Preparation of Au  quantum clusters with catalytic activity in β-cyclodextrin polyurethane nanosponges

Vasconcelos, Diego Andrade; Kubota, Tatiana; Santos, Douglas C.; Araújo, Márcia Valéria Gaspar de; Teixeira, Zaine; Gimenez, Iara F.

doi:10.1016/j.carbpol.2015.09.010

Cited by 22 publications

(7 citation statements)

References 34 publications

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“…Thus, using microwave synthesis, it is possible to obtain highly crystalline CDNSs with a narrow particle size distribution ( Ciesielska et al, 2020 ) by reacting CD with an appropriate crosslinker (mostly DPC), using polar aprotic solvents such as DMF ( Anandam and Selvamuthukumar, 2014 ; Zainuddin et al, 2017 ; Sharma et al, 2021 ). As the solvent condensation synthesis can be performed using microwave irradiation, Vasconcelos et al ( Vasconcelos et al, 2016 ) reported the use of tin octanoate catalyst to promote the reaction between βCD and HDI crosslinker using DMF as solvent in a microwave system at 80°C for 30 min.…”

Section: Cyclodextrin-based Nanosponges: Synthesis and Propertiesmentioning

confidence: 99%

Cyclodextrin-Based Nanosponges: Overview and Opportunities

et al. 2022

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Nanosponges are solid cross-linked polymeric nano-sized porous structures. This broad concept involves, among others, metal organic frameworks and hydrogels. The focus of this manuscript is on cyclodextrin-based nanosponges. Cyclodextrins are cyclic oligomers of glucose derived from starch. The combined external hydrophilicity with the internal hydrophobic surface constitute a unique “microenvironment”, that confers cyclodextrins the peculiar ability to form inclusion host‒guest complexes with many hydrophobic substances. These complexes may impart beneficial modifications of the properties of guest molecules such as solubility enhancement and stabilization of labile guests. These properties complemented with the possibility of using different crosslinkers and high polymeric surface, make these sponges highly suitable for a large range of applications. Despite that, in the last 2 decades, cyclodextrin-based nanosponges have been developed for pharmaceutical and biomedical applications, taking advantage of the nontoxicity of cyclodextrins towards humans. This paper provides a critical and timely compilation of the contributions involving cyclodextrins nanosponges for those areas, but also paves the way for other important applications, including water and soil remediation and catalysis.

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Section: Cyclodextrin-based Nanosponges: Synthesis and Propertiesmentioning

confidence: 99%

Cyclodextrin-Based Nanosponges: Overview and Opportunities

et al. 2022

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“…Gimenez et al cross-linked βCD nanosponges (βCD nanosp ) with 1,6-hexamethylene diisocyanate and then employed the polyurethane (PU) product as template to prepare Au n quantum clusters [(Au n ) clust -PU-βCD nanosp ]. [47] These were produced by treating HAuCl 4 solutions with NaBH 4 in the presence of glutathione. This process, called core-etching performed in 72 h, resulted in the formation of Au clusters of 11-15 nm and > 25 nm as detected by UV-vis reflectance spectroscopy.…”

Section: Reduction Of Nitrobenzenesmentioning

confidence: 99%

“…Gimenez et al. cross‐linked βCD nanosponges (βCD nanosp ) with 1,6‐hexamethylene diisocyanate and then employed the polyurethane (PU) product as template to prepare Au n quantum clusters [(Au n ) clust ‐PU‐βCD nanosp ] [47] . These were produced by treating HAuCl 4 solutions with NaBH 4 in the presence of glutathione.…”

Section: Reductionsmentioning

confidence: 99%

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

Molnár

2020

ChemCatChem

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Cyclodextrins are green, environmentally benign products available through the enzymatic degradation of starch for a multitude of varied applications. This review attempts to collect useful information with respect to catalytic studies performed with the use of cyclodextrin and modified cyclodextrin preparations applied in combination of or loaded with varied catalytically active species including metal ions, complexes, and metal particles. Major sections are about their use in hydrogenation, reduction, oxidation, hydroformylation and coupling reactions. Additional sections include their utilization in ring formation and ring opening as well as degradation of pollutants. In the last part, examples about ester hydrolysis, hydroboration and hydrosilylation, as well as hydrogen production are treated. Data collected and analyzed indicate the importance and high potential of cyclodextrin-based catalysts in sustainable chemistry.

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“…This result may reflect diffusion of RIF into the water droplet, or increased presentation of polar functionalities that conceal nonpolar HDI crosslinks at the surface as RIF molecules complex with CD subunits. Normalized FTIR spectra (Fig 3) revealed that increased crosslinking ratio led to relatively larger peak sizes at 1256cm -1 , 2856 cm -1 , and 2926 cm -1 corresponding to alkane C-H stretch 87,88,[90][91][92] , at 3332 cm -1 corresponding to both hydrogen-bonded alcohol O-H and secondary amide N-H stretch 90,93 , at 1576 cm -1 corresponding to urethane N-H stretch 87,94 , at 1624 cm -1 corresponding to urethane C=O bending 87 , at 1278 cm -1 corresponding to urethane C-N stretch 90 , and at 1460 cm -1 corresponding to C-H bending 92 . Together, these peak size increases confirm increased abundance of HDI crosslinks with increased crosslink ratio.…”

Section: Effects Of Hdi-crosslinking On Physicochemical Properties Ofmentioning

confidence: 99%

“…Together, these peak size increases confirm increased abundance of HDI crosslinks with increased crosslink ratio. Additionally, for pCD spectra, disappearance of the peak seen in the HDI spectrum at 2270 cm -1 indicates that isocyanates were fully converted (most likely to urethanes) in crosslinking reactions 90,91,94,95 . for the alkane C-H stretch peak, 2270 cm -1 for the isocyanate peak only seen in the HDI spectrum, and 1576 cm -1 for the urethane N-H stretch peak which appears only after pCD crosslinking.…”

Section: Effects Of Hdi-crosslinking On Physicochemical Properties Ofmentioning

confidence: 99%

Cyclodextrin polymer coatings resist protein fouling, mammalian cell adhesion, and bacterial attachment

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Lai

Recum

2020

Preprint

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Undesired attachment of proteins, cells/bacteria, and organisms on material surfaces is problematic in industrial and health care settings. In this study, polymer coatings are synthesized from subunits of cyclodextrin, an additive/excipient found in food/pharmaceutical formulations. These unique polymers, which have been applied mainly towards sustained drug delivery applications, are evaluated in this study for their ability to mitigate non-specific protein adsorption, mammalian cell (NIH/3T3) adhesion, and bacterial cell (Staphylococcus aureus, Escherichia coli) attachment. Effects of cyclodextrin polymer composition, particularly incorporation of nonpolar crosslinks, on material properties and passive anti-biofouling performance are investigated. Results suggest that lightly-crosslinked cyclodextrin polymers possess excellent passive resistance to protein, cell, and bacterial attachment, likely due to the hydrophilic and electrically neutral surface properties of these coatings. At the same time, anti-biofouling performance decreased with increasing crosslink ratios, possibly a reflection of decreased polymer mobility, increased rigidity, and increased hydrophobic character. Cyclodextrin-based materials may be broadly useful as coatings in industrial or medical applications where biofouling-resistant and/or drug-delivering surfaces are required.

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Preparation of Au quantum clusters with catalytic activity in β-cyclodextrin polyurethane nanosponges

Cited by 22 publications

References 34 publications

Cyclodextrin-Based Nanosponges: Overview and Opportunities

Cyclodextrin-Based Nanosponges: Overview and Opportunities

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

Cyclodextrin polymer coatings resist protein fouling, mammalian cell adhesion, and bacterial attachment

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