TY  - JOUR
A1  - Adesina, Morenike O.
A1  - Block, Inga
A1  - Günter, Christina
A1  - Unuabonah, Emmanuel Iyayi
A1  - Taubert, Andreas
T1  - Efficient Removal of Tetracycline and Bisphenol A from Water with a New Hybrid Clay/TiO2 Composite
JF  - ACS Omega
N2  - New TiO2 hybrid composites were prepared fromkaolinclay, predried and carbonized biomass, and titanium tetraisopropoxideand explored for tetracycline (TET) and bisphenol A (BPA) removalfrom water. Overall, the removal rate is 84% for TET and 51% for BPA.The maximum adsorption capacities (q (m))are 30 and 23 mg/g for TET and BPA, respectively. These capacitiesare far greater than those obtained for unmodified TiO2. Increasing the ionic strength of the solution does not change theadsorption capacity of the adsorbent. pH changes only slightly changeBPA adsorption, while a pH > 7 significantly reduces the adsorptionof TET on the material. The Brouers-Sotolongo fractal modelbest describes the kinetic data for both TET and BPA adsorption, predictingthat the adsorption process occurs via a complex mechanism involvingvarious forces of attraction. Temkin and Freundlich isotherms, whichbest fit the equilibrium adsorption data for TET and BPA, respectively,suggest that adsorption sites are heterogeneous in nature. Overall,the composite materials are much more effective for TET removal fromaqueous solution than for BPA. This phenomenon is assigned to a differencein the TET/adsorbent interactions vs the BPA/adsorbent interactions:the decisive factor appears to be favorable electrostatic interactionsfor TET yielding a more effective TET removal.
Y1  - 2023
U6  - https://doi.org/10.1021/acsomega.3c00184
SN  - 2470-1343
VL  - 8
IS  - 24
SP  - 21594
EP  - 21604
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ahnert, Karsten
A1  - Abel, Markus
A1  - Kollosche, Matthias
A1  - Jorgensen, Per Jorgen
A1  - Kofod, Guggi
T1  - Soft capacitors for wave energy harvesting
JF  - Journal of materials chemistry
N2  - Wave energy harvesting could be a substantial renewable energy source without impact on the global climate and ecology, yet practical attempts have struggled with the problems of wear and catastrophic failure. An innovative technology for ocean wave energy harvesting was recently proposed, based on the use of soft capacitors. This study presents a realistic theoretical and numerical model for the quantitative characterization of this harvesting method. Parameter regions with optimal behavior are found, and novel material descriptors are determined, which dramatically simplify analysis. The characteristics of currently available materials are evaluated, and found to merit a very conservative estimate of 10 years for raw material cost recovery.
Y1  - 2011
U6  - https://doi.org/10.1039/c1jm12454d
SN  - 0959-9428
SN  - 1364-5501
VL  - 21
IS  - 38
SP  - 14492
EP  - 14497
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Akampurira, Denis
A1  - Akala, Hoseah M.
A1  - Derese, Solomon
A1  - Heydenreich, Matthias
A1  - Yenesew, Abiy
T1  - A new C-C linked benzophenathridine-2-quinoline dimer, and the antiplasmodial activity of alkaloids from Zanthoxylum holstzianum
JF  - Natural product research
N2  - The CH2Cl2/MeOH (1:1) extract of Zanthoxylum holstzianum stem bark showed good antiplasmodial activity (IC50 2.5 +/- 0.3 and 2.6 +/- 0.3 mu g/mL against the W2 and D6 strains of Plasmodium falciparum, respectively). From the extract five benzophenanthridine alkaloids [8-acetonyldihydrochelerythrine (1), nitidine (2), dihydrochelerythine (3), norchelerythrine (5), arnottianamide (8)]; a 2-quinolone alkaloid [N-methylflindersine (4)]; a lignan [4,4 '-dihydroxy-3,3 '-dimethoxylignan-9,9 '-diyl diacetate (7)] and a dimer of a benzophenanthridine and 2-quinoline [holstzianoquinoline (6)] were isolated. The CH2Cl2/MeOH (1:1) extract of the root bark afforded 1, 3-6, 8, chelerythridimerine (9) and 9-demethyloxychelerythrine (10). Holstzianoquinoline (6) is new, and is the second dimer linked by a C-C bond of a benzophenanthridine and a 2-quinoline reported thus far. The compounds were identified based on spectroscopic evidence. Amongst five compounds (1-5) tested against two strains of P. falciparum, nitidine (IC50 0.11 +/- 0.01 mu g/mL against W2 and D6 strains) and norchelerythrine (IC50 value of 0.15 +/- 0.01 mu g/mL against D6 strain) were the most active.
KW  - Antiplasmodial
KW  - benzophenanthridine alkaloid
KW  - holstzianoquinoline;
KW  - rutaceae
KW  - Zanthoxylum holstzianum
Y1  - 2022
U6  - https://doi.org/10.1080/14786419.2022.2034810
SN  - 1478-6419
SN  - 1478-6427
VL  - 37
IS  - 13
SP  - 2161
EP  - 2171
PB  - Taylor & Francis
CY  - London [u.a.]
ER  - 
TY  - JOUR
A1  - Akarsu, Pinar
A1  - Grobe, Richard
A1  - Nowaczyk, Julius
A1  - Hartlieb, Matthias
A1  - Reinicke, Stefan
A1  - Böker, Alexander
A1  - Sperling, Marcel
A1  - Reifarth, Martin
T1  - Solid-phase microcontact printing for precise patterning of rough surfaces
BT  - using polymer-tethered elastomeric stamps for the transfer of reactive silanes
JF  - ACS applied polymer materials
N2  - We present a microcontact printing (mu CP) routine suitable to introduce defined (sub-) microscale patterns on surface substrates exhibiting a high capillary activity and receptive to a silane-based chemistry. This is achieved by transferring functional trivalent alkoxysilanes, such as (3-aminopropyl)-triethoxysilane (APTES) as a low-molecular weight ink via reversible covalent attachment to polymer brushes grafted from elastomeric polydimethylsiloxane (PDMS) stamps. The brushes consist of poly{N-[tris(hydroxymethyl)-methyl]acrylamide} (PTrisAAm) synthesized by reversible addition-fragmentation chain-transfer (RAFT)-polymerization and used for immobilization of the alkoxysilane-based ink by substituting the alkoxy moieties with polymer-bound hydroxyl groups. Upon physical contact of the silane-carrying polymers with surfaces, the conjugated silane transfers to the substrate, thus completely suppressing ink-flow and, in turn, maximizing printing accuracy even for otherwise not addressable substrate topographies. We provide a concisely conducted investigation on polymer brush formation using atomic force microscopy (AFM) and ellipsometry as well as ink immobilization utilizing two-dimensional proton nuclear Overhauser enhancement spectroscopy (H-1-H-1-NOESY-NMR). We analyze the mu CP process by printing onto Si-wafers and show how even distinctively rough surfaces can be addressed, which otherwise represent particularly challenging substrates.
KW  - microcontact printing
KW  - capillary-active substrates
KW  - silane chemistry
KW  - PDMS surface grafting
KW  - surface patterning
KW  - shuttled RAFT-polymerization
Y1  - 2021
U6  - https://doi.org/10.1021/acsapm.1c00024
SN  - 2637-6105
VL  - 3
IS  - 5
SP  - 2420
EP  - 2431
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - THES
A1  - Akdemir, Özgür
T1  - Synthesis of novel non-viral gene carriers via atom transfer radical polymerization and click chemistry
Y1  - 2009
CY  - Potsdam
ER  - 
TY  - THES
A1  - Al Nakeeb, Noah
T1  - Self-assembly and crosslinking approaches of double hydrophilic linear-brush block copolymers
BT  - a biocompatible platform for the next generation of nanoreactors
Y1  - 2019
ER  - 
TY  - JOUR
A1  - Al Nakeeb, Noah
A1  - Kochovski, Zdravko
A1  - Li, Tingting
A1  - Zhang, Youjia
A1  - Lu, Yan
A1  - Schmidt, Bernhard V. K. J.
T1  - Poly(ethylene glycol) brush-b-poly(N-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked via crystalline alpha-cyclodextrin domains
JF  - RSC Advances
N2  - Self-assembly of block copolymers is a significant area of polymer science. The self-assembly of completely water-soluble block copolymers is of particular interest, albeit a challenging task. In the present work the self-assembly of a linear-brush architecture block copolymer, namely poly(N-vinylpyrrolidone)-b-poly(oligoethylene glycol methacrylate) (PVP-b-POEGMA), in water is studied. Moreover, the assembled structures are crosslinked via alpha-CD host/guest complexation in a supramolecular way. The crosslinking shifts the equilibrium toward aggregate formation without switching off the dynamic equilibrium of double hydrophilic block copolymer (DHBC). As a consequence, the self-assembly efficiency is improved without extinguishing the unique DHBC self-assembly behavior. In addition, decrosslinking could be induced without a change in concentration by adding a competing complexation agent for alpha-CD. The self-assembly behavior was followed by DLS measurement, while the presence of the particles could be observed via cryo-TEM before and after crosslinking.
Y1  - 2019
U6  - https://doi.org/10.1039/c8ra10672j
SN  - 2046-2069
VL  - 9
IS  - 9
SP  - 4993
EP  - 5001
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Al-Naji, Majd
A1  - Schlaad, Helmut
A1  - Antonietti, Markus
T1  - New (and old) monomers from biorefineries to make polymer chemistry more sustainable
JF  - Macromolecular rapid communications
N2  - This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.
KW  - biodegradable polymers
KW  - biorefineries
KW  - carbohydrate‐ based
KW  - monomers
KW  - green polymers
KW  - lignocellulosic biomass
Y1  - 2020
U6  - https://doi.org/10.1002/marc.202000485
SN  - 1022-1336
SN  - 1521-3927
VL  - 42
IS  - 3
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - GEN
A1  - Al-Naji, Majd
A1  - Schlaad, Helmut
A1  - Antonietti, Markus
T1  - New (and old) monomers from biorefineries to make polymer chemistry more sustainable
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1385 
KW  - biodegradable polymers
KW  - biorefineries
KW  - carbohydrate‐ based
KW  - monomers
KW  - green polymers
KW  - lignocellulosic biomass
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-570614
SN  - 1866-8372
IS  - 3
ER  - 
TY  - THES
A1  - Alahverdjieva, Veneta
T1  - Experimental study of mixed protein/surfactant systems at the aqueous solution/air interface
Y1  - 2007
CY  - Potsdam
ER  -