Superabsorbent alginate aerogels

Mallepally, Rajendar R.; Bernard, Ian; Marin, Michael A.; Ward, Kevin R.; McHugh, Mark A.

doi:10.1016/j.supflu.2012.11.024

Cited by 88 publications

(48 citation statements)

References 15 publications

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“…This is similar to alginate hydrogels whose swelling behavior is influenced by the crosslinker concentration as well 15 . Thereby aerogels made by amidated pectin can also be tuned to possess superabsorbent property similar to those reported for alginate aerogels 16 . By using the CO 2 induced gelation considering amidated pectin (or alginate) as the primary system, further diversity can be incorporated into the aerogels by introducing different cross linking agents and biopolymer combinations.…”

Section: Discussionsupporting

confidence: 63%

Preparation of Biopolymer Aerogels Using Green Solvents

Subrahmanyam

Gurikov

Meissner

et al. 2016

JoVE

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Although the first reports on aerogels made by Kistler 1 in the 1930s dealt with aerogels from both inorganic oxides (silica and others) and biopolymers (gelatin, agar, cellulose), only recently have biomasses been recognized as an abundant source of chemically diverse macromolecules for functional aerogel materials. Biopolymer aerogels (pectin, alginate, chitosan, cellulose, etc.) exhibit both specific inheritable functions of starting biopolymers and distinctive features of aerogels (80-99% porosity and specific surface up to 800 m 2 /g). This synergy of properties makes biopolymer aerogels promising candidates for a wide gamut of applications such as thermal insulation, tissue engineering and regenerative medicine, drug delivery systems, functional foods, catalysts, adsorbents and sensors. This work demonstrates the use of pressurized carbon dioxide (5 MPa) for the ionic cross linking of amidated pectin into hydrogels. Initially a biopolymer/salt dispersion is prepared in water. Under pressurized CO 2 conditions, the pH of the biopolymer solution is lowered to 3 which releases the crosslinking cations from the salt to bind with the biopolymer yielding hydrogels. Solvent exchange to ethanol and further supercritical CO 2 drying (10 -12 MPa) yield aerogels. Obtained aerogels are ultra-porous with low density (as low as 0.02 g/cm 3 ), high specific surface area (350 -500 m 2 /g) and pore volume (3 -7 cm 3

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Section: Discussionsupporting

confidence: 63%

Preparation of Biopolymer Aerogels Using Green Solvents

Subrahmanyam

Gurikov

Meissner

et al. 2016

JoVE

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“…There are natural anionic polysaccharides with ability to form strong hydrogels with divalent and trivalent cations, although divalent ions cause contraction of polymer network (during crosslinking process) affecting the water absorption capacity. On the other hand, these hydrogels can be readily transformed to aerogel by scCO 2 -assisted drying [82]. The aerogel possesses highly porous polymeric network with connected pathways throughout the material.…”

Section: Physically (Non Covalent) Hydrogels Based On Polysaccharidesmentioning

confidence: 99%

Superabsorbent hydrogels based on polysaccharides for application in agriculture as soil conditioner and nutrient carrier: A review

Guilherme

Aouada

Fajardo

et al. 2015

European Polymer Journal

581

325

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a b s t r a c t Superabsorbent hydrogels (SH) continue being a very important issue in both academic and industrial fields due to their applications in several technologies. This is proved by the impressive number of publications, through papers and patents as well, dealing with SH. This review is targeted to update and discuss some important aspects of synthesis, characterization and application of SH in agriculture, mainly those based on polysaccharides, as soil conditioners and as polymer carriers for nutrient release. Basic properties of SH and some methods for chemically modifying polysaccharides are given and some directions for hydrogels preparation are highlighted as well. Mechanisms associated with water transport into the 3D matrix, taking into account the transference of mass from hydrogelsoil system to plant, are discussed in the light of some mathematical models. Release of nutrients either from granules coated by hydrophilic polymer or from SH, targeting applications in agriculture, is also discussed on the basis of often used mathematical models (the swelling-based kinetic models) and on a diffusion-based kinetic model with a partition activity coefficient. Examples of recent applications in agriculture as soil conditioners and carriers for nutrient release (fertilizers, etc.) are given. At the final, future trends and perspectives are considered. More than two hundreds references are cited in the whole text.

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“…This synergy of properties has prompted to view biopolymer aerogels as promising candidates for a wide gamut of applications. Up-to-date reports on biopolymer aerogels describe their use for thermal insulation [3][4][5][6][7][8], tissue engineering and regenerative medicine [9], drug delivery systems [10,11], functional foods [12], as catalysts and sensors [13,14], adsorbents [15][16][17]and as starting materials for carbon aerogels [18] and porous mixed-oxides [13,19].…”

Section: Introductionmentioning

confidence: 99%