TAPPI ‐ Proposed New TAPPI Standard: Standard Terms and Their Definition for Cellulose Nanomaterial WI 3021 1. Scope 1.1. This standard shall establish and define terms of cellulose nanomaterial including terms of the different types of cellulose nanomaterials. 2. Introduction 2.1. This document provides standard definitions of cellulose nanomaterial and different types of cellulose nanomaterial. Cellulose nanomaterials are described as a type of nano‐object where the term nano‐object is defined according to ISO publications. When an alternative term of a cellulose nanomaterial is available and warrants mention, the alternative term will be included in the document as a synonym (informative). Cellulose microcrystals and cellulose microfibrils are described as aggregated nanostructured nanomaterials in the Appendix (informative) of this document. Since new production methods are still being developed for cellulose nanomaterials, the standards developing committee decided it is sufficient to define cellulose nanomaterilas by their properties, rather than by their manufacturing methods. 3. Safety Precautions 3.1. There are no safety precautions required for this Standard Glossary. 4. Applicable Standards 4.1. ISO Technical Specification ISO/TS 27687, Nanotechnologies – Terminology and definitions for nano‐objects – Nanoparticle, nanofiber and nanoplate. International Organization for Standardization, 2008. 4.2. ISO Technical Specification ISO/TS80004‐1, Nanotechnologies – Vocabulary – Part 1: Core Terms. International Organization for Standardization, 2010. 4.3. ISO Technical Specification ISO/TS8004‐4, Nanotechnologies ‐ Vocabulary ‐ Part 4: Nanostructured materials. International Organization for Standardization, 2011. 4.4. Standard Terminology Relating to Nanotechnology. ASTM 2456‐06. ASTM International, 2006. 5. Definition 5.1. Prerequisite Terms 5.1.1. Nanoscale ‐ size range from approximately 1 nm to 100 nm (1) Note 1. Properties that are not extrapolations from a larger size will typically, but not exclusively, be exhibited in this size range. For such properties the size limits are considered approximate. Note 2. The lower limit in this definition (approximately 1 nm) is introduced to avoid P a g e | 1 5.1.2.
5.1.3.
TAPPI ‐ single and small groups of atoms from being designated as nano‐objects (to be defined in this section) or elements of nanostructures, which might be implied by the absence of a lower limit. Nanomaterial ‐ material with any external dimension in the nanoscale or having internal structure or surface structure in the nanoscale (1) Note 1. This generic term is inclusive of nano‐object and nanostructured material. Nano‐object ‐ material with one, two or three external dimensions in the nanoscale (1) Note 1. Generic term for all discrete nanoscale objects. 5.1.4.
Nanostructure ‐ composition of inter‐related constituent parts, in which one or more of those parts is a nanoscale region (1) Note 1. A region is defined by a boundary representing a discontinuity in properties. 5.1.5.
Nanostructured material ‐ material having internal nanostructure or surface nanostructure (1) Note 1. This definition does not exclude the possibility for a nano‐object to have internal structure or surface structure. If external dimension(s) are in the nanoscale, the term nano‐object is recommended. 5.1.6.
Aggregate ‐ particle comprising strongly bonded or fused particles where the resulting external surface area may be significantly smaller than the sum of calculated surface areas of the individual components (2) Note 1. The forces holding an aggregate together are strong forces, for example covalent bonds, or those resulting from sintering or complex physical entanglement. Note 2. Aggregates are also termed secondary particles and the original source particles are termed primary particles. 5.1.7.
Agglomerate ‐ collection of weakly bound particles or aggregates or mixtures of the two where the resulting external surface area is similar to the sum of the surface areas of the individual components (2) Note 1. The forces holding agglomerates together are weak forces, for example van der Waals forces, or simple physical entanglement. Note 2. Agglomerates are also termed secondary particles and the original source particles are termed primary particles. P a g e | 2 TAPPI ‐ 5.1.8.
Nanofibre ‐ nano‐object with two similar external dimensions in the nanoscale and the third dimension significantly larger (2) Note 1. A nanofibre can be flexible or rigid. Note 2. The two similar external dimensions are considered to differ in size by less than three times and the significantly larger external dimension is considered to differ from the other two by more than three times. Note 3. The largest external dimension is not necessarily in the nanoscale. 5.1.9. Cellulose ‐ material consisting of linear polymeric chains of one hundred to over ten thousand β‐D‐glucopyranose units linked by glucosidic bonds at their C1 and C4 positions 5.1.10. Cellulosic – of, containing or derived from cellulose Note 1. The word cellulosic encompasses cellulose that has been chemically or biologically derivatized, intentionally or unintentionally; cellulose that has been brokeneakdown (or reduced in size) by chemical, mechanical, enzymatic or biological processes; cellulose from plant and nonplant sources. 5.2. Cellulosic Nanomaterial Terms 5.2.1. Cellulose Nanomaterial – cellulosic nanomaterial Note 1. Cellulose nanomaterials are composed of cellulose nanocrystal (CNC), cellulose nanofibril (CNF), cellulose microcrystal (CMC) and cellulose microfibril (CMF). Note 2. The term cellulose nanomaterial is synonymous with nanocellulose (NC). 5.2.2. Cellulose nano‐object – cellulosic nano‐object 5.2.3. Cellulose nanostructured material – cellulosic nanostructured material 5.2.4. Cellulose nanofiber – cellulosic nanofiber 5.2.5.Cellulose nanocrystal (CNC) – a type of cellulose nanofiber with pure crystalline structure, with dimensions of 3‐10 nm in width and aspect ratio of greater than 5 Note 1. Cellulose nanocrystals are usually produced, by acid hydrolysis, oxidation or other methods. Note 2. The aspect ratio of cellulose nanocrystal is usually less than 50. Note 3. The term cellulose nanocrystal (CNC) is synonymous with the term nanocrystalline cellulose (NCC). P a g e | 3 Comment [NW-1]: Try this: since there isn’t a definition of polymer based on the number of repeating units. TAPPI ‐ Note 4. The term, cellulose nanowhisker, has been used to describe cellulose nanocrystals in aggregate or individual forms produced by acid hydrolysis. 5.2.5.5.2.6.
5.2.7. Cellulose nanofibril (CNF) – a type of cellulose nanofiber that contains both crystalline regions and amorphous regions, with dimensions of 5‐30 nm in width and , aspect ratio usually greater than 50., reminiscent of elementary fibrils in plant cell walls. Note 1. Cellulose nanofibrils are either formed by bacteria or by mechanical treatment, possibly preceded by pretreatment, of plant material; cellulose nanofibrils produced by mechanical treatment of plant material usually contain hemicellulose. Note 2. The term cellulose nanofibril (CNF) is synonymous with the term nanofibrilar cellulose. The term nanofibrilated cellulose (NFC) has been used to describe cellulose nanofibrils produced by mechanical treatment of plant materials. 6. Key Words 6.1. Terminology, nanotechnology, cellulose nanomaterial, cellulose nano‐object, cellulose nanostructured material, cellulose nanofiber, cellulose nanocrystal, cellulose nanofibril, cellulose microcrystal, cellulose microfibril, nanocrystalline cellulose, nanofibrilar cellulose, microcrystalline cellulose, microfibrilar cellulose. 7. Additional Information Date of issuance xx‐xx‐xxxx. 8. Appendix (Informative) 8.1. Aggregated cellulose nanomaterials 8.1.1. Introduction Appendix 8.1 is an informative section that defines cellulose microcrystals and cellulose microfibrils as aggregated cellulose nanostructured materials that contain internal or surface structures in the nanoscale. Alternative terms of cellulose microcrystals and cellulose microfibrils that warrant mention are described in this section as synonyms. 8.1.2. Definitions of Specific Aggregated Cellulose Nanomaterials 8.1.2.1.
Cellulose Microcrystal (CMC) – a type of cellulose nanostructured material that is approximately 10 ‐15 μm in diameter, contains a higher degree of crystallinity, and are is composed of aggregated bundles of cellulose. Note 1. Cellulose Microcrystal (CMC) is usually manufactured by partially depolymerizing high purity cellulose, has a with degree of polymerization P a g e | 4 Comment [NW-2]: Committee to discuss this. Or Define cellulose nanowhiskers as a separate term? TAPPI ‐ typically less than 400, is composed of particles where with not more than 10% of which of the particles have ing a diameters below 5 μm and usually has an aspect ratio usually less than 2. Note 2. The term cellulose microcrystal (CMC) is synonymous with microcrystalline cellulose (MCC). Note 3. The acronym CMC has also been used for carboxymethyl cellulose or carboxymethylated cellulose. 8.1.2.2.
Cellulose Microfibril (CMF) ‐ a type of cellulose nanofiber structured material containing multiple elementary fibrils with both crystalline and amorphous regions, , has a high aspect ratio with width of 10 ‐ 100 nm wide, and length of 0.5 – 10 µm long, contains both crystalline and amorphous regions Note 1. Cellulose microfibrils are usually produced by mechanical treatment of highly purified wood pulp or non‐wood plant pulp, often preceded by pretreatment methods (3) and , usually contain residual hemicelluloses. Note 2. The term cellulose microfibril (CMF) is synonymous with the term microfibrilar cellulose. The term microfibrilated cellulose has been used to describe cellulose microfibrials manufactured from mechanical processes. 8.2. Hierarchical Structure of Cellulose Nanomaterials (informative). Fig. 1 describes the hierarchical relationship of cellulose nanomaterial terms, normative and informative, defined in this standard. P a g e | 5 Comment [NW-3]: Is this the right dimension? TA
APPI ‐ Cellulose Nanomaterial
Cellulose Nano‐
object
Cellulose N
Nano‐
structured M
Material
Cellulose Microcrrystal (CMC)
C
Cellulose Nanofibe
er
Cellulosee Nanocrystal (CNC)
Cellulose MF)
Microfibril (CM
Cellu
ulose Nanofibril (CNF)
Figure 1. Hierarchical relatiionship of cellulose nanomaterial terms (inform
mative). 9. Referrences 1. Nanoteechnologies ‐ Vocabulary ‐ Part 1: Core Terms. Switzeerland : International Orgaanization for Standardization, 2010.. ISO/TS 8000
04‐1. objects ‐ Nano
oparticle, nan
nofiber and 2. Nanoteechnologies ‐ Terminology and definitions for nano‐o
nanoplatee. Switzerland
d : Internation
nal Organizattion for Stand
dardization, 20
008. ISO/TS 2
27687. P a g e | 6