7 Overview About the Existing Materials Related
to Water Contaminants in Literature
7.1 Supramolecule with Polymer Membrane
Supramolecular chemistry is the study of objects having larger complexity than
distinct fragments assemblies of molecules that bond and unify over intermolecular
interconnects. The design and synthesis of supramolecular systems comprises of
exchanges beyond the covalent linkage, e.g. hydrogen bonding, metal coordinate
bonds and p-interactions to fetch distinct building blocks together [39]. Therefore,
best fitting tailoring of molecules for desired host-guest interaction is possible and
when supra is embedded into polymers, and then it will enhance sensitivity and
selectivity to many folds.
Among various supramolecules, in order to sense heavy metals, calixarenes have
been found appropriate because they provides a route to fragments with
well-defined hollows, and offers synchronized polar and non-polar features.
Therefore, they can form annexation complexes with a extensive variety of guest
species. Calix[4]arenes derivatives with thioether, thioamide, and dithiocarbamoyl
were reported. calix[4] arene (2) with two diametrically replaced thioether ionophore with PVC membrane towards Ag (I) (selectivity 60 mV/decade); calix[4]
arene, with four dithiocarbamoyl PVC membrane for Cu (II) ions (30 mV/decade);
calix[4]arene, with four dimethylthiocarbamoylmethoxyethoxy substituents based
PVC membrane is used for Cd(II) ions (selectivity 30 mV/decade) and oxamide
and thioamide ionophores functionalised PVC membrane was reported for Pb(II)
ions [40]. Another calixarene structure; 4-tert-butylcalix[4]arene (NaTPB: DBP:
PVC) doped PVC based membrane is used for selective sensing towards Pb
(II) with selectivity 30 mV/decade, and author acclaimed the stability of the electrode up to 6 months without change in its potential state [41].
In order to resolve the adhesion problem between polymeric membrane and the
transducer, poly(vinyl chloride vinyl alcohol-vinyl acetate) (PVC-PVA-PVAc)
polymer was used instead of Poly vinyl chloride (PVC). Dipropyloctadecyl
Dioxadiamide was entrapped within modified polymeric membrane to make graphitic solid state sensor (CSSD or CHEMFET) and ISE towards Pb (II) & Cd
(II) sensing [42]. Cutting-edge evolution in polymeric materials, as new class
materials known as conducting polymers were also gained interest in order to
improve the sensing application. The conducting polymers are not only hydrophilic
in nature but also improve adhesion properties with the transducer. The OFETs
based on this class materials reports low cost, low toxicity, enhanced conductance
properties and good adhesions of the membrane spin coated high mobility
polyisoindigo-based polymer with siloxane-containing solubilizing chains33
(PII2T-Si) was reported to form polymer OFET, suitable for sensing of Hg (II) ions
in fresh water as well as marine water [43]. in the modification of FETs with
different variants, an extended gate FETs are also getting popular to use as a solid
state device. Alternative factual pentacene surface functionalised Pyrene with thiol
116
C. Sharma et al.
to Water Contaminants in Literature
7.1 Supramolecule with Polymer Membrane
Supramolecular chemistry is the study of objects having larger complexity than
distinct fragments assemblies of molecules that bond and unify over intermolecular
interconnects. The design and synthesis of supramolecular systems comprises of
exchanges beyond the covalent linkage, e.g. hydrogen bonding, metal coordinate
bonds and p-interactions to fetch distinct building blocks together [39]. Therefore,
best fitting tailoring of molecules for desired host-guest interaction is possible and
when supra is embedded into polymers, and then it will enhance sensitivity and
selectivity to many folds.
Among various supramolecules, in order to sense heavy metals, calixarenes have
been found appropriate because they provides a route to fragments with
well-defined hollows, and offers synchronized polar and non-polar features.
Therefore, they can form annexation complexes with a extensive variety of guest
species. Calix[4]arenes derivatives with thioether, thioamide, and dithiocarbamoyl
were reported. calix[4] arene (2) with two diametrically replaced thioether ionophore with PVC membrane towards Ag (I) (selectivity 60 mV/decade); calix[4]
arene, with four dithiocarbamoyl PVC membrane for Cu (II) ions (30 mV/decade);
calix[4]arene, with four dimethylthiocarbamoylmethoxyethoxy substituents based
PVC membrane is used for Cd(II) ions (selectivity 30 mV/decade) and oxamide
and thioamide ionophores functionalised PVC membrane was reported for Pb(II)
ions [40]. Another calixarene structure; 4-tert-butylcalix[4]arene (NaTPB: DBP:
PVC) doped PVC based membrane is used for selective sensing towards Pb
(II) with selectivity 30 mV/decade, and author acclaimed the stability of the electrode up to 6 months without change in its potential state [41].
In order to resolve the adhesion problem between polymeric membrane and the
transducer, poly(vinyl chloride vinyl alcohol-vinyl acetate) (PVC-PVA-PVAc)
polymer was used instead of Poly vinyl chloride (PVC). Dipropyloctadecyl
Dioxadiamide was entrapped within modified polymeric membrane to make graphitic solid state sensor (CSSD or CHEMFET) and ISE towards Pb (II) & Cd
(II) sensing [42]. Cutting-edge evolution in polymeric materials, as new class
materials known as conducting polymers were also gained interest in order to
improve the sensing application. The conducting polymers are not only hydrophilic
in nature but also improve adhesion properties with the transducer. The OFETs
based on this class materials reports low cost, low toxicity, enhanced conductance
properties and good adhesions of the membrane spin coated high mobility
polyisoindigo-based polymer with siloxane-containing solubilizing chains33
(PII2T-Si) was reported to form polymer OFET, suitable for sensing of Hg (II) ions
in fresh water as well as marine water [43]. in the modification of FETs with
different variants, an extended gate FETs are also getting popular to use as a solid
state device. Alternative factual pentacene surface functionalised Pyrene with thiol
116
C. Sharma et al.