Rheological and swelling behavior of semi-interpenetrating networks of polyacrylamide and scleroglucan

2009 ◽  
Vol 20 (12) ◽  
pp. 1102-1106 ◽  
Author(s):  
Jamal Aalaie ◽  
Ali Rahmatpour ◽  
Ebrahim Vasheghani-Farahani
Keyword(s):  
Swelling Behavior ◽  
Interpenetrating Networks

Effect of N-Isopropylacrylamide on the Structure and Swelling Behavior of Microporous Polyurethane Film

2010 ◽  
Vol 148-149 ◽  
pp. 1652-1655
Author(s):  
Hai Ning Lv ◽  
Zai Sheng Cai ◽  
Cheng Qian ◽  
Yuan Xue
Keyword(s):  
Composite Films ◽  
Swelling Behavior ◽  
Stimuli Responsive ◽  
Interpenetrating Networks ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Polyurethane Film ◽  
Responsive Membranes ◽  
Important Approach ◽  
Ft Ir

Preparation of membranes from stimuli-responsive polymers, copolymers, and polymer-additive mixtures is an important approach in the design of responsive membranes. N-isopropylacrylamide(NIPPAm) was dispersed in polyurethane(PU) solution, crosslinked with N,N’-methylene bisacrylamide(BIS) and then cast in bathes to get a thermosensitive microporous film. The ratio of NIPAAm with BIS amount and the cast medium were varied. The structure, surface and cross-section images of polyurethane/poly(N-isopropylacrylamide) (PU/PNIPPAm) semi- interpenetrating networks (semi-IPNs) were characterized by FT-IR and SEM. The swelling behavior of pure PU films and PU/PNIPPAm semi-IPNs were compared. The results showed that incorporation of PNIPPAm had great effect on the structure and swelling behavior of composite films. This approach enables fabrication of membranes with the desired pore structure.

scholarly journals Microstructured Macromaterials Based on IPN Microgels

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1078 ◽  
Author(s):  
Irina Rashitovna Nasimova ◽  
Vladimir Yurievich Rudyak ◽  
Anton Pavlovich Doroganov ◽  
Elena Petrovna Kharitonova ◽  
Elena Yurievna Kozhunova
Keyword(s):  
Computer Simulations ◽  
Polyacrylic Acid ◽  
Ph Sensitive ◽  
Conformational State ◽  
Swelling Behavior ◽  
Environmental Sensitivity ◽  
Interpenetrating Networks ◽  
Material Development ◽  
Microgel Particles

This study investigates the formation of microstructured macromaterials from thermo- and pH-sensitive microgels based on interpenetrating networks of poly-N-isopropylacrylamide (PNIPAM) and polyacrylic acid (PAA). Macromaterials are produced as a result of the deposition of microgel particles and subsequent crosslinking of polyacrylic acid subnetworks to each other due to the formation of the anhydride bonds during annealing. Since both PNIPAM and PAA are environment-sensitive polymers, one can expect that their conformational state during material development will affect its resulting properties. Thus, the influence of conditions of preparation for annealing (pH of the solution, the temperature of preliminary drying) on the swelling behavior, pH- and thermosensitivity, and macromaterial inner structure was investigated. In parallel, the study of the effect of the relative conformations of the IPN microgel subnetworks on the formation of macromaterials was carried out by the computer simulations method. It was shown that the properties of the prepared macromaterials strongly depend both on the temperature and pH of the PNIPAM-PAA IPN microgel dispersions. This opens up new opportunities to obtain materials with pre-chosen characteristics and environmental sensitivity.

scholarly journals Preparation and Swelling Behavior of L-Lactide Interpenetrating Networks

2016 ◽  
Vol 06 (04) ◽  
pp. 119-133 ◽  
Author(s):  
Zainab J. Sweah ◽  
Hadi S. Al-Lami ◽  
Athir M. Haddad
Keyword(s):  
Swelling Behavior ◽  
Interpenetrating Networks

Characterization of Genipin Crosslinked Hydrogels Composed of Chitosan and Partially Hydrolyzed Poly(vinyl alcohol)

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Ashveen V. Nand ◽  
David R. Rohindra ◽  
Jagjit R. Khurma
Keyword(s):  
Vinyl Alcohol ◽  
Crosslinking Agent ◽  
Bound Water ◽  
Deionized Water ◽  
Swelling Behavior ◽  
Poly Vinyl Alcohol ◽  
Interpenetrating Networks ◽  
Scanning Calorimetry ◽  
Naturally Occurring

AbstractChitosan and 80 % hydrolyzed poly(vinyl alcohol) (PVA) were used to prepare semi-interpenetrating networks of varying ratios of the constituents. The hydrogels were crosslinked using genipin, a naturally occurring nontoxic crosslinking agent. The swelling behavior of these hydrogels was studied in deionized water at 25, 35 and 45 °C and in media of different pH at 25 °C. The swelling behavior of the gels was found to be dependent on temperature, pH of the medium and the amount of PVA present in the gel. States of water in the hydrogels swollen at 25 °C and pH 7 were determined using Differential Scanning Calorimetry (DSC). The amount of freezing water in the swollen hydrogels increased whereas the amount of nonfreezing bound water decreased with the increase in PVA concentration in the gels. The gelation behaviour of the pregel solutions were also studied.

Triply-periodic nanostructures in surfactant, block copolymer, and biomembrane systems, and simulation of TEMs

1993 ◽  
Vol 51 ◽  
pp. 884-885
Author(s):  
David M. Anderson ◽  
Tomas Landh
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Cubic Phase ◽  
List Type ◽  
Interpenetrating Networks ◽  
Triply Periodic ◽  
Wide Range ◽  
Bicontinuous Cubic ◽  
Phase Liquid ◽  
Dividing Surface

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.

Supramolecular Assembly of U(IV) Clusters and Superatoms

2020 ◽  
Author(s):  
Ian Colliard ◽  
Gregory Morrosin ◽  
Hans-Conrad zur Loye ◽  
May Nyman
Keyword(s):  
Quantum Dots ◽  
Supramolecular Assembly ◽  
Emergent Properties ◽  
Organic Media ◽  
Body Centered Cubic ◽  
Cluster Anions ◽  
Charge Balance ◽  
Interpenetrating Networks ◽  
Hierarchical Assembly ◽  
Two Parameters

Superatoms are nanometer-sized molecules or particles that can form ordered lattices, mimicking their atomic counterparts. Hierarchical assembly of superatoms gives rise to emergent properties in superlattices of quantum-dots, p-block clusters, and fullerenes. Here, we introduce a family of uranium-oxysulfate cluster anions whose hierarchical assembly in water is controlled by two parameters; acidity and the countercation. In acid, larger Ln<sup>III</sup> (Ln=La-Ho) link hexamer (U<sub>6</sub>) oxoclusters into body-centered cubic frameworks, while smaller Ln<sup>III</sup> (Ln=Er-Lu &Y) promote linking of fourteen U<sub>6</sub>-clusters into hollow superclusters (U<sub>84</sub> superatoms). U<sub>84</sub> assembles into superlattices including cubic-closest packed, body-centered cubic, and interpenetrating networks, bridged by interstitial countercations, and U<sub>6</sub>-clusters. Divalent transition metals (TM=Mn<sup>II </sup>and Zn<sup>II</sup>), with no added acid, charge-balance and promote the fusion of 10 U<sub>6</sub> and 10 U-monomers into a wheel–shaped cluster (U<sub>70</sub>). Dissolution of U<sub>70</sub> in organic media reveals (by small-angle Xray scattering) that differing supramolecular assemblies are accessed, controlled by TM-linking of U<sub>70</sub>-clusters. <br>

Swelling behavior and viscoelastic properties of a polyacetal hydrogel

2008 ◽  
Vol 33 (5) ◽  
pp. 387-395
Author(s):  
Hayet Bendaikha ◽  
Saliha Chaoui ◽  
Seghier Ould Khada ◽  
Abdelghani Krallafa
Keyword(s):  
Viscoelastic Properties ◽  
Swelling Behavior

Development and Characterization of LBG-PVA Interpenetrating Networks Incorporating Gliclazide for Sustained Release

2020 ◽  
Vol 15 ◽  
Author(s):  
Ashish Katoch ◽  
Manju Nagpal ◽  
Malkiet Kaur ◽  
Manjinder Singh ◽  
Geeta Aggarwal ◽  
...  
Keyword(s):  
Solid State ◽  
Sustained Release ◽  
Half Life ◽  
Solid State Nmr ◽  
Oral Dosage ◽  
Cross Linking ◽  
Interpenetrating Networks ◽  
Dsc Studies ◽  
Biological Half Life ◽  
Percentage Yield

Background: Controlled oral dosage forms have always been preferred for drugs with variable absorption, and short biological half life and frequent dosing. The prime goal with sustained release systems is to maintain uniform therapeutic blood levels for longer periods of time. Interpenetrating networks (IPNs) have been evidenced as uniform sustained release systems. In current study, polyvinyl alcohol (PVA) and locust bean gum (LBG) based IPNs were developed for the oral sustained release drug delivery of gliclazide (shows variable absorption). Method: The IPNs were synthesized by emulsion cross-linking method using glutaraldehyde (GA) as a cross linking agent. Gliclazide is a potential second generation, short-acting sulfonylurea oral hypoglycemic agent is having a short biological half-life (2-4 h), variable absorption and poor oral bioavailability. Various batches of IPNs were formulated by varying LBG: PVA ratio and evaluated for percentage yield, drug entrapment efficiency (DEE), swelling properties and in vitro drug release studies. Further characterizations were done by Fourier Transform Infrared Spectroscopy (FTIR), C13 Solid state NMR, X-Ray diffraction study (XRD), Scanning electron microscopy (SEM), and Differential scanning microscopy (DSC) studies. Results: The percentage yield, drug entrapment and equilibrium swelling was observed to be dependent on PVA-LBG ratio and GA amount. Sustained release of drug was observed in all IPN formulations (approx 59 - 86% in 8 h in various batches) with variable release kinetics. SEM studies revealed the regular structures of IPNs. FTIR, XRD, C13 Solid state NMR and DSC studies proposed that drug was successfully incorporated into the formed IPNs. Conclusion: IPNs of LBG and PVA can be used as a promising carrier with uniform sustained release characteristics.

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