channels are formed only above 75 % RH. The amount of absorbed water was shown to depend on the membrane surface charge and counter ions (Na+or H+). The high affinity of CNF for water and the high aspect ratio of the nanofibers, together with a well-defined and homogenous membrane structure, ensures a proton conductivity exceeding 1 mS cm-1at 30 °C between 65 and 95 % RH. This is two orders of magnitude larger than previously reported values for cellulose materials and only one order of magnitude lower than Nafion 212. Moreover, the CNF membranes are characterized by a lower hydrogen crossover than Nafion, despite being ≈ 30 % thinner. Thanks to their environmental compatibility and promising fuel cell performance the CNF membranes should be considered for new generation proton exchange membrane fuel cells.

Download Full-text