scholarly journals Novel long-chain aliphatic polyamide/surface-modified silicon dioxide nanocomposites: in-situ polymerization and properties

2021 ◽  
Vol 20 ◽  
pp. 100450
Author(s):  
H. Baniasadi ◽  
J. Seppälä
Keyword(s):  
Silicon Dioxide ◽  
In Situ Polymerization ◽  
Surface Modified ◽  
Long Chain ◽  
Aliphatic Polyamide

scholarly journals Delaminated Polymer/Lamellar Aluminophosphate Nanocomposites Prepared via in SITU Polymerization

2006 ◽  
Vol 15 (5) ◽  
pp. 096369350601500 ◽  
Author(s):  
Jingyu Wang ◽  
Guoping Chen ◽  
Quan Zhou
Keyword(s):  
Polymer Matrix ◽  
In Situ Polymerization ◽  
Short Chain ◽  
Long Chain

A method to synthesize completely delaminated polymer/lamellar aluminophosphate (Mu-4) nanocomposites has been successfully developed, wherein organo-modification of Mu-4 followed by in situ polymerization was applied. It can be found that the long chain n-dodecylamine molecules can favor the intercalation of Mu-4 and thus readily make the Mu-4 layers delaminated in the polymer matrix compared with the short chain N,N-dimethylpropane-1,3-diamine.

scholarly journals Humidity Sensing Properties of Surface Modified Polyaniline Metal Oxide Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. C. Nagaraju ◽  
Aashis S. Roy ◽  
J. B. Prasanna Kumar ◽  
Koppalkar R. Anilkumar ◽  
G. Ramagopal
Keyword(s):  
In Situ Polymerization ◽  
High Sensitivity ◽  
Thermal Coefficient ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Praseodymium Oxide ◽  
Surface Modified ◽  
Oxide Composites ◽  
Polymerization Method

Polyaniline- (PANI) praseodymium Oxide (Pr2O3) composites have been synthesized by in situ polymerization method with different weight percentages. The synthesized composites have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The temperature dependent conductivity shows that the conductivity is due to the hopping of polarons and bipolarons. These composites show negative thermal coefficient (α) behavior as a function of temperature, which is characteristic behavior of semiconducting materials. Sensor studies have been carried out by two-probe method and found that the sensitivity increases with increase in % RH. It is noticed that stability increase is due to the presence of Pr2O3in polyaniline up to 30 wt%. A fast recovery and response time along with high sensitivity make these composites suitable for humidity sensors.

scholarly journals Using In Situ Polymerization to Increase Puncture Resistance and Induce Reversible Formability in Silk Membranes

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2252 ◽  
Author(s):  
Nicholas S. Emonson ◽  
Daniel J. Eyckens ◽  
Benjamin J. Allardyce ◽  
Andreas Hendlmeier ◽  
Melissa K. Stanfield ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
In Situ Polymerization ◽  
Tensile Modulus ◽  
Needle Puncture ◽  
Puncture Resistance ◽  
Potential Applications ◽  
Novel Material ◽  
Medical Materials ◽  
Surface Modified

Silk fibroin is an excellent biopolymer for application in a variety of areas, such as textiles, medicine, composites and as a novel material for additive manufacturing. In this work, silk membranes were surface modified by in situ polymerization of aqueous acrylic acid, initiated by the reduction of various aryldiazonium salts with vitamin C. Treatment times of 20 min gave membranes which possessed increased tensile strength, tensile modulus, and showed significant increased resistance to needle puncture (+131%), relative to ‘untreated’ standards. Most interestingly, the treated silk membranes were able to be reversibly formed into various shapes via the hydration and plasticizing of the surface bound poly(acrylic acid), by simply steaming the modified membranes. These membranes and their unique properties have potential applications in advanced textiles, and as medical materials.

In-situ polymerization and multifunctional properties of surface-modified multiwalled carbon nanotube-reinforced polyimide nanocomposites

2016 ◽  
Vol 29 (7) ◽  
pp. 797-807 ◽  
Author(s):  
Chunyan Wang ◽  
Jianping Xu ◽  
Junxin Yang ◽  
Yong Qian ◽  
Hesheng Liu
Keyword(s):  
Carbon Nanotube ◽  
High Performance ◽  
In Situ Polymerization ◽  
Multiwalled Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Amide Bonds ◽  
Amine Functionalized ◽  
High Performance Polymer ◽  
Surface Modified

In this study, strong multiwalled carbon nanotube (MWNT)–polyimide (PI) matrix interfaces were designed and constructed to obtain high-performance nanocomposites via in-situ polymerization. MWNTs with reactive amino groups were produced by the covalent linking of phenylenediamine to the surface of MWNTs by amide bonds; this material exhibited excellent dispersibility and compatibility with the PI matrix. The incorporation of amine-functionalized MWNT (MWNT-NH2) significantly improved the macroscopic properties of the PI-based nanocomposites. A 50.5% increase in the tensile strength and an 83.1% increase in the Young’s modulus were achieved by 3.0 wt% MWNT-NH2 loading. Furthermore, the storage modulus, thermal stability, and glass transition temperature of the nanocomposite clearly increased by adding MWNT-NH2. The success of this method provides a good rational for developing high-performance polymer-based nanocomposites.

Biophysics (and sociology) of ceramides.

2005 ◽  
Vol 72 ◽  
pp. 177-188 ◽  
Author(s):  
Félix M. Goñi ◽  
F-Xabier Contreras ◽  
L-Ruth Montes ◽  
Jesús Sot ◽  
Alicia Alonso
Keyword(s):  
Cell Biology ◽  
Positive Curvature ◽  
Acyl Chain ◽  
Cell Signalling ◽  
Hexagonal Structure ◽  
Lipid Monolayer ◽  
Flip Flop ◽  
Long Chain ◽  
Bilayer Permeability

In the past decade, the long-neglected ceramides (N-acylsphingosines) have become one of the most attractive lipid molecules in molecular cell biology, because of their involvement in essential structures (stratum corneum) and processes (cell signalling). Most natural ceramides have a long (16-24 C atoms) N-acyl chain, but short N-acyl chain ceramides (two to six C atoms) also exist in Nature, apart from being extensively used in experimentation, because they can be dispersed easily in water. Long-chain ceramides are among the most hydrophobic molecules in Nature, they are totally insoluble in water and they hardly mix with phospholipids in membranes, giving rise to ceramide-enriched domains. In situ enzymic generation, or external addition, of long-chain ceramides in membranes has at least three important effects: (i) the lipid monolayer tendency to adopt a negative curvature, e.g. through a transition to an inverted hexagonal structure, is increased, (ii) bilayer permeability to aqueous solutes is notoriously enhanced, and (iii) transbilayer (flip-flop) lipid motion is promoted. Short-chain ceramides mix much better with phospholipids, promote a positive curvature in lipid monolayers, and their capacities to increase bilayer permeability or transbilayer motion are very low or non-existent.

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