Goerg Hannes Prof. em. Dr. habil. Michler

Martin Luther University Halle-Wittenberg | MLU

For the investigations, scaffolds for bone regeneration (in the form of non-woven mats) were fabricated based on a polymer blend based on polycaprolactone, poly-L-lactic acid and gelatin by electrospinning which were partly modified using vitamin D3 and reinforced with 0 – 12 % nano-hydroxyapatite (nano-HAp extracted from ostrich bones) to improve...

Overview of the main directions of electron microscopy and the requirements for the samples to be examined. Presentation of transmission electron microscopy (TEM) including ultrahigh-voltage TEM, ultrahigh-resolution TEM and analytical TEM, the techniques of scanning electron microscopy (SEM), emission electron microscopy and scanning probe microsc...

The concluding chapter points out future requirements for preparation and microscopic examination.

Image processing and image analysis serve an improved representation of structures and their quantitative evaluation including spatial structure analysis. Methods of image simulation are required in particular for the interpretation of ultrahigh-resolution images.

Starting with an overview on the main lines of preparation of compact materials for the different microscopy techniques, etching techniques including the focused ion beam technique and (cryo)ultramicrotomy are outlined with some possibilities for spatial structural analysis (3D analysis). Chemical and physical sample treatments are mentioned for an...

Historical overview of the development of light microscopy and the early years of electron microscopy; Abbé’s formula for microscope resolution.

For bone tissue engineering, nano‐hydroxyapatite (nano‐HAp) is a widely used bioceramic filler in polymer fibrous scaffolds that changes the morphology and micromechanical behavior of fibers. In this study, different volume fraction percentages of nano‐HAp and vitamin D3 (VD3) are incorporated into electrospun polymer blend fibrous scaffolds compri...

Star-shaped polystyrene-block-polybutadiene-block-polystyrene (SBS) block copolymer (BCP) was subjected to epoxidation reaction using m-chloroperoxy benzoic acid (MCPBA). The epoxidized SBS block copolymer (eSBS) was then blended with diglycidyl ether of bisphenol-A based epoxy resin (EP) and cross-linked with methylene dianiline (MDA). The materia...

Historischer Überblick zur Entwicklung der Lichtmikroskopie und die frühen Jahre der Elektronenmikroskopie; Abbésche Formel zur Auflösung von Mikroskopen.

Das abschließende Kapitel weist auf zukünftige Anforderungen bei der Präparation und der mikroskopischen Untersuchung hin.

Bildverarbeitung und Bildanalyse dienen einer verbesserten Darstellung von Strukturen und deren quantitativen Auswertung einschließlich der räumlichen Strukturanalyse. Methoden der Bildsimulation sind insbesondere zur Interpretation von Höchstauflösungsaufnahmen erforderlich.

Beginnend mit einem Überblick zu den Hauptlinien der Präparation kompakter Materialien für die verschiedenen Mikroskopieverfahren werden die Ätztechniken einschließlich der Focused-Ion-Beam Technik und die (Kryo-)Ultramikrotomie mit einigen Möglichkeiten zur räumlichen Strukturanalyse (3D-Analyse) umrissen. Für eine oftmals notwendige Verbesserung...

Übersicht zu den Hauptrichtungen der Elektronenmikroskopie und zu den Anforderungen an die zu untersuchenden Proben. Darstellung der Transmissions-Elektronenmikroskopie (TEM) einschließlich der Höchstspannungs-TEM, Höchstauflösungs-TEM und Analytischen TEM, der Techniken der Raster-Elektronenmikroskopie (REM), der Emissions-Elektronenmikroskopie un...

Atomic force microscopy (AFM), also commonly known as scanning force microscopy, has evolved as an extremely useful tool for the study of the structure and properties of nanostructured systems including nanoparticles (NPs), composites, and soft matters such as polymers and biological tissues. In particular, AFM serves as an excellent complement to...

Die elektronenmikroskopischen Techniken haben auf nahezu allen Gebieten der naturwissenschaftlichen, technischen und medizinischen Forschung außerordentliche Bedeutung als Methoden zur direkten Abbildung submikroskopischer Strukturen erlangt. Sie sind heute Schlüsseltechniken in der Materialwissenschaft bei der Entwicklung verbesserter und neuer We...

The objective of the present work is to fabricate and develop growth factor-PDLLA nano-composites by electrospinning into 2D fleece or 3D tubular scaffolds that can mimic the nature and function of the native extracellular matrix of bone tissue or artificial blood vessels. The bioactive growth factors 125 I-rhVEGF 165 , 125 I-rhBMP-2 and the fibrou...

Electro spun PDLLA-nanofibers were functionalized with 125 I-rhBMP-2 and 125 I-rhVEGF165, either by protein-adsorption to, or by incorporation into electrospun PDLLA-nanofibers. Both, adsorbed and incorporated growth factors could be visualized via autoradiography. By fitting the release data according the two phase exponential decay, release rates...

For the successful regeneration of lost bone, the use of biomaterial-based substitutes in combination with factors that promote the regenerative process, such as vascular endothelial growth factor (VEGF) or bone morphogenetic protein 2 (BMP-2), might be promising. In this study, a model was used which generated capillary-like vessels by co-cultivat...

A star shaped polystyrene-block-polybutadiene-block-polystyrene (SBS) block copolymer was subjected to epoxidation reaction using different reagents such as m-chloroperoxy benzoic acid (MCPBA), peracetic acid (PAA), performic acid (PFA) and hexaflouro-isopropanol (HFIP). All the methods led to the targeted modification of the block copolymer satisf...

The values of the fragility index of polycarbonate/poly(methylmetacrylate) multilayer films have been determined for materials having thicknesses varying from micro- to nano-scales. The influence of the layer thickness reduction down to 12 nm has been shown to have very different influence on the glass transition parameters of the two polymers. Pol...

In this article the role of voids or particulate inclusions of different sizes on mechanical properties and particularly on toughness in several polymers is discussed. With decreasing void sizes and intervoid distances, the influence of the interphase material around the voids becomes more important and characteristic changes in the nano- and micro...

The aim of this work is to study the morphological changes after alkali treatment and functionalisation of cellulosic materials present in crude bamboo and sisal flours using ionic liquid as solvents. The flours of bamboo (BF) and sisal (SF) were subjected to acetylation and silylation using acetic anhydride (AA) and hexamethyldisilazane (HMDS) as...

In this work, a commercially available Styrene-Isoprene-Styrene (SIS)triblock copolymer was modified into epoxidised version (ESIS)using performic acid generated in situ from hydrogen peroxide and formic acid. The epoxidised sample was further acrylated to prepare acrylated version (ASIS). The nanocomposites of each sample (SIS, ESIS and ASIS) were...

In this work, using different microscopic techniques, and tensile testing, we investigate the micro-deformation processes in the blends and nanocomposites based on a highly asymmetric star shaped polystyrene/polybutadiene block copolymer. As one of the blends and composites components, we use general purpose polystyrene (GPPS) and organophilic modi...

The influence of the morphology of multilayered composites of poly(methyl‐methacrylate) (PMMA) and polycarbonate (PC) fabricated by layer multiplying coextrusion technique on their mechanical and especially their micromechanical deformation behavior was investigated. Electron microscopic studies revealed that the PC/PMMA multilayered composites hav...

Multilayered composites of polypropylene (PP) and polystyrene (PS) fabricated by a layer‐multiplying coextrusion technique are described. The aim of this investigation was to find a correlation between the morphology and the mechanical and micromechanical deformation behavior. The multilayered films had primarily continuous layers, exhibiting only...

Aiming at development of completely biodegradable composite materials based on locally available low-cost bamboo flour (BF) as filler, structure properties correlations in aliphatic–aromatic copolyester/BF composites fabricated by melt mixing have been studied by means of different techniques such as electron microscopy, X-ray diffraction, tensile...

Polystyrene-block-polyisoprene-block-polystyrene (SIS) triblock copolymer was modified into an epoxidised version (ESIS) using performic acid. The ESIS was further acrylated to prepare the acrylated version (ASIS). The nanocomposites of each sample (SIS, ESIS and ASIS) were prepared using boehmite nanofiller via solution casting, which were charact...

Using electrospinning technique polystyrene (PS) nanofibers in the thickness range from 150 to 800 nm have been produced. Electron microscope inspections reveal the relatively uniform thickness of the obtained fibers. The mechanical deformation mechanisms have been studied in tension tests using micro‐tensile devices for a scanning electron microsc...

In this work, the polybutadiene (PB) block of an asymmetric lamellae forming polystyrene/polybutadiene based triblock copolymer was epoxidized to different extent in order to study its effect on morphology and mechanical behaviour of the copolymer. The products were analyzed by means of different microscopic techniques, Fourier transform infrared (...

The comparative studies on the thermal, mechanical and morphological behavior of compression molded poly(propylene) (PP)/wood flour (WF) composites were performed using wood flours (WFs) of different origins. The comparison has been made on the basis of results obtained from thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),...

The contribution describes the development of a biocompatible nanocomposite material consisting of a resorbable polymeric matrix and osteoinductive nanoparticles that can be used to manufacture compact products, porous scaffolds, hybrid nanofibers, and alternating porous/compact structures. It is shown that the material has a good balance of stiffn...

In multilayered polymer films, the influence of thickness reduction on the glass transition temperature (T-g) and cooperatively rearranging region (CRR) size was investigated using temperature modulated differential scanning calorimetry (TMDSC). The materials used in this work are multilayered films comprising tens to thousands of alternating layer...

The effectiveness of reinforcement of a polymer is known to depend on the strength of the interfaces between the reinforcement and the matrix. We have used polystyrene and a styrene– butadiene–styrene (SBS) copolymer as matrixes and ceramic boehmite c-AlO(OH) as reinforce-ment. We have applied boehmite both untreated and treated with sulphonic acid...

The present work is concerned with the study of the crystalline morphology and the nanostructure of a multilayered system of two alternating immiscible semicrystalline polymers: isotactic polypropylene (iPP) and polyamide 6 (PA6). Films with a volume ratio of 70/30 were prepared by means of layer multiplying coextrusion. Contrary to previous experi...

Morphological analysis of nanocomposites of polyethylene glycol (PEG) based polyurethanes (TPU) and polyhedral oligomeric silsesquioxanes (POSS) were performed using different techniques (transmission electron microscopy, small and wide X-ray scattering, differential scanning calorimetry) as a function of molecular weight of PEG and the PEG/POSS mo...

The comparative studies on the thermal, mechanical and morphological behavior of compression molded poly(propylene) (PP)/wood flour (WF) composites were performed using wood flours (WFs) of different origins. The comparison has been made on the basis of results obtained from thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),...

The comparative studies on the thermal, mechanical and morphological behavior of compression molded poly(propylene) (PP)/wood flour (WF) composites were performed using wood flours (WFs) of different origins. The comparison has been made on the basis of results obtained from thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),...

This book is unique in its focus on micromechanical processes of polymers and their role to improve the properties of polymeric materials. It combines the detailed knowledge of structure and morphology of polymers with the explanation and theoretical interpretation of micro- and nanoscopic processes and mechanisms in different polymers. Thus, it of...

To reveal the features of the structure of UHMWPE that depend on the catalytic system used for synthesis, a comparative study of the sets of laboratory and commercial powders of UHMWPE synthesized on different catalysts in the slurry process under different conditions is conducted. This study includes the use of various modern physical methods, suc...

The nanocomposites based on sulfonated ethylene/1-octene copolymer (sEOC) and organophilic modified layered silicate were synthesized. The morphology of the ionomeric product was studied with the help of Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR) spectroscopy and microhardness measurements....

Aiming at better understanding the influence of reactor powder morphology of ultra-high-molecular-weight polyethylene (UHMWPE) on its processing ability, the transformation of a number of lab-scale and commercial polyethylene reactor powders to mechanically coherent film by sintering of pre-compacted powders at temperature lower than that of meltin...

Studies of thermal and fire-resistant properties of the polyethylene/organically modified montmorillonite (PE/MMT) nanocomposites prepared by means of melt intercalation are discussed. The sets of the data acquired with the aid of non-isothermal TGA experiments have been treated by the model kinetic analysis. The extra acceleration of thermal-oxida...

The nanocomposites based on sulfonated ethylene/1-octene copolymer (sEOC) and organophilic modified layered silicate were synthesized. The morphology of the ionomeric product was studied with the help of Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR) spectroscopy and microhardness measurements....

Nanofibers were prepared by electrospinning from pure polyvinyl alcohol (PVA), polyhydroxybutyrate (PHB), and their blends. Miscibility and morphology of both polymers in the nanofiber blends were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and differential s...

The influence of the catalytic system and synthesis conditions on the reactor powder morphology and the molecular packing in the nascent UHMWPE is studied with the help of various electron microscopic methods. The potentiality of different morphologies for producing strong consolidated material by sintering at temperature lower than the melting tem...

Deformation behavior of nanocomposites based on an ethylene/1-octene copolymer and multiwalled carbon nanotube (CNT) was investigated by means of an atomic force microscope (AFM). Via a special tensile module integrated to an optical microscope, it was possible to record the stress-strain diagrams of the composites using miniaturized tensile specim...

Electrospun micro- and nanofiber scaffolds have gained interest in biomedical applications, especially in tissue engineering, because they can be used to reproduce the structure of the extracellular matrix (ECM) of natural tissue. The selection of the solvent is an important factor which affects the diameter, the surface morphology and the crystall...

Mixtures of polystyrene-block-polyisoprene-block-polystyrene (SIS) triblock copolymer and various styrenic block copolymers (having diblock and triblock architectures) as well as polystyrene homopolymer (PS) were prepared via solution blending to determine the influence of molecular coupling on the large strain mechanical performance of the block c...

The treatment of bone and cartilage defects with bioengineered constructs of artificial scaffolds and autogenous cells became the main challenge of contemporary regenerative medicine. Early defect repair may prevent secondary injury. Recent studies could prove that bone and cartilage cells are sensitive to microscale and nanoscale patterns of surfa...

Nanocomposite scaffold materials based on biodegradable polymers, as there are poly(3-hydroxybutyrate (PHB), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) and polycaprolactone (PCL), and nanocrystalline hydroxyapatite (HA) have been developed for the application as biomimetic bone substitution materials and materials for the tissue engineering o...

Using transmission electron microscopy (TEM) and tensile testing, we investigated the morphology and the micro-deformation processes in a new kind of highly asymmetric polystyrene/polybutadiene based triblock copolymer and its blends with general purpose polystyrene (GPPS). The emphasis has been put on the analysis of blends morphology evolved unde...

Nanostructured polymers and ultra-thin polymer layers are used more and more in technical applications like nanotechnology and microelectronics. Therefore, it is really important to understand the size-scale dependent properties as bulk polymers become thinner and more two-dimensional. Here the morphology as well as the macroscopic and the microsco...

Polypropylene samples in a wide molecular weight range between approx. 100 kg/mol to 1 600 kg/mol were processed by injection molding to thin walled micro specimens with respect to study shear induced crystallization phenomena under high shear rate and subsequently possible self reinforcement effects. The specimens nano structures were investigated...

Morphological analyses of nanocomposites based on TPU and polyhedral oligomeric silsesquioxanes (POSS) was performed using different techniques (transmission electron microscopy, small- and wide-angle X-ray scattering, differential scanning calorimetry) as a function of molecular weight of poly(ethylene glycol) (PEG) and PEG/POSS mol ratio. A stron...

With the aid of layer multiplying coextrusion techniques, polymer composites comprising up to thousand of uniform and alternating layers polyethylene terephthalate (PET) and polycarbonate (PC) were produced. Morphology and micromechanical deformation processes in these composites were investigated by means of transmission electron microscopy (TEM)...

The micromechanical behaviour of various thermoplastics based nanocomposites was investigated with the aid of the microindentation technique. The materials studied were microphase separated styrene-butadiene block copolymer systems and several thermoplastics reinforced with nano-sized fillers having variable dimensionality. It was found that the mi...

This work reports on morphological, mechanical, and micromechanical properties of polyamide 6 (PA 6), a styrene-acrylonitrile copolymer (SAN), and their blends, which were reactively compatibilized using a styrene-acrylonitrile maleic anhydride (SANMA) terpolymer. Transmission electron microscopy (TEM) investigations revealed the phase morphology o...

The structure of blown films of blends of low-density polyethylene (PE-LD) and isotactic polybutene-1 (iPB-1) with different content of iPB-1 was investigated using wide- and small-angle X-ray scattering (WAXS and SAXS), transmission electron microscopy (TEM), and polarizing optical microscopy (POM). TEM proves formation of a matrix–particle phase...

Polyvinyl alcohol (PVA) nanofibers, PVA/Type I Collagen (Col) and their composites with hydroxyapatite nanoparticles (nano-HAp) were prepared by electrospinning techniques. The composite nanofibrous membranes were subjected to detailed analysis. Morphological investigations show that the generated nanofibers (NFs) have uniform morphology with an av...

Studies of thermal and fire-resistant properties of the polyethylene/organically modified montmorillonite (PE/MMT) nanocomposites prepared by means of melt intercalation are discussed. The sets of the data acquired with the aid of non-isothermal TG experiments have been treated by the model kinetic analysis. The extra acceleration of thermal-oxidat...

Abstract Hydroxyapatite has become the most common material to replace bone or to guide its regeneration. Nanocrystalline hydroxyapatite suspension had been introduced in the clinical use recently under the assumption that small dimension of crystals could improve resorption. We studied the resorption and osteointegration of the nanocrystalline hyd...

Glass transition temperature (Tg) of core-shell particles-toughened poly(methyl- methacrylate) (CSPTPMMA) and natural rubber-toughened PMMA (NRTPMMA), which are basically the PMMA/elastomer blends with different concentrations of elastomer heterogeneously distributed in the samples, was investigated by means of differential scanning calorimetry (DS...

Electron microscopy (EM), complemented by other techniques, has played a very important role in the elucidation of morphology and structure-property correlations of polymers including homopolymers, copolymers, blends, and composite materials. When employed vigilantly by an experienced microscopist with proper care during sample preparation, electro...

In this work, in situ investigations of the micromechanical properties of reactively compatibilized blends of polyamide 6 (PA6) and an acrylonitrile–butadiene–styrene copolymer (ABS) were performed with transmission electron microscopy. Three PA6/ABS blends were prepared with a disperse morphology (inclusions of PA6 or ABS) and with a cocontinuous...

The development of the morphology and the alignment of lamellae in melt elongation of blends of an asymmetric linear styrene-butadiene block copolymer (LN3) and polystyrene (PS 158K) was investigated. PS 158K and LN3 formed two-phase polymer blends with PS 158K resp. LN3 inclusions, depending on the concentration of polystyrene. The block copolymer...

In dieser Arbeit wurden die morphologischen und mechanischen Eigenschaften von Blends aus Polyamid 6 (PA 6) und einem Acrylnitrilbutadienstyrolcopolymer (ABS) untersucht. Schwerpunkt der Untersuchungen waren die mikromechanischen Deformationsmechanismen unter Zugbelastung sowie Ermüdungsrissausbreitungsversuche. Dazu wurden in situ-Zugversuche in e...

Studies of thermal and fire-resistant properties of the polyethylene/organically modified montmorillonite (PE/MMT) nanocomposites prepared by means of melt intercalation are discussed. The sets of the data acquired with the aid of non-isothermal TG experiments have been treated by the model kinetic analysis. The extra acceleration of thermal-oxidat...

Based on the biomimetic approaches the present work describes a straightforward technique to mimic not only the architecture (the morphology) but also the chemistry (the composition) of the lowest level of the hierarchical organization of bone. This technique uses an electrospinning (ES) process with polyvinyl alcohol (PVA) and hydroxyapatite (HAp)...

In this study, we investigated the development of the morphology in melt extension of blends of a linear styrene‐butadiene block copolymer (LN3) and polystyrene (PS 158K). After melt mixing, PS 158K and LN3 formed two‐phase polymer blends. The block copolymer was arranged in a lamellar phase. Our rheological experiments in shear and elongation clea...

The influence of the catalyst system and synthesis conditions on the morphology and molecular dynamics of reactor (nascent) powders of ultrahigh-molecular-weight PE synthesized over supported Ziegler-Natta catalysts in laboratory reactors was studied by means of electron microscopy and 1H broadline NMR spectroscopy. For comparison, commercial react...

Nanocomposites based on a SBS triblock copolymer and organomodified layered silicates were prepared by solution casting followed by melt shearing. The dispersion of the nanofiller in the polymer matrix and its influence on the mechanical behavior of the composites were determined by means of different microscopic techniques, tensile testing, dynami...

Pure anatase TiO2 submicrotubes were successfully fabricated by a template-directed method. Electrospun poly(vinyl pyrrolidone) (PVP) fibers were used as a soft template for coating with titanium dioxide using an atomic layer deposition (ALD) technique. The deposition was conducted onto a template at 70 °C by using titanium tetraisopropyl oxide (TI...