Semi‐interpenetrating polymer networks composed of poly(<i>N</i>‐isopropyl acrylamide) and polyacrylamide hydrogels

Djonlagić, Jasna; Petrovìć, Zoran S.

doi:10.1002/polb.20247

Cited by 41 publications

(28 citation statements)

References 58 publications

(55 reference statements)

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“…For instance HEMA-gelatin gels reach strengths of 65 kPa, just slightly above gelatin alone [64] and polyacrylamide/poly-N-isopropylacrylamide IPN gels reach strengths of just 10 kPa [65]. Templating gels on a colloidal crystal and then removing the colloid has also been reported to give good toughness, although the modulus and strength remain low [66].…”

Section: Pamps-paammentioning

confidence: 99%

Polymer Gel Actuators: Fundamentals

Calvert

2009

Biomedical Applications of Electroactive Polymer Actuators

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One view of materials development is to search for what materials correspond to empty spaces on a hypothetical multi-dimensional map of the properties of available materials. Following a biomimetic philosophy, for instance, it can be seen that tough ceramics and moldable short fiber composites with high moduli are possible but absent from the list of available synthetic materials. Likewise artificial muscle is missing, where the properties are defined as a developed stress of over 300 kPa, a linear contraction of 25 % and a response time of below one second. Currently dielectric elastomers come closest but have disadvantages [1,2].The actin-myosin muscle system provides the performance target for electroactive polymer actuators [3,4]. The process is driven chemically by the energy change from hydrolysis of the polyphosphate bond as ATP (adenosine triphosphate) binds to myosin and is converted to ADP (adenosine diphosphate) and phosphate. A simple chemical analogy suggests that muscle-like gels should be feasible but it is now clear that the task is much harder than it seems.Early work on gel actuation by Katchalsky-Katzir demonstrated that engines could be built using the chemical energy in diluting a lithium bromide solution to drive contraction and expansion of a collagen belt [5]. In essence, the collagen expands to take up the salt solution or contract to exclude the water. This change is both a molecular conformation change and a volume change. Other chemically driven gels, for instance polyacrylic acid fibers [6] which respond to a pH change, also rely on a solubility change giving rise to a volume change.

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Section: Pamps-paammentioning

confidence: 99%

Polymer Gel Actuators: Fundamentals

Calvert

2009

Biomedical Applications of Electroactive Polymer Actuators

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“…Young's modulus was found to be slightly dependent on the temperature however the cross-linker concentration presented a strong influence. Semi-interpenetrating polymer networks were synthesized to improve the mechanical properties of NIPA gels [9] . These networks reinforced with cationic and nonionic PAAm exhibited higher tensile strength and elongations at break than NIPA hydrogels, whereas the presence of anionic PAAm caused a reduction in the mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Elastic Properties of a Swollen PAAm-NIPA Copolymer with Various NIPA Contents

Evingür

Pekcan

2014

Polymer-Plastics Technology and Engineering

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Copolymer based on cross-linked polyacrylamide (PAAm) having N-isopropylacrylamide (NIPA) was prepared and their elastic properties were studied as a function of NIPA contents. NIPA content dependency of the shear modulus, S of the PAAm-NIPA copolymers due to volume phase transition was measured using tensile testing technique at 30 degrees C. It was observed that its shear modulus and toughness were found to be strongly dependent on NIPA content. It is understood that the shear modulus was found to increase with NIPA contents, keeping constant temperature at 30 degrees C. Elastic properties of the PAAm-NIPA copolymers show compositional dependence

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“…There were some experimental publications investigating the effect of comonomer type and concentration on the properties of the hydrogels. It was shown that the cationic and anionic linear polyacrylamide (PAAm) could increase the swelling rate of the hydrogels, whereas nonionic PAAm diminished it . The swelling/deswelling performance and drug release could also be improved by increasing the amount of comonomer .…”

Section: Introductionmentioning

confidence: 99%

“…It was shown that the cationic and anionic linear polyacrylamide (PAAm) could increase the swelling rate of the hydrogels, whereas nonionic PAAm diminished it. [8] The swelling/ deswelling performance and drug release could also be improved by increasing the amount of comonomer. [9] The concentration and type of cross-linker were also known to be the important factors in preparation of the semi-IPN hydrogels.…”

Section: Introductionmentioning

confidence: 99%

Effects of Cross-Link Density on Structures and Properties of Dual-Sensitive Semi-Interpenetrating Polymer Networks Hydrogel Microspheres

Lai

Wang

et al. 2017

Macromol. Chem. Phys.

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Semi-interpenetrating polymer network (semi-IPN) strategy is employed to fabricate uniform microspheres with temperature and pH dual-responsive behavior, which is composed of poly(Nisopropylacrylamide) and poly(acrylic acid) in the presence of N,N′-methylenebisacrylamide (MBA) as the cross-linker. The influences of MBA amount (M m ) on the structures and properties of the microspheres are investigated in terms of particle size, surface morphology, pH sensitivity, and thermo-sensitivity with low critical solution temperature in the range M m = 2.5-15%. Additionally, functional group distributions in the microspheres are probed by titration and employing the Henderson-Hasselbalch equation. The results show that all the properties strongly change depending on M m . Based on transmission electron microscopy and confocal laser scanning microscopy measurements, and these properties, the M m -induced changes in the structures of the semi-IPN microspheres are discussed. body, the hydrogels that respond to pH and temperature simultaneously have attracted significant attention. Poly(N-isopropylacrylamide) (PNIPAM) is one of the most extensively studied thermo-sensitive polymers, which can exhibit lowest critical solution temperature (LCST) at ≈32 °C close to human body temperature. To obtain the pH-responsive behavior of PNIPAM-based hydrogels, the formation of semi-interpenetrating polymer network (semi-IPN) has been proved to be a useful method. In 2001, Lee et al. prepared thermo-and pH-sensitive semi-IPN hydrogels composed of PNIPAM and alginate by cross-linking with calcium ions. [2] Subsequently, many efforts were devoted to prepare the pH/temperature dual-sensitive hydrogels based on PNIPAM and other polymers with semi-IPN structure, such as chitosan, poly(acrylic acid) (PAAc), and poly(aspartic acid) (PAS). [3][4][5] The resultant hydrogels exhibited improved temperature and pH responsiveness.However, the slow response rate of macroscopic semi-IPN hydrogels was still a drawback, which limited their further application in bioengineering. Considering the

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Semi‐interpenetrating polymer networks composed of poly(N‐isopropyl acrylamide) and polyacrylamide hydrogels

Cited by 41 publications

References 58 publications

Polymer Gel Actuators: Fundamentals

Polymer Gel Actuators: Fundamentals

Elastic Properties of a Swollen PAAm-NIPA Copolymer with Various NIPA Contents

Effects of Cross-Link Density on Structures and Properties of Dual-Sensitive Semi-Interpenetrating Polymer Networks Hydrogel Microspheres

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