Introduction of Anionic Surfactants to Copolymer Micelles: A Key to

Article

Introduction of Anionic Surfactants to Copolymer Micelles: A Key to Improving Utilization Efficiency of P123 in Synthesis of Mesoporous Aluminosilicates Xiaotong Mi, Jiongliang Yuan, Yueming Han, Honghai Liu, Hongtao Liu, Xionghou Gao, Chunyan Xu, and Jingchang Zhang Ind. Eng. Chem. Res., Just Accepted Manuscript • Publication Date (Web): 31 May 2017 Downloaded from http://pubs.acs.org on June 2, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Industrial & Engineering Chemistry Research is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 16

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Industrial & Engineering Chemistry Research

Introduction of Anionic Surfactants to Copolymer Micelles: A Key to Improving Utilization Efficiency of P123 in Synthesis of Mesoporous Aluminosilicates Xiaotong Mi,a Jiongliang Yuan,a Yueming Han,a Honghai Liu,c Hongtao Liu,* a Xionghou Gao,c Chunyan Xu,* a Jingchang Zhanga, c a

State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical

Technology, Beijing 100029, P. R. China b

c

Petrochemical Research Institute, Petrochina Company Limited, Beijing, 100195, P. R. China

Hainan Institute of Science and Technology, Haikou, 571126, P. R. China

ABSTRACT: Mesoporous aluminosilicates (MAs) with high hydrothermal stability by assembly of zeolite Y precursors have been emerging as the most promising materials to cracking heavy oil molecules. How to improve utilization efficiency of organic surfactants is of vital importance in synthesis of MAs. In this work, this goal was achieved by the introduction of ionic surfactants micelles in low concentration of copolymer. It is found that the strong interactions between hydrophobic chain of Sodium dodecyl sulfate (SDS) and PPO units of P123 lead to the formation of mixed micelles even at low concentration of P123. The self-aggregation of SDS molecules could induced the formation of mixed micelles with a core consisting of SDS micelles with PPO units and a corona of PEO units. The mixed surfactants (SDS/P123) exhibited excellent performance for enhancing utilization efficiency of P123. This strategy developed a novel route for synthesis of MAs with high efficiency and low-cost.

1. INTRODUCTION *

Corresponding authors: Email: [email protected] (Liu H.).

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

MAs have been paid much attention because of its large surface area, uniform mesopore size and thick pore walls, which have a opened up promising way to crack large molecules such as heavy oil.1,2 However, poor hydrothermally stability derived from their inherent characteristics hinders their practical application in the industrial scale. Self-assembly of zeolite precursors has been found to be efficient way of improving the hydrothermal stability of MAs.3-6 For example, the retaining ratio of the total surface area was 33% after the hydrothermal treatment in 100% water vapor at 800 oC for 15 h, the hydrothermal stability is comparable to that of USY.7 However, one key problem remains unresolved for the MAs reported previously. That is, large amount of P123 template is used in the obtaining of MAs (only 0.52 g MAs was obtained by per g P123). Therefore, it is of great importance to increase P123 utilization efficiency (which is defined as “g number” of the final product per g P123) in preparation of MAs. Different methods for enhancing the utilization of organic surfactants in the preparation of MAs have been developed. “Crystal seeds” is effective method used for decreasing the amount of templates in synthesis of MAs, which was firstly reported by the authors of the present investigation.8 However, the efficiency of crystal seeds is always low; that is, 0.5 g crystal seeds are necessary for per g products. Mother liquor recycling (MLR) procedures have been performed for preparation of various microporous zeolites, such as Y,9 ZSM-5,10 and TS-1.11 On the basis of above study, our group reported the application of MLR in preparation of MAs with significantly decreased amount of organic surfactants and water.12 However, MLR mentioned above is a relatively complicated procedure, and in some cases the process


Page 2 of 16

Page 3 of 16

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


is difficult to be controlled. Another disadvantage of MLR is that the accumulation of inorganic salts will decrease the cloud point of P123. As a direct result of this, the micelles will be destroyed and well-ordered MAs cannot be obtained in recycling process. From microscopic aspects, self-assembly of P123 (comprising PEO and PPO) and the micelles formed in acidic media is the key to the formation of MAs. Generally, the amphiphilic character of P123 arises from a difference in the hydrophobicity of PEO and PPO blocks. Micelles comprising PPO blocks as the core and hydrated PEO blocks as the corona formed due to the difference in the solubility of the PPO and PEO blocks.13-15 On the other hand, it has been established that copolymer can bind cooperatively with ionic surfactants micelles.16,17 At very low concentration of copolymers, copolymer-ionic surfactant complexes can be also formed and template the formation of mesopores. From the strong interactions between hydrophobic chain of SDS and PPO units of P123, it can be reasonably concluded that mixed micelle, which is characterized by a core consisting of SDS micelles with PPO units and a corona of PEO units, will be the key to underline the amount of copolymers in the self-assembly system. However, the effects of mixed micelles on the utilization efficiency of copolymers have not yet been investigated. This inspires us to challenge the goal of enhancing the utilization of P123 via mixed micelles technique. Herein, we report an effective and convenient method for improving the utilization efficiency of P123 in synthesis of MAs by self-assembly of Y precursors. In this method, mixed surfactants (SDS/P123) are introduced into this synthesis system at very low concentration of P123. Due to the peculiar properties of mixed surfactants,



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

utilization of P123 was improved greatly.

2. EXPERIMENTAL SECTION 2.1. Chemical materials. SDS (Xilong Chemical Company). Water glass (containing 23.8% SiO2, 8.8% Na2O). Triblock copolymer P123 (EO20PO70EO20, Mw=5800) was purchased from Sigma-Aldrich Co. LLC. sodium hydroxide (NaOH), sulfuric acid (H2SO4) and aluminium sulfate (Al2(SO4)3·18H2O) were purchased from Tianjin Fuchen Company. 2.2. Synthesis procedures of MAs. (a) zeolite Y precursors were prepared according to literature.8 (b) In a typical synthesis of ordered hexagonal MAs from mixed P123 and SDS, 0.8 g of P123 and 0.05-0.3 g of SDS were dissolved in 250 mL H2O, followed by addition of certain amount of Y precursors, H2SO4 was used to adjust the pH value of the mixed gel in the range of 1.5-1.8. In this gels, the weight ratio of SiO2/P123 were 2.5-5. Then the mixed solutions were assembled for 20 h at 30 °C. After that, the obtained products were transferred into Teflon autoclaves for crystallization at 100 °C for 48 h. After filtration, washing and drying, the as-synthesis products were calcined at 550 °C for 5 h to remove the P123 and SDS. The samples prepared with various weight ratio of SiO2/P123 at 2.5, 3, 4, and 5 and constant mass of SDS at 0.1 g are denoted as H2.5, H3, H4, and H5 respectively. The sample synthesized with constant weight ratio of SiO2/P123 at 2.5 and various mass of SDS at 0 g, 0.05 g, 0.1 g, 0.2 g, and 0.3 g are denoted as S0, S0.05, S0.1, S0.2, and S0.3 respectively. (c) In comparison, conventional MAs were synthesized according to literature.8


Page 4 of 16

Page 5 of 16

2.3. Characterization. X-ray diffraction (XRD) patterns of the synthesized aluminosilicates were obtained with a Rigaku D/Max 2500VB2+/PC diffractometer using Cu Kα radiation. Transmission electron microscopy (TEM) images were recorded by a JEM 100CX instrument with an acceleration voltage of 200 kV. The isotherms of nitrogen were measured at the temperature of liquid nitrogen using a Micromeritics ASAP 2405N system. The pore-size distribution was calculated using the Barrett-Joyner-Halenda (BJH) model. FTIR spectra were measured with spectrometer of Nicolet 8700, and KBr was using as an internal standard sample.

3. RESULTS AND DISCUSSION 3.1. Mechanism proposal. In this study, P123 concentration is 5.5210-4 mol/L, much lower than CMC of P123.20 As a results of this, no micelles but unimers and oligomers21 are present in the aqueous solution. From XRD patterns (Figure 1), it can be seen that no ordered mesoporous materials for sample S0 are obtained.22,23 With the addition of SDS, the ordering of mesophase increases and reaches highest at the SDS addition of 0.1 g. 12000

10000

e 8000

d Intensity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


6000

4000

c

2000

b

0

a 0

2

4

6

2-Theta/deg

Figure 1. XRD patterns of samples: (a) S0, (b) S0.05, (c) S0.1, (d) S0.2, and (e) S0.3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

In this investigation, counter ions H+ in the aqueous solution can compress the

double-layer of micelles and reduce the electrostatic repulsion among those SDS ions by compensating the negative charge of SDS.24 As a consequence, CMC of SDS reduced greatly and SDS micelles aggregated to micelles in the present synthesis system. Due to the strong interactions between hydrophobic chain of SDS and PPO units of P123, free monomers and oligomers of P123 will bind to the SDS micelles. Therefore, more and more P123 will be attracted to the SDS micelles with the increment of SDS amount. As a result of this, mixed micelles are formed with a core consisting of SDS micelles with PPO units and a corona of PEO units. In this process, P123-rich micelles with large amount of P123 molecules are formed gradually. The mixed micelles will template the formation of well-ordered mesophase (also increased surface area) with continuously increasing pore size. However, with increment of SDS, there is a transformation of P123-rich complex to P123-poor complex. It is a gradual incorporation of P123 into the newly formed SDS micelles with the release of P123 units from P123-rich complex until P123-poor micelles are formed. P123-poor micelles cannot favor the formation of well-ordered mesophase.25 It can be seen from table 1 that BET surface area of samples from S0.1 to S0.3 decrease gradually. Meanwhile, decreased size of P123-poor micelles lead to the gradual decrease of the average pore size. These results are fully consistent with those of XRD and BET studies. The specific synthesis mechanism is illustrated in Figure 2.

Figure 2. Proposed mechanism for the synthesis of MAs using P123 and SDS as template


Page 6 of 16

Page 7 of 16

Table 1 Physicochemical properties of samples SBET

Smeso

Smicro

Vtotal

Vmeso

Vmicro

Dave

(m2/g)

(m2/g)

(m2/g)

(cm3/g)

(cm3/g)

(cm3/g)

(nm)

S0

483

102

381

0.37

0.17

0.20

-

S0.05

612

494

118

1.14

0.93

0.21

6.8

S0.1

721

443

278

1.03

0.72

0.31

7.8

S0.2

543

468

75

0.85

0.82

0.03

6.0

S0.3

625

555

70

0.88

0.84

0.04

3.9

611

503

108

0.76

0.65

0.11

6.6

sample

Conventional MAs

Figure 3 shows the adsorption-desorption isotherms and pore size distribution of S0 to S0.3. All samples obtained from mixed template show typical IV isotherms. The surface area, mesopore volume, and micropore volume of S0.1 are all greater than those of MAs. These results indicated that P123-rich mixed micelles favored the formation of well-ordered mesophase. In addition, the average pore size of S0.1 is also larger than that of MAs. This result can be considered as the result of increased size of P123-rich micelles. However, surface area of S0.2 and S0.3 decrease gradually when SDS amount is further increased. Those result is consistent with Poyraz’ report.26 This is the direct result of decreased size of P123-poor micelles. Therefore, mixed surfactants technique is a good method for obtaining well-ordered mesostructured with increased size of mesopores. 2400

e

A

2000

d 1600 3

Volume cm /g

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


c 1200

800

b

400

a 0 0.0

0.4

0.8

Relative Pressure P/P0


1.2


B

e 14

3

dV/dlogD (cm /g)

d

7

c

0

a

b

0

10

20

30

40

50

Diameter (nm)

Figure 3. N2 adsorption-desorption isotherms: (A) and pore size distribution (B) of the samples: (a) S0, (b) S0.05, (c) S0.1, (d) S0.2, and (e) S0.3

Figure 4 gives the FT-IR spectra of samples S0.1 and S0. There is no difference about the FT-IR spectra of sample S0.1 and S0. According to the spectra, the band at 570 cm-1 belongs to double six member rings of zeolite Y,27-31 indicating the precursors of zeolite Y have been introduced to the walls of the sample.

200

b 570

160

Transmittance (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 16

120

80

a 570

40

0 2000

1800

1600

1400

1200

1000

800

600

400

Wavenumber (cm-1)

Figure 4. FT-IR spectra of samples (a) S0.1 and (b) S0

To evaluate the hydrothermal stability of samples obtained by the mixed template. S0.1 was hydrothermally treated in 100% water vapor at 800 °C for 16 h (denoted as


Page 9 of 16

HS0.1). As can be seen from Figure 5, HS0.1 exhibited one strong (100) diffraction peak and two overlapped diffraction peaks, indicating the high hydrothermal stability of HS0.1.

4000

3000

Intensity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2000

a 1000

0

b 0

1

2

3

4

5

2-Theta/deg

Figure 5. XRD patterns of samples (a) S0.1 and (b) HS0.1

3.2. P123 utilization efficiency. Figure 6 displays the XRD patterns of samples prepared by mixed surfactants method with various SiO2/P123 ratios and conventional method (MAs, without SDS). Although 2-theta of three reflections changes slightly from sample to sample, three well-resolved diffraction peaks corresponding to (100), (110), and (200) crystal planes are exhibited. In addition to this, no decrease in peak intensity were observed with the increase of SiO2/P123 even if the SiO2/P123 increased to 5.0. Conventional MAs are synthesized at SiO2/P123 weight ratio 0.87.8 As a direct consequence, low weight ratio of SiO2/P123 results in low P123 utilization efficiency. However, SDS molecules firstly aggregate to micelles in the present synthesis system. Free monomers and oligomers of P123 will bind to the SDS micelles due to the strong interactions between hydrophobic chain of SDS and PPO units of P123. Mixed micelles formed with a core consisting of SDS micelles with



PPO units and a corona of PEO units. Moreover, amount of introduced P123 in this micellar composite, is much lower than that of conventional P123 micelles. As a result of these, well-ordered mesophase can be synthesized with high weight ratio of SiO2/P123=2.5-5. For example, utilization of P123 for H5 is 1.51 (Table 2), almost 3 times that of conventional method. These results indicate that mixed surfactants method allows a greatly improved utilization of organic surfactants while retaining a well-ordered mesophase. 16000

e

12000

d

Intensity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 16

8000

c 4000

b a

0

0

1

2

3

4

5

2-Theta/deg

Figure 6. XRD patterns of samples: (a) conventional MAs, (b) H2.5, (c) H3, (d) H4, and (e) H5

Table 2 Yields of conventional MAs and ordered mesoporous materials synthesized with various weight ratio of SiO2/P123 Sample Conventional MAs H2.5 H3 H4 H5

Copolymer P123/g

SDS /g

Calcined /g

g zeolite / g P123

0.8

-

0.42

0.52

0.8 0.8 0.8 0.8

0.1 0.1 0.1 0.1

0.67 0.79 1.12 1.21

0.84 0.99 1.40 1.51

From wide-angle XRD pattern of H5 (Figure 7), it can be seen that crystalline zeolite Y is not formed in this process. Therefore, it could be reasonably deduced that Y precursors (primary and secondary units of Y zeolite) had been introduced into the


Page 11 of 16

walls of mesophases (from FT-IR spectrum). 160

120

Intensity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


80

40

0 0

10

20

30

40

50

2-Theta/deg

Figure 7. Wide-angle XRD pattern of H5

3.3. Morphologies. Figure 8 exhibits the TEM images of sample conventional MAs, S0, H2.5, H3, H4, and H5. It can be seen that samples have well-ordered hexagonal arrays of mesopores, indicating that samples prepared by mix surfactants method have similar images to that of conventional MAs. These results are consistent with those of XRD studies. It can be seen from these results that mixed surfactants method is favorable for maintaining well-ordered mesophase while improving greatly the utilization of organic surfactants.

Figure 8. TEM images of samples: (a) conventional MAs, (b) S0, (c) H2.5, (d) H3, (e) H4, and (f) H5



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

4. CONCLUSIONS “Mixed surfactants” is a novel method for synthesis of well-ordered MAs with greatly increased P123 utilization efficiency. The procedure of this method is as the same as the conventional method. Using this method, P123 efficiency has been improved 3 times that of conventional method. The obtained products have large surface area, pore volume of both micropores and mesopores, and increased average mesopore size. In addition, this novel method can potentially be expanded to other copolymer surfactants.

AUTHOR INFORMATION Corresponding Author *Fax: +86-10-64448327. E-mail: [email protected]

Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT The authors acknowledge the financial supports from the PetroChina Company Limited (Grants Nos. 2016E-0701, 2016A-1801, and 2016A-1804) and the Natural Science Foundation of China (Grant No. 20606003).

REFERENCES (1) Klimova, T.; Reyes, J.; Gutiérrez, O.; Lizama, L. Novel Bifunctional NiMo/Al-SBA-15 Catalysts for Deep Hydrodesulfurization: Effect of Support Si/Al ratio. Appl. Catal. A 2008, 335,


Page 12 of 16

Page 13 of 16

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


159. (2) Léonard, A.; Su, B. L. Hierarchical Aluminosilicate Macrochannels with Structured Mesoporous Walls: Towards a Single Catalyst for Multistep Reactions. Colloids Surf. A 2007, 300, 129. (3) Liu, Y.; Pinnavaia, T. J. Assembly of Hydrothermally Stable Aluminosilicate Foams and Large-Pore Hexagonal Mesostructures from Zeolite Seeds under Strongly Acidic Conditions. Chem. Mater. 2002, 14, 3. (4) Liu, Y.; Pinnavaia, T. J. Assembly of Wormhole Aluminosilicate Mesostructures from Zeolite Seeds. J. Mater. Chem. 2004, 14, 1099. (5) Han, Y.; Sun, Y.; Li, D.; Xiao, F. Hydrothermally Stable Ordered Hexagonal Mesoporous Aluminosilicates Assembled from a Triblock Copolymer and Preformed Aluminosilicate Precursors in Strongly Acidic Media. Chem. Mater. 2002, 14, 1144. (6) Huang, L.; Wang, Z.; Sun, J.; Miao, L.; Li, Q.; Yan, Y.; Zhao, D. Fabrication of Ordered Porous Structures by Self-Assembly of Zeolite Nanocrystals. J. Am. Chem. Soc. 2000, 122, 3530. (7) Liu, H.; Wang, L.; Feng, W.; Li, C.; Gao, X.; Liu, H.; Xu, C. Hydrothermally Stable Bimodal Aluminosilicates with Enhanced Acidity by Combination of Zeolite Y Precursors Assembly and the pH-Adjusting Method. Ind. Eng. Chem. Res. 2013, 52, 3618. (8) Jin, J.; Cao, L.; Hu, Q.; Xu, C.; Gao, X.; Feng, W.; Liu, H.; Liu, H. An Efficient Synthesis of Hydrothermally Stable Mesoporous Aluminosilicates with Significant Decreased Organic Templates by a Seed-Assisted Approach. J. Mater. Chem. A 2014, 2, 7853. (9) Liu, C.; Gao, X.; Ma, Y.; Pan, Z.; Tang, R. Study on the Mechanism of Zeolite Y Formation in the Process of Liquor Recycling. Microporous Mesoporous Mater. 1998, 25, 1. (10) Pan, H.; Pan, Q.; Zhao, Y.; Luo, Y.; Shu, X.; He, M. A Green and Efficient Synthesis of ZSM-5 Using NaY as Seed with Mother Liquid Recycling and in the Absence of OrganicTemplate. Ind. Eng. Chem. Res. 2010, 49, 7294. (11) Zuo, Y.; Wang, X.; Guo, X. Synthesis of Titanium Silicalite-1 with Small Crystal Size by using Mother Liquid of Titanium Silicalite-1 as Seed. Ind. Eng. Chem. Res. 2011, 50, 8485. (12) Cao, L.; Hu, Q.; Jin, J.; Xu, C.; Gao, X.; Liu, H.; Lan, L.; Yuan, X.; Liu, H. A Multiple-Assembly/One-Pot-Crystallization Strategy for a Relatively More Eco-Friendly Synthesis of Hydrothermally Stable Mesoporous Aluminosilicates. RSC ADV. 2014, 4, 61631.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 16

(13) Bharatiya, B.; Guo, C.; Ma, J.; Kubota, O.; Nakashima, K.; Bahadur, P. Urea-Induced Demicellization of Pluronic L64 in water. Colloid. Polym. Sci. 2009, 287, 63. (14) Desai, H.; Varade, D.; Aswal, V. K.; Goyal, P. S.; Bahadur, P. Micellar Characteristics of Diblock Polyacrylate-Polyethylene Oxide Copolymers in Aqueous Media. Eur. Polym. J. 2006, 42, 593. (15) Ma, J.; Guo, C.; Tang, Y.; Chen, L.; Bahadur, P.; Liu, H. Interaction of Urea with Pluronic Block Copolymers by 1H NMR Spectroscopy. J. Phys. Chem. B 2007, 111, 5155. (16) Ganguly, R.; Aswal, V. K.; Hassan, P. A. Gopalakrishnan, I. K.; Kulshreshtha, S. K., Effect of SDS

on

the

Self-assembly

Behavior

of

the

PEO-PPO-PEO

Triblock

Copolymer

(EO)20(PO)70(EO)20. J. Phys. Chem. B 2006, 110, 9843. (17) Kumbhakar, M. Aggregation of Ionic Surfactants to Block Copolymer Assemblies: a Simple Fluorescence Spectral Study. J. Phys. Chem. B 2007, 111, 14250. (18) Desai, P. R.; Jain, N. J.; Sharma, R. K.; Bahadur, P. Effect of Additives on the Micellization of PEO/PPO/PEO Block Copolymer F127 in Aqueous Solution. Colloids Surf. A, 2001, 178, 57. (19) Wang, R.; Tang, Y.; Wang, Y. Effects of Cationic Ammonium Gemini Surfactant on Micellization of PEO-PPO-PEO Triblock Copolymers in Aqueous Solution. Langmuir. 2014, 30, 1957. (20) Jansson, J.; Schillén, K.; Olofsson, G.; Silva, R. C. D.; Loh, W. The Interaction Between PEO-PPO-PEO Triblock Copolymers and Ionic Surfactants in Aqueous Solution Studied Using Light Scattering and Calorimetry. J. Phys. Chem. B 2004, 108, 772. (21) Filip, D.; Macocinschi, D.; Vlad, S. Micellar Behavior of Some Amphiphilic Block Polyurethanes in Aqueous/Nonaqueous Media. Eur. Polym. J. 2012, 48, 464. (22) Li, D.; Guan, X.; Song, J.; Di, Y.; Zhang, D.; Ge, X.; Zhao, L.; Xiao, F. Highly Efficient Synthesis of Ordered Mesoporous Silica Materials with Controllable Microporosity Using Surfactant Mixtures as Templates. Colloids Surf. A, 2006, 272, 194. (23) Zhao, D.; Feng, J.; Huo, Q.; Melosh, N.; Fredrickson, G. H.; Chmelka, B. F.; Stucky, G. D. Triblock Copolymer Syntheses of Mesoporous Silica with Periodic 50 to 300 Angstrom Pores. Science. 1998, 279, 548.


Page 15 of 16

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(24) Li, H.; Wu, H.; Shi, J. L. Competition Balance between Mesoporous Self-Assembly and Crystallization of Zeolite: A key to the Formation of MesoporousZeolite. J. Alloys Compd. 2013, 556, 71. (25) Zhang, W.; Zhang, L.; Xiu, J.; Shen, Z.; Li, Y.; Ying, P.; Li, C. Pore Size Design of Ordered Mesoporous Silicas by Controlling Micellar Properties of Triblock Copolymer EO20 PO70 EO20. Microporous Mesoporous Mater. 2006, 89, 179. (26) Poyraz, A. S.; Dag, Ö. Role of Organic and Inorganic Additives on the Assembly of CTAB-P123 and the Morphology of Mesoporous Silica Particles. J. Phys. Chem. C 2009, 113, 18596. (27) Tan, Q.; Bao, X.; Song, T.; Fan, Y; Shi, G.; Shen, B.; Liu, C.; Gao, X. Synthesis, Characterization,

and

Catalytic

Properties

of

Hydrothermally

Stable

Macro-Meso-Micro-Porous Composite Materials Synthesized via in Situ Sssembly of Preformed Zeolite Y Nanoclusters on Kaolin. J. Catal. 2007, 251, 69. (28) Kotrel, S.; Lunsford, J. H.; Knözinger, H. Characterizing Zeolite Acidity by Spectroscopic and Catalytic Means: A Comparison. J. Phys. Chem. B 2003, 105, 3917. (29) Wang, X.; Zhang, X.; Wang, Y.; Liu, H.; Qiu, J.; Wang, J.; Han, W.; Yeung, K. L. Investigating the Role of Zeolite Nanocrystal Seeds in the Synthesis of Mesoporous Catalysts with Zeolite Wall Structure. Chem. Mater. 2011, 23, 4469. (30) Zhang, Y.; Liu, Y.; Li, Y. Synthesis and Characteristics of Y-Zeolite/MCM-48 Biporous Molecular Sieve. Appl. Catal. A 2008, 345, 73. (31) Prokešová-Fojtí ková, P.; Mintova, S.; Čejka, J.; Žilková, N.; Zukal, A. Porosity of Micro/Mesoporous Composites. Microporous Mesoporous Mater. 2006, 92, 154.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Page 16 of 16

Introduction of Anionic Surfactants to Copolymer Micelles: A Key to

Recommend Documents