Translucent, hydrophobic, and mechanically tough aerogels constructed from trimethylsilylated chitosan nanofibers

Takeshita, Satoru; Yoda, Satoshi

doi:10.1039/c7nr04051b

Cited by 50 publications

(61 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

Section: Biopolymer Aerogel Systemsmentioning

confidence: 99%

“…The trifunctional silanes discussed above tend to self‐polymerize through ≡Si‐O‐Si≡ cross‐linking and form larger polysiloxane structures or layers on the biopolymer surface, thereby leading to a strong adhesion of the polysiloxane phase to the biopolymer through multiple covalent bonds and hydrogen bonding as well as dipole–dipole and van der Waals interactions. In contrast, hydrophobization with trimethylsilyl (TMS) groups (Figure ), which is a standard procedure for silica aerogels, is more challenging because the TMS groups can be removed from the biopolymer surfaces through the hydrolysis of a single ≡Si‐O‐C≡ bond. Non‐silane‐based hydrophobization strategies include the grafting of trityl groups for the ambient‐pressure drying of cellulose aerogels and the reaction of alkylaldehydes with the amino groups of chitosan …”

Section: Functionalization Of Biopolymer Aerogelsmentioning

confidence: 99%

See 1 more Smart Citation

Biopolymer Aerogels and Foams: Chemistry, Properties, and Applications

Zhao

Malfait

Guerrero‐Alburquerque

et al. 2018

Angew Chem Int Ed

515

410

View full text Add to dashboard Cite

Biopolymer aerogels were among the first aerogels produced, but only in the last decade has research on biopolymer and biopolymer-composite aerogels become popular, motivated by sustainability arguments, their unique and tunable properties, and ease of functionalization. Biopolymer aerogels and open-cell foams have great potential for classical aerogel applications such as thermal insulation, as well as emerging applications in filtration, oil-water separation, CO capture, catalysis, and medicine. The biopolymer aerogel field today is driven forward by empirical materials discovery at the laboratory scale, but requires a firmer theoretical basis and pilot studies to close the gap to market. This Review includes a database with over 3800 biopolymer aerogel properties, evaluates the state of the biopolymer aerogel field, and critically discusses the scientific, technological, and commercial barriers to the commercialization of these exciting materials.

show abstract

Section: Biopolymer Aerogel Systemsmentioning

confidence: 99%

Section: Functionalization Of Biopolymer Aerogelsmentioning

confidence: 99%

Biopolymer Aerogels and Foams: Chemistry, Properties, and Applications

Zhao

Malfait

Guerrero‐Alburquerque

et al. 2018

Angew Chem Int Ed

515

410

View full text Add to dashboard Cite

show abstract

Section: Biopolymer‐aerogelsystemeunclassified

Biopolymer‐Aerogele und ‐Schäume: Chemie, Eigenschaften und Anwendungen

Zhao

Malfait

Guerrero‐Alburquerque

et al. 2018

Angewandte Chemie

View full text Add to dashboard Cite

Biopolymer‐Aerogele gehören zu den ersten Aerogelen, die hergestellt wurden, aber erst im letzten Jahrzehnt kam es zu einer Belebung der Forschung über Biopolymer‐ und Biopolymer‐Verbundstoff‐Aerogele, die durch Fragen der Nachhaltigkeit, einstellbare spezielle Eigenschaften und einfache Funktionalisierung motiviert wird. Biopolymer‐Aerogele und offenzellige Biopolymer‐Schäume haben Potenzial für klassische Aerogel‐Anwendungen wie Wärmedämmung und neue Anwendungen bei der Filtration, Öl‐Wasser‐Trennung, CO2‐Abscheidung, Katalyse und in der Medizin. Das Gebiet der Biopolymer‐Aerogele wird heute von der empirischen Materialentwicklung auf dem Labormaßstab beherrscht und benötigt eine bessere theoretische Grundlage und Test in Pilotanlagen. Unser Aufsatz umfasst eine Datenbank mit über 3800 Biopolymer‐Aerogel‐Eigenschaften, beurteilt den Forschungsstand auf dem Gebiet und diskutiert wissenschaftliche, technologische und wirtschaftliche Hindernisse bei der Kommerzialisierung dieser faszinierenden Materialien.

show abstract

“…Applying natural biopolymers has several advantages, with the most important ones being: (1) in most cases it leads to a reduction of the time required for the synthesis of the hybrid gels, and (2) purely aqueous processing is possible and (c) by carefully controlling the rates of hydrolysis and condensation, a homogeneously mixed hybrid is obtained by simultaneously initiating the sol-gel transition of the biopolymer and silane phase [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Silica-silk fibroin hybrid (bio)aerogels: two-step versus one-step hybridization

Maleki

Huesing

2019

J Sol-Gel Sci Technol

View full text Add to dashboard Cite

In this study, silk fibroin as a highly promising naturally occurring biopolymer extracted from silkworm cocoon is applied to mechanically reinforce silica aerogels. To this aim, two different approaches for the incorporation of silk fibroin into the silica network are compared: (1) a one-step acid catalyzed and (2) a two-step acid-base catalyzed sol-gel reaction. The total organosilane concentration, as well as the SF to silane mass fractions, regulated the hybridization process to proceed either through a one-step or two-step sol-gel reaction. In both processes, for an efficient chemical mixing the silk fibroin components with the silane phase, a silane coupling agent, 5-(trimethoxysilyl) pentanoic acid (TMSPA), comprising carboxylic acid groups and a pentyl hydrocarbon chain has been used. For a low organosilane content (3.4 mmol) along with a high SF to silane mass ratio (15-30%), the gelation of the silane and silk fibroin phases took place in a one-pot/one-step process in the presence of an acid catalyst in an entirely aqueous system. In the two-step synthesis approach, which was applied for high initial silane contents (17 mmol), and low SF to silane mass ratios (1-4%), first, the gelation of the silk fibroin phase was triggered by addition of an acid catalyst followed by a more pronounced condensation of the silane catalyzed by the addition of the base. Both synthesis approaches led to materials with promising mechanical propertiesbeing 1) the one-step process resulting in gels with much better compressibility (up to 70% of strain), low density (0.17-0.22 g cm −3 ) and three orders of magnitude improvement in the Young's modulus (13.5 MPa) compared to that of the pristine silica aerogel but with rather high shrinkage (30-40%). The two-step process in principle could result in the hybrid aerogel with interesting bulk density (0.17-0.28 g cm −3 ) with lower shrinkage (10%), but the resultant aerogel was stiff and fragile. Also, both approaches led to a significant reduction in the time required to prepare strong hybrid aerogels compared to conventional hybrid polymer-silica aerogels with the utilization of an entirely aqueous synthesis approach for a wide range of applications. ;,: 1234567890();,:Highlights • Silk fibroin (SF) biopolymer is an interesting biopolymer for mechanical reinforcement of silica aerogel.• Two sustainable sol-gel based approaches are proposed for hybridization of silica with SF. •Hybrids obtained by the one step sol-gel synthesis approach demonstrate better mechanical performance.• Molar ratio of SF to organosilanes is the most determinant factor for resulting final properties.• Both synthesis approaches led to significant reduction in the time required for preparation of strong hybrid aerogels.

show abstract

Translucent, hydrophobic, and mechanically tough aerogels constructed from trimethylsilylated chitosan nanofibers

Cited by 50 publications

References 43 publications

Biopolymer Aerogels and Foams: Chemistry, Properties, and Applications

Biopolymer Aerogels and Foams: Chemistry, Properties, and Applications

Biopolymer‐Aerogele und ‐Schäume: Chemie, Eigenschaften und Anwendungen

Silica-silk fibroin hybrid (bio)aerogels: two-step versus one-step hybridization

Contact Info

Product

Resources

About