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Madsen H.T.,University of Aalborg | Nissen S.S.,Applied Biomimetic | Sogaard E.G.,University of Aalborg
Chemical Engineering Science | Year: 2016

Pressure retarded osmosis (PRO) has traditionally been focused on the mixing of seawater and river water, but in pilot scale tests, this mixing scheme has been found to be economically unattractive due to power densities that are too low. One way of obtaining higher power densities may be through use of hypersaline draw solutions. In this work, the theoretical framework for calculation of the free energy of mixing, the maximum extractable work in batch and co-current PRO systems, and the potential power densities of hypersaline solutions is presented. Calculations show that very high values in all categories are realizable. By diluting 26wt% (saturated NaCl) to seawater concentration, 15.7kWh/m3 draw is released and a maximum power density of 143W/m2 membrane can be obtained with a commercially available FO membrane. In cases where the hypersaline solution is the limiting solution, large losses of energy can be expected if the process is carried out as a constant pressure single stage operation. To minimize losses, a serial setup can be applied. Although the practical challenges for hypersaline PRO may be greater than for seawater based PRO, the high potential gains may make hypersaline PRO a more promising way of making the PRO concept realizable. © 2015 Elsevier Ltd.


Nissen S.,Applied Biomimetic | Grzelakowski M.,Applied Biomimetic
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2016

A facile click chemistry method of immobilizing surface-functionalized polymer vesicles on casted polymeric PAN substrates is described. Microporous PAN membranes were subjected to hydrochloric acid hydrolysis to obtain surface carboxylates. The carboxylic groups were activated with EDC/NHS-solution and were then reacted with propargylamine to introduce alkyne groups for CuAAC reactions. The alkyne functionality of the modified membrane surface was verified by reaction with an azide functional click dye both before and after the immobilization of azide-functionalized ABA vesicles. The efficient postfunctionalization of the membrane with alkyne allowed quantitative coverage of the membrane surface with a polymersome monolayer, as confirmed by immobilization of polymerzomes loaded with a fluorescent dye. Polymersome monolayers immobilized on alkyne functionalized PAN-membranes were characterized by cryo-SEM and monolayers were confirmed by atom force microscopy. These methods opens up new avenues for preparing membrane based filtration and sensor technologies. © 2016 Wiley Periodicals, Inc.


Zhou X.,CAS Shanghai Institute of Organic Chemistry | Zhou X.,Applied Biomimetic | Constant J.-F.,CNRS Molecular Chemistry Department
Bioorganic and Medicinal Chemistry | Year: 2010

Oligonucleotide-selenium conjugate was designed and synthesized and its sequence-specific cross-linking ability was investigated. The selenide derivatives can generate covalent interstrand cross-linking with its complementary strand through the formation of o-QM intermediate induced by periodate oxidation. A cross-linking reaction yield of up to 50% was obtained. Hydroxyl radical footprinting experiment revealed that the quinone appendage specifically alkylated the cytosine base extending the duplex formed between the conjugate and the target strand. © 2009 Elsevier Ltd. All rights reserved.


Lai H.,Hubei University | Xiao Y.,Hubei University | Yan S.,Hubei University | Tian F.,Hubei University | And 6 more authors.
Analyst | Year: 2014

In this study, we present a fluorescent switch-on probe based on a cyanovinyl-pyridinium triphenylamine (CPT) derivative that exhibited a 190-fold increase in fluorescence upon binding to G-quadruplex-forming oligonucleotide 22AG. This probe showed specificity and selectivity towards an antiparallel G-quadruplex, indicating its promising potential in G-quadruplex imaging. © 2014 the Partner Organisations.


Grzelakowski M.,Applied Biomimetic | Kita-Tokarczyk K.,Applied Biomimetic
Nanoscale | Year: 2016

The terminal groups of amphiphilic block copolymers are shown to control macromolecular self-assembly in aqueous solutions, in the micellar/lamellar region of the phase diagram. At the same concentration and using the same self-assembly conditions, dramatic differences are observed in polymer hydration and the resulting nano-/microstructure for two series of polymers with identical block chemistry and hydrophilic-lipophilic balance (HLB). This suggests a strong contribution from end groups to the hydration as the initial step of the self-assembly process, and could be conveniently used to guide the particle morphology and size. Additionally, for polymers with those head groups which drive vesicular structures, differences in membrane organization affect their physical properties, such as permeability. © The Royal Society of Chemistry 2016.


Feroz H.,Pennsylvania State University | Vandervelden C.,Pennsylvania State University | Ikwuagwu B.,Pennsylvania State University | Ferlez B.,Pennsylvania State University | And 6 more authors.
Biotechnology and Bioengineering | Year: 2016

Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl-β-D glucoside (OG), and decyl-β-D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122–2130. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.


Grzelakowski M.,Applied Biomimetic | Cherenet M.F.,Applied Biomimetic | Shen Y.-X.,Pennsylvania State University | Kumar M.,Pennsylvania State University
Journal of Membrane Science | Year: 2015

Aquaporin based membranes (ABMs) are considered a promising biomimetic desalination technology and have been intensively studied over the last few years. The most common strategy to synthesize ABMs is to deposit the aquaporin incorporated lipid or block copolymer (BCP) vesicles onto porous substrates or more recently to integrate them within the active layer of polyamide membranes. However, ABMs with orders of magnitude improvement in permeability and perfect salt rejections proposed in initial work have not been realized. Early results were based on materials and methods that were rudimentary, especially considering the progress that has been made in this field. In particular, low signal to noise ratios (SNRs <50) of stopped flow measurements for vesicle-based assays have led to large inaccuracies in permeability estimation. We show that such low SNRs can result from using vesicle samples with a high concentration of micelles and provide a connection between morphology and data quality. We have conducted a comprehensive evaluation of the true promise of these membranes using improved methods for polymer synthesis, self-assembly, experimental evaluation as well as calculations that more directly compare the outcome of biophysical evaluations to those used in the desalination membrane industry. We propose these as standard methods for use in ABM research. The role of concentration polarization in introducing error into vesicle based permeability measurements is identified. We further describe a simple technique to calculate the expected flux from a membrane synthesized using vesicle immobilization on a permeable substrate that can be used to estimate realistic membrane fluxes from stopped flow data. These calculations show that it is possible to achieve permeabilities one to two orders of magnitude higher than current membranes using ABMs but several innovations will be needed to reach this potential. © 2015 Elsevier B.V.


PubMed | Pennsylvania State University and Applied Biomimetic
Type: Journal Article | Journal: Biotechnology and bioengineering | Year: 2016

Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl--D glucoside (OG), and decyl--D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So ), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122-2130. 2016 Wiley Periodicals, Inc.


Trademark
Applied Biomimetic | Date: 2016-09-30

Turbines for power generation; generators of electricity; membrane filters for use as part of machines. Apparatus and instruments for accumulating and storing energy; Apparatus, instruments and installations for osmotic generation of power from geothermal wells; inverters; controls for use in connection with generation of power; surveillance equipment in connection with generation of power; software; membranes for filtration for scientific use. Water filtration apparatus; membranes for the filtration of water; reverse osmosis water filtration equipment. Commercial advisory services relating to exploitation of osmotic power generation. Energy production; rental of energy production equipment; generation of power; production of electrical power from renewable sources. Scientific and technological services; research and development in connection with energy production and generation of power; consultancy relating to membrane technology; consultancy relating to osmosis technology; consultancy relating to CO2 reduction and renewable energy; design and development of production equipment for renewable energy production.


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