This set of Nanotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Fullerene Containing Polymers”.
1. What kind of fullerene polymers resembles the shape of flagellated unicellular protozoa?
a) Organometallic polymers
b) End-capped polymers
c) Main-chain polymers
d) Star-shaped polymers
View Answer
Explanation: Star shaped polymers have a shape similar to that of flagellated – unicellular protozoa. This class of fullerene polymers has structures resembling sea-stars. Here, several long and flexible polymer chains remain covalently linked to the fullerene unit.
2. Which of the following is not a use of organometallic polymer films?
a) Batteries
b) Photovoltaic solar cell
c) Wall paints
d) Electrochemical sensor
View Answer
Explanation: Organometallic films formed from fullerene or fullerene derivatives and certain transition metal complexes may find potential applications. These include electrochemical sensors, photovoltaic devices and charge storage materials for batteries.
3. Supramolecular polymer fullerenes are of various kinds depending upon their method of production. Which among the following is not a type of supramolecular polymer?
a) Systems obtained by interaction between functionalized polymers and fullerenes
b) Several dendrons remain attached to the fullerene core forming a globular structure
c) Concave – convex complementary interactions involving ditopic concave guests and fullerene
d) Assemble of self-complementary C60 derivatives
View Answer
Explanation: Fullerenes containing supramolecular polymer systems are of different kinds, depending upon their synthesis pathway. These kinds involve i) Systems obtained by interactions between functionalized polymers and fullerenes, ii) Aggregation of self – complementary C60, iii) Concave – convex complementary interactions involving ditopic concave guests and fullerene, iv) Complementary polymer backbones and multisubstituted fullerene derivatives.
4. Which of the following metal has led to the most promising organometallic polymer?
a) Rubidium
b) Palladium
c) Calcium
d) Iridium
View Answer
Explanation: There are several metals used for copolymerization with fullerenes in order to form organometallic polymers. However, palladium out of all metals, has led to the most promising copolymers possessing outstanding properties.
5. Which of the following is not a kind of fullerodendrimers?
a) Fullerenes linked to the peripheral position of the dendrimer
b) Fullerenes located at the connection point
c) Fullerenes are located in the dendrimer backbone forming a pearl-necklace structure
d) Dendrimer anchored to the fullerene surface
View Answer
Explanation: Fullerenes are suitable as core for hosting several dendrons because of its spherical shape which often leads to the globular structure. There are mainly four types of fullerodendrimers – (i) Fullerene surface has a dendrimer anchored to it, (ii) Fullerenes are linked to the outlying sites of the dendrimer, (iii) Fullerenes are placed at the connection points of dendrimers, (iv) Fullerenes form cores to which multiple dendrons are linked forming a globular structure.
6. Choose from the following a method that is used for the synthesis of side chain polyfullerenes.
a) C60 or its derivatives are mixed and randomly allowed to react
b) Polymers embedded with pendant reacting moieties are reacted with C60
c) C60 or its derivatives are directly homopolymerized together with other monomers
d) Synthesis of polymer first, followed by addition of fullerenes
View Answer
Explanation: The preparation of side-chain polymers can be performed in the following ways: – (a) By the direct insertion of fullerene or its derivatives into a pre-formed polymer, (b) Homopolymerization or copolymerization of fullerenes with monomers.
7. What happens on addition of living polystyrene to C60?
a) Formation of flagellans
b) Formation of fullerols
c) Formation of fullerenols
d) Formation of fullerides
View Answer
Explanation: When living polystyrene is added to C60 fullerene, it results in the formation of “flagellans” which are dendritic systems. The products formed are highly soluble, melt-processable and they producenano-phase separated solids.
8. Which property is not exhibited by end–capped polymers?
a) Increased conductivity
b) Non – telechelic
c) Modified hydrophobicity
d) Radical scavengers
View Answer
Explanation: End – capped polymers are those that have one or two units of fullerene attached at the terminal positions of the polymeric chain. These are telechelic polymers having increased conductivity and modified hydrophobicity. They are also known to exhibit radical scavenging properties.
9. This polyfullerene has a necklace type structure and is synthesized by the polycondensation between a fullerene bisadduct and a difunctionalized monomer. Which polyfullerene is it?
a) Cross-linked polymers
b) Star-shaped polymers
c) C60-dendrimers
d) Main-chain polymers
View Answer
Explanation: Main-chain fullerene polymers are also called ‘in-chain’ or ‘pearl-necklace’, due to their necklace-type structure. In these fullerene polymers, the fullerenes are located in the polymer backbone. Owing to the lower control of double addition to C60 – fullerene, formation of eight isomers are possible.
10. Which of the following reasons does not account for the considerable interest of polymers containing C60?
a) Fullerene properties can be combined with those of specific polymers
b) Fullerene polymers are spin-coatable and solvent-castable
c) Fullerene polymers exhibit enhanced optical and electronic properties
d) Fullerene on combination with polymers completely tears down their structure
View Answer
Explanation: Polymers consisting of fullerenes such as C60 are of considerable interests because of the following reasons. First, certain polyfullerenes are spin-coatable, solvent castable or metal extrudable. Second, these molecules exhibit remarkable electronic, optical and catalytic properties. Third, fullerene properties can be combined with that of suitable polymers.
11. Choose from the following a method that is not used for the preparation of cross-linked C60 containing polymers?
a) Polycondensation between a fullerene bisadduct and difunctionalized monomer
b) C60 and monomers are mixed and made to react
c) Polymers embedded with pendant reacting moieties are reacted with C60
d) Multisubstituted C60 derivative is homopolymerized in three-dimensions
View Answer
Explanation: Cross-linked polymers are formed from random and quick reactions that take place in the presence of C60 fullerenes. They can be prepared by the following ways:- i) C60 or its derivatives are mixed with monomer and allowed to react randomly, ii) Multisubstituted C60 derivative is homopolymerized in 3D, iii) Reaction between fullerenes and a preformed polymer functionalized at the end termini, iv) C60 made to react with polymers embedded with pendant reacting moieties.
12. Star – shaped polymers can be synthesized only by the “graft-in” approach and not by “graft-from” approach.
a) True
b) False
View Answer
Explanation: Star-shaped polymers can be synthesized by the following methods. First, the “graft-in” approach which involves linking of preformed polymers to the fullerene unit. Second,the “graft-from” approach in which the polymeric chains grow-up from the surface of the functionalized fullerene-derivatives.
Sanfoundry Global Education & Learning Series – Nanotechnology.
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