Quantitative Imaging from Single Molecules to (Bio)Polymers

Atomic force microscopy (AFM) has become an important tool for the field of material science for probing sample surfaces and determining the material properties in nanoscale detail. The technique gives fast, reliable results for the physicist, chemist, engineer, and material scientist. AFMs have enhanced much of the technological progress of the last three decades.

To characterize polymers on a nanometer scale, a high-resolution instrument is required which enables the user to probe different aspects of the sample in questions. Traditional imaging modes of AFMs have well known drawbacks for samples that have steep edges, are soft or sticky, or are loosely attached to the surface. Common modes such as contact mode or intermittent contact mode introduce unwanted forces that can damage the sample. Loosely attached objects may be moved due to lateral forces.

Bruker has released the new imaging mode, Quantitative Imaging (QI) which works without applying any lateral force and allows the user to control the vertical force at each pixel. The principles of QI and example applications are detailed in this app note.

Readers can expect to learn about:

• The basic principle and the benefits of the force-curve based QI mode when investigating soft and challenging samples;
• Dedicated instrumentation and accessories of Bruker's NanoWizard AFM for utmost flexibility in experimental setup; and
• Prominent examples of various types of membranes, nanofibers, alkanes, block co-polymers and dendronized polymers showcasing the easy operation and the potential of the QI mode for studying structure and properties of polymers under different environmental conditions.