Mechanical Properties and Phase Transition of High Clay Content Clay/Poly(N-isopropylacrylamide) Nanocomposite Hydrogel

Liu, Yang; Zhu, Meifang; Liu, Xiaoli; Jiang, Yunmeng; Ma, Yu; Qin, Zongyi; Kuckling, Dirk; Adler, Hans-Jürgen P.

doi:10.1002/masy.200790084

Cited by 4 publications

(5 citation statements)

References 32 publications

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“…However, in spite of the benefits for the use of the hydrogel, the final price of the product in the market ends up making its application unfeasible. To solve that problem, one of the alternatives is to form a nanocomposite from hydrogels with clay minerals − in high proportions, which reduces the final value of the product drastically and still improves some very important properties, such as ion exchange capacity, , water absorption speed, and mechanical resistance. , The viability for hydrogel use is enhanced even more by the hydrolysis treatment of the material because such treatment improves its hydrophilic properties considerably …”

Section: Introductionmentioning

confidence: 99%

“…To solve that problem, one of the alternatives is to form a nanocomposite from hydrogels with clay minerals 8−10 in high proportions, which reduces the final value of the product drastically and still improves some very important properties, such as ion exchange capacity, 11,12 water absorption speed, and mechanical resistance. 13,14 The viability for hydrogel use is enhanced even more by the hydrolysis treatment of the material because such treatment improves its hydrophilic properties considerably. 15 As such this, in this work, we conducted the synthesis of a new hydrogel nanocomposite, composed of polyacrylamide (PAAm), using the biodegradable polysaccharide methylcellulose (MC) and the clay mineral calcic montmorillonite (MMt) as modifiers.…”

Section: ■ Introductionmentioning

confidence: 99%

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Nanocomposite PAAm/Methyl Cellulose/Montmorillonite Hydrogel: Evidence of Synergistic Effects for the Slow Release of Fertilizers

Bortolin

Aouada

Mattoso

et al. 2013

J. Agric. Food Chem.

210

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In this work, we synthesized a novel series of hydrogels composed of polyacrylamide (PAAm), methylcellulose (MC), and calcic montmorillonite (MMt) appropriate for the controlled release of fertilizers, where the components presented a synergistic effect, giving very high fertilizer loading in their structure. The synthesized hydrogel was characterized in relation to morphological, hydrophilic, spectroscopic, structural, thermal, and kinetic properties. After those characterizations, the application potential was verified through sorption and desorption studies of a nitrogenated fertilizer, urea (CO(NH2)2). The swelling degree results showed that the clay loading considerably reduces the water absorption capability; however, the hydrolysis process favored the urea adsorption in the hydrogel nanocomposites, increasing the load content according to the increase of the clay mass. The FTIR spectra indicated that there was incorporation of the clay with the polymeric matrix of the hydrogel and that incorporation increased the water absorption speed (indicated by the kinetic constant k). By an X-ray diffraction technique, good nanodispersion (intercalation) and exfoliation of the clay platelets in the hydrogel matrix were observed. Furthermore, the presence of the montmorillonite in the hydrogel caused the system to liberate the nutrient in a more controlled manner than that with the neat hydrogel in different pH ranges. In conclusion, excellent results were obtained for the controlled desorption of urea, highlighting the hydrolyzed hydrogels containing 50% calcic montmorillonite. This system presented the best desorption results, releasing larger amounts of nutrient and almost 200 times slower than pure urea, i.e., without hydrogel. The total values of nutrients present in the system show that this material is potentially viable for application in agriculture as a nutrient carrier vehicle.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Nanocomposite PAAm/Methyl Cellulose/Montmorillonite Hydrogel: Evidence of Synergistic Effects for the Slow Release of Fertilizers

Bortolin

Aouada

Mattoso

et al. 2013

J. Agric. Food Chem.

210

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“…18,19 In the past years, most researches on the nanocomposite hydrogels have been focused on the use of clays such as laponite, [20][21][22][23][24][25] montmorillonite, [26][27][28][29][30] hydrotalcite, [31][32][33] and bentonite 34 as nanoparticles. Furthermore, some nanocomposite hydrogels have been prepared using the other types of nanoparticles e.g., silver 35,36 and iron oxide (Fe 3 O 4 ) 37 particles.…”

Section: Introductionmentioning

confidence: 99%

Swelling behavior and structural characteristics of polyvinyl alcohol/montmorillonite nanocomposite hydrogels

Sirousazar

Kokabi

Hassan

2011

J of Applied Polymer Sci

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A series of nanocomposite hydrogels based on polyvinyl alcohol containing 0-10 wt % of the organically modified montmorillonite clay were prepared by freezing-thawing cyclic method. The morphology of the nanocomposite hydrogels was observed by the scanning electron microscopy technique. The structural properties were determined by measuring the network mesh size, crosslinking density, and average molecular weight of polymer chains between crosslinks. The swelling behavior and the effect of swelling medium temperature on the swelling kinetics and characteristics of the nanocomposite hydrogels were also investigated. The results showed that two structural characteristics i.e., network mesh size and average molecular weight of polymer chains between crosslinks have inverse dependence on the clay loading level in the nanocomposite hydrogel, while crosslinking density shows completely direct dependence. Swelling measurements demonstrated a linear relation between the degree of swelling and the square root of immersion time at all swelling medium temperatures. The results indicated that the swelling characteristics of the nanocomposite hydrogels including the equilibrium degree of weight and volume swelling and the equilibrium water content were decreased by increasing the quantity of the clay incorporated into the hydrogel as well as by decreasing the temperature of swelling medium. While, the time required to reach to the equilibrium condition, as another swelling characteristic of the hydrogels, exhibited a completely opposite behavior.

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“…It is well established that NIPAm can be polymerized in the presence of laponite to form NC hydrogels with good mechanical properties. ,, The laponite particles appear to act as cross-linking points and provide additional strength to the hydrogels. The approach has been extended to prepare NIPAm-based microgel particles .…”

Section: Introductionmentioning

confidence: 99%

Temperature-Triggered Gelation of Aqueous Laponite Dispersions Containing a Cationic Poly(N-isopropyl acrylamide) Graft Copolymer

et al. 2008

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In this work, temperature-triggered gelation of aqueous laponite dispersions containing a cationic poly(N-isopropylacrylamide) (PNIPAm) graft copolymer was investigated. The copolymer used was PDMA(+)(30)-g-(PNIPAm(210))(14) [Liu et al. Langmuir 2008, 24, 7099]. DMA(+) is quarternarized N,N-dimethylaminoethyl methacrylate. The presence of small concentrations of laponite enabled temperature-triggered gel formation to occur at low copolymer concentrations (e.g., 1 wt %). Dynamic rheological measurements of the gels showed that they had storage modulus values of up to 400 Pa when the total solid volume fraction (polymer and laponite) was only about 0.02. The storage modulus was dependent on both the temperature and the composition of the dispersion used for preparation. The key component that provided the temperature-triggered gels with their elasticity was found to be self-assembled nanocomposite (NC) sheets. These NC sheets spontaneously formed at room temperature upon addition of laponite to the copolymer solution. The NC sheets had lateral dimensions on the order of hundreds of micrometers and a thickness of a few micrometers. The NC sheets were present within the temperature-triggered gels and formed elastically effective chains. The NC sheets exhibited temperature-triggered contraction with a contraction onset temperature of 27 degrees C. A conceptual model is proposed to qualitatively explain the relationship between gel elasticity and dispersion composition.

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Mechanical Properties and Phase Transition of High Clay Content Clay/Poly(N-isopropylacrylamide) Nanocomposite Hydrogel

Cited by 4 publications

References 32 publications

Nanocomposite PAAm/Methyl Cellulose/Montmorillonite Hydrogel: Evidence of Synergistic Effects for the Slow Release of Fertilizers

Nanocomposite PAAm/Methyl Cellulose/Montmorillonite Hydrogel: Evidence of Synergistic Effects for the Slow Release of Fertilizers

Swelling behavior and structural characteristics of polyvinyl alcohol/montmorillonite nanocomposite hydrogels

Temperature-Triggered Gelation of Aqueous Laponite Dispersions Containing a Cationic Poly(N-isopropyl acrylamide) Graft Copolymer

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