Preamble
For your convenience I have listed below other posts featuring my prints on paper that has featured on this blogspot:
Made to Order
Unique State (Partners in Print)
Veiled Curtains
A Letter to a Friend
Beyond the Fear of Freedom
Travelling Solander Project
Star Series
Imprint
Cry for the Wilderness
Federation on Hold – Call Waiting
Wish You Were Where?
The Four Seasons
The Creation of Hurricane Katrina – The Disruptor
The Creation of ‘Whose Place? My Place, Your Space’
The ‘Vine Glow’ Series
Vine Glow - Series 2
Vine Glow - Series 3
‘Whose Church?’
‘A Journey Ends . . . Another Nightmare Begins’
Introduction
Collagraphs are intaglio prints taken from specially designed collages. Intaglio is a family of printmaking techniques in which the image is cut or incised into a surface, known as the matrix or plate. To print an intaglio plate, ink is applied to the surface and then rubbed with a tarlatan cloth to remove most of the excess. Note: tarlatan is a starch or open-weave fabric not unlike cheese-cloth.
The marks and textures on a collagraph plate must have a low profile in order to pass through the etching press. The textured or incised areas hold the ink and so create tone. The plate can be inked with a roller and/or paintbrush etc. Substances such as carborundum powder, acrylic textured mediums, sandpapers, string, leaves and grasses can all be used in creating the collagraph plate. In some instances, leaves can be used as a source of pigment by rubbing them onto the surface of the plate.
Artists can incorporate screen-printed marks, including photographic imagery, on collagraph plates by dusting the wet printed image on the plate with carborundum powder immediately after printing. Once this is dry, the excess carborundum powder is shaken from the plate, and then the plate is inked up in intaglio, wiped and printed using the normal process. The carborundum-coated areas print with a dense, velvety appearance.
Using the same plate, each collagraph print is nevertheless unique since the amount of ink in the incisions can never be exactly reproduced and so the tonality alters from print to print.
Synopsis of Artwork: Cry For the Wilderness
Bare, barren, boulders without soil and soil without life. Where has the Flora and Fauna gone? Gone are the corridors that ushered life from one region to another. Gone is the wilderness, which witnessed survival, which witnessed diversity of life in an on-going creation.
“This is the dead land
This is cactus land
Here the stone images
Are raised, here they receive
The supplication of a dead man’s hand
Under the twinkle of a fading star.”
Thomas Sterns Eliot - The Hollow Men
This collagraph represents the hand of a new creator. This creator controls the flora and fauna, as the top gum leaf depicts. This represents the controlled plantings. The bottom gum leaf represents plantings that were allowed to remain. In between these leaves there are no corridors that can usher life from one region to another. Isolation prevents diversity. The lack of leaves between the top and bottom leaf symbolizes the denuding of uncontrolled Flora and Fauna. The contouring of land above the bottom leaf, symbolizes the farming practice of the new creator. The presence of the new creator is witnessed by the refuse and found objects below the top leaf. There is no water here (and so blues do not work well). The cry is for the return of the wilderness.
Cry For The Wilderness I.
Size: 80 cm (length) x 60 cm (width).
Cry For The Wilderness II.
Size: 80 cm (length) x 60 cm (width).
Cry For The Wilderness III.
Size: 80 cm (length) x 60 cm (width).
Cry For The Wilderness IV.
Size: 80 cm (length) x 60 cm (width).
Australia has a rich history in growing and making fibers. For example, in 1788 the First Fleet brought sheep to Australian shores. In 1797 John Macarthur and Samuel Marsden acquired Spanish merinos from South Africa. In 1800 Governor King saw Australia’s potential for producing wool and shipped fleeces from Macarthur’s and other flocks to England for appraisal. In November of 1807 the Reverend Samuel Marsden arrived in England with a barrel of Australian wool for sale, thereby initiating Australia’s first "European" export to the world.
The face of an Australian merino ram.
The history of cotton in Australia parallels that of wool. The First Fleet brought cottonseeds to Australia and in 1830 three bags of cotton were exported to England for sale. Australia also produces synthetic fibers such as viscose rayon staple fibers etc. Hence in the case of raw materials that are required to create textiles - Australia is one of the leading lights in the world.
Should the driest continent in the world use its water resources to grow cotton?
Farmer Andrew Parkes and wife Vanessa, with children Sam and Sarah, on one of his company's six cotton farms near Moree in NSW.
Photograph: Peter Lorimer.
Source: The Australian
Some uses of textiles are obvious (e.g. wall hangings, quilts, felts, weaves, ArtCloth, clothing, curtains, towels, carpets etc.), whereas other uses are embedded and so less visible (e.g. furnishings, air-conditioning filters, shade cloths etc.) Australia manufactures or creates items in all of these areas.
Margo Lewers’ ArtCloth Wall Hanging – Orange and Red (1975).
It is clear that in producing wearable art Australia has a breadth and depth of creativity far beyond its relatively small population. Jenny Kee, Linda Jackson and Deborah Leser are all world renowned for their wearable art and fabrics. At the top end of fashion – that is at the haute couture level – Australia has some leading fashion designers such as Alex Perry, Collette Dinnigan and Alannah Hill etc.
The Wearable Art of Jenny Kee.
In the art of weaving there were Larry and Mary Beeston and of course, the Australian Tapestry Workshop (formerly Victorian Tapestry Workshop) that produced art of magnificence in both size and quality. Quilting has a long tradition in Australia and there are none better than Dijanne Cevaal, Carolyn Sullivan and Judy Hooworth etc. - just to name few!
The Reception Hall Tapestry – Detailed View.
Note: The design depicts a landscape at Shoal Haven NSW (Australia) and it now hangs in the Reception Hall in Parliament House, Canberra (Australia).
Designer: Authur Boyd.
Interpretation: Leonie Bessant.
Weavers: Leonie Bessant, Sue Carstairs, Irene Creedon, Robyn Daw, Owen Hammond, Kate Hutchinson, Pam Joyce, Peta Meredith, Robyn Mountcastle, Joy Smith, Jennifer Sharp, Irja West.
Size: 9.18 x 19.90 meters.
In the area of ArtCloth – my passion – there are a number of outstanding Australian artists, some of whom were showcased in the exhibition I curated – ArtCloth: Engaging New Visions. The longest continuing ArtCloth practice in Australia is that due to the batik ArtCloth of Ernabella. Their journey in ArtCloth started in 1971 and has remained unabated to this day.
Tjunkaya Tapaya: Untitled.
ArtCloth: Engaging New Visions.
So who collects textiles in Australia? There is no better collection of Aboriginal ArtCloth in the world than in the National Gallery of Victoria. However, textiles are just one thin sliver of their artworks. On the other hand, the Power House Museum (NSW) has in its collection some excellent wearable art. It has over 100,679 objects collected from 1880 to the present day from steam engines to fine glassware to postage stamps to robot dogs - hardly a dedicated textile museum. The National Gallery of Australia has an excellent collection of costumes from the Ballets Russes etc. Nonetheless, it is less occupied with these art objects than with the many others in its collection. The National Museum of Australia in Canberra collects quilts as part of its collection to reflect Australian history.
Does regional Australia come to the rescue? There is a National Wool Museum in Geelong. Narrabri in New South Wales hosts a major cotton exhibition once a year namely, the Australian Cotton Fibre Expo. Orange Regional Gallery (NSW), Fairfield City Museum and Gallery (NSW), and Wangaratta Art Gallery (Victoria) have textile collections. Tamworth Regional Gallery has the largest collection of textiles in Australia and holds the Tamworth Textile Triennial Exhibition. The only Gallery in Australia that is specifically earmarked for promoting and supporting contemporary textile art is Ararat Regional Art Gallery (Victoria). Its main focus is on embroidery and soft sculpture etc. Moreover, to put its activities into perspective, its 2011/2012 budget was $271,000 or ca. 1.3 cents per head of population. With its limited budget it can barely cover all aspects of textiles within Australia. It is clear for a population of 21 million we barely scratch the surface of Australian’s interest in the production, functionality and creative aspects of textiles.
Ararat Art Gallery (Victoria).
Let us compare our efforts with Canada, a land of 34 million peoples, ranging in ethnic diversity not that much different from our own. Canada’s major textile museum is aptly named - The Textile Museum of Canada (TMC) and is located in Toronto – a major city in Canada. It is an engaging visual arts organization with more than 12,000 textile objects from more than 200 countries and regions. The TMC's permanent collection celebrates cultural diversity and includes traditional fabrics, garments, carpets and related artifacts such as beadwork and basketry. The Museum offers a broad variety of exhibitions including themed shows based on its permanent collection and contemporary exhibitions of the work of Canadian and international artists.
The Textile Museum Of Canada.
To put this comparison in better perspective, the Canadian dollar is nearly on parity with the Australian dollar. In 2010 the TMC revenue alone was $3,322,869 and its expenditure was $3,333,030. Its total assets were of the order of $15,759,512. Its mission is simple: “TMC engages the public by fostering knowledge, creativity and awareness. The Museum explores the continuum of textile work from antiquity to the present through all its activities including, exhibitions, collections, education programs, research and documentation.” Its vision is direct: “TMC promotes an understanding of human identity through textiles.” Its values are guided by four key personal and professional values namely: respect, excellence, education and innovation. On this one museum, Canadians are spending ca. 10 cents per head of population.
Where do we go from here? An umbrella organization such as the national committee of the Australian Textile & Surface Design Association (ATASDA) could ask members of embroiderers guilds, textile manufacturers, fashion designers, quilters, weavers, ArtCloth artists, growers of natural fibers etc. to sign a petition calling on the Federal Government for a dedicated textile museum similar to TMC. It could be a newly built museum or it may be an existing museum that must hold a wider brief (e.g. not just wool as in The Wool Museum in Geelong). It could involve a State competition for such a museum, with State Governments providing additional long term funding to secure the museum for their State.
So what do you think? Is Australian textile art mature enough to secure a dedicated museum?
Preamble
For your convenience I have listed below other posts on Australian aboriginal textiles and artwork.
Untitled Artworks
(Exhibition - ArtCloth: Engaging New Visions) Tjariya (Nungalka) Stanley and Tjunkaya Tapaya, Ernabella Arts (Australia)
ArtCloth from the Tiwi Islands
Aboriginal Batik From Central Australia
ArtCloth from Utopia
Aboriginal Art Appropriated by Non-Aboriginal Artists
ArtCloth from the Women of Ernabella
ArtCloth From Kaltjiti (Fregon)
Australian Aboriginal Silk Paintings
Contemporary Aboriginal Prints
Batiks from Kintore
Batiks From Warlpiri (Yuendumu)
Aboriginal Batiks From Northern Queensland
Artworks From Remote Aboriginal Communities
Urban Aboriginal ArtCloths
Western Australian Aboriginal Fabric Lengths
Northern Editions - Aboriginal Prints
Aboriginal Bark Paintings
Contemporary Aboriginal Posters (1984) - (1993)
The Art of Arthur Pambegan Jr
Aboriginal Art - Colour Power
Aboriginal Art - Part I
Aboriginal Art - Part II
The Art of Ngarra
The Paintings of Patrick Tjungurrayi
Warlimpirrnga Tjapaltjarri
Australian Aboriginal Rock Art - Part I
Australian Aboriginal Rock Art - Part II
Introduction
Ernabella was the first Aboriginal community to produce batik textiles. The Ernabella (“Anangu” women) artists perfected the complexities of dye-resist process in order to adopt it into their artistic voice.
Kaltjiti (Fregon) is approximately 45 kilometers South of the Musgrave Mountains. It is situated 350km East of Uluru and 500km South-West of Alice Springs in the remote North-West of South Australia. The community straddles the Officer Creek, which only flows occasionally during high rainfall.
Fregon's (Kaltjiti’s) Location.
Kaltjiti, formerly known as Fregon, had its beginning in 1934 when Harold Brown was granted the water permit for the Shirley Well block, 60 kilometres South-West of Ernabella. It was named Fregon, after the name of a benefactor, who donated five to ten thousand pounds (Australian currency in 1960s) to help the missionaries set up a bore on what now is situated on the lands of the Kaltjiti community.
Kaltjiti’s population is approximately 350 people, composed mostly of the Anangu people and so they are related to the peoples of Ernabella. The Anangu’s first language is Pitjantjatjara, which is usually the language spoken at home. The Kaltjiti people envisaged themselves as related to the land and other species, and so each group has special rights and obligations in relation to the land, stories, rituals and resources of their region.
Fregon.
The lead taken by Ernabella was quickly adopted by smaller Anangu communities, such as the women in Kaltjiti, who were living closer to their sources of spiritual power due to their more “closet” existence[1-2].
Kaltjiti Aboriginal ArtCloth
In 1971 a batik program was started in Ernabella as a source of income for their women [1]. In 1974 the Kaltjiti women were inspired by the batik work coming out of Ernabella and so created their own ArtCloth [1]. Women - such as Jullian Davy or Inawinytji (Tjingilya) Williamson, who learned batik in Ernabella - moved to Fregon where they became a major exponent of batik art in Fregon and so were important in the establishment of Kaltjiti Arts.
Kaltjiti ArtCloth works should not be considered just as a derivative of the artwork established by Ernabella. Rather this community of artists developed a voice of their own, reflecting the greater isolation and its unique spiritual connection to its environment. Thus, there appears a greater emphasis on flora and fauna and a greater distinction of curvilinear topological features than would be present in the works of Ernabella [2]. Moreover, the Kaltjiti artists made greater use of the cracking of paraffin wax, in order to create streaky visual striations and egg shell effects, all placed within a more fluid composition [2]. Nevertheless, Ernabella and Kaltiji women come from the same spiritual source and so culturally they have traced their iconography and their marking making (aboriginal word – walka) from their traditional sand drawings. Note: "Raiki wara" may be translated as “long cloth”.
The National Gallery of Victoria has the largest collection of Aboriginal ArtCloth in Australia [2]. Below is the batik ArtCloth of the women artists of Kaltjiti (Fregon).
Manyinta (Katie) Curley – Raiki wara (1995).
Technique: Batik on silk.
Size: 91.6 cm (width) x 290 cm (length).
Courtesy reference[2].
Manyinta (Katie) Curley – Raiki wara (1995).
Technique: Batik on cotton.
Size: 152 cm (width) x 315 cm (length).
Courtesy reference[2].
Matjangka (Nyukana) Norris – Raiki wara (1995).
Technique: Batik on silk.
Size: 90 cm (width) x 194 cm (length).
Courtesy reference[2].
Matjangka (Nyukana) Norris – Raiki wara (1995).
Technique: Batik on cotton.
Size: 150.5 cm (width) x 223.7 cm (length).
Courtesy reference[2].
Tjangili (Tjapukula) George – Raiki wara (1995).
Technique: Batik on silk.
Size: 84.2 cm (width) x 270.5 cm (length).
Courtesy reference[2].
Inawinytji (Tjingilya) Williamson – Raiki wara (1995).
Technique: Batik on silk.
Size: 115 cm (width) x 290 cm (length).
Courtesy reference[2].
References:
[1] J. Ryan and R. Healy, Raiki Wara, National Gallery of Victoria, Melbourne (1998).
[2] J. Ryan et al., Across The Desert – Aboriginal Batik from Central Australia, Council of Trustees of the National Gallery of Victoria, Melbourne (2008).
Preamble
This is the fourteenth post in the "Art Resource" series, specifically aimed to construct an appropriate knowledge base in order to develop an artistic voice in ArtCloth.
Other posts in this series are:
Glossary of Cultural and Architectural Terms
Units Used in Dyeing and Printing of Fabrics
Occupational, Health & Safety
A Brief History of Color
The Nature of Color
Psychology of Color
Color Schemes
The Naming of Colors
The Munsell Color Classification System
Methuen Color Index and Classification System
The CIE System
Pantone - A Modern Color Classification System
Optical Properties of Fiber Materials
General Properties of Fiber Polymers and Fibers - Part I
General Properties of Fiber Polymers and Fibers - Part II
General Properties of Fiber Polymers and Fibers - Part III
General Properties of Fiber Polymers and Fibers - Part IV
General Properties of Fiber Polymers and Fibers - Part V
Protein Fibers - Wool
Protein Fibers - Speciality Hair Fibers
Protein Fibers - Silk
Protein Fibers - Wool versus Silk
Timelines of Fabrics, Dyes and Other Stuff
Cellulosic Fibers (Natural) - Cotton
Cellulosic Fibers (Natural) - Linen
Other Natural Cellulosic Fibers
General Overview of Man-Made Fibers
Man-Made Cellulosic Fibers - Viscose
Man-Made Cellulosic Fibers - Esters
Man-Made Synthetic Fibers - Nylon
Man-Made Synthetic Fibers - Polyester
Man-Made Synthetic Fibers - Acrylic and Modacrylic
Man-Made Synthetic Fibers - Olefins
Man-Made Synthetic Fibers - Elastomers
Man-Made Synthetic Fibers - Mineral Fibers
Man Made Fibers - Other Textile Fibers
Fiber Blends
From Fiber to Yarn: Overview - Part I
From Fiber to Yarn: Overview - Part II
Melt-Spun Fibers
Characteristics of Filament Yarn
Yarn Classification
Direct Spun Yarns
Textured Filament Yarns
Fabric Construction - Felt
Fabric Construction - Nonwoven fabrics
A Fashion Data Base
Fabric Construction - Leather
Fabric Construction - Films
Glossary of Colors, Dyes, Inks, Pigments and Resins
Fabric Construction – Foams and Poromeric Material
Knitting
Hosiery
Glossary of Fabrics, Fibers, Finishes, Garments and Yarns
Weaving and the Loom
Similarities and Differences in Woven Fabrics
The Three Basic Weaves - Plain Weave (Part I)
The Three Basic Weaves - Plain Weave (Part II)
The Three Basic Weaves - Twill Weave
The Three Basic Weaves - Satin Weave
Figured Weaves - Leno Weave
Figured Weaves РPiqu̩ Weave
Figured Fabrics
Glossary of Art, Artists, Art Motifs and Art Movements
Crêpe Fabrics
Crêpe Effect Fabrics
Pile Fabrics - General
Woven Pile Fabrics
Chenille Yarn and Tufted Pile Fabrics
Knit-Pile Fabrics
Flocked Pile Fabrics and Other Pile Construction Processes
Glossary of Paper, Photography, Printing, Prints and Publication Terms
Napped Fabrics – Part I
Napped Fabrics – Part II
Double Cloth
Multicomponent Fabrics
Knit-Sew or Stitch Through Fabrics
Finishes - Overview
Finishes - Initial Fabric Cleaning
Mechanical Finishes - Part I
Mechanical Finishes - Part II
Additive Finishes
Chemical Finishes - Bleaching
Glossary of Scientific Terms
Chemical Finishes - Acid Finishes
Finishes: Mercerization
Finishes: Waterproof and Water-Repellent Fabrics
Finishes: Flame-Proofed Fabrics
Finishes to Prevent Attack by Insects and Micro-Organisms
Other Finishes
Shrinkage - Part I
Shrinkage - Part II
Progressive Shrinkage and Methods of Control
Durable Press and Wash-and-Wear Finishes - Part I
Durable Press and Wash-and-Wear Finishes - Part II
Durable Press and Wash-and-Wear Finishes - Part III
Durable Press and Wash-and-Wear Finishes - Part IV
Durable Press and Wash-and-Wear Finishes - Part V
The General Theory of Dyeing – Part I
The General Theory Of Dyeing - Part II
Natural Dyes
Natural Dyes - Indigo
Mordant Dyes
Premetallized Dyes
Azoic Dyes
Basic Dyes
Acid Dyes
Disperse Dyes
Direct Dyes
Reactive Dyes
Sulfur Dyes
Blends – Fibers and Direct Dyeing
The General Theory of Printing
There are currently eight data bases on this blogspot, namely, the Glossary of Cultural and Architectural Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, the Glossary of Colors, Dyes, Inks, Pigments and Resins, the Glossary of Fabrics, Fibers, Finishes, Garments and Yarns, Glossary of Art, Artists, Art Motifs and Art Movements, Glossary of Paper, Photography, Printing, Prints and Publication Terms and the Glossary of Scientific Terms, which has been updated to Version 3.5. All data bases will be updated from time-to-time in the future.
If you find any post on this blog site useful, you can save it or copy and paste it into your own "Word" document etc. for your future reference. For example, Safari allows you to save a post (e.g. click on "File", click on "Print" and release, click on "PDF" and then click on "Save As" and release - and a PDF should appear where you have stored it). Safari also allows you to mail a post to a friend (click on "File", and then point cursor to "Mail Contents On This Page" and release). Either way, this or other posts on this site may be a useful Art Resource for you.
The Art Resource series will be the first post in each calendar month. Remember - these Art Resource posts span information that will be useful for a home hobbyist to that required by a final year University Fine-Art student and so undoubtedly, some parts of any Art Resource post may appear far too technical for your needs (skip over those mind boggling parts) and in other parts, it may be too simplistic with respect to your level of knowledge (ditto the skip). The trade-off between these two extremes will mean that Art Resource posts will hopefully be useful in parts to most, but unfortunately may not be satisfying to all!
Introduction
When you consider the different fabrics used for clothing, furnishing and in geotextiles, it is easy to identify the different properties between different types of fabrics. Understanding why different types of fabrics have different properties brings us to fiber chemistry. I will try to make this as painless as possible, but inevitably - where there is no pain there is no gain!
A generic classification of fibers is based on the type of building blocks they are made from. These building blocks are called molecules, which are composed of a collection of atoms held together by various forces. For example, cotton and linen are composed of cellulose molecules, and so have many features in common, whereas wool and silk are composed of molecules called proteins, and so the latter two fibers have similar properties, but possess properties that are different from those composed of cellulose fibers.
Electron micrograph of cotton fibers.
Forces That Hold Atoms Together To Form Molecules
The building blocks of all polymers that make up a fiber are derived from units that are molecular in nature. Molecules are composed of atoms that are held together by forces, which are generically called - bonding mechanisms. There are several types of bonding mechanisms, and these in turn impart many of the properties of molecules, which in turn manifest in the properties of fibers and that of fabrics.
Covalent Bonds
Covalent bonds are characterized by atoms that share their electrons in order to form molecules. For example, the water molecule consists of two covalent bonds - each is formed from one electron from the oxygen atom (symbol “O”) hooking onto an electron from the hydrogen atom (symbol “H”).
Schematic of a water molecule (symbol - H2O). The covalent bonds are represented in the schematic above by two lines. Each bond holds two electrons, one from the oxygen (O) atom and one from the hydrogen (H) atom.
Covalent bonds are usually very strong and so it takes a lot of energy to break them. For example, to break up one mole of liquid water (H2O(l)) into hydrogen gas (H2(g)) and oxygen gas (O2(g)) via:
H2O(l) → H2(g)) + 1/2 O2(g))
takes 68,320 calories at 25oC to achieve such a break-up.
Diamond is composed of carbon-carbon covalent bonds and it is even more stable than liquid water.
A diamond is held together by numerous covalent bonds and so can be thought of as a large covalent molecule.
In general, molecules containing single bonds are said to be “saturated” (e.g. as in saturated fats) and are generally less reactive than molecules containing double bonds (e.g. carbon dioxide contains two double bonds - it is a green-house gas).
Schematic of covalent bonding in carbon dioxide (symbol: CO2). Here each linkage, represented by a single line, is formed by one electron from oxygen atom and one electron from a carbon atom (represented by symbol C) hooking together. There is a total of eight electrons involved in four bonds, creating two double bonds. It is an unsaturated molecule.
Molecules containing double bonds are more firmly held together, but they are more susceptible to react with other chemical entities, since the most loosely held electrons are very reactive. Hence, they are called “unsaturated” (as in unsaturated fats) since they contain more than just a single bond between each atom.
Ionic Bonds
There are atoms that are hungry for loosely held electrons (i.e. have a high electron affinity or electron attraction e.g. chlorine – symbol: Cl) and there are atoms that do not have an appetite for them (i.e. have a low electron affinity or electron attraction e.g. sodium – symbol: Na). When these two unlike atoms come close to each other, the electron (which has a negative charge) migrates from the atom with a low affinity to the atom with a high affinity. Hence when sodium and chlorine get together they form a molecule, which is bonded together because of its ionic nature; that is Na+Cl-. (Note: the attraction is called an electrostatic or ionic attraction).
If we flow chlorine gas (symbol:Cl2) over sodium solid we get,
2NaSOLID + 2Cl2(gas) → 2Na+Cl-SOLID
The solid form - Na+Cl-SOLID - is known as common table salt, a perservative you sprinkle on your food. Its crystal structure is given below, where the green dots represent the chlorine atom and the blue dots the sodium atom. Note: The chlorine anion (Cl-) is physically larger in size compared to the sodium cation (Na+).
Crystal structure of sodium chloride – common table salt.
Sodium chlorine or table salt can readily dissolve in water because the water molecules surround the sodium cation (Na+) and the chloride anion (Cl-) keeping them well apart and so screening their attraction for each other (see below).
Hydrogen Bonds
Liquid water is composed of water molecules that are held together due to the water covalent bonds being unequally shared by the oxygen and hydrogen atoms. The electrons in the covalent bond spend more time close to the oxygen atom and so less time near the hydrogen atoms since the oxygen atom has a higher electron affinity compared with the hydrogen atom.
The uneven electron affinity means that there is a partial negative pole on the oxygen atom and a partial positive pole on the hydrogen atoms. Hence the water molecule can be represented as below.
Polarity in the water molecule. The unequal time spent by electron on each atom is represent by a “+” and “–“ sign. A “+” sign represents less time spent by the electrons and so it creates a partial positive pole, whereas “-“ sign means more time spent and so it creates a partial negative pole.
When two of more water molecules are near to each other, they orientate themselves to maximize the forces of attraction between them, forming what is called “hydrogen bonds”.
Two water molecules orientating themselves in order to maximize their attraction to each other. Note: The δ sign indicates a partial loss or gain of the electrons’ time near the respective atom. The negative pole is attracted to the positive pole forming a hydrogen bond. The hydrogen bond is the dashed line between a negative pole oxygen atom (O) and a positive pole hydrogen atom (H).
Liquid water is made of millions-upon-millions of water molecules positioning themselves to maximize their attraction to each other. It is the millions upon millions of hydrogen bonds that make water a liquid and not a gas.
Orientation of a section of a water droplet. Note how the water molecules position themselves in water to maximize their attraction. Here for clarity we have not shown the partial negative and positive poles.
Millions of water molecules make up a drop of liquid water.
Hydrogen bonding is strong, since it takes 100oC in order to break the hydrogen bonds in liquid water in order to produce steam (which is composed of individual water molecules).
Water molecules can effectively break down ionic compounds such as table salt by separating the ions from each other and shielding them from each other. This severely reduces the positive sodium ions (Na+) from electrostatically being attracted to the negative chloride ions (Cl-).
The blue dots are the oxygen atoms and the red dots are the hydrogen atoms in the water molecule. The silver and green dots are the sodium cation and the chloride anion of NaCl, which is common table salt. Note: Table salt is broken down by liquid water since the polarity of the water, enables the water molecules to surround each ion and so negate the attraction of the sodium cations to the chloride anions.
Hydrogen bonds may occur within other molecular systems, such as in ethanol - the alcohol you drink!.
Ethanol is a liquid due to hydrogen bonding. It is completely miscible (i.e. totally soluble in all proportions) in water. That is, there will be no visible layer between a mixture of ethanol and water, whereas there is a visible layer between petrol and water.
In summary, hydrogen bonds are formed between hydrogen and oxygen atoms, and hydrogen and nitrogen atoms on adjacent molecules or in polymer systems when they are less than 0.5 x 10-9 meters apart. It should be noted that the hydrogen-oxygen hydrogen bond is stronger than the hydrogen-nitrogen hydrogen bond. The bond strength is of the order of 20.9 kJ mol-1. Compared to ionic or covalent bonds its relative bond strength is very weak. It is a bonding mechanism that occurs between molecules, or more specifically between polymers of natural, regenerated cellulose, nylon, polyvinyl alcohol, polyester, protein and secondary cellulose acetate fibers.
Hydrogen bonds are mainly responsible for the tenacity and the elastic-plastic nature of natural, regenerated cellulose, nylon, polyvinyl alcohol and protein fibers. They contribute significantly towards the heat setting property of nylon and protein fibers.
Hydrogen bonds occurring in a polymer system of polyester fibers are very weak and not considered to be important. Insignificant hydrogen bonds are formed in the polymer system of secondary cellulose fibers. There is no doubt about hydrogen bond formation in the polymer systems of acrylic and mod-acrylic fibers.
van der Waals Forces
van der Waals forces are very weak forces of attraction, named after the Dutch physicist Johannes Diederik van der Waals, who first postulated their existence when studying the weak attractions associated with gas molecules.
They are a particular form of a more generic force of attraction called dispersion forces. To explain these forces accurately we need to resort to quantum mechanics, a field of study well outside the scope of most fiber artists!
These forces are very weak in nature since they involve the electrostatic attraction of neutral molecules (e.g. attraction between organic solids such as in fibers). They become an important attraction mechanism when the molecules that make up the fibers are held by mechanical and other means, very close to each other. For example if a dye pops into an empty space (called a void) between fibers, the molecules that make up the fiber can attract the dye by this electrostatic mechanism. Fiber molecules (called polymers – see below) need to be at least 2x10-10 meters apart in order for this force to come into play.
van der Waals’ forces formed between both sets of atoms in the curly brackets: (a) Two adjacent or very closely aligned polyvinylidene chloride polymers (see below); (b) Two adjacent or closely aligned polyethylene polymers.
The influence of the difference in strength of van der Waals’ forces in the above two fibers is illustrated by their melting points. In general, the stronger the inter-molecular forces of attraction the higher the melting points of the fiber systems. Hence,
Fiber Melting Point Range
Polyethylene 110 – 140oC
Polyvinyl Chloride 170 – 200oC
van der Waals’ forces are also formed between the fiber molecules and dye molecules when these molecules come close enough together. In this way, van der Waals’ forces contribute to color-fastness of dyed or printed fabric fibers.
In summary, van der Waals’ forces are formed between atoms along the length of adjacent polymers (see below) when these are less than 0.3 x 10-9 meters apart but no closer than 0.2 x 10-9 meters. The strength of the interaction is of order of 8.4 kJ mol-1. It occurs between the molecules or more specifically, the polymers of all fibers. They are the only inter-molecular or more precisely the inter-polymer force of attraction existing in the polymer system of polyethylene, polypropylene, polyvinylchloride, polyvinylidene chloride, primary cellulose acetate and 100% polyacrylonitrile fibers. These forces are considered to be the predominate inter-polymer force of attraction in the polymer system of attraction in the polymer system of acrylic, mod-acrylic and polymer fibers.
Salt Bridges
These bonding mechanisms or forces are also called salt linkages. They are electrovalent or ionic bonds. Salt linkages occur between positively and negatively charged radicals on very close or adjacent fiber polymers. Radicals are entities that have an unpaired electron available for further possible reaction and because electrons are a negatively charge entity, radicals are shown with a small negative sign. Ozone is a radical molecule.
In the formation of a positively charged radical, an electron is lost by the radical, leaving a remaining unpaired electron. Losing electrons causes the radical to become positively charged. The number of small positive signs shown on the radical indicates not only its positive charge but also the number of electrons it has lost. In this case the radical is called an ion.
Salt bridges can be formed between a carboxyl radical (-C-O-) on one fiber polymer and a positively charged or protonated amino group (-NH3+) on an adjacent polymer.
Salt bridge between two fiber polymers.
These salt bridges are said to be ionic bonds or electrovalent bonds. The latter is a composite word “electro” meaning “electric”, because of the strongly positive or negative charges, which must always be present. The “valent“ part of the word springs from the fact that these charges arise from the most outer part of the electronic system of the molecular entity.
If the radicals of the fiber polymers carry only one charge (i.e. one negative and one positive sign as shown above) then they will form only one electrovalent bond or salt linkage.
They are called salt linkages because ionic or electrovalent bonds are formed between the ions and/or radicals of chemical compounds called salts (see table or common salt). They form strong bonds, typically having bond energy or bond strength of 54.5 kJ mol-1. The bonding mechanism occurs between polymers of protein and nylon fibers. They contribute towards the tenacity, elastic-plastic nature and durability of the fiber. They attract water molecules and so enhance the hygroscopic nature of fiber (e.g. hydrophilic nature of the fiber, making it more absorbent and hence, more comfortable to wear). They also attract the anion of acid dyes and so they are very good dye sites. However, they may make the fiber’s polymer system liable to chemical degradation, since salt bridges make the fiber system more reactive than those without these inter-polymer forces of attraction.
Conclusion
You now have some rudimentary understanding of the main bonding mechanisms that occurs between and within polymers that make up fibers and which are responsible for the properties that they possess. Hopefully, you have not been mentally damaged by this brief journey into the world of Chemistry!
References:
[1] E.P.G. Gohl and L.D. Vilensky, Textile Science, Longman Cheshire, Melbourne (1989).
[2] A Fritz and J. Cant, Consumer Textiles, Oxford University Press, Melbourne (1986).
Cry For The Wilderness I.
Cry For The Wilderness II.
Cry For The Wilderness III.
Cry For The Wilderness IV.
