Effect of Inorganic/Organic Hybrid on the Wettability of Polymer Nanofibrous Membranes

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Ning Wu ◽  
Ying Sun ◽  
Yanan Jiao ◽  
Li Chen
Keyword(s):  
Water Contact ◽  
Tem Analysis ◽  
New Approach ◽  
Force Microscopy ◽  
Organic Hybrid ◽  
Atomic Force ◽  
Hybrid Nanofibers ◽  
Nanofibrous Membranes ◽  
Fibrous Membranes ◽  
Composite Fibrous Membranes

We report a new approach for improving the wettability of a poly (vinyl acetate) (PVAc) nanofiber membrane. The pure PVAc and hybrid PVAc/titanium dioxide (TiO2) nanofibrous membranes can be obtained by electrospinning the PVA solution and PVA/TiO2 hybrid sol with different TiO2 contents, respectively. The resultant samples were characterized by scanning electron microscopy (SEM), nitrogen volumetric adsorption apparatus (NVAA), water contact angle (WCA), atomic force microscopy (AFM) energy dispersive X-ray spectroscopy (EDX) and transmission electronic microscopy (TEM). It was found that the WCA of composite fibrous membranes was decreased from 109 to 36° as the TiO2 content increased. The AFM, EDX and TEM analysis indicate that the wettability of PVAc/TiO2 hybrid nanofibers was mainly improved by surface roughness and surface hydrophilic groups.

Visualization of molecular binding sites at the nanoscale in the lift-up mode by amplitude-modulation atomic force microscopy

Nanoscale ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 4213-4220
Author(s):  
Tatsuhiro Maekawa ◽  
Takashi Nyu ◽  
Evan Angelo Quimada Mondarte ◽  
Hiroyuki Tahara ◽  
Kasinan Suthiwanich ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Molecular Recognition ◽  
Amplitude Modulation ◽  
Binding Sites ◽  
Local Distribution ◽  
New Approach ◽  
Molecular Binding ◽  
Force Microscopy ◽  
Atomic Force ◽  
Recognition Sites

We report a new approach to visualize the local distribution of molecular recognition sites with nanoscale resolution by amplitude-modulation atomic force microscopy.

Development of leftover rice/gelatin interpenetrating polymer network films for food packaging

2021 ◽  
Vol 10 (1) ◽  
pp. 37-48
Author(s):  
Sijia Li ◽  
Chun Shao ◽  
Zhikun Miao ◽  
Panfang Lu
Keyword(s):  
Food Packaging ◽  
Polymer Network ◽  
Raw Material ◽  
Interpenetrating Polymer Network ◽  
Waste Biomass ◽  
Practical Application ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Morphology Of Films

Abstract Waste biomass can be used as a raw material for food packaging. Different concentrations of gelatin (GEL) were introduced into the leftover rice (LR) system to form an interpenetrating polymer network (IPN) for improving the properties of the films. The structure and morphology of films were evaluated by Fourier transform infrared, scanning electron microscopy, and atomic force microscopy, which showed good compatibility between LR and GEL. The moisture content and oil absorption rate of IPN films were down by 105% and 182%, respectively, which showed better water and oil resistance than the LR film. In addition, increasing GEL concentration led to enhancement in the tensile strength of films from 2.42 to 11.40 MPa. The water contact angle value of the IPN films (117.53°) increased by 147% than the LR film (47.56°). The low haze of IPN films was obtained with the increment of the mutual entanglement of LR and GEL. The 30–50% GEL addition improved the water vapor barrier and thermal stability properties of the IPN films. This study highlights that LR as waste biomass can have a practical application in food packaging.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

scholarly journals Superhydrophilic Coating with Antibacterial and Oil-Repellent Properties via NaIO4-Triggered Polydopamine/Sulfobetaine Methacrylate Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2008
Author(s):  
Hsiu-Wen Chien ◽  
Hong-Yu Lin ◽  
Chau-Yi Tsai ◽  
Tai-Yu Chen ◽  
Wei-Nian Chen
Keyword(s):  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Deposition Process ◽  
Water Contact ◽  
Water Separation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oil Water Separation ◽  
One Step ◽  
Oil Repellent

Superhydrophilic coatings have been widely used for the surface modification of membranes or biomedical devices owing to their excellent antifouling properties. However, simplifying the modification processes of such materials remains challenging. In this study, we developed a simple and rapid one-step co-deposition process using an oxidant trigger to fabricate superhydrophilic surfaces based on dopamine chemistry with sulfobetaine methacrylate (SBMA). We studied the effect of different oxidants and SBMA concentrations on surface modification in detail using UV–VIS spectrophotometry, dynamic light scattering, atomic force microscopy, X-ray photoelectron spectroscopy, and surface plasmon resonance. We found that NaIO4 could trigger the rate of polymerization and the optimum ratio of dopamine to SBMA is 1:25 by weight. This makes the surface superhydrophilic (water contact angle < 10°) and antifouling. The superhydrophilic coating, when introduced to polyester membranes, showed great potential for oil/water separation. Our study provides a complete description of the simple and fast preparation of superhydrophilic coatings for surface modification based on mussel-inspired chemistry.

scholarly journals Development of a new hybrid approach combining AFM and SEM for the nanoparticle dimensional metrology

2019 ◽  
Vol 10 ◽  
pp. 1523-1536 ◽  
Author(s):  
Loïc Crouzier ◽  
Alexandra Delvallée ◽  
Sébastien Ducourtieux ◽  
Laurent Devoille ◽  
Guillaume Noircler ◽  
...  
Keyword(s):  
Hybrid Approach ◽  
Proof Of Concept ◽  
Characteristic Parameters ◽  
Dimensional Metrology ◽  
New Approach ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spherical Silica ◽  
Spatial Dimensions ◽  
Complementary Nature

At this time, there is no instrument capable of measuring a nano-object along the three spatial dimensions with a controlled uncertainty. The combination of several instruments is thus necessary to metrologically characterize the dimensional properties of a nano-object. This paper proposes a new approach of hybrid metrology taking advantage of the complementary nature of atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques for measuring the main characteristic parameters of nanoparticle (NP) dimensions in 3D. The NP area equivalent, the minimal and the maximal Feret diameters are determined by SEM and the NP height is measured by AFM. In this context, a kind of new NP repositioning system consisting of a lithographed silicon substrate has been specifically developed. This device makes it possible to combine AFM and SEM size measurements performed exactly on the same set of NPs. In order to establish the proof-of-concept of this approach and assess the performance of both instruments, measurements were carried out on several samples of spherical silica NP populations ranging from 5 to 110 nm. The spherical nature of silica NPs imposes naturally the equality between their height and their lateral diameters. However, discrepancies between AFM and SEM measurements have been observed, showing significant deviation from sphericity as a function of the nanoparticle size.

Study of Defects in p-type Layers in III-nitride Laser Diode Structures Grown by Molecular Beam Epitaxy

2006 ◽  
Vol 955 ◽  
Author(s):  
Huixin Xiu ◽  
Pedro MFJ Costa ◽  
Matthias Kauer ◽  
Tim M Smeeton ◽  
Stewart E Hooper ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Extended Defects ◽  
Tem Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
P Type ◽  
Nitride Laser ◽  
Cladding Layers

ABSTRACTThis paper reports on the study of defects in p-type layers in III-nitride laser structures grown by molecular beam epitaxy. Characterization of the heterostructures was carried out using atomic force microscopy and transmission electron microscopy. The results show that a high density of extended defects – possibly inversion domains – exist in the p-type cladding layers of as-grown structures with either AlGaN/GaN superlattices or bulk AlGaN cladding layers. TEM analysis of operated and aged devices does not reveal any significant structural modification of the p-type material which might be the cause of deterioration in the lasing performance or failure.

scholarly journals Use of Atomic Force Microscopy and Transmission Electron Microscopy for Correlative Studies of Bacterial Capsules

2008 ◽  
Vol 74 (17) ◽  
pp. 5457-5465 ◽  
Author(s):  
Oleg Stukalov ◽  
Anton Korenevsky ◽  
Terry J. Beveridge ◽  
John R. Dutcher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Shewanella Oneidensis ◽  
Geobacter Sulfurreducens ◽  
Phase Imaging ◽  
Tem Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACT Bacteria can possess an outermost assembly of polysaccharide molecules, a capsule, which is attached to their cell wall. We have used two complementary, high-resolution microscopy techniques, atomic force microscopy (AFM) and transmission electron microscopy (TEM), to study bacterial capsules of four different gram-negative bacterial strains: Escherichia coli K30, Pseudomonas aeruginosa FRD1, Shewanella oneidensis MR-4, and Geobacter sulfurreducens PCA. TEM analysis of bacterial cells using different preparative techniques (whole-cell mounts, conventional embeddings, and freeze-substitution) revealed capsules for some but not all of the strains. In contrast, the use of AFM allowed the unambiguous identification of the presence of capsules on all strains used in the present study, including those that were shown by TEM to be not encapsulated. In addition, the use of AFM phase imaging allowed the visualization of the bacterial cell within the capsule, with a depth sensitivity that decreased with increasing tapping frequency.

Sign in / Sign up

Export Citation Format

Share Document