1. A method for preparing a transparent gas barrier composite film, comprising:
providing a polyvinyl alcohol containing aqueous solution;
providing a graphene oxide dispersed aqueous solution;
performing a blending procedure, to blend the polyvinyl alcohol containing aqueous solution with the graphene oxide dispersed aqueous solution to obtain a casting solution wherein a weight ratio of graphene oxide in the graphene oxide dispersed aqueous solution to polyvinyl alcohol in the polyvinyl alcohol containing aqueous solution is less than 0.1 wt %;
performing a cross-linking procedure, to add a cross-linking agent into the casting solution to have in-situ cross-linking reaction; and
performing a film-casting procedure, to coat the casting solution after the in-situ cross-linking reaction on a substrate to form a coating and dry the coating so as to obtain a composite film.
2. The method according to claim 1, further comprising:
performing an isothermal crystallization procedure after the film-casting procedure, to maintain a specific period of time at a specific temperature to have crystals of polyvinyl alcohol grow and to have graphene oxide induce the crystals of polyvinyl alcohol to grow so as to incorporate with graphene oxide and the cross-linking agent to form a hybrid network structure of the crystals of polyvinyl alcohol, graphene oxide and the cross-linking agent.
3. The method according to claim 1, wherein, in the cross-linking procedure, the cross-linking agent is glutaraldehyde or sodium tetraborate and cross-linking time for perform the cross-linking procedure is 1\u02dc6 hours.
4. The method according to claim 3, wherein the cross-linking agent is glutaraldehyde and the cross-linking agent in the casting solution (being 100 wt %) is 0.2\u02dc0.85 wt %.
5. The method according to claim 3, wherein the cross-linking agent is sodium tetraborate and the cross-linking agent in the casting solution (being 100 wt %) is 0.1\u02dc1.0 wt %.
6. The method according to claim 2, wherein the specific temperature is within 80\u02dc120\xb0 C. and the specific period of time is 2\u02dc6 hours.
7. The method according to claim 2, wherein the specific temperature is within 90\u02dc100\xb0 C. and the specific period of time is 1\u02dc6 hours.
8. The method according to claim 1, wherein, in the blending procedure, a weight ratio of graphene oxide to polyvinyl alcohol is 0.1 wt % and the obtained composite film has light transmittance larger than 85%.
9. The method according to claim 1, wherein the substrate is polyethylene terephthalate and the coating after dried has a thickness of 10 \u03bcm.
10. The method according to claim 1, wherein polyvinyl alcohol in the polyvinyl alcohol containing aqueous solution has concentration of 5\u02dc10 wt %.
11. A transparent gas barrier composite film, being formed by having polyvinyl alcohol, graphene oxide and a crosslinking agent undergo blending, crosslinking, film casting and isothermal crystallization procedures wherein a weight ratio of graphene oxide to polyvinyl alcohol is 0.1 wt %, graphene oxide induces crystallization of polyvinyl alcohol to form a hybrid structure compose of polyvinyl alcohol crystals, graphene oxide and the crosslinking agent, crystallinity of polyvinyl alcohol is more than 30%, and transmittance of the composite film is more than 85%.
12. The transparent gas barrier composite film according to claim 11, wherein the material of said reservoir and said supporting portion is selected from the following group: metal, ceramic, plastic and glass.
13. The transparent gas barrier composite film according to claim 11, wherein the cross-linking agent is sodium tetraborate; sodium tetraborate forms B\u2014O\u2014C bonds together with polyvinyl alcohol and graphene oxide; and a cross-linking rate defined as a ratio of numbers of B\u2014O\u2014C bonds to numbers of \u2014CH2 bonds is 1.05\u02dc1.15.
14. The transparent gas barrier composite film according to claim 11, wherein the composite film has an oxygen transmission rate less than 0.005 ccm2day.
15. The transparent gas barrier composite film according to claim 12, wherein the cross-linking agent is glutaraldehyde; glutaraldehyde forms C\u2014O\u2014C bonds together with polyvinyl alcohol and graphene oxide; and a cross-linking rate defined as a ratio of numbers of C\u2014O\u2014C bonds to numbers of \u2014CH2 bonds is 1.02\u02dc1.05.
16. The transparent gas barrier composite film according to claim 12, wherein blending, crosslinking, film casting and isothermal crystallization procedures comprises the following steps:
providing a polyvinyl alcohol containing aqueous solution;
providing a graphene oxide dispersed aqueous solution;
performing a blending procedure, to blend the polyvinyl alcohol containing aqueous solution with the graphene oxide dispersed aqueous solution to obtain a casting solution wherein a weight ratio of graphene oxide in the graphene oxide dispersed aqueous solution to polyvinyl alcohol in the polyvinyl alcohol containing aqueous solution is less than 0.1 wt %;
performing a cross-linking procedure, to add a cross-linking agent into the casting solution to have in-situ cross-linking reaction; and
performing a film-casting procedure, to coat the casting solution after the in-situ cross-linking reaction on a substrate to form a coating and dry the coating so as to obtain a composite film.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of accessing information in a hierarchical file system having a plurality of directories arranged in a hierarchical tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least some of the plurality of directories in the tree correspond to a period of time subsumed by a period of time corresponding to its respective parent directory, the method comprising acts of:
(A) receiving a request to access a unit of information in the file system, wherein the request includes an identifier for the unit of information, and wherein the identifier does not identify a time related to a time of storage of the unit of information;
(B) mapping the identifier into a time value using a mapping function that produces a reproducible time value for the identifier; and
(C) selecting a directory from the plurality of directories, wherein the selected directory corresponds to the time value to which the identifier is mapped.
2. The method of claim 1, further comprising an act of:
(D) storing the unit of information in the selected directory.
3. The method of claim 2, further comprising acts of:
(E) receiving a request to retrieve the unit of information, wherein the request identifies the unit of information using the identifier;
(F) mapping the identifier into the time value using the mapping function; and
(G) selecting the directory corresponding to the time value to which the identifier is mapped.
4. The method of claim 3, further comprising an act of:
(H) retrieving the unit of information from the selected directory.
5. The method of claim 1, wherein the identifier is a content address that is computed, at least in part, based on the content of the information unit.
6. The method of claim 2, wherein the act (D) further comprises an act of:
storing the unit of information in the directory as a file.
7. The method of claim 6, wherein the identifier is used as a filename for the file.
8. At least one computer readable medium encoded with instructions that, when executed on a computer system, perform a method of accessing information in a hierarchical file system having a plurality of directories arranged in a hierarchical tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least some of the plurality of directories in the tree correspond to a period of time subsumed by a period of time corresponding to its respective parent directory, the method comprising acts of:
(A) receiving a request to access a unit of information in the file system, wherein the request includes an identifier for the unit of information, and wherein the identifier does not identify a time related to a time of storage of the unit of information;
(B) mapping the identifier into a time value using a mapping function that produces a reproducible time value for the identifier; and
(C) selecting a directory from the plurality of directories, wherein the selected directory corresponds to the time value to which the identifier is mapped.
9. The at least one computer readable medium of claim 8, wherein the method further comprises an act of:
(D) storing the unit of information in the selected directory.
10. The at least one computer readable medium of claim 9, wherein the method further comprises acts of:
(E) receiving a request to retrieve the unit of information, wherein the request identifies the unit of information using the identifier;
(F) mapping the identifier into the time value using the mapping function; and
(G) selecting the directory corresponding to the time value to which the identifier is mapped.
11. The at least one computer readable medium of claim 10, wherein the method further comprises an act of:
(H) retrieving the unit of information from the selected directory.
12. The at least one computer readable medium of claim 8, wherein the identifier is a content address that is computed, at least in part, based on the content of the information unit.
13. The at least one computer readable medium of claim 9, wherein the act (D) further comprises an act of:
storing the unit of information in the directory as a file.
14. The at least one computer readable medium of claim 13, wherein the identifier is used as a filename for the file.
15. At least one computer that maintains a hierarchical file system having a plurality of directories arranged in a hierarchical tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least some of the plurality of directories in the tree correspond to a period of time subsumed by a period of time corresponding to its respective parent directory, the at least one computer comprising:
at least one input; and
at least one controller, coupled to that at least one input, that
(A) receives, from the at least one input, a request to access a unit of information in the file system, wherein the request includes an identifier for the unit of information, and wherein the identifier does not identify a time related to a time of storage of the unit of information;
(B) maps the identifier into a time value using a mapping function that produces a reproducible time value for the identifier; and
(C) selects a directory from the plurality of directories, wherein the selected directory corresponds to the time value to which the identifier is mapped.
16. The at least one computer of claim 15, wherein the at least one controller stores the unit of information in the selected directory.
17. The at least one computer of claim 16, wherein the at least one controller:
receives a request to retrieve the unit of information, wherein the request identifies the unit of information using the identifier;
maps the identifier into the time value using the mapping function; and
selects the directory corresponding to the time value to which the identifier is mapped.
18. The at least one computer of claim 17, wherein the at least one controller retrieves the unit of information from the selected directory.
19. The at least one computer of claim 15, wherein the identifier is a content address that is computed, at least in part, based on the content of the information unit.
20. The at least one computer of claim 16, wherein the at least one controller stores the unit of information in the directory as a file.
21. The at least one computer of claim 20, wherein the identifier is used as a filename for the file.