Stimuli-Responsive Films Based on N-Substituted Polyurethane with Different Alkyl Length

2013 ◽  
Vol 66 (11) ◽  
pp. 1361 ◽  
Author(s):  
Yanyan Wang ◽  
Libin Liu ◽  
Congde Qiao ◽  
Tianduo Li
Keyword(s):  
Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Remarkable Change ◽  
Water Contact ◽  
Force Microscopy ◽  
Poly Propylene ◽  
Chain Lengths

N-Alkyl-substituted polyurethanes with different alkyl chain lengths were prepared from the corresponding bromoalkane (1-bromooctane, 1-bromotetradecane, and 1-bromooctadecane) and polyurethane consisting of poly(propylene glycol) (PPG), 4,4′-diphenylmethane diisocyanate, and 1,4-butanediol. The synthesised materials were characterised by 1H NMR and FTIR spectroscopy and the degrees of substitution were discussed by changing the reaction conditions. Differential scanning calorimetry and X-ray diffraction were used to characterise the thermal properties and crystalline state. Microphase-separated nanostructures, with hard segments (nanofibre-like) embedded into amorphous PPG soft segments, are observed by atomic force microscopy and scanning electron microscopy. A reversible behaviour of the films was revealed by contact angle measurement. Stimuli-responsive films were realised by solvent vapour annealing and heat treatment, and exhibited a reversible switching in surface wettability with a remarkable change in the water contact angle of 21°.

Surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric through oxidant-induced polydopamine deposition

2019 ◽  
Vol 50 (3) ◽  
pp. 364-379
Author(s):  
Yanfen Zhou ◽  
Liang Jiang ◽  
Zhiqing Jiang ◽  
Shaojuan Chen ◽  
Jianwei Ma
Keyword(s):  
Contact Angle ◽  
Glass Fiber ◽  
Water Contact Angle ◽  
Mechanical Stability ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fiber Fabric

This paper reports surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric by employing bio-inspired polydopamine functionalization. The modification process was accelerated by introducing sodium periodate (NaIO4) as oxidant. Surface morphology and chemical composition of the modified polytetrafluoroethylene/glass fiber fabric were characterized by using scanning electron microscopy, atomic force microscopy (AFM), and Fourier transform infrared spectroscopy, respectively. Hydrophilicity of the polytetrafluoroethylene/glass fiber fabric was investigated through water contact angle measurement. It was found that polydopamine successfully deposited on the surface of polytetrafluoroethylene/glass fiber fabric and the uniformity of the polydopamine coating increased with increasing modification time. Water contact angle of polytetrafluoroethylene/glass fiber fabric decreased after polydopamine modification and reached 29° when the sample was treated for 120 min, indicating an improved hydrophilic performance. The formed polydopamine coating was also demonstrated to have reliable chemical and mechanical stability.

Structure and properties of polytetrafluoroethylene (PTFE) fibers

e-Polymers ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 215-220 ◽  
Author(s):  
Ruiliu Wang ◽  
Guangbiao Xu ◽  
Yuechao He
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Cross Sections ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Excellent Thermal Stability ◽  
Ft Ir

AbstractStructure and properties of polytetrafluoroethylene (PTFE) fibers were characterized thoroughly by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analyzing (TG) and water contact angle measurement. It was found that the longitudinal surface of the fiber was not smooth and was full of grooves. The cross sections of fibers were sheet-like and irregular. The infrared spectrum of PTFE fibers was the same as that of PTFE films except the 626 cm-l bands which were associated with the helix-reversal defect. The range of fineness distribution (2.09–11.50 dtex) was wide and the average strength was 1.37 cN/dtex. PTFE fibers began to be decomposed at 508.6°C and showed excellent thermal stability. The water contact angle of fibers layers was 120° indicating it to be a hydrophobic material. All these results provide a theoretical foundation for applications of PTFE fibers.

scholarly journals Superhydrophobic functionalized cellulosic paper by copper hydroxide nanorods for oils purification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Filter Paper ◽  
Separation Efficiency ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Absorption Capacity ◽  
Morphological Properties ◽  
Copper Hydroxide ◽  
Immersion Method ◽  
Water Contact

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.

Preparation of TiO2–SiO2 Hybrid Nanosols Coated Flame-Retardant Polyester Fabric Possessing Dual Contradictory Characteristics of Superhydrophobicity and Self Cleaning Ability

2020 ◽  
Vol 20 (3) ◽  
pp. 1780-1789 ◽  
Author(s):  
Priyanka Katiyar ◽  
Shraddha Mishra ◽  
Anurag Srivastava ◽  
N. Eswara Prasad
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Flame Retardant ◽  
Protective Clothing ◽  
Sol Gel ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Vis Spectroscopy ◽  
Self Cleaning

TiO2, SiO2 and their hybrid nanocoatings are prepared on inherent flame retardant textile substrates from titanium(IV)iso-proproxide (TTIP) and tetraethoxysilane (TEOS) precursors using a sol–gel process followed by hydrothermal treatment. The coated samples are further functionalized by hexadecyltrimethoxysilane (HDTMS) to impart superhydrophobicity. Sample characterization of the nanosols, nanoparticles and coated samples are investigated using, X-ray diffractometer, transmission electron microscopy, scanning electron microscopy, UV-Vis spectroscopy, contact angle measurement. Stain degradation test under mild UV irradiation shows almost 54% degradation of coffee stain within 4 hours measured by Spectrophotometer. UV-Vis Absorption Spectroscopy demonstrates complete degradation of methyl orange colorant within 3 hours. Hybrid nanosol coated and HDTMS modified inherent flame retardant polyester surfaces show apparent water contact angle as ~145°, which is much closer to proximity of superhydrophobic surfaces. Thus, the novelty of present work is, by using sol–gel technique, a bi-functional textile surface has been developed which qualifies the very specific requirements of protective clothing like self-cleaning property (imparted by TiO2 nanoparticles) and superhydrophobicity (imparted by SiO2 nanoparticles and further surface modification by HDTMS), which are entirely contradictory in nature, in a single fabric itself. Thus developed textile surfaces also possess the other attributes of protective clothing like flame retardancy and air permeability.

Effect of Plasma-Induced Polymerization on Contact Angle of Paper

2011 ◽  
Vol 396-398 ◽  
pp. 1619-1623
Author(s):  
Zhao Ping Song ◽  
Jun Rong Li ◽  
Hui Ning Xiao
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Polymer Grafting ◽  
Hydrophobic Property ◽  
Cellulose Fibres ◽  
Water Contact ◽  
X Ray ◽  
Factors Associated

Hydrophobic modification of cellulose fibres was conducted by plasma-induced polymer grafting in an attempt to increase the hydrophobicity of paper. Two hydrophobic monomers, i.e., butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) were grafted on cellulose fibres, induced by atmospheric cold plasma. Various influencing factors associated with the plasma-induced grafting were investigated, including the contact time and reaction temperature with monomers, and the dosage of monomers. Contact-angle measurement, infrared spectrum (IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used to ascertain the occurrence of the grafting. The results showed that the hydrophobic property of the modified paper sheet was improved significantly after the plasma-induced grafting. The water contact angle on the surface of the paper reached up to higher than125°.

scholarly journals Surface Properties of Alginate/Chitosan Biofilm for Wound Healing Application

2020 ◽  
Vol 1010 ◽  
pp. 602-607
Author(s):  
Maizlinda Izwana Idris ◽  
Mohammed Firdaus Adzhari ◽  
Siti Natrah Abdul Bakil ◽  
Tee Chuan Lee ◽  
Mohamad Ali Selimin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wound Healing ◽  
Surface Properties ◽  
Healing Process ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Force Microscopy ◽  
Good Surface ◽  
Atomic Force ◽  
Biopolymer Film

This work focuses on the fabrication of film based on natural biopolymers for wound healing application. Alginate and chitosan were choosen because of their oustanding properties such as biocompatible, hydrophilic and non-toxic. Earlier, the biopolymer film was fabricated by using alginate 1% wt and chitosan 1% wt. solutions at volume ratios of 99:1 and 97:3. Next, the biopolymer film solution was cross-linked with 1M CaCl2.2H2O for two hours and later dried for 24 hours at room temperature. Then, the surface properties of the prepared biopolymer films were characterised via Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM) and contact angle measurement. It was observed that the surface of the biopolymer film became rougher as the volume of the chitosan increases. This condition was confirmed with average surface roughness, RA for biopolymer film with ratio of 97:3 resulted in higher values. Also it was found that the surface of biopolymer films were hydrophilic after the contact angle was less than 90°. This can be concluded that the biopolymer based on alginate/chitosan is a promising candidate for wound healing materials particularly with good surface properties for faster healing process at the wound areas.

Picoliter Water Contact Angle Measurement on Polymers

Langmuir ◽  
2007 ◽  
Vol 23 (13) ◽  
pp. 6875-6878 ◽  
Author(s):  
Michael Taylor ◽  
Andrew J. Urquhart ◽  
Mischa Zelzer ◽  
Martyn C. Davies ◽  
Morgan R. Alexander
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Water Contact Angle Measurement

SYNTHESIS AND CHARACTERIZATION OF SUPERHYDROPHOBIC ZnO HIERARCHICAL STRUCTURES

NANO ◽  
2011 ◽  
Vol 06 (03) ◽  
pp. 265-269 ◽  
Author(s):  
QUNBING ZHANG ◽  
SHIHE CAO ◽  
JUN WANG
Keyword(s):  
Contact Angle ◽  
Hydrothermal Process ◽  
Hierarchical Structures ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Films ◽  
Water Contact ◽  
Simple Method ◽  
Microscopy Images

ZnO films with well-aligned hierarchical structures have been successfully synthesized at moderate temperatures using a simple catalyst-free hydrothermal process. The synthesized ZnO films are found to be single-phase, with a hexagonal wurtzite-type structure. Scanning electron microscopy images show that the well-aligned hierarchical structures are assembled with interlaced parallel sheets grown on the (400) silica surface. The water contact angle measurement indicates that the water on the films has a contact angle of about 156.3°. This clearly demonstrates that the ZnO films synthesized by this simple method have superhydrophobic properties and may be important for applications in self-cleaning surfaces, biology, and so on.

Fabrication of Hydrophobic Surfaces and its Electrochemical Research on Copronickel B30

2011 ◽  
Vol 347-353 ◽  
pp. 560-563 ◽  
Author(s):  
Qun Jie Xu ◽  
Xi Hong Cai ◽  
Hong Yun ◽  
Xian Qin Deng
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Stearic Acid ◽  
Inhibition Efficiency ◽  
Electrochemical Techniques ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Nacl Solution ◽  
Film Properties ◽  
Water Contact

A novel hydrophobic film was prepared by Stearic acid (SA) chemically adsorbed onto the cupronickel B30 surface. The film properties were characterized by means of water contact angle measurement and electrochemical techniques. The results indicate that the structure of the adsorbed film is hydrophobic, and the contact angle is 113.82° for water. AC impedance and polarization curve measurements show that the corrosion resistance of cupronickel B30 modified by stearic acid is improved remarkably, and the inhibition efficiency reached 66.85%. After hydrophobic modified by stearic acid, the inhibition efficiency could reach 88.85% in 3% NaCl solution with the concentration of 0.1 g/L Na2WO4.

Sign in / Sign up

Export Citation Format

Share Document