Hydrolytic stability of polyetherimide investigated in ultrathin films

AbstractIncreasing the surface hydrophilicity of polyetherimide (PEI) through partial hydrolysis of the imide groups while maintaining the length of the main-chain was explored for adjusting its function in biomedical and membrane applications. The outcome of the polymer analogous reaction, i.e., the degree of ring opening and chain cleavage, is difficult to address in bulk and microstructured systems, as these changes only occur at the interface. Here, the reaction was studied at the air–water interface using the Langmuir technique, assisted by atomic force microscopy and vibrational spectroscopy. Slow PEI hydrolysis sets in at pH > 12. At pH = 14, the ring opening is nearly instantaneous. Reduction of the layer viscosity with time at pH = 14 suggested moderate chain cleavage. No hydrolysis was observed at pH = 1. Hydrolyzed PEI films had a much more cohesive structure, suggesting that the nanoporous morphology of PEI can be tuned via hydrolysis. Graphic abstract

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Phase Transitions in Phospholipid Monolayers Studied by Atomic Force Microscopy and Langmuir-Blodgett Technique

Revista de Chimie ◽

10.37358/rc.08.11.2008 ◽

2008 ◽

Vol 59 (11) ◽

Author(s):

Maria Tomoaia-Cotisel ◽

Aurora Mocanu

Keyword(s):

Atomic Force Microscopy ◽

Lipid Membrane ◽

Phase Behaviour ◽

Membrane Interface ◽

Force Microscopy ◽

Langmuir Blodgett ◽

Atomic Force ◽

Phospholipid Monolayers ◽

Air Water Interface ◽

Condensed Liquid

The phase behaviour and surface structure of dipalmitoyl phosphatidyl choline (DPPC) monolayers at the air/water interface, in the absence and the presence of procaine, have been investigated by Langmuir-Blodgett (LB) technique and atomic force microscopy. The LB films were transferred on mica, at a controlled surface pressure, characteristic for the expanded liquid to condensed liquid phase transition of pure DPPC monolayers. The results indicate that procaine penetrates into and specifically interacts with phospholipid monolayers stabilizing the lipid membrane interface.

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Lateral Size of Self-Patterned Nanostructures Controlled by Multi-Step Deposition

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.106.117 ◽

2005 ◽

Vol 106 ◽

pp. 117-122 ◽

Cited By ~ 3

Author(s):

Izabela Szafraniak ◽

Dietrich Hesse ◽

Marin Alexe

Keyword(s):

Electron Microscopy ◽

Ultrathin Films ◽

Lateral Size ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Non Volatile Memory ◽

Ferroelectric Capacitors ◽

Scanning Electron

Self-patterning presents an appealing alternative to lithography for the production of arrays of nanoscale ferroelectric capacitors for use in high density non-volatile memory devices. Recently a self-patterning method, based on the use of the instability of ultrathin films during hightemperature treatments, was used to fabricate nanosized ferroelectrics. This paper reports the use of the method for the preparation of PZT nanoislands on different single crystalline substrates - SrTiO3, MgO and LaAlO3. Moreover, a multi-step deposition procedure in order to control lateral the dimension of the crystals was introduced. The nanostructures obtained were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction.

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Self-assembly layer-by-layer fabrication using porphyrin dye anion and polycation

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424609001030 ◽

2009 ◽

Vol 13 (07) ◽

pp. 774-778 ◽

Cited By ~ 1

Author(s):

Byung-Soon Kim ◽

Young-A Son

Keyword(s):

Ultrathin Films ◽

Self Assembly ◽

Film Surface ◽

Layer By Layer ◽

Preparation Technique ◽

Force Microscopy ◽

Atomic Force ◽

Diallyldimethylammonium Chloride ◽

Afm Analysis ◽

Progressive Growth

In this study, self-assembled alternating film using poly(diallyldimethylammonium chloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin (MTCP) was prepared as a multilayer deposition on glass substrate. This preparation technique for dye deposition may provide new feasibilities to achieve the manufacture of ultrathin films for nanotechnology application. The deposition films were characterized by UV-vis spectrophotometer and Atomic Force Microscopy (AFM) analysis. The results of UV-vis spectra showed that the absorbance characteristic of the multilayer films linearly increased with an increased number of PDDAC and MTCP bilayers. AFM analysis showed the film surface was relatively uniform and the progressive growth of layers was determined.

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Structural and Morphological Characterization of Ultrathin Films of an Asymmetric Polydiacetylene

MRS Proceedings ◽

10.1557/proc-440-221 ◽

1996 ◽

Vol 440 ◽

Cited By ~ 3

Author(s):

H. C. Wang ◽

D. W. Cheong ◽

J. Kumar ◽

C. Sung ◽

S. K. Tripathy

Keyword(s):

Second Harmonic ◽

Morphological Characterization ◽

Lb Films ◽

Force Microscopy ◽

Langmuir Blodgett ◽

Glass Substrates ◽

Atomic Force ◽

Transmission Electron ◽

Air Water Interface

AbstractA soluble, asymmetrically substituted polydiacetylene, poly(BPOD), has been reported to form stable monolayers at the air-water interface by the Langmuir-Blodgett (LB) technique [2]. Preformed polydiacetylene has been deposited onto hydrophobic substrates as multilayers to form second order nonlinear optical thin films. Second harmonic generation was found to increase with the number of layers. From previous atomic force microscopy (AFM) studies backbone orientation along the dipping direction with an interchain spacing of about 5 A° was indicated [2].The film morphology and preferential molecular orientation of these LB films are further investigated by transmission electron microscopy (TEM). A specifically tailored sample preparation method for the ultrathin LB films was used. Multilayer films were deposited on hydrophobic collodion covered glass substrates for this purpose. Electron diffraction was employed to study the crystalline organization of mono and multilayers of LB films as well as cast films.

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Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.167 ◽

2017 ◽

Vol 8 ◽

pp. 1671-1679 ◽

Cited By ~ 4

Author(s):

Markus Moosmann ◽

Thomas Schimmel ◽

Wilhelm Barthlott ◽

Matthias Mail

Keyword(s):

Atomic Force Microscopy ◽

Current Knowledge ◽

Biological Species ◽

Optical Methods ◽

Water Interface ◽

Contact Mode ◽

Structured Surfaces ◽

Force Microscopy ◽

Atomic Force ◽

Air Water Interface

Underwater air retention of superhydrophobic hierarchically structured surfaces is of increasing interest for technical applications. Persistent air layers (the Salvinia effect) are known from biological species, for example, the floating fern Salvinia or the backswimmer Notonecta. The use of this concept opens up new possibilities for biomimetic technical applications in the fields of drag reduction, antifouling, anticorrosion and under water sensing. Current knowledge regarding the shape of the air–water interface is insufficient, although it plays a crucial role with regards to stability in terms of diffusion and dynamic conditions. Optical methods for imaging the interface have been limited to the micrometer regime. In this work, we utilized a nondynamic and nondestructive atomic force microscopy (AFM) method to image the interface of submerged superhydrophobic structures with nanometer resolution. Up to now, only the interfaces of nanobubbles (acting almost like solids) have been characterized by AFM at these dimensions. In this study, we show for the first time that it is possible to image the air–water interface of submerged hierarchically structured (micro-pillars) surfaces by AFM in contact mode. By scanning with zero resulting force applied, we were able to determine the shape of the interface and thereby the depth of the water penetrating into the underlying structures. This approach is complemented by a second method: the interface was scanned with different applied force loads and the height for zero force was determined by linear regression. These methods open new possibilities for the investigation of air-retaining surfaces, specifically in terms of measuring contact area and in comparing different coatings, and thus will lead to the development of new applications.

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Enzyme-catalyzed hydrolysis of the supported phospholipid bilayers studied by atomic force microscopy

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/j.bbamem.2012.09.010 ◽

2013 ◽

Vol 1828 (2) ◽

pp. 642-651 ◽

Cited By ~ 17

Author(s):

HengLiang Wu ◽

Le Yu ◽

Yujin Tong ◽

Aimin Ge ◽

Shuehlin Yau ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Phospholipid Bilayers ◽

Force Microscopy ◽

Atomic Force ◽

Hydrolysis Of

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High-Speed Atomic Force Microscopy Reveals Factors Affecting the Processivity of Chitinases during Interfacial Enzymatic Hydrolysis of Crystalline Chitin

ACS Catalysis ◽

10.1021/acscatal.0c02751 ◽

2020 ◽

Vol 10 (22) ◽

pp. 13606-13615

Author(s):

Mingbo Qu ◽

Takahiro Watanabe-Nakayama ◽

Shaopeng Sun ◽

Kenichi Umeda ◽

Xiaoxi Guo ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Enzymatic Hydrolysis ◽

High Speed ◽

Factors Affecting ◽

Force Microscopy ◽

Atomic Force ◽

Hydrolysis Of

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Characterization of Asymmetric Polydiacetylene Ultrathin Films

MRS Proceedings ◽

10.1557/proc-382-265 ◽

1995 ◽

Vol 382 ◽

Author(s):

D. W. Cheong ◽

V. Shivshankar ◽

H. C. Wang ◽

C. M. Sung ◽

J. Kumar ◽

...

Keyword(s):

Ultrathin Films ◽

Second Harmonic ◽

Film Deposition ◽

Asymmetric Structure ◽

Blodgett Film ◽

Force Microscopy ◽

Langmuir Blodgett ◽

Atomic Force ◽

Ft Ir

ABSTRACTNonlinear optical (NLO) ultrathin films of a preforrned asymmetric polydiacetylene have been fabricated by Z-type Langmuir-Blodgett film deposition from the air-water interface. Induced in-plane orientation of the polydiacetylene backbone on the substrates has been confirmed by UV/Vis, FT-IR dichroism, and degenerate four wave mixing (DFWM) studies. All the measurements indicate that the backbone is prefe rentially oriented along the dipping direction. Second harmonic generation study suggests that the LB multilayers form an asymmetric structure (Z-type) due to the accumulation of 2-dimensional ordered monolayer and the dominant induced second order polarization is in the plane of the film. The film morphology and molecular orientation have been investigated by atomic force microscopy (AFM).

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