Silicates are minerals composed of silicon and oxygen that make up approximately 90% of the Earth's crust. They exist as silicate minerals and aluminosilicate clays in the crust. Silicates can be classified based on their crystal structure as orthosilicates containing single SiO4 tetrahedra, pyrosilicates with linked pairs of tetrahedra, ring silicates containing silica rings, chain silicates with linked tetrahedral chains, sheet silicates with shared oxygen atoms between sheets, and framework silicates with a three-dimensional networked structure. Important aluminosilicates include micas, clays, zeolites, and many common rock-forming minerals.
A silicate is an anions consisting of silicon and oxygen.
Silicates occur in earth’s crust in abundantly in the form of silicate minerals and aluminosilicate clay.
Silicate anions are often large polymeric molecules with an extense variety of structures,including chains and rings.double chains and sheets.
Silicates are extremely important materials, both natural and artificial, for all sorts of technological and artistic activities.
In this topic , I have classified the classifications of silicates as well as its uses and functions in this modern age . Same goes to silicon and silicone . I also have discussed also the structure of silicone itself . Other than silicon , silicone and silicate , I have also discussed about Zeolites and Tin & Alloys . Enjoy .
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
A silicate is an anions consisting of silicon and oxygen.
Silicates occur in earth’s crust in abundantly in the form of silicate minerals and aluminosilicate clay.
Silicate anions are often large polymeric molecules with an extense variety of structures,including chains and rings.double chains and sheets.
Silicates are extremely important materials, both natural and artificial, for all sorts of technological and artistic activities.
In this topic , I have classified the classifications of silicates as well as its uses and functions in this modern age . Same goes to silicon and silicone . I also have discussed also the structure of silicone itself . Other than silicon , silicone and silicate , I have also discussed about Zeolites and Tin & Alloys . Enjoy .
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Silicones are a group of organosilicon polymers which are also known as siloxanes. Organosilicon compounds are those in which organic group is attached to silicon. preparations properties, types and applications of silicones.
references for study of silicones.
• Ligands
– an ion or molecule which donates electron density to a metal
atom/ion to form a complex
- Lewis base bonded (coordinated) to a metal ion in a coordination complex.
• Coordination Complex
– a central metal atom/ion and its set of ligands
– often an ion itself
• Coordination Compounds
– a neutral species made up in some part of a complex
– often the salt of a coordination complex
• Coordination Number
– the number of ligands in the primary or inner shell of ligands
A brief introduction to lanthanide elements is given.
Order .ppts like this at <https://www.fiverr.com/anikmal/teamup-with-you-to-prepare-the-best-presentation>
Along with their physical and chemical properties are also shown. Helpful for quick understanding on lanthanide series.
Zeolites (clinoptilolite) are volcanic tuff minerals,
which are formed when ash and lava from a volcano have a
chemical reaction with cool sea water, are naturally
negatively charged with a cage-like structure. The most
prominent features of Zeolites include the exchange of
cations and absorption of inorganic and organic molecules of
specific dimensions. Their high mechanical strength,
chemical stability,and abrasion values make Zeolites a
special material for water purifications and many more
applications. The negative chargesact as a magnet to attract
positively charged toxins and heavy metals to the Zeolites
Silicones are a group of organosilicon polymers which are also known as siloxanes. Organosilicon compounds are those in which organic group is attached to silicon. preparations properties, types and applications of silicones.
references for study of silicones.
• Ligands
– an ion or molecule which donates electron density to a metal
atom/ion to form a complex
- Lewis base bonded (coordinated) to a metal ion in a coordination complex.
• Coordination Complex
– a central metal atom/ion and its set of ligands
– often an ion itself
• Coordination Compounds
– a neutral species made up in some part of a complex
– often the salt of a coordination complex
• Coordination Number
– the number of ligands in the primary or inner shell of ligands
A brief introduction to lanthanide elements is given.
Order .ppts like this at <https://www.fiverr.com/anikmal/teamup-with-you-to-prepare-the-best-presentation>
Along with their physical and chemical properties are also shown. Helpful for quick understanding on lanthanide series.
Zeolites (clinoptilolite) are volcanic tuff minerals,
which are formed when ash and lava from a volcano have a
chemical reaction with cool sea water, are naturally
negatively charged with a cage-like structure. The most
prominent features of Zeolites include the exchange of
cations and absorption of inorganic and organic molecules of
specific dimensions. Their high mechanical strength,
chemical stability,and abrasion values make Zeolites a
special material for water purifications and many more
applications. The negative chargesact as a magnet to attract
positively charged toxins and heavy metals to the Zeolites
In the continuation of previous upload. This presentation is Part 2 of Advances in Special Steels. This is a overview of fundamentals of different carbides found in steels.
A brief discussion of a few of the non-clastic sedimentary rocks, specifically carbonates (limestone), evaporites, and siliceous non-clastic sedimentary rocks.
Porosity Permeability Relationship in carbonate rock pptAmar Gaikwad
A information about porosity and permeability in a carbonate rock. in which we studied the porosity measurement , carbonate rock ,permeability and correlation between them.
Silicone Biomaterial Applications: Past, Present and FutureUBMCanon
Silicone Biomaterial Recap
Enabled by the intrinsic properties of silicone materials…
… manifest in the aggregated properties of biocompatibility and biodurability,silicone in its 66 th year as a biomaterial
Silicone biomaterials can help enable further improvements in medical technology and care
Ring n chain compounds
Silicates
Types of silicates
Principle of Silicate minerals
Soluble silicates
Amphiboles, Zeolites, Ultramarines,
Feldspars
Silicates in technology
Glass, quartz, micas
Zeolites are eco-friendly alternatives to many products
The largest application of the synthetic zeolites is the production of home laundry detergent powders, then goes the production of catalysts and adsorbents
Natural zeolites which dominate the global market, are consumed in concrete, water treatment and pet litter sectors
North America, Western Europe and Japan zeolites markets are mature and will post moderate growth
The other regions demand will increase more noticeably, especially in Asia Pacific
Zeolites Market Review is a source for detailed information on the market situation.
The Lecture contains descriptive and analytical parts, enriched with tables and figures for national and global markets. Market forecasts for the next five years complete the Lecture.
zeolites, types, nature, synthetic, processes, Deposits and properties;Physical characteristics of some naturally occurring zeolites; molecular sieves;Adsorption and related molecular sieving; zeolite catalysts
silicates, types of silicates and their chemical and structural composition.pptxulasaef
The slides explain the silicates and types of silicates as well as their chemical and structural composition. Silicates are the primary building elements of rocks. They comprise the majority of crustal rocks including igneous, sedimentary and metamorphic rocks.
CLASSIFICATION, STRUCTURE, CHEMICAL COMPOSITION AND PROPERTIES OF CLAY MINERA...BarathKumar163434
Soil clays can exist in crystalline, structurally disordered or amorphous form.
Amorphous : has no recognizable shape or geometrical internal arrangement of atoms
Crystalline: atomic arrangement repeated at regular pattern in 3 dimensional directions
spatial arrangement of atoms producing building unit of a crystal is called the unit cell
By placing several unit cells together, the crystal arrangement produced is then called a lattice structure
unit cells has a volume of approximately 1µm3
packing of silica tetrahedran and aluminum octahedran sheets, forms a layered clay structure
the total assembly of a layer plus interlayer material is called an unit structure
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
2. •Silicates occur in the earth’s crust in the
form of silicates minerals and aluminosilicate
clays.
•The silicates are the largest, the most
interesting and the most complicated class of
minerals than any other minerals.
• Approximately 30% of all minerals are
silicates and some geologists estimate that
90% of the Earth's crust is made up of
silicates, SiO4- based material.
4
•oxygen and silicon are the two most abundant
elements in the earth's crust.
3. -Very Common
- 95% of All
Minerals
- Silicon (Si) and
Oxygen (O) bond
Easily
SILICATES
Minerals Containing
Silicon and Oxygen
Si
O
SINGLE SILICA TETRAHEDRON
SiO4
4. • Sodium silicates is the only common silicate which
is soluble in water
• Most of the silicates are insoluble in water .this
is due to great strength of Si-O bond this bond
can be broken only on treatment with strong
reagents like hydrofluoric acid.
• The Si-O bond – 50% covalent, 50% ionic
• Electronegativity of O is 3.5 and of Si is 1.9
difference is 1.6.
4- tetrahedra which
• All silicates comprises of SiO4
are formed by sp3 hybrisidisation of Si orbitals.Si
forms 4 bonds with oxygen atoms.
6. PREPARATION
Sodium silicate is commonly manufactured
using a reaction in liquid phase or in solid
phase. Both processes use alkaline and quartz
sand as raw materials
A mixture of caustic soda, quartz sand, and
water are prepared in a mixing tank, then fed
into a reactor, where steam is introduced. The
reaction is
n SiO2 + 2 NaOH → Na2O•nSiO2 + H2O
7. • This process uses quartz sand with either
sodium carbonate or sodium sulfate. The feed
materials are heated in a reflection furnace.
The reaction is
Na2CO3 + x SiO2 → (Na2O)•(SiO2)x + CO2
2 Na2SO4 + C + 2 SiO2 → 2 Na2SiO3 + 2 SO2 +
CO2
8. Talc is primarily formed via hydration and
carbonation via the following reaction;
serpentine + carbon dioxide→ talc+ magnesite+ water
2 Mg3Si2O5(OH)4 + 3CO2 → Mg3Si4O10(OH)2 + 3
MgCO3 + 3 H2O
Talc can also be formed via a reaction between
dolomite and silica,
dolomite+ silica+ water → talc + calcite+ carbon dioxide
3 CaMg(CO3)2 + 4 SiO2 + H2O → Mg3Si4O10(OH)2 + 3
CaCO3 + 3 CO2
9. ZSM-5 is a synthetic zeolite. There are many ways
to synthesize ZSM-5, a common method is as
follows:
SiO2 + NaAlO2 + NaOH + N(CH2CH2CH3)4Br + H2O →
ZSM-5 + analcime + alpha-quartz
ZSM-5 is typically prepared at high temperature
and high pressure in a Teflon-coated
autoclave and can be prepared using
varying ratios of SiO2 and Al containing
compounds.
10. Different types of silicates
Orthosilicates
Pyrosilicates
Ring and chain silicates
Double chain silicates
Silicates with sheet structures
Silicates with 3-dimensional framework
11. Orthosilicates
• Orthosilicates are minerals consisting of only
single SiO4
4- units. The cations are some other
metals.
• the following minerals are orthosilicates:The Be
and Zn ions are tetrahedrally bonded to the
oxygen of the silicate in these two minerals:
phenacite, Be2SiO4 and willemite, Zn2SiO4 ,zircon.
12. • In olivine, (Fe, Mg)2SiO4, the cations are
either Fe2+ or Mg2+.
• This formula suggests that this mineral is a
mixed salt of iron and magnesium silicates.
• These cations are octahedrally coordinated to
the oxygen atoms of the silicate.
• Pure salt Fe2SiO4 is called fayalite, and
Mg2SiO4 is called forsterite.
13. Pyrosilicates
4- units are linked together, they
• When two SiO4
6-. For example,
form the pyrosilicate group, Si2O7
thortveitite, Sc2Si2O7 is a pyrosilicate,
hemimorphite [Zn4(OH)2Si2O7 ]
14. Ring and chain silicates
4- units share with other SiO4
• When two oxygen of SiO4
4-
units, the silicates form a ring or an infinite chain.
• The stoichiometry of the silicates becomes (SiO3)n
2n-
Benitoite BaTi(SiO3)3 contain three silica rings.
• The precious stone beryl Be3Al2(SiO3)6 contain six-silica
rings.
15. • Single chain silica are called pyroxenes.
• Some synthetic silicates Na2(SiO3) have been
shown to contain the simple chain silicates
(SiO3)n,
• in which the Si-O bonds of the type Si-O-Si
are 168 nm, with the Si-O-Si angles of 137o.
The Si=O bonds are shorter, 1.57 nm.
• The natural pyroxenes include enstatite,
MgSiO3, diopside, CaMg(SiO3)2, and jadeite,
NaAl(SiO3)2, Spodumene LiAl(SiO3)2
16. Double chain silicates
• Double chain silicates are called amphiboles, chains have a
stoichiometry of (Si4O11)n
6n.
• Tremolite, Ca2Mg5(Si4O11)2(OH)2, is such a mineral.
• crocidolite Na2Fe3
IIFe2
IIISi8O22(OH)2 or blue asbestos
consist of double chain silicates.
• Asbestoses have been identified as carcinogens, and its
application has since been limited due to a ban to limit its
exposure to the public.
• Most comercial asbestoses are chrysotile, which contain
layers of silicate sheet
18. Silicates with sheet structures
• Sheet slilicates are called phyllosilicates (phyllo
means leaflike).
• These silicates are easy to cleave (as does
graphite).
• Talc is a typical sheet silicate, Mg3(OH)2(Si2O5 ).
Talc is a main ingredient of the soapstone
(steatite).
• Formed by sharing 3 bridging O per Si atom.
• Sometimes Si atoms are partly replaced by Al
atoms. Eg-Biotite K(MgFe)3(OH)3(AlSi3O10),
miscoviteKAl(OH)2(AlSi3O10)
19.
20. Silicates with 3-dimensional
framework
• the SiO4
4- units can share every oxygen with other
units to form a three dimensional network, and
quartz has such a structure.
• In this arrangement, the stoichiometry is reduced
to SiO2, which is often called silica. A collection of
small pieces of quartz is sand.
21. Aluminosilicate
• when some of the Si4+ ions in silicates are replaced
by Al3+ ions.
• For each Si4+ ion replaced by an Al3+, the charge
must be balanced by having other positive ions such
as Na+, K+, and Ca2+ ions.
• Radius ratio is .43 close to CN 4 to 6
• Sanidine, [(K,Na)AlSi3O8]4
Orthoclase, [(K, Na)AlSi3O8]4
Albite, [NaAlSi3O8]4
Anorthite, Ca[Al2Si2O8]
22. • The alkali ions are held in place to balance the
charges due to the presence of Al3+ ions
instead of Si4+ ions.
• The Al3+ ions replace Si4+ ions in the chains of
corner shared tetrahedra of SiO4 groups.
• However, the bonding between Al and Si can
be different.
• Silicon atoms or ion tend to be bonded to 4
oxygen atoms in a tetrahedral fashion, but
aluminum ions tend to be bonded to 6 oxygen
atoms in an octahedral fashion.
24. MICA
4-
SiO4
Micas are amphiboles made up of sheets of
4- is replaced by (AlO4)5-
tetrahedre in which SiO4
tetrahedra.
They are chemically inert and thermally stable
have high dielectric constant.
Due to which micas are used in furnance windows
and electrical appliances.
powdered mica is used as a filters for rubbers
plastics and insulation boards
25. CLAY
• Produced by weatering and decomposition of
ignious rocks.
• Eg- china clay Al2(OH)4Si2O5,.e kaoline has sheet
structure sheets are hald by OH bridges.
• Used in making chinaware, fire bricks etc
• At 900°C clay forms multite Al6SiO2O13. this has
glassy appearance.
26. FULLER’S EARTH
• It is montmorillonite in which principle
exchangable ion is Ca+2.
• Ii has strong absorbtive power and cation
exchange properties.
• Used as adsorbent and cation exchanger.
27. ZEOLITES
• is a class of hydrated aluminosilicates found
in certain volcanic rocks.
• Once upon a time, geologists thought these
minerals were interesting because they
consist of large cage-like structures with
open channelways.
• Today, these materials are highly valued for
their applications.
28. • Zeolites have a porous structure that can
accommodate a wide variety of cations, such as
Na+, K+, Ca2+, Mg2+ and others. These positive
ions are rather loosely held and can readily be
exchanged for others in a contact solution.
• An example mineral formula is:
Na2Al2Si3O10·2H2O, the formula for natrolite.
29. • The name 'zeolite' is said to have its origin in
the two Greek words zeo and lithos which mean
'to boil' and 'a stone'.
• The phenomena of melting and boiling at the
same time is a novel property.
• The name 'zeolite' was first used by
the Swedish mineralogist Axel Fredrik
Cronsted , the first recognized mineral zeolite,
which was discovered in 1756.
30. • Zeolites are the aluminosilicate members of
the family of microporous solids known as
"molecular sieves."
• The term molecular sieve refers to a
particular property of these materials, i.e., the
ability to selectively sort molecules based
primarily on a size exclusion process.
• At present over 150 synthetic zeolites &
zeotypes and 40 natural zeolites are
known. Synthesis of zeolite is a very active
field of study
31. • industrially important zeolites are produced
synthetically.
• Typical procedures heating aqueous solutions
of alumina and silica with sodium hydroxide.
• Equivalent reagents include sodium aluminate
and sodium silicate.
• Further variations include changes in the cations to
include quaternary ammonium cations.
32. APPLICATIONS
• there are many different kinds of zeolites, each
with a definite structure and associate with it are
unique properties.
• In terms of applications, we are assuming zeolites
as porous aluminosilicates with large tunnels and
cages for a fluid (gas and liquid) to pass through.
• The applications are based on the interactions
between the fluid phase and the atoms or ions of
the zeolites.
33. IN GENERAL TERMS, ZEOLITES HAVE MANY
APPLICATIONS:
• As selective and strong adsorbers: remove
toxic material, selective concentrate a
particular chemical, as Molecular Sieve.
• As selective ion exchangers: for example used
in water softener.
• Superb solid acid catalysts, when the cations
are protons H+.
34. • As catalysts, their environmental advantages include
decreased corrosion, improved handling, decreased
environmentally toxic waste and minimal undesirable
byprducts.
• As builder a material that enhance or protecting the
cleaning power of a detergent.
• Sodium aluminosilicate is an ion exchange builder often used
in lundary detergent as a builder.
• A builder inactive the hardness of water by either keeping
calcium ions in solution, by precipitation, or by ion exchange.
35. APPLICATIONS OF SILICATES
Microchips
• Unique properties of silicates include the ability to
conduct electricity, produce a high-frequency vibration
and provide thermal insulation.
• Silicon is the central component of silicates.
• It is a very hard crystal that can be cut to minuscule
sizes, and it conducts electricity.
• It is because of these characteristics that silicon is
the perfect material to make microchips, which run
every computer, cell phone and gaming device.
36. QUARTZ CRYSTALS
• Quartz crystals are another silicate with a
unique ability to produce a rhythmic high-frequency
vibration.
• For this reason, these crystals are used to
make oscillators used in watches, radios and
pressure gages.
37. Glass
• Silicates are also used to make glass and ceramics.
• To do so, hard, formless material like sand or
ceramic clay is heated to high temperatures,
turning it into malleable material that can be
formed to make drinking glasses,
38. Ceramics
• Silicate ceramics have clearly defined thermal
properties and, as such, are particularly useful
for advanced engineering and technology.
• For example, silicate ceramic tiles are used on
the space shuttle to shield it from the extreme
temperatures of the outer atmosphere.
39. High and Low Technology
• Silicates are the most abundant mineral class on
Earth.
• In general, they are hard and cut easily to micro
pieces, produce a rhythmic high-frequency
vibration, and provide thermal insulation
properties.
• These unique characteristics make them highly
useful for myriad high- and low-tech products,
from microchips to watches