@article {48417,
	title = {Dual nanomechanics in anisotropic porous covalent organic framework janus-type thin films},
	journal = {Journal of the American Chemical Society},
	volume = {144},
	year = {2022},
	month = {JAN},
	pages = {400-409},
	type = {Article},
	abstract = {<p>
	Empowered by crystalline ordered structures and homogeneous fabrication techniques, covalent organic frameworks (COFs) have been realized with uniform morphologies and isotropic properties. However, such homogeneity often hinders various surface-dependent properties observed in asymmetric nanostructures. The challenge remains to induce heterogeneity in COFs by creating an asymmetric superstructure such as a Janus thin film. In this regard, we propose a versatile yet straightforward interfacial layer-grafting strategy to fabricate free-standing Janus-type COF-graphene thin films. Herein, two-dimensional graphene sheets were utilized as the suitable grafter due to the possibility of noncovalent interactions between the layers. The versatility of the approach was demonstrated by fabricating two distinct Janus-type films, with the COF surface interwoven with nanofibers and nanospheres. The Janus-type films showcase opposing surface morphologies originating from graphene sheets and COF nanofibers or nanospheres, preserving the porosity (552-600 m(2) g(-1)). The unique surface chemistries of the constituent layers further endow the films with orthogonal mechanical properties, as confirmed by the nanoindentation technique. Interestingly, the graphene sheets favor the Janus-type assembly of COF nanofibers over the nanospheres. This is reflected in the better nanomechanical properties of COFfiber-graphene films (E-gra(phene) = 300-1200 MPa; E-COF( )= 15-60 MPa) compared to the COFsphere-graphene films (E-gra(phe)ne = 11-14 MPa; E-CO(F )= 2-5 MPa). These results indicate a direct relationship between the mechanical properties and homo/heterogeneity of Janus-type COF films.</p>
},
	issn = {0002-7863},
	doi = {10.1021/jacs.1c10263},
	author = {Mohata, Shibani and Dey, Kaushik and Bhunia, Surojit and Thomas, Neethu and Gowd, E. Bhoje and Ajithkumar, Thalasseril G. and Reddy, C. Malla and Banerjee, Rahul}
}
@article {48209,
	title = {Porous covalent organic nanotubes and their assembly in loops and toroids},
	journal = {Nature Chemistry},
	volume = {14},
	year = {2022},
	month = {MAY},
	pages = {507+},
	type = {Article},
	abstract = {<p>
	Carbon nanotubes, and synthetic organic nanotubes more generally, have in recent decades been widely explored for application in electronic devices, energy storage, catalysis and biosensors. Despite noteworthy progress made in the synthesis of nanotubular architectures with well-defined lengths and diameters, purely covalently bonded organic nanotubes have remained somewhat challenging to prepare. Here we report the synthesis of covalently bonded porous organic nanotubes (CONTs) by Schiff base reaction between a tetratopic amine-functionalized triptycene and a linear dialdehyde. The spatial orientation of the functional groups promotes the growth of the framework in one dimension, and the strong covalent bonds between carbon, nitrogen and oxygen impart the resulting CONTs with high thermal and chemical stability. Upon ultrasonication, the CONTs form intertwined structures that go on to coil and form toroidal superstructures. Computational studies give some insight into the effect of the solvent in this assembly process.</p>
},
	issn = {1755-4330},
	doi = {10.1038/s41557-022-00908-1},
	author = {Koner, Kalipada and Karak, Shayan and Kandambeth, Sharath and Karak, Suvendu and Thomas, Neethu and Leanza, Luigi and Perego, Claudio and Pesce, Luca and Capelli, Riccardo and Moun, Monika and Bhakar, Monika and Ajithkumar, Thalasseril G. and Pavan, Giovanni M. and Banerjee, Rahul}
}
