Thuringian Institute of Textile and Plastics Research

Rudolstadt, Germany

Thuringian Institute of Textile and Plastics Research

Rudolstadt, Germany
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Dammak A.,French National Institute for Agricultural Research | Moreau C.,French National Institute for Agricultural Research | Beury N.,French National Institute for Agricultural Research | Schwikal K.,Thuringian Institute of Textile and Plastics Research | And 4 more authors.
Holzforschung | Year: 2013

Multilayered thin films have been prepared by means of the "spin-assisted electrostatic layer-by-layer self-assembly" method, in which cellulose nanocrystals (CN) and cationic xylans (CX) are alternatively deposited up to 10 times on a rotating silicon wafer. The film growth process was studied and the thickness increment was found to be equal to 23 nm per bilayer. This value is relatively high in comparison with that of previous studies. Atomic force microscopy revealed that the surface of the films consists of thick layers of CX, which are deposited as a compact network of aggregates on the CN layers. After a few deposition cycles, structural color appears. When the film is submitted to enzymatic hydrolysis of xylans, the thickness of the film decreases and a visible color change is induced. The sensitivity of the test was evaluated in comparison with a usual colorimetric measurement, which relies on the detection of reducing sugars set free by enzymatic hydrolysis. The assay sensitivity was found to be similar to that of the colorimetric method. The presented new method is simple, fast, and easy to use. These findings show that the method based on multilayer thin films might open new opportunities to optimize the screening assays for xylanase discovery. © 2013 by Walter de Gruyter Berlin Boston 2013.


Maenz S.,Friedrich - Schiller University of Jena | Kunisch E.,Jena University Hospital | Muhlstadt M.,Friedrich - Schiller University of Jena | Bohm A.,Thuringian Institute of Textile and Plastics Research | And 4 more authors.
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2014

Injectable, brushite-forming calcium phosphate cements (CPCs) have great potential as bone replacement materials due to enhanced degradability and long-term inclusion in bone remodeling. However, the use of such brushite-forming CPCs in load-bearing areas is limited by their low mechanical strength. One approach to overcome this limitation is the use of reinforcing fibers. Thus, an injectable, biodegradable, brushite-forming CPC based on beta-tricalcium phosphate/phosphoric acid with fiber reinforcement was developed for minimally invasive surgery. The fibers (diameter 25. μm; length 0.25, 1 or 2. mm) were extruded from poly(l-lactide co-glycolide) acid (PLGA) and added to the CPC (2.5, 5 or 7.5% (w/w)). Independent of the fiber content, injectability of the CPC was retained up to a fiber length of 1. mm. The addition of all PLGA fiber types increased diametral tensile strength, biaxial flexural strength, and flexural strength by up to 25% (p≤0.05 for the diametral tensile strength for the CPC with 5% (w/w) 1. mm fibers and the biaxial flexural strength of the CPC with 5% (w/w) 0.25. mm fibers). In contrast, the work of fracture strongly and significantly increased (p<0.01) by up to 12.5-fold. At constant fiber content, the mechanical properties of the fiber-reinforced CPC were mostly augmented with increasing fiber length. Also, the addition of PLGA fibers to the brushite-forming CPC (up to 7.5% (w/w)) only transiently delayed cell growth and did not decrease cell viability. Fiber reinforcement of CPCs thus augments their mechanical strength while preserving the injectability and biocompatibility required for their application in modern surgery. © 2014 Elsevier Ltd.


Stark A.,University of Leipzig | Sellin M.,Thuringian Institute of Textile and Plastics Research | Ondruschka B.,Friedrich - Schiller University of Jena | Massonne K.,BASF
Science China Chemistry | Year: 2012

It is nowadays well-known that ionic liquids can dissolve cellulose. However, little systematic data has been published that shed light onto the influence of the ionic liquid structure on the dissolution of cellulose. We have conducted 1H NMR spectroscopy of ethanol in a large number of ionic liquids, and found an excellent correlation of the data obtained with the hydrogen acceptor properties (β-values). With this tool in hand, it is possible to distinguish between cellulose-dissolving and non-dissolving ionic liquids. A modulating effect of both, the anion of the non-dissolving ionic liquid and its cation was found in solubility studies with binary ionic liquid mixtures. The study was extended to other non-dissolving liquids, namely water and dimethylsulfoxide, and the effect of the cation was also investigated. © Science China Press and Springer-Verlag Berlin Heidelberg 2012.


PubMed | Thuringian Institute of Textile and Plastics Research, Friedrich - Schiller University of Jena and Jena University Hospital
Type: | Journal: Journal of the mechanical behavior of biomedical materials | Year: 2014

Injectable, brushite-forming calcium phosphate cements (CPCs) have great potential as bone replacement materials due to enhanced degradability and long-term inclusion in bone remodeling. However, the use of such brushite-forming CPCs in load-bearing areas is limited by their low mechanical strength. One approach to overcome this limitation is the use of reinforcing fibers. Thus, an injectable, biodegradable, brushite-forming CPC based on beta-tricalcium phosphate/phosphoric acid with fiber reinforcement was developed for minimally invasive surgery. The fibers (diameter 25 m; length 0.25, 1 or 2mm) were extruded from poly(l-lactide-co-glycolide) acid (PLGA) and added to the CPC (2.5, 5 or 7.5% (w/w)). Independent of the fiber content, injectability of the CPC was retained up to a fiber length of 1mm. The addition of all PLGA fiber types increased diametral tensile strength, biaxial flexural strength, and flexural strength by up to 25% (p 0.05 for the diametral tensile strength for the CPC with 5% (w/w) 1mm fibers and the biaxial flexural strength of the CPC with 5% (w/w) 0.25 mm fibers). In contrast, the work of fracture strongly and significantly increased (p<0.01) by up to 12.5-fold. At constant fiber content, the mechanical properties of the fiber-reinforced CPC were mostly augmented with increasing fiber length. Also, the addition of PLGA fibers to the brushite-forming CPC (up to 7.5% (w/w)) only transiently delayed cell growth and did not decrease cell viability. Fiber reinforcement of CPCs thus augments their mechanical strength while preserving the injectability and biocompatibility required for their application in modern surgery.


Petzold-Welcke K.,Friedrich - Schiller University of Jena | Schwikal K.,Thuringian Institute of Textile and Plastics Research | Daus S.,Friedrich - Schiller University of Jena | Heinze T.,Friedrich - Schiller University of Jena
Carbohydrate Polymers | Year: 2014

The chemical modification of xylan is a promising path to new biopolymer ethers and esters with specific properties depending on the functional groups, the degree of substitution, and the substitution pattern. The reaction of 4-O-methylglucuronoxylan (GX) from birch with sodium monochloroacetate and 2,3-epoxypropyltrimethylammonium chloride in aqueous sodium hydroxide/slurry medium is described. The influence of the conditions of activation on product structure and properties are discussed in some detail. Methylation of GX was investigated under completely heterogeneous conditions or starting with dissolved polymer using methyl halides as reagents in the presence of NaOH. An activation of the biopolymer has been carried out before the reaction to enhance the accessibility of the reagents. Furthermore, novel xylan esters were efficiently synthesized by conversion of the hemicellulose with furan- and pyroglutamic acid as well as ibuprofen and N,N′-carbonyldiimidazole as activating agent under homogeneous conditions in dimethyl sulfoxide. This conditions are also appropriate to synthesize novel xylan ester containing xylan-4-[N,N,N-trimethylammonium]butyrate chloride moieties. Homogeneous syntheses of xylan sulfates could be carried out in a N,N-dimethylformamide (DMF)/LiCl as solvent applying sulfur trioxide complexes with DMF or pyridine. Advanced analytical techniques including NMR spectroscopy, HPLC, scanning electron microscopy, rheology, measurements of turbidity and surface tension allow description of structure-property-relationships; selected results will be briefly discussed. Xylan esters may form spherical nanoparticles of a size down to 60 nm and a narrow particle size distribution applying a simple dialysis process and may be used for drug delivery applications. For cationic xylan derivatives a wide range of applications as paper strength additives, flocculation aids, and antimicrobial agents are proposed. © 2012 Elsevier Ltd.


Gladitz M.,Thuringian Institute of Textile and Plastics Research | Bauer J.,Thuringian Institute of Textile and Plastics Research | Bruckner P.,Thuringian Institute of Textile and Plastics Research | Reinemann S.,Thuringian Institute of Textile and Plastics Research | And 7 more authors.
BioNanoMaterials | Year: 2014

Antimicrobial organic-inorganic hybrids based on amphiphilic dendritic hyperbranched polyethylenimine with zinc were prepared. To study their property profile and potential as an antimicrobial modifier they were incorporated via melt extrusion into cast films or injection molded into plates of polyamide (PA). The antimicrobial efficacy, bacterial adhesion, cytotoxicity and blood compatibility of the respective PA composites were investigated as a function of material composition and morphology. It could be demonstrated that the polymers with the developed zinc-hybrids possess a high antimicrobial efficacy as well as good cyto- and hemo-compatibility in vitro. Furthermore, they showed reduced bacterial adhesion. Finally, it can be stated that the developed zinc-hybrids are suitable as advanced additive agents for the production of antimicrobial polymer materials with promising properties particular for various medical applications.


Meister F.,Thuringian Institute of Textile and Plastics Research | Kosan B.,Thuringian Institute of Textile and Plastics Research
Nordic Pulp and Paper Research Journal | Year: 2015

As part of independent Lyocell process design and development it is required to identify and to install selected analytical approaches for chemical and physical characterization of dissolving pulps, spinning dopes and resulting cellulose man-made fibers. Impurities introduced by used pulps and the dope behavior at elevated temperatures have to be investigated because of the chemical and thermal sensivity of N-methyl-morpholine-N-oxide. Polymer degradation, undissolved pulp fiber fractions and gel particles may negatively affect dopes flow and spinning performance. Finally, rheological behavior of spinning dopes offers valuable evidence to select adequate process equipment and the exactly required spinning parameter. The practical procedures and analytical approaches for characterization of dissolving pulp and of cellulose dopes are not so familiar to current researchers as they have unfortunately not been summarized in one common document. The executed studies demonstrated that nature and amount of inorganic and organic impurities in pulp (heavy metal ion or non-cellulosic components) and the adequate molecular structure of pulp (molecular weight and molecular weight distribution) are just as well significant information as refractive index, concentration of undissolved particle and particle size distribution (PSD) or rheological data of spinning dope like zero shear viscosity or storage and loss modulus and relaxation time spectrum of spinning dopes. © 2015, SPCI. All rights reserved.


Meister F.,Thuringian Institute of Textile and Plastics Research | Kolbe A.,Thuringian Institute of Textile and Plastics Research | Krieg M.,Thuringian Institute of Textile and Plastics Research | Mooz M.,Thuringian Institute of Textile and Plastics Research
Macromolecular Symposia | Year: 2010

Metal cations are valuable antimicrobial additives for controlling of bacteria growth on textile fibres. By means of multiple actions they are able to suppress the undesirable microbe action also during wound healing. Dry-wet shaping technology offers numerous opportunities for implementation of antimicrobial activities into textile structures (fibres, yarn, fabrics). The degree of load, insertion step as well as type of additive (Ag, Cu, Zn) presents a broad field of physical modification of dry-wet spun cellulose fibres. The investigation of antimicrobial activities of manufactured fibres and yarns exhibit bactericide or bacteriostatic effects against typical pathogenic germs. Ag contents higher than 30ppm in fibres and 0.06 per cent in yarns as well as Cu contents higher than 100 ppm in fibres and about 0.5 per cent in yarns are fairly effective for a permanent antimicrobial effect. Fabrics based on the developed fibres and yarns could already been successfully commercialised by innovative small and medium sized enterprises (SME). Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Loewenstein T.,Justus Liebig University | Rudolph M.,Justus Liebig University | Mingebach M.,Justus Liebig University | Strauch K.,Justus Liebig University | And 4 more authors.
ChemPhysChem | Year: 2010

A strategy is presented to realize textile-based photovoltaic cells motivated by developments of textile-based electronics and their demand of grid-independent energy supply. Beyond this, a development of textile-based photovoltaics also represents an attractive pathway towards very flexible and rugged solar cells. The need for compatibility of an appropriate photovoltaic technology with the physical limitations of textiles is stressed. Electrodeposition from aqueous solutions is presented as a successful strategy to realize semiconductor structures on textiles and detailed control and influence of the deposition conditions is discussed. The role of microelectrode effects, options of forced convection, deposition under pulsed potential, alternative deposition baths and different substrate metals are emphasized. An active electrode material is presented which reaches a conversion efficiency close to the 1% limit under AM 1.5 illumination conditions and thereby opens the door for a further optimization towards devices of technical interest. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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