253:
1315:
1290:
1327:
223:
139:
17:
199:
126:
1302:
236:
laboratory-made nanocones. The distribution of their apex angle also shows a strong feature at 60°, but other expected peaks, at 20° and 40°, are much weaker, and the distribution is somewhat broader for large angles. This difference is attributed to the different wall structure of the natural cones. Those walls are relatively irregular and contain numerous
357:
215:
its tip with a certain apex angle (e.g. 84°), but then abruptly changed the apex angle (e.g. to 39°) at a single point on its surface, thus producing a break in the observed cross-section of the cone. Another anomaly was a cone with the apex extended from a point to a line segment, as in the expanded
210:
patterns were recorded at different cone orientations. Their analysis suggests that the walls contain 10–30% ordered material covered with amorphous carbon. High-resolution electron microscopy reveals that the ordered phase consists of nearly-parallel layers of graphene. The amorphous fraction can be
214:
The remarkable feature of the open carbon nanocones produced by the CBH process is their almost ideal shape, with straight walls and circular bases. Non-ideal cones are also observed, but these are exceptions. One such deviation was a "double" cone, which appeared as if a cone started to grow from
190:
Electron microscopy observations confirm the model prediction of discrete cone angles, though two experimental artifacts must be considered: charging of the poorly-conducting carbon samples under electron beam, which blurs the images, and that electron microscopy observations at a fixed sample tilt
235:
Carbon cones have also been observed, since 1968 or even earlier, on the surface of naturally occurring graphite. Their bases are attached to the graphite and their height varies between less than 1 and 40 micrometers. Their walls are often curved and are less regular than those of the
195:. Combined with significant statistics on the number of cones, it yields semi-discrete apex angles. Their values deviate from prediction by about 10% due to the limited measurement accuracy and slight variation of the cone thickness along its length.
264:
owing to their high chemical stability and electrical conductivity, but their tips are prone to mechanical wear due to the high plasticity of gold. Adding a thin carbon cap mechanically stabilizes the tip without sacrificing its other properties.
571:
Cano-Marquez, Abraham G.; Schmidt, Wesller G.; Ribeiro-Soares, Jenaina; Gustavo Cançado, Luiz; Rodrigues, Wagner N.; Santos, Adelina P.; Furtado, Clascidia A.; Autreto, Pedro A.S.; Paupitz, Ricardo; Galvão, Douglas S.; Jorio, Ado (2015).
23:
images of a carbon disk (top left image) and free-standing hollow carbon nanocones produced by pyrolysis of heavy oil in the
Kvaerner Carbon Black & Hydrogen Process. Maximum diameter is about 1 micrometer.
191:
only yield a two-dimensional projection whereas a 3D shape is required. The first obstacle is overcome by coating the cones with a metal layer a few nanometers thick. The second problem is solved through a
66:
sheets, where the geometrical requirement for seamless connection naturally accounted for the semi-discrete character and the absolute values of the cone angle. A related carbon nanoform is the
38:
and which have at least one dimension of the order one micrometer or smaller. Nanocones have height and base diameter of the same order of magnitude; this distinguishes them from tipped
62:) of the cones is not arbitrary, but has preferred values of approximately 20°, 40°, and 60°. This observation was explained by a model of the cone wall composed of wrapped
647:
107:. At certain well-optimized and patented conditions, the solid carbon output consists of approximately 20% carbon nanocones, 70% flat carbon discs, and 10%
206:
The cone wall thickness varies between 10 and 30 nm, but can be as large as 80 nm for some nanocones. To elucidate the structure of the cone walls,
1046:
355:, Lynum S, Hugdahl J, Hox K, Hildrum R and Nordvik M, "Production of micro domain particles by use of a plasma process", issued 2000-07-12
1076:
640:
1166:
150:
sheet. In order to have strain-free, seamless wrapping, a sector must be cut out of the sheet. That sector should have an angle of
1100:
1352:
1247:
1039:
633:
67:
1123:
20:
1219:
103:
Carbon Black & Hydrogen
Process (CBH) and it is relatively "emission-free", i.e., produces rather small amount of
114:
Plasma-assisted decomposition of hydrocarbons has long been known and applied, for example, for production of carbon
1013:
256:
Sequential electron micrographs showing the process of capping a gold needle with a CBH carbon nanocone (top left)
244:). This breaks down the angular requirement for a seamless cone and therefore broadens the angular distribution.
1306:
1234:
1086:
1081:
1071:
1063:
261:
158: = 1, ..., 5. Therefore, the resulting cone angle should have only certain, discrete values
1257:
1201:
1186:
1096:
1032:
779:
118:. Even if not optimized, it yields small amounts of carbon nanocones, which had been directly observed with an
1294:
1242:
1191:
1178:
839:
666:
352:
1118:
970:
965:
717:
656:
585:
476:
380:
308:
207:
202:
Image of a coffee filter illustrating one of the anomalous structures in the carbon nanocone growth.
1265:
1154:
119:
55:
252:
1196:
754:
736:
211:
converted into well-ordered graphite by annealing the cones at temperatures near 2700 °C.
170: = 1, ..., 5, respectively. The graphene sheet is composed solely of carbon
260:
Carbon nanocones have been used to cap ultrafine gold needles. Such needles are widely used in
1331:
611:
508:
334:
226:
Statistical distribution of the apex values measured over 554 cones grown on natural graphite.
463:
Krishnan, A.; Dujardin, E.; Treacy, M. M. J.; Hugdahl, J.; Lynum, S.; Ebbesen, T. W. (1997).
1275:
993:
923:
829:
601:
593:
550:
523:
484:
442:
415:
388:
324:
316:
96:
51:
1224:
1211:
1149:
878:
834:
800:
742:
59:
541:
Gillot, J; Bollmann, W; Lux, B (1968). "181. Cigar-shaped conical crystals of graphite".
589:
480:
384:
320:
312:
1319:
1113:
1055:
975:
784:
748:
606:
573:
329:
296:
192:
104:
42:, which are much longer than their diameter. Nanocones occur on the surface of natural
574:"Enhanced Mechanical Stability of Gold Nanotips through Carbon Nanocone Encapsulation"
527:
1346:
1133:
1008:
862:
761:
727:
554:
446:
392:
216:
122:
already in 1994, and their atomic structure was modeled theoretically the same year.
99:
having a plasma temperature above 2000 °C. This method is often referred to as
1314:
1270:
1161:
1108:
998:
406:
Terrones, Humberto (1994). "Curved graphite and its mathematical transformations".
295:
Naess, Stine Nalum; Elgsaeter, Arnljot; Helgesen, Geir; Knudsen, Kenneth D (2009).
241:
108:
222:
178:
must be added to form a curved cone tip, and their number is correspondingly
960:
939:
682:
237:
142:
Statistical distribution of the apex values measured over 1700 hollow nanocones.
138:
84:
47:
16:
1326:
198:
125:
1141:
894:
712:
115:
615:
338:
166:/6) = 112.9°, 83.6°, 60.0°, 38.9°, and 19.2° for
1003:
844:
707:
701:
175:
147:
100:
92:
63:
43:
39:
955:
676:
625:
419:
171:
83:
Carbon nanocones are produced in an industrial process that decomposes
597:
371:
Ge, Maohui; Sattler, Klaus (1994). "Observation of fullerene cones".
88:
35:
489:
464:
251:
221:
197:
174:, which can not form a continuous cone cap. As in the fullerenes,
137:
124:
15:
1024:
31:
1028:
629:
465:"Graphitic cones and the nucleation of curved carbon surfaces"
46:. Hollow carbon nanocones can also be produced by decomposing
433:
Balaban, A; Klein, D; Liu, X (1994). "Graphitic cones".
1256:
1233:
1210:
1177:
1132:
1095:
1062:
984:
914:
853:
820:
770:
691:
663:
70:which typically form aggregates 80–100 nm in size.
297:"Carbon nanocones: wall structure and morphology"
146:The open carbon cone can be modeled as a wrapped
129:Atomic model of a cone with the 38.9° apex angle.
1040:
641:
34:structures which are made predominantly from
8:
301:Science and Technology of Advanced Materials
1047:
1033:
1025:
648:
634:
626:
605:
488:
328:
162: = 2 arcsin(1 −
274:
502:
500:
290:
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284:
282:
280:
278:
458:
456:
219:(flat form is shown in the picture).
7:
1301:
566:
564:
509:"Naturally occurring graphite cones"
182: = 1, ..., 5.
14:
408:Journal of Mathematical Chemistry
1325:
1313:
1300:
1289:
1288:
58:reveals that the opening angle (
683:Lonsdaleite (hexagonal diamond)
1:
1248:Scanning tunneling microscope
528:10.1016/S0008-6223(03)00214-8
321:10.1088/1468-6996/10/6/065002
68:single-walled carbon nanohorn
555:10.1016/0008-6223(68)90485-5
447:10.1016/0008-6223(94)90203-8
393:10.1016/0009-2614(94)00167-7
1220:Molecular scale electronics
1369:
1014:Aggregated diamond nanorod
193:geometrical shape analysis
74:Free-standing hollow cones
1284:
1235:Scanning probe microscopy
812:(cyclo[18]carbon)
262:scanning probe microscopy
1258:Molecular nanotechnology
1202:Solid lipid nanoparticle
1187:Self-assembled monolayer
796:(cyclo[6]carbon)
780:Linear acetylenic carbon
373:Chemical Physics Letters
154: × 60°, where
1243:Atomic force microscope
1192:Supramolecular assembly
1179:Molecular self-assembly
840:Carbide-derived carbon
722:(buckminsterfullerene)
257:
248:Potential applications
227:
203:
143:
130:
24:
1332:Technology portal
255:
225:
201:
141:
128:
79:History and synthesis
19:
1353:Carbon nanoparticles
1119:Green nanotechnology
657:Allotropes of carbon
507:Jaszczak, J (2003).
208:electron diffraction
1266:Molecular assembler
590:2015NatSR...510408C
481:1997Natur.388..451K
385:1994CPL...220..192G
313:2009STAdM..10f5002N
120:electron microscope
56:Electron microscopy
1320:Science portal
1197:DNA nanotechnology
935:(cyclopropatriene)
916:hypothetical forms
737:Fullerene whiskers
578:Scientific Reports
420:10.1007/BF01277556
258:
228:
204:
144:
131:
25:
1340:
1339:
1022:
1021:
890:(diatomic carbon)
822:mixed sp/sp forms
598:10.1038/srep10408
1360:
1330:
1329:
1318:
1317:
1304:
1303:
1292:
1291:
1276:Mechanosynthesis
1167:characterization
1049:
1042:
1035:
1026:
994:Activated carbon
950:
949:
948:
934:
933:
932:
905:
904:
903:
889:
888:
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873:
872:
871:
830:Amorphous carbon
811:
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240:(positive-wedge
28:Carbon nanocones
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1225:Nanolithography
1212:Nanoelectronics
1206:
1173:
1128:
1091:
1082:Popular culture
1058:
1053:
1023:
1018:
980:
971:Metallic carbon
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926:
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902:
899:
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874:(atomic carbon)
870:
867:
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865:
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849:
835:Carbon nanofoam
816:
808:
805:
804:
803:
801:
792:
789:
788:
787:
785:
766:
731:
721:
687:
677:Diamond (cubic)
659:
654:
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1114:Nanotoxicology
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1079:
1074:
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1056:Nanotechnology
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1019:
1017:
1016:
1011:
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979:
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976:Penta-graphene
973:
968:
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105:air pollutants
80:
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13:
10:
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1162:Nanoparticles
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1134:Nanomaterials
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1077:Organizations
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951:(prismane C8)
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762:Glassy carbon
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490:10.1038/41284
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475:(6641): 451.
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307:(6): 065002.
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268:
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242:disclinations
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217:coffee filter
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33:
29:
22:
18:
1305:
1293:
1271:Nanorobotics
1109:Nanomedicine
1101:applications
1009:Carbon fiber
999:Carbon black
985:
966:Cubic carbon
915:
854:
821:
771:
753:
747:
741:
735:
726:
716:
715:, including
700:
692:
675:
664:
581:
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546:
542:
536:
522:(11): 2085.
519:
515:
472:
468:
438:
434:
428:
411:
407:
401:
379:(3–5): 192.
376:
372:
366:
347:
304:
300:
259:
238:line defects
234:
213:
205:
189:
179:
167:
163:
159:
155:
151:
145:
113:
109:carbon black
97:plasma torch
85:hydrocarbons
82:
48:hydrocarbons
27:
26:
961:Haeckelites
906:(tricarbon)
855:other forms
755:Nanoscrolls
231:Other cones
186:Observation
1155:Non-carbon
1146:Nanotubes
1142:Fullerenes
1124:Regulation
713:Fullerenes
549:(2): 237.
441:(2): 357.
353:EP 1017622
269:References
116:fullerenes
743:Nanotubes
584:: 10408.
176:pentagons
40:nanowires
1347:Category
1295:Category
1064:Overview
1004:Charcoal
845:Q-carbon
772:sp forms
749:Nanobuds
708:Graphene
702:Graphite
693:sp forms
616:26083864
339:27877312
172:hexagons
148:graphene
134:Modeling
101:Kvaerner
93:hydrogen
64:graphene
44:graphite
1307:Commons
1087:Outline
1072:History
986:related
956:Chaoite
607:4470435
586:Bibcode
477:Bibcode
414:: 143.
381:Bibcode
330:5074450
309:Bibcode
95:with a
54:torch.
50:with a
32:conical
1150:Carbon
1097:Impact
614:
604:
543:Carbon
516:Carbon
469:Nature
435:Carbon
359:
337:
327:
89:carbon
52:plasma
36:carbon
667:forms
512:(PDF)
87:into
1099:and
612:PMID
335:PMID
91:and
60:apex
30:are
665:sp
602:PMC
594:doi
551:doi
524:doi
485:doi
473:388
443:doi
416:doi
389:doi
377:220
325:PMC
317:doi
111:.
21:SEM
1349::
807:18
752:,
746:,
740:,
734:,
730:70
725:,
720:60
610:.
600:.
592:.
580:.
576:.
563:^
545:.
520:41
518:.
514:.
499:^
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467:.
455:^
439:32
437:.
412:15
410:.
387:.
375:.
333:.
323:.
315:.
305:10
303:.
299:.
277:^
1048:e
1041:t
1034:v
946:6
941:C
930:3
925:C
901:3
896:C
885:2
880:C
869:1
864:C
802:C
791:6
786:C
758:)
728:C
718:C
649:e
642:t
635:v
618:.
596::
588::
582:5
557:.
553::
547:6
530:.
526::
493:.
487::
479::
449:.
445::
422:.
418::
395:.
391::
383::
341:.
319::
311::
180:n
168:n
164:n
160:α
156:n
152:n
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