Oriented Nanochannels for Nanowire Synthesis

This thesis aims at the synthesis of oriented nanochannel systems for the synthesis of metallic or semiconducting nanowires. Three different synthesis strategies have been developed. First, horizontal macro- to mesoporous anodic aluminum oxide (AAO) structures with individually addressable channel systems were fabricated in collaboration with the group of Dr. Anna Fontcuberta at TU München. For this purpose, a multi-contact design of aluminum finger structures on silicon wafers was developed. Each finger structure can be individually contacted and between 2 - 5 contacts were generated on a single silicon wafer. The aluminum contacts were electrically isolated from each other, thus each contact can be individually anodized. This way it is possible to synthesize different pore diameters, pore densities, and channel lengths on a single chip. After the anodization, these channels were successfully filled by electro-deposition and thermal chemical vapor deposition. The resulting metal (Au, Cu, Ni, Co) and semiconductor (Te, Si) nanowires embedded within the AAO mold were characterized by SEM and EDX measurements. The second strategy deals with hierarchical channel structures formed from columnar silica mesophases inside AAO membranes. These channels were then used for the fabrication of high-aspect ratio copper, silver, and tellurium nanowires. The resulting wires were structurally and spectroscopically characterized within the host matrix, in the partially dissolved matrix, and completely removed from the matrix with electron microscopy methods. Plan-view images of wires featuring 10 nm diameter within the intact matrix showed the successful replication of the hexagonal arrangement of the columnar mesoporous system. The concept of hierarchical structures within PAA templates was again utilized for the third strategy, where the structural behavior of periodic mesoporous organosilica (PMO) mesophases within the AAO pores was studied. PMO mesophases with different orientations with respect to the alumina pores were obtained; one of the observed mesophases (cubic Im-3m) has not been reported before. After successful template removal, the hexagonal circular mesophase could be used for the synthesis of nanowires by electrodeposition

Conflicting Identities during Digital Transformation Efforts of an Incumbent Automotive Firm

Most manufacturing firms that undergo digital transformation fail to seize the expected benefits. A key reason is that those firms fail to extend their identity of operational excellence with a digital service provider identity, leading to tensions at the interface – the product. Although research has addressed individual aspects of organizational identity, it remains to be understood how organizational identity evolves in incumbent firms in a period of liminality. In a case study with a leading automotive manufacturer, we show how two conflicting identities lead to paradoxical tensions and how separating them through a spinoff shifts those tensions. This study provides the first results on conflicting organizational identities during the liminal period of digital transformation

Pathways for Digital Transformation: An Organizational Identity Perspective

In the rapidly evolving digital transformation (DT) landscape, understanding organizational identity (OI) complexities becomes imperative. Leveraging a comparative analysis of AutoCorp and its spinoff, SoftCorp, this paper unfolds OI tensions in the context of DT. Despite advances in the literature on OI and DT, a gap exists in understanding how conflicting identities within a parent company and its spinoff can impact the organizations and the products they develop. We unearth that the dominant identity in AutoCorp, rooted in traditional manufacturing, creates tensions with the digital service-provider identity in SoftCorp. Additionally, we find that such separation may temporarily relieve internal tensions but introduce new challenges at the organizations’ boundaries, affecting the digitized product. Our findings contribute to the theoretical discourse in OI and provide insights for companies undergoing DT. In our ongoing research project, we plan to develop an integrative framework reconciling these diverging identities for optimal digitized product development

Hierarchically structured biphenylene-bridged periodic mesoporous organosilica

Novel composites of highly ordered and stable biphenyl-bridged periodic mesoporous organosilica (PMO) materials confined within the pores of anodic alumina membranes (AAM) were successfully synthesized by evaporation-induced self-assembly (EISA). 4,40-Bis(triethoxysilyl)biphenyl (BTEBP) was used as a precursor in combination with the ionic surfactant cetyltrimethylammonium bromide (CTAB) or triblock-copolymer F127 as structure-directing agents. The resulting mesophases were characterized by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). With ionic CTAB as a structure directing agent, samples with a mixture of the 2D-hexagonal columnar and a lamellar mesophase were obtained within the AAM channels. When using the nonionic surfactant F127, mesophases with a 2D-hexagonal circular structure were formed in the AAM channels. Additionally, a cubic Im3m phase could also be obtained with the same nonionic surfactant after the addition of lithium chloride to the precursor solution. The stability of both the circular and cubic biphenylene-bridged PMO against calcination temperatures of up to 250 °C was confirmed by NMR spectroscopy. Nitrogen sorption in the porous composite membrane shows typical type IV isotherms and narrow pore size distributions. All the biphenyl PMO/AAM composites show fluorescence due to the existence of biphenyl chromophores in the stable organosilica framework

Formation of hexagonal and cubic fluorescent periodic mesoporous organosilicas in the channels of anodic alumina membranes

The synthesis of periodic mesoporous organosilicas (PMOs) in the confinement of porous anodic alumina membranes (AAMs) was successfully achieved through a modified evaporation-induced self-assembly (EISA) process. 1,3,5-Tris(4-triethoxysilylstyryl)benzene, (a three-armed oligo(phenylenevinylene) organosilane compound, abbr. 3a-OPV), the precursor of the first reported charge-conducting PMO, was used as an organosilica source. Triblock-copolymers Pluronic F127 (EO106 PO70 EO106) or F108 (EO132 PO50 EO132) were used as structure directing agents. The block-copolymer F127 led to a 2D-hexagonal circular mesostructure within the AAM channels and the block copolymer Pluronic F108 resulted in a mesophase with a body-centered cubic (Im3 with combining macronm) structure. Compared to the previously reported 3a-OPV-PMO film{,} the resulting hierarchical PMO/AAM systems have improved features{,} that is{,} the synthesized PMOs have a pore size of around 10 nm and the compounds are found to be stable against thermal treatment at temperatures of up to 200 degreeC and they are also stable in the electron beam of the electron microscope. Additionally{,} both of the resulting hierarchical mesoporous composites show fluorescence in the visible region due to the strongly interacting phenylenevinylene chromophores in the PMO frameworks

Unpacking Digital Transformation Tensions through Workers’ Perceptions: A Technological Frame and Paradox Theory Approach

This study proposes that actors’ perceptions of digital transformation (DT), constructed through technological frames, can explain organizational tensions that firms experience during DT initiatives. We conducted a qualitative case study with a large manufacturer over 12 months, analyzing how different hierarchical employee groups’ technological frames shape their perception of DT. The results illustrate that actors’ perceptions of DT comprise three dimensions (reasons for DT, contributions to DT, and communication during DT initiatives), and how these perceptions explain four different organizational tensions in DT. We contribute to theory on DT by showing how classifying actors’ perceptions of DT through technological frames and paradox theory enables an understanding of how organizational tensions in DT may originate on the individual level

Formation of hexagonal and cubic fluorescent periodic mesoporous organosilicas in the channels of anodic alumina membranes

The synthesis of periodic mesoporous organosilicas (PMOs) in the confinement of porous anodic alumina membranes (AAMs) was successfully achieved through a modified evaporation-induced self-assembly (EISA) process. 1,3,5-Tris(4-triethoxysilylstyryl)benzene, (a three-armed oligo(phenylenevinylene) organosilane compound, abbr. 3a-OPV), the precursor of the first reported charge-conducting PMO, was used as an organosilica source. Triblock-copolymers Pluronic F127 (EO106 PO70 EO106) or F108 (EO132 PO50 EO132) were used as structure directing agents. The block-copolymer F127 led to a 2D-hexagonal circular mesostructure within the AAM channels and the block copolymer Pluronic F108 resulted in a mesophase with a body-centered cubic (Im3 with combining macronm) structure. Compared to the previously reported 3a-OPV-PMO film{,} the resulting hierarchical PMO/AAM systems have improved features{,} that is{,} the synthesized PMOs have a pore size of around 10 nm and the compounds are found to be stable against thermal treatment at temperatures of up to 200 degreeC and they are also stable in the electron beam of the electron microscope. Additionally{,} both of the resulting hierarchical mesoporous composites show fluorescence in the visible region due to the strongly interacting phenylenevinylene chromophores in the PMO frameworks