scholarly journals Micromechanism of the Dispersion Behavior of Polymer-Modified Rejuvenators in Aged Asphalt Material

2018 ◽  
Vol 8 (9) ◽  
pp. 1591 ◽  
Author(s):  
Mingyu Zhao ◽  
Fan Shen ◽  
Qingjun Ding
Keyword(s):  
Asphalt Binder ◽  
Gel Permeation Chromatography ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dispersion Behavior ◽  
Dispersion Agent ◽  
Resistance To Deformation ◽  
Aged Asphalt ◽  
Dispersal Behavior ◽  
Pavement Engineering

Polymer-modified rejuvenator has a different composition and dispersion behavior to traditional rejuvenators. The objective of this study was to investigate the micromechanism of polymer-modified rejuvenators on the behavior of aged asphalt binder. Firstly, gel permeation chromatography (GPC) analysis was conducted to determine the dispersion effectiveness. Secondly, the dispersal behavior of polymer-modified rejuvenators was studied by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Rheological, toughness-tenacity, and force–ductility analyses of the rejuvenated asphalt binder were additionally performed. The results indicate that the contacted asphaltenic micelles in aged asphalt binder were dispersed by dispersion agent in the polymer-modified rejuvenator, and that the dispersion ability of the polymer-modified rejuvenator was promoted to the commercial rejuvenator level. Additionally, the polymer-modified rejuvenator was found to improve the rejuvenated asphalt binder’s resistance to deformation, through the formation of polymeric network structures in the asphalt binder. The results may be used to improve the performance of rejuvenated asphalt binder in recycled-pavement engineering.

Nanoscale Evaluation of Multi-Walled Carbon Nanotube’s Performance on Resisting Oxidization of Asphalt

2020 ◽  
Vol 982 ◽  
pp. 195-200
Author(s):  
Abdullah Al Mamun ◽  
Okan Sirin
Keyword(s):  
Adhesive Force ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Resistance To Oxidation ◽  
Pavement Engineering ◽  
Multi Walled Carbon Nanotubes ◽  
Polymer Modified Asphalt ◽  
Styrene Butadiene ◽  
Walled Carbon Nanotubes

Nanotechnology has contributed significantly to different subfields of the construction industry, including asphalt pavement engineering. The improved properties and new functionalities of the nanomaterials have provided different desired properties of asphalt. In this study, the effectiveness of multi-walled carbon nanotubes (MWCNT) in resisting the oxidation of polymer-modified asphalt was measured. A total of three different percentages (0.5%, 1%, and 1.5%) of MWCNT were used to modify the Styrene-Butadiene (SB) and styrene–butadiene–styrene (SBS) modified asphalt (4% and 5%). The laboratory oxidized asphalt samples were evaluated by an atomic force microscopy machine. The oxidation of the polymer-MWCNT modified asphalt is measured by simulating the existing functional group of the asphalt and as a function of the adhesive force. It is observed that the use of MWCNT in SB and SBS can increase the resistance to oxidation.

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.

Dispersibility of Carbon Nanotubes

2007 ◽  
Vol 537-538 ◽  
pp. 161-168 ◽  
Author(s):  
T. Gábor ◽  
D. Aranyi ◽  
Katalin Papp ◽  
F.H. Kármán ◽  
Erika Kálmán
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Ionic Surfactant ◽  
Geometrical Parameters ◽  
Stable Carbon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dispersion Agent

Availability of a stable carbon nanotube suspension is a prerequisite for production of polymer composites with carbon nanotube as additives. In this work nanotube suspensions, which have been prepared from various nanotubes in different dispersion agents, were compared. Dispersibility of the samples was investigated by scanning electon microscopy and atomic force microscopy. Solution of a non-ionic surfactant was also used successfully as a new dispersion agent. Geometrical parameters of the carbon nanotubes were determined by using atomic force microscopy. Correlation was found between the dispersibility and the parameters of the nanotubes and relative permittivity of the different solvents.

Synthesis and Characterization of Linear Polymers for Non-Linear Optics through Click Chemistry Route

2012 ◽  
Vol 584 ◽  
pp. 8-12 ◽  
Author(s):  
Balakrishna Kolli ◽  
Sarada P. Mishra ◽  
Mukesh P. Joshi ◽  
S. Raj Mohan ◽  
T.S. Dhami ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Second Harmonic ◽  
Gel Permeation Chromatography ◽  
Linear Polymers ◽  
Linear Optics ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Molecular Weights ◽  
Non Linear Optics ◽  
Atomic Force

Click chemistry is used for synthesizing polymers for second order NLO study. The molecular weights found by gel-permeation chromatography (GPC), were in the range of 7000-55000 g/mol. Differential scanning calorimetry shows glass transition temperature (Tg) above 120 oC. From electronic spectra order parameter of the poled films were calculated to be 0.1-0.5. The change in surface morphology after poling was checked by atomic force microscopy. By using a pulsed Nd:YAG laser (1064nm), the second harmonic generation (SHG) intensity was measured. The SHG intensity was also studied as a function of against temperature and time respectively.

Synthesis of Poly(Methylmethacrylate) Latex with Enhanced Rigidity through Surfactant Control

2008 ◽  
Vol 1134 ◽  
Author(s):  
Alex Wu ◽  
Kwun Lun Cho ◽  
Irving Ian Liaw ◽  
Hua Zhang ◽  
Robert Lamb
Keyword(s):  
Film Formation ◽  
Porous Ceramics ◽  
Particle Deformation ◽  
Force Microscopy ◽  
Dimethyl Siloxane ◽  
Atomic Force ◽  
Resistance To Deformation ◽  
Volatile Organic ◽  
Roughness Analysis ◽  
Long Chain

AbstractWater-based polymer latexes have attracted much attention since their invention in the early 1950s. Its advantages for both general health and the environment were recognized as they emit far less volatile organic compounds (VOCs) than their solvent-based counterparts.The performance of latex paints and coatings is directly proportional to the ease of particle deformation. This is the main driving force for the paints and coatings industry to focus its research efforts towards understanding its mechanism.In contrast, little has been published with respect to enhancing latex's resistance against deformation despite such needs in applications such as templating porous ceramics for catalysis and biomaterial engineering. Specifically, the latex's resistance to deformation is crucial to retain a network of uniform pores for applications relating to enzyme immobilization and materials reinforcement.The current study reports increased heat-resistance observed in latexes when synthesized using a rigid surfactant, dimethyl siloxane – ethylene oxide block copolymer (PDMS-PEO). The film formation process for this latex was deduced using atomic force microscopy and subsequent roughness analysis. A comparative study using a non-ionic long-chain hydrocarbon surfactant, morpholine oleate, was also conducted.

scholarly journals Structural characterization of polysaccharide from jujube (Ziziphus jujuba Mill.) fruit

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaolong Ji ◽  
Yanqiu Cheng ◽  
Jingyuan Tian ◽  
Siqi Zhang ◽  
Yongshuai Jing ◽  
...  
Keyword(s):  
High Performance ◽  
Gel Permeation Chromatography ◽  
Structural Features ◽  
Resonance Spectroscopy ◽  
Acidic Polysaccharide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ziziphus Jujuba ◽  
Ft Ir ◽  
Fast Flow

Abstract Background Jujube (Ziziphus jujuba Mill.) fruit is one of the largest productions in China and its increasing production has drawn considerable attention from researchers. Polysaccharide is one of the most abundant components of jujube, and it represents a major group of biolotegically active constituents. This study intended to investigate the special structure of a homogeneous acidic polysaccharide (PZMP4) produced from Ziziphus Jujuba cv. Muzao fruit using novel methods, including DEAE-Sepharose Fast Flow and Sephacryl S-300 column chromatography. Results The structure of PZMP4 was determined via high-performance gel permeation chromatography (HPGPC), gas chromatography (GC), Fourier transform infrared spectroscopy (FT-IR), methylation analysis, nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results reveal that PZMP4 with a molecular weight of 27.90 kDa was composed of rhamnose, arabinose, mannose, glucose, galactose, and galacturonic acid at a ratio of 2.32:2.21:0.22:0.88:2.08:8.83. Advanced structural analysis revealed a netted structure with molecular aggregates of PZMP4. Structural features demonstrated that the basic backbone of PZMP4 appeared to mainly consist of (1→4)-linked GalpA with three branches bonded to O-3 of (1→3)-linked Araf, (1→2)-linked Rhap, and terminated with GalpA. Conclusions PZMP4’s unique structure could imply distinct bioactivities and have considerable utilization in functional food. Graphic abstract

SYNTHESIS OF THICK PORPHYRIN MOLECULAR WIRES BY A PALLADIUM CATALYZED OLIGOMERIZATION

2002 ◽  
Vol 01 (05n06) ◽  
pp. 483-487
Author(s):  
HIROAKI OZAWA ◽  
TAKUJI OGAWA
Keyword(s):  
Molecular Weight ◽  
Electron Beam Lithography ◽  
Gel Permeation Chromatography ◽  
Molecular Wires ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gel Permeation ◽  
Palladium Catalyzed ◽  
Nanogap Electrodes ◽  
Tof Ms

In the aim to prepare thick porphyrin molecular wires, which is visible by atomic force microscopy (AFM), even on the rough surfaces of nanogap electrodes fabricated by electron beam lithography, dendrimer protected porphyrins whose two meso-positions are substituted with ethynyl groups. The porphyrin monomer was reacted with palladium catalyst to make oligomers. Analyses of them with time-of-flight mass spectroscopy (TOF-MS), gel-permeation-chromatography (GPC) revealed that the oligomers were distributed up to 16 mer, whose molecular weight was about 38 000 Daltons.

MICROSTRUCTURE OF NANOSILICA MODIFIED BINDER BY ATOMIC FORCE MICROSCOPY

2016 ◽  
Vol 78 (7-3) ◽  
Author(s):  
Ahmad Kamil Arshad ◽  
Mohamad Saifullah Samsudin ◽  
Juraidah Ahmad ◽  
Khairil Azman Masri
Keyword(s):  
Atomic Force Microscopy ◽  
Physical Properties ◽  
Asphalt Binder ◽  
Visual Evaluation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Stiffness ◽  
Before And After ◽  
Modified Binder ◽  
Temperature Susceptibility

In this paper, the effect of nanosilica (NS) on the physical properties as well as aging on the morphology of asphalt binder was investigated. Asphalt binder penetration grade 60/70 (PEN 60/70) was modified with NS at concentrations of 1% to 5% by weight of binder. Scanning electron microscopy (SEM) was used to have a visual evaluation of Nanosilica dispersion. The physical properties tested include is softening point, penetration, ductility, viscosity and storage stability. Temperature susceptibility was evaluated using penetration index (PI) and penetration viscosity number (PVN). Nanosilica modified binder (NSMB) were aged using the rolling thin film oven test (RTFO) and pressure aging vessel (PAV). The morphology of the virgin asphalt binder and NSMB before and after aging was characterized by tapping mode atomic force microscopy (AFM). From the physical properties test, the addition of NS was found to improve the asphalt binder properties and can resist high temperature susceptibility. The results of the AFM imaging showed that the addition of nanosilica in asphalt binder improved its surface stiffness. The overall surface stiffness of the asphalt binder after aging also increased. It can be concluded from this study that 2% to 4% of NS gave the optimum performance for the binder.

scholarly journals Synthesis and Characterization of Syndiotactic Polystyrene-Polyethylene Block Copolymer

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 698 ◽  
Author(s):  
Lamparelli ◽  
Speranza ◽  
Camurati ◽  
Buonerba ◽  
Oliva
Keyword(s):  
Direct Synthesis ◽  
Gel Permeation Chromatography ◽  
Syndiotactic Polystyrene ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Force Microscopy ◽  
Synthetic Strategy ◽  
Atomic Force

The direct synthesis of syndiotactic polystyrene-block-polyethylene copolymer (sPS-b-PE) with a diblock structure has been achieved. The synthetic strategy consists of the sequential stereocontrolled polymerization of styrene and ethylene in the presence of a single catalytic system: cyclopentadienyltitanium(IV) trichloride activated by modified methylaluminoxane (CpTiCl3/MMAO). The reaction conditions suitable for affording the partially living polymerization of these monomers were identified, and the resulting copolymer, purified from contaminant homopolymers, was fully characterized. Gel permeation chromatography coupled with two-dimensional NMR spectroscopy COSY, HSQC, and DOSY confirmed the block nature of the obtained polymer, whose thermal behaviour and thin film morphology were also investigated by differential scanning calorimetry, powder wide angle x-ray diffraction, and atomic force microscopy.

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