Functional Surfaces

Functional Surfaces

Stimuli-Responsive Switching of Optical Properties of Polymer Films

M.Sc. Sunna Möhle-Saul (2018 – )

For the development of polymer films whose optical properties can be switched by an external stimulus, scattering phenomena, thermodynamics and kinetics of the used polymer system have to be understood. Several systems for the polymer films are explored, such as homo polymers, block copolymers, polymer blends, combined with or without additives.

In addition to the choice of material, the influence of the synthesis as well as the application method (e.g. coating method and cooling rates) are investigated.

Merck Lab – Functional Papers

Classical assembly of an lateral flow assay (home-use pregnancy test)
Classical assembly of an lateral flow assay (home-use pregnancy test)

M.Sc. Laura Riedler (2017 – )

Within the Merck Lab we are focused on the development of novel paper- based, low- instrumented analytical devices. This implies an extensive understanding of the interactions between paper and analytes, the fluid flow properties and ways how paper can be functionalized with antigens, enzymes etc. Newly developed paper based materials have to be tailored, functionalized and investigated. Well- established platform which are widely used in diagnostics and life science, as e.g. the home-use pregnancy test, are used for benchmarking.

The functionalization of paper to simplify sample preparation steps in medical or research analytics is one research goal of the MerckLab. For this, different immobilization strategies and their feasibility for paper, as well as different types of functionalities are investigated. By linking all the different MerckLab projects together, the overriding goal is the development of new paper-based microfluidic devices by combining the knowledge from the research areas of paper engineering, printing technology, antigen synthesis, functionalization and fluid flow properties of paper.

Wetting and transport on swellable, surface-immobilized polymer brushes and polymer networks

M.Sc. Beatrice Fickel (2016 – )

To understand transport and wetting processes of complex fluids on swellable surfaces, polymer brushes and networks of several photoreactive copolymers are grafted from Si wafer and glass slides by SI-ATRP. Subsequently, their interaction with a lying drop, the topography and the swelling is characterized. Central questions are the influence of the swelling on the wetting and pinning. As fluids, aqueous solutions of different pH values and ionic strengths as well as organic fluids are used. The connections between transport and wetting processes are to be utilized in the long term in microfluidic applications and biosensors.

Related publictaions

[1] https://www.sfb1194.tu-darmstadt.de/teilprojekte_4/a/a05_1/index.de.jsp

Surface functionalization of polymer membranes with switchable polymer films for the modulation of ion transport

M.Sc. Mathias Diefenbach (2015 – )

The LOEWE Research Cluster iNAPO focuses on the chemical and biological modification of nanoporous polymer membranes produced by irradiation with heavy ions and subsequent chemical etching. The chemical modification aims will allow a control of the flux of small molecules and ions through the nanopores by a triggered swelling/deswelling of surface-immobilized polymers (figure). The latter will be addressed e.g. by external stimuli (Temperature, salt concentration or light), as depicted in the figure.

The long-term aim of the project is the integration of such membranes into lab-on-chip devices for analytical applications.

For further information follow this link: iNAPO

Cellulose-based low adhesion coating for adhesive tapes

M.Sc. Sebastian von Gradowski ( 2014 – )

Low adhesion paper coatings are produced in industrial scale and they are mainly composed of silicone. The silicone layer of the “release liner” protects the adhesive against dirt and enables an easy and undamaged release of the adhesive tape without loss of adhesion. Most release-liner are coated with clay to close the porous paper surface and prevent silicone penetration. The silicone is coated onto the paper surface and thermally cured by hydrosilylation reaction. An expensive platinum catalyst is necessary for this crosslinking reaction and it is difficult to recycle the siliconized papers. A Silicone-free release coating based on modified cellulose is developed. This coating is applied to the paper surface by blade coater and it is thermally dried. This coating represents a new bio-based alternative to the common used silicone coatings for low adhesion without using an expensive catalyst.

Related publication

[1] S. von Gradowski, M. Biesalski, 253rd ACS National Meeting and Exposion, 2017