Controlling self-organization in precipitation reactions has received growing attention in the efforts of engineering highly ordered spatial structures. Experiments have been successful in regulating the band patterns of the Liesegang phenomenon on various scales. Herein, we show that by adjusting the composition of the hydrogel medium, we can switch the final pattern between the classical band structure and the rare precipitate spots with hexagonal symmetry. The accompanying modeling study reveals that besides the modification of gel property, tuning of the time scale of diffusional spreading of hydroxide ions with respect to that of the phase separation drives the mode selection between one-dimensional band and two-dimensional spot patterns.

1.
C. R.
Kapral
and
K.
Showalter
,
Chemical Patterns and Waves
(
Kluwer
,
Dordrecht
,
1995
).
2.
I. R.
Epstein
and
J. A.
Pojman
,
An Introduction to Nonlinear Dynamics: Oscillations, Waves, Patterns, and Chaos
(
Oxford University Press
,
Oxford
,
1998
).
3.
L.
Szirovicza
,
I.
Nagypál
, and
E.
Boga
,
J. Am. Chem. Soc.
111
,
2842
(
1989
).
4.
D.
Horváth
and
Á.
Tóth
,
J. Chem. Phys.
108
,
1447
(
1998
).
5.
A. M.
Turing
,
Philos. Trans. R. Soc. London, Ser. B
237
,
37
(
1952
).
6.
V.
Castets
,
E.
Dulos
,
J.
Boissonade
, and
P.
De Kepper
,
Phys. Rev. Lett.
64
,
2953
(
1990
).
7.
Precipitation Patterns in Reaction-Diffusion Systems
, edited by
I.
Lagzi
(
Research Signpost
,
India
,
2010
).
8.
E.
Nakouzi
and
O.
Steinbock
,
Sci. Adv.
2
,
e1601144
(
2016
).
9.
R. E.
Liesegang
,
Naturwiss. Wochenschr.
11
,
353
(
1896
).
10.
M. M.
Ayass
,
M.
Al-Ghoul
, and
I.
Lagzi
,
J. Phys. Chem. A
118
,
11678
(
2014
).
11.
M.
Matsue
,
M.
Itatani
,
Q.
Fang
,
Y.
Shimizu
,
K.
Unoura
, and
H.
Nabika
,
Langmuir
34
,
11188
(
2018
).
12.
M.
Itatani
,
Q.
Fang
,
K.
Unoura
, and
H.
Nabika
,
J. Phys. Chem. C
122
,
3669
(
2018
).
13.
K.
Jablczinsky
,
Bull. Soc. Chim. Fr.
33
,
1952
(
1923
).
14.
S. C.
Müller
,
S.
Kai
, and
J.
Ross
,
J. Phys. Chem.
86
,
4078
(
1982
).
15.
H. W.
Morse
and
G. W.
Pierce
,
Proc. Am. Acad. Arts Sci.
38
,
625
(
1903
).
16.
R.
Matalon
and
A.
Packter
,
J. Colloid Sci.
10
,
46
(
1955
).
19.
J. B.
Keller
and
S. I.
Rubinow
,
J. Chem. Phys.
74
,
5000
(
1981
).
20.
G.
Venzl
,
J. Chem. Phys.
85
,
1996
(
1986
).
21.
A. A.
Mansour
and
M.
Al-Ghoul
,
J. Phys. Chem. A
119
,
9201
(
2015
).
22.
A.
Arango-Restepo
,
D.
Barragán
, and
J. M.
Rubi
,
Phys. Chem. Chem. Phys.
20
,
4699
(
2018
).
23.
R.
Feeney
,
S. L.
Schmidt
,
P.
Strickholm
,
J.
Chandam
, and
P.
Ortoleva
,
J. Chem. Phys.
78
,
1293
(
1983
).
24.
G.
Venzl
,
J. Chem. Phys.
85
,
2006
(
1986
).
26.
I.
Lagzi
,
Phys. Chem. Chem. Phys.
4
,
1268
(
2002
).
27.
I.
Bena
,
M.
Droz
,
I.
Lagzi
,
K.
Martens
,
Z.
Rácz
, and
A.
Volford
,
Phys. Rev. Lett.
101
,
075701
(
2008
).
28.
S.
Thomas
,
I.
Lagzi
,
F.
Molnár
, Jr.
, and
Z.
Rácz
,
Phys. Rev. Lett.
110
,
078303
(
2013
).
29.
A.
Toramaru
,
T.
Harada
, and
T.
Okamura
,
Physica D
183
,
133
(
2003
).
30.
M.
Fialkowski
,
A.
Bitner
, and
B. A.
Grzybowski
,
Phys. Rev. Lett.
94
,
018303
(
2005
).
31.
I. T.
Bensemann
,
M.
Fialkowski
, and
B. A.
Grzybowski
,
J. Phys. Chem. B
109
,
2774
(
2005
).
32.
I.
Lagzi
,
B.
Kowalczyk
, and
B. A.
Grzybowski
,
J. Am. Chem. Soc.
132
,
58
(
2010
).
34.
H.
Nabika
,
M.
Sato
, and
K.
Unoura
,
Langmuir
30
,
5047
(
2014
).
35.
J.
Jiang
and
K.
Sakurai
,
Langmuir
32
,
9126
(
2016
).
36.
H.
Hayashi
,
S.
Aoki
, and
H.
Abe
,
ACS Omega
3
,
4494
(
2018
).
37.
M.
Dayeh
,
M.
Ammar
, and
M.
Al-Ghoul
,
RSC Adv.
4
,
60034
(
2014
).
38.
M.
Saad
,
A.
Safieddine
, and
R.
Sultan
,
J. Phys. Chem. A
122
,
6043
(
2018
).
39.
Á.
Tóth
,
I.
Lagzi
, and
D.
Horváth
,
J. Phys. Chem.
100
,
14837
(
1996
).
40.
S.
Kotrlý
and
L.
Šucha
,
Handbook of Chemical Equilibria in Analytical Chemistry
(
Ellis Horwood Limited
,
England
,
1985
).
41.
J.
Cahn
and
J.
Hilliard
,
J. Chem. Phys.
28
,
258
(
1958
).
42.
S. D.
Cohen
and
A. C.
Hindmarsh
,
Comput. Phys.
10
,
138
(
1996
).
43.
A. C.
Hindmarsh
,
P. N.
Brown
,
K. E.
Grant
,
S. L.
Lee
,
R.
Serban
,
D. E.
Shumaker
, and
C. S.
Woodward
,
ACM Trans. Math. Software
31
,
363
(
2005
).
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