26 hb Nov 2008

My 1st conference yang aku jadi oral presenter. cuak gak r. seram sejuk dibuatnya. aku antara yang group 1st yang kena present dulo. 2nd speaker taw. mana x cuak.hampir sebulan gak aku siapkan paper untuk present ni. n dah banyak kali dah aku kena ubah macam2. Dr. Azmi dari USM kejuruteraan memulakan soalan2 yang membunuh aku. aku apa lagi mencurahkan sambil menggoreng segala ilmu yg aku ada la kat c2. budak2 aku ckp aku nampak confident time melalut sini sana tu. ahaaahaa..anyway i think my Q-A session is suck bila ada sorng budak ni tanya soklan berkaitan FTIR yang aku wat. actually time 4 Q-A dah abis dah tyme 2. tp aku lak dengan confident nya nak jawap soklan 2. klu aku taw sklan pasal FTIR mmg aku x tanya dah. wat xnmpak ja..about presentaion i think ok. cuma mic tu wat sleck skit cilakak la. pas abis 2 aku rasa lega sgt2. puas. tapi pasni ada lagi 1 conference lagi kat Port Dickson, RCSSST2008. Tiara Beach resort. ni 3hari 2mlm lak. manala… aku nak tdo. dinner mlm ni di Naza Hotel, menu adalah BBQ. tahap kesedapannya hanyalah biasa2 saja. tp yg menariknya ke”hevoc”kan geng kami yang melalak2 sesuka hati mengikot alunan lagu2 selepas habis dinner tu hahaaa….ari2 berakhir dgn kepenatan yang teramat sangat. kul 1230mlm baru sampai umah sejak kluar dari kul 530 pagi td.

27hb Nov 2008

pagi ni len skit, mak aku yang drive sbb nnt ptg kami aku trus balik ke UKM nek bus. sementara tgu conference stat aku jalan2 bersama2 adik2 ku di tepian pantai lu menghabiskan masa2 terluang aku. lagpon dah nak balik ukm sat g.

arini turn kak mina, ieda n jamilah lak present hehee… aku dah lega dah. ieda punya ketaq samapi xlalu nak lunch tghari2 hahaa…. ni muka2 takot orng2 yg nak present

kul 3 lebey cm2 kami nek bus nak balik dah…tp sempat lagi nak begambar tu ehehee… pic kat bawah tu semua deligasi UKm bersama Dr. Azizan

xabis lagiii…. seblum balik tu sempat lagi round2 penang taw. yerla bukan sume penah g penang ni.. dalam kul 12mlm 2 khamis elamat sampai kat ukm…

This paper was presented at VIIIth National Symposium On Polymeric Materials 2008 (NSPM 2008), Naza Hotel. Penang.

Preparation and Characterization of Solid Polymer Electrolytes

49% Poly(Methyl Methacrylate)-Grafted Natural Rubber - Poly(Methyl Methacrylate) - Lithium Perchlorate Salts.

¹M.S. Su’ait, ^1*A. Ahmad, ¹H. Hamzah and ²M.Y.A. Rahman

¹ School of Chemical Sciences and Food Technology, Faculty of Sciences and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.

² College of Engineering, Universiti Tenaga Nasional, 43009 Kajang, Selangor, Malaysia.

^*Corresponding Author : azizan@ukm.my

Abstract: The potential of hybrid polymer 49% poly(methyl methacrylate)–grafted natural rubber (MG49) and poly(methyl methacrylate) (PMMA) as a polymer host in solid polymer electrolyte (SPE) film for rechargeable batteries system has been investigated. The hybrid films were prepared by solution casting technique. The ionic conductivity was investigated by alternating current electrochemical impedances spectroscopy (EIS). The highest conductivity is 1.47×10^-8 S.cm^-1 at 20 wt. % of LiClO₄. The observation on structural studies done by X-ray diffraction (XRD) showed that the crystallinity phase is reduced at the highest conductivity. The Fourier transform infrared spectroscopy (FTIR) analysis showed that the interaction between lithium ion and oxygen atoms occurred at carbonyl (C=O) and ether (C-O-C) groups.

Keywords: Ionic conductivity, MG49, PMMA, Lithium perchlorate, Solid polymer electrolyte

1. Introduction

Research on polymer electrolyte was firstly conducted by Fenton et al. [1]. They found that the non-conducting polymer, polyethylene oxide (PEO) become conductive when lithium salt was added into the polymer matrix. However, research on PMMA based SPE was only conducted in 1985 by Iijima and co-workers [2]. The finding of ionic conductivity in these polymer material complexes with salts has led to the development of electrochemical devices such as rechargeable batteries, electrochromic windows and sensing devices for chemicals/gases [3].

PMMA has been used as a polymer host due to its high transparency in the visible region as preferred solid electrolytes in electrochromic window [4], high stability at lithium-electrolyte surface [5] and able to be diluted in various organic solvents [6]. PMMA based electrolyte is also less reactive towards the lithium electrode. It induces more favourable passivation film on the electrode surface. Therefore, it is expected that a higher cyclibility of lithium electrode in PMMA based electrolyte [7]. PMMA also acts as a stiffener that fast ion transport occurs through a continuous conduction path which does not affect the electrochemical stability of the electrolyte [8]. The increasing in surface exposure of PMMA could increase the mechanical properties and increase the melting level of lithium salts due to the high dielectric properties of lithium salts. In addition, PMMA has a polar functional group in their main polymer chain that shows high affinity for lithium ions to transport. Oxygen atom from carbonyl group (C=O) will form a coordinate bond with lithium ion from doping salts [7]. The main drawback of plasticized gel-based PMMA system is its poor mechanical properties. Its mechanical properties can only be improved by modifying the ratio between polymer host and plasticizer/solvent. However, this will adversely affect the ionic conductivity and easily corrode the lithium metal anode in an electrochemical cell [9]. Polymer electrolyte must have enough mechanical strength to hold the pressure between anode and cathode, as gel polymer electrolyte (GPE) is unable to do so as compared to solid polymer electrolyte.

To overcome the drawback of GPE and mechanical properties of PMMA film, PMMA was hybrided with elastomer material such as modifier natural rubber to improve the segmental motion in polymer hybrid systems and hence a more flexible and elastic material. Natural rubber and synthetic rubber like poly(styrene-co-butadiene) (SBR) and poly(acrylonitrie-co-butadiene) (NBR) rubber were not suitable because natural rubber has sticky properties and not compatible with PMMA [10]. Besides, natural rubber does not has polar group to enhance the ion mobility in the SPE system. Whereas, synthetic rubber gives a poor mechanical properties at low polymer concentrations [11]. Recently, modified natural rubber such as epoxidized natural rubber (ENR) and PMMA–grafted natural rubber (MG) based SPE had drawn the attention of many researchers [9,11-13,15,17-19]. This is due to the attractive attributes such as low glass transition temperature (T_g), soft elastomer characterization at room temperature, and good elasticity. Suitable elasticity can result in flat, thin, and flexible film. Furthermore, modified NR gives excellent contact between an electrolytic layer and an electrode in batteries system. It can also act as a polymeric solvent and the ionic conductivity is higher as compared to glassy or crystalline state of polymer [3]. On the other hand, modified NR has oxygen atoms, which can act as electron donor atoms in the structure of the polymer host. Research conducted by Kamuta et al. [12], Alias et al. [15] and Ali et al. [19] found that the oxygen atoms with lone pair of electron formed a coordinate bond with lithium ion from perchlorate salt and hence a polymer-complex. However ENR based SPE shows a drawback to its mechanical properties such as slightly sticky and difficult to peel off from substrate [9,13,14] as compared to MG film which is more free standing, elastic and flexible. Previous studies on various MG was conducted elsewhere [3,12,15-18]. Fig. 1 shows the structure of MG monomer [16].

Fig. 1. Structure of MG monomer

In this work, polymer hybrid MG49-PMMA with ratio 30:70 is doped with LiClO₄ salt to prepare SPE by solution casting technique. All the sample were characterized by using AC electrochemical impedences spectroscopy (EIS), X-ray diffraction (XRD) and Fourier transform spectroscopy (FTIR). It is expected that LiClO₄ salt gives an optimum value for ionic conductivity studies in polymer hybrid (30:70) MG49-PMMA.

2. materials and methods

2.1 Materials.

MG49 was commercially obtained. PMMA low molecular weight and LiClO₄ salt were supplied by Fluka. All the materials were used without further purification.

2.2 Sample preparation.

All the polymer electrolyte samples were prepared by solution casting technique. MG49 rubber was sliced into a grain size. The quantity of MG49 was dissolved in stopped flasks containing toluene. After 24 hours, the solution was stirred with efficient magnetic stirring for the next 24 hours until complete dissolution of MG49 into clear viscous solution. PMMA solution was prepared in another stopped flask containing toluene and stirring for 24 hours. These two solutions were then mixed together for 24 hours to obtain a homogenous solution. LiClO₄ salt was dissolved in THF solution for 12 hours and doped to the solutions for the next 24 hours with continue stirring to obtain a homogenous solution. The electrolyte solutions were casted onto a glass Petri dish and the solvent were allowed to slowly evaporate in a fume hood at room temperature. A free standing film was obtained when the solvent completely evaporated. Residual solvents were then removed in vacuum oven for 48 hours at 50C. The samples were then stored in a desiccator until further use. The same experimental procedure was repeated for different weight percent salts loading.

2.3 Characterization.

The ionic conductivity measurements were carried out by AC EIS using High Frequency Resonance Analyzer (HFRA) model 1255 with applied frequency from 6500 Hz to 0.1 Hz at perturbation voltage of 2500 mV. The disc shaped sample of 16 mm in diameter was sandwiched between two stainless steel block electrodes. XRD model D-5000 Siemen was used to observe on the appearance and disappearance of crystalline or amorphous phase as a function of salt content. The data was collected from the range of diffraction angle 2θ from 2° to 80° at rate 0.04° s^-1. FTIR spectrum was recorded by computer interfaced Perkin Elmer GX Spectrometer. The electrolyte was casted onto NaCl windows and was analyze in the frequency range of 4000 cm^-1 to 400 cm^-1 with scan resolution of 4 cm^-1. All the analysis was conducted at room temperature.

3. Results and Discussion

3.1. Ionic conductivity

Typical impedance plots are shown in Fig. 2. According to Rajendran et al. [7] and Kim et al. [29], the complex impedance plots showed two well-defined regions, there is a semicircle in the high frequency range which is related to conduction process in the bulk of complex and the linear region in the low frequency range that is attributed to the effect of blocking electrodes. At low frequency, the complex impedance plot shows a straight line parallel to the imaginary axis, but the double layer at blocking electrodes causes the curvature.

Fig. 2. Typical impedence plot of 30/70 MG49-PMMA 20 wt. % LiClO₄

The bulk resistance (R_b) was obtained from the intercept on real impedance axis (Z’ axis). The ionic conductivity (σ) was calculated from the R_b, the film thickness (l) and contact area of the thin film (A=2πr), according to the equation σ= [l/(A.R_b)]. Ionic conductivity and O/Li ratio of SPE MG49-PMMA-LiClO₄ is showed in Table 1. Ionic conductivity at 0 wt. % of LiClO₄ salt content is 4.07×10^-12 S.cm^-1 and the highest ionic conductivity is 1.47×10^-8 S.cm^-1 at 20 wt. % LiClO₄ salt. The ionic conductivity increased as the salt loading increases up to its optimum level in polymer host. This is due to the increase of the number in conducting species in the electrolyte. This optimum value indicates the maximum and an effective interaction between oxygen atoms and Li⁺ ion in the electrolyte.

The interaction that occurs was explained by FTIR investigation from elsewhere [7,9,12,15,17,19,20,24]. It was founded that a coordinate bond was formed in the polymer-salt complexes between Li⁺ and oxygen atoms. The O/Li ratio for the optimum LiClO₄ salt loading is 7 of oxygen atoms to 1 lithium ion or can be simply written as 7/1. The different value in O/Li is due to the difference of weight percent (wt. %) of the lithium salt. The higher ionic conductivity in addition of 20 wt. % LiClO₄ salt was caused by the large anion size and low lattice energy of LiClO₄ salt generally expected to promote greater dissociation of salts, thereby providing higher concentration of ions [21]. Nevertheless, the ionic conductivity decreases after the optimum salt loading due to the ions association or ions aggregation [18] and the effect of lithium salt’s crystallization in the polymer host as shown in the XRD diffractograms in Fig. 3.

However these findings are slightly lower than the finding by Latif et al. [9], Idris et al. [11] and Ali et al. [18] because in this research, there is no plasticizer such as polypropylene carbonate (PC) and ethylene carbonate (EC) added into SPE and a different type of lithium salt used. The presence of PC and EC in polymer electrolyte can easily corrode the lithium metal electrode in electrochemical cell [14].

Table 1. The ionic conductivity and [O/Li] ratio of SPE MG49-PMMA-LiClO₄

3.2. Structural studies

The XRD analysis is used to determine the structure and crystallization of polymer-salts complex by observing the appearance and disappearance of crystalline or amorphous region. Fig. 3 shows the XRD diffractograms of SPE MG49-PMMA-LiClO₄ in the angle range 2 to 80°. The bell shaped intense curve in Fig. 3 shows the semi-crystalline region occurs in the polymer host (PMMA) while the amorphous region occurs when the intensity of the peak became broader at 20 wt. % LiClO₄ salt loading [25].

However, the system is not fully amorphous based on the presence of LiClO₄ peak at 23.0° and PMMA single peak at 13.2°. In addition, a high ionic conductivity level do still occurs due to the reduction in the intensity of the PMMA crystallization peak from bell shaped curve to a broadening shape. This finding approved the suggestion from elsewhere [1,13,18,20-26] that either the amorphous region or the reduction of crystalline region gives high ionic conductivity as compared to the crystalline or semi-crystalline region. The presence of LiClO₄ peaks at angle 23.0°, 31.4° and 35.3° in Fig. 3 showed that the crystalline phase occurred in SPE MG49-PMMA doped with 25 wt. % LiClO₄ salt. This is because of the recrystallization of LiClO₄ salt due to the ion association between Li⁺ and ClO₄^- in the electrolyte at the high salt concentration. There are no significant changes from 5 wt. % to 15 wt. % salt loading in SPE MG49-PMMA. The salt affect the overall ionic conductivity through crystalline complexes formation, intramolecular crosslinking of the polymer chains and degree of salts dissociation-number of charge carriers [1].

Fig. 3. XRD diffractograms of 30/70 MG49-PMMA-LiClO₄ from 2 to 80°

3.3. FTIR Spectrum studies

FTIR spectroscopy is used to observe the vibration energy of covalent bond in the polymer host and the interaction occurs in the polymer-salt complexes. Since each type of bonds has a different natural frequency of vibration, so the identification of absorption peak in the vibration portion of infrared region will give a specific type of bonding [27,28]. In this research, the main interests are shown on the oxygen atoms of the carbonyl (C=O) (1750 cm^-1-1730 cm^-1) and ether group (C-O-C) (1300 cm^-1-1000 cm^-1) from PMMA and MG49 [27]. According to the literature [5,7,12,17-20,22,24], the oxygen atoms acted as electron donor atoms in the structure of polymer host and form a coordinate bond with lithium ion from doping salts to form polymer-salt complexes. Carbonyl from ester group shows a very strong peak appearing in the range of 1750 cm^-1 to 1735 cm^-1 for simple aliphatic esters and shift to lower wavenumbers by about 15 cm^-1 to 25 cm^-1 in the polymer salt complexes [18,27].

From the experiment conducted, the C=O symmetrical stretching frequency of PMMA and MG49 in polymer-salt complexes gives rise to an intense, very strong and sharp peak at 1733 cm^-1 and 1734 cm^-1 respectively. With addition of lithium salt loading, the intensity of C=O symmetric stretching of MMA peak reduced and shifted to the lower wave number from 1732 cm^-1 to 1735 cm^-1. The shifting of C=O symmetric stretching of MMA peak are demonstrated in Fig. 4(a). The shifting of the intensity peaks confirmed the interaction between lithium ion from doping salt and oxygen atoms in the structure of polymer host to form a coordinate bond and subsequently forming polymer-salt complexes. Previous study reported that the shifting of the intensity peaks still occur even though in insignificant range. Kamuta et. al [17] reported that the C=O stretching of MMA at 1729 cm^-1 is shifted to 1728 cm^-1 in the MG30-EC with LiCF₃SO₃ salt complex. The inconsistent changes in wavenumbers are observed in O-CH₃ asymmetric deformation of MMA and C-O symmetric stretching of MMA. However, in term of peak intensities illustrated in Fig. 4(b), the intense, strong and sharp peak became weak and broader with addition of lithium salt. This is due to the weak interaction between oxygen atoms and lithium ion from doping salt. This change has not been reported before. It was also observed, that there is no significant changes at C=C stretching of polyisoprene and CH₃ asymmetric stretching of MMA/rubber structure.

(a)

(b)

Fig. 4. FTIR spectrum for (a) carbonyl group and (b) ether group

4. Conclusion

SPE MG49-PMMA doped with LiClO₄films have been successfully prepared by solution casting technique. The highest conductivity is 1.47×10^-8 S.cm^-1 at 20 wt. % of LiClO₄ salt loading. The observation on structural studies done by XRD showed that the crystallinity phase is reduced at the highest conductivity and FTIR analysis showed that the interaction between lithium ion and oxygen atoms occurred at carbonyl (C=O) and ether (C-O-C) groups.

5. ACKNOWLEDGEMENTS

The authors would like to extend their gratitude towards Universiti Kebangsaan Malaysia for allowing this research to be carried out. This work is supported by the MOSTI grant 03-01-02-SF0423.

6. References

[1] Fenton, D.E., J.M. Parker and P.V. Wright. 1973. Complexes of Alkali Metal Ions with Poly(Ethylene Oxide). J. Polymer. 14: 589

[2] Iijima, T., Y. Tyoguchi and N. Eda. 1985. Quasi-Solid Organic Electrolytes Gelatinized with PMMA and Their Applications for Lithium Batteries. Dengki Kagaku. 53: 619

[3] Gray, F. M. 1997. Polymer Electrolytes, London: RSC Material Monographs.

[4] Ahmad, Sh., Sf. Ahmad and S.A. Agnihotry. 2004. Nanocomposite Electrolytes with Fumed Silica in PMMA: Thermal, Rheological & Conductivity Studies. J. Power Sources. 140: 151-156

[5] Chen, H.W., T.P. Lin and F.C. Chang. 2002. Ionic Conductivity Enhancement of the Plasticized PMMA/LiClO₄ Polymer Nanocomposite Electrolyte containing Clay. J. Polymer. 43: 5281-5288

[6] Ahmad, Sh., T.K. Saxena, Sf. Ahmad, & S.A. Agnihotry. 2006. The Effect of Nanosized TiO₂ addition on PMMA Polymer Electrolytes. J. Power Sources. 159: 205-209

[7] Rajendran, S., O. Mahendran and R. Kannan. 2002. Characterisation of [(1-x)PMMA-xPVdF] Polymer Blend Electrolyte with Li⁺ ion. J. Fuel. 81: 1077-1081

[8] Rajendran, S., T. Uma and T. Mahalingam.1999. Characterization of Plasticized PMMA Based Solid Polymer Electrolytes. Ionics. 5: 232-235

[9] Latif, F., A. M. Aziz, N. Katun, A.M.M. Ali and M.Z. Yahya, 2006. The Role and Impact of Rubber in PMMA-LiCF₃SO₃ Electrolytes. J. Power Sources. 159: 1401-1404

[10] Li, W., M. Yang, M. Yuan, Z. Tang and J.Q. Zhang. 2007. Dual-Phase Polymer Electrolytes Based on Blending Poly(MMA-g-NBR) and PMMA. J. App. Polymer Science. 106: 3084-3090.

[11] Idris, R., M.D. Glasse, R.J. Latham, R.G. Linford and W.S. Schlindwein. 2000. Polymer Electrolytes Based on Modified Natural Rubber for use in Rechargeable Lithium Batteries. J. Power Sources 94: 206-211

[12] Kamuta, K., and Y. Alias, 2006.FTIR Spectra of Plasticized Grafted Natural Rubber LiCF₃SO₃ Electrolytes. J. Spectrochimica Acta. Part A. 64: 442-447

[13] Glasse, M.D., R. Idris , R.J. Latham, R.G. Linford, and W.S. Schlindwein. 2002. Polymer electrolytes based on modified Natural Rubber PEO-ENR25/ENR50-LiCF₃SO₃. Solid State Ionics. 147: 289–294

[14] Lu, G., Z-F. Li, S-D. Li and J. Xie. 2001. Blends of Natural Rubber Latex and Methyl Methacrylate-Grafted Rubber Latex. J. Applied Polymer Science. 85: 1736–1741

[15] Alias, Y., I. Ling and K. Kumutha. 2005. Structural and Electrochemical Characteristics of 49% PMMA Grafted Polyisoprene-LiCF₃SO₃-PC Based Polymer Electrolytes. Ionics. 11: 414

[16] de Oliveira, P.C., A.M. de Oliveira, A. Garcia, J.C. de Souza Barboza, C.A. de Carvalho Zavaglia and A.M. dos Santos. 2005. Modification of Natural Rubber: A Study by H NMR to Assess the Degree of Graphitization of PDMAEMA or PMMA onto Rubber Particles Under Latex Form in the Presence of Redox Couple Initiator.European Polymer J. 41: 1883–1892

[17] Kamuta, K., Y. Alias and R. Said. 2005.FTIR and Thermal Studies of Modified Natural Rubber Based Solid Polymer Electrolytes. Ionics. 11: 472-476

[18] Ali, A.M.M., M.Z.A. Yahya, H. Bahron and R.H.Y. Subban. 2006. Electrochemical Studies on Polymer Electrolytes Based on PMMA-grafted Natural Rubber for Lithium Polymer Battery. Ionics. 12: 303–3075

[19] Ali, A.M.M., R.H.Y. Subban, H. Bahron, T. Winie, F. Latif and M.Z.A. Yahya. 2008. Grafted NR Based Polymer Electrolytes, ATR-FTIR and Conductivity Studies. Ionics (in press).

[20] Subban, R.H.Y., and A.K. Arof. 2003. Experimental Investigations on PVC-LiCF₃SO₃-SiO₂ Composite Polymer Electrolytes. J. New Materials for Electrochemical Systems. 6: 197-203.

[21] Mahendran, O and S. Rajendran. 2003. Ionic Conductivity Studies in PMMA-PVdF Polymer Blend Electrolyte with Lithium Salts. Ionics. 9: 282-288

[22] Baskaran, R., S. Selvasekarapandian, N. Kuwata, J. Kawamura and T. Hattori. 2006. Conductivity and Thermal Studies of Blends Solid Polymer Electrolytes Based on PVAc-PMMA. Solid State Ionics. 177: 2679-2682

[23] Rajendran, S., O. Mahendran, and R. Kannan. 2002. Ionic Conductivity Studies in Composite Solid Polymer Electrolytes Based on PMMA. J. Physics and Chemistry of Solid. 63: 303-307

[24] Rajendran, S., and T. Uma. 2000. Characterization of Plasticized PMMA-LiBF₄ Based Solid Polymer Electrolytes. Bulletin of Materials Sciences. 23(1): 27-29

[25] Y-J. Wang, Y. Pan, & D. Kim. 2006. Conductivity Studies on Ceramic Li_1.3Al_0.3Ti_1.7(PO₄)₃ -filled PEO-Based Solid Composite Polymer Electrolytes. J. Power Sources. 159: 690-710

[26] Mohapatra, S.R., A.K. Thakur, and R.N.P. Choudhary. 2008. Studies on PEO-Based Sodium Ion Conducting Composite Polymer Films. Ionics. 14: 255-262

[27] Pavia, D.L., G.M. Lampman and G.S. Kriz. 2001. Introduction to spectroscopy, 3^rd Ed. USA. Brooks/Cole Publishing.

[28] Skoog, D.A., F.J. Holler and T.A. Nieman. 1998. Principle of Instrumental Analysis, 5^th USA. Saunders College Publishing and Harcourt Brace College Publishing.

[29] Kim, C., G. Lee, K. Liou, K.S. Ryu, S.G. Kang, and S.H. Chang. 1999. Polymer Electrolytes Prepared by Polymerizing Mixtures of Polymerizable PEO-Oligomers, Copolymer of PVDC and PAN, and LiCF₃SO₃. Solid State Ionics 123: 251–257

Fly FM 3rd anniversary party last week was been held at one Utama Damansara. mmg sgt best dgan kehadiran band2 antaranya MEET UNCLE HUSIN, BITTERSWEET, ESTRANGE, 7COLOR T-SHIRT n da latest HEartBroken : BUNKFACE-situasi uhuhuu… mmg best. sblum g gig tu Lat yg baru dapat gaji tu sempat la g shuppin kasut (brand pe ntah lupe nak snap2) yg terus dipakai tanpa segan silu (hahahaaa…..) walaubagaimanapon aku kurang bernasib baik untuk turut serta memilih serta mengomen2 kasut pilihan Lat itu sebab depa membeli serta belah terlebih dahulu tanpa menuggu aku (actually aku dari shah alam tyme 2, so xdtg sklai ng diorg dr ukm). apapon Congratulation Lat kasut mmg agak lawa walaupon ada esiden-esiden hampir terpegang benda-benda yang diharamkan hahaaa….anyway dat very enjoyable nite walupon ade skit tetibe moody ng cokelat tapi tu sume xmenghalang aku dari terus meloncat-loncat sambil terajang kiri n kanan di lautan kanak-kanak sekolah tu. ahahahaa….

pas penat terkija-kija sampai berpeloh n basah kuyup ng peloh kat fly party tu lat pon menunaikan janjinya tok belanja makan. kami pilih bubur kg baru sbagai menu hari ini ya…. Thnx Lat, dalam kepenatan n kekenyangan kami melangkah pulang ke UKM dengan hati yg bercampur2. uhuhu…

“syg…. By SoulMate”

i dunno wat i feel dis time, i’m really2 down. it’s hard 4 not 2 think. it pain 2 noe da true…God Help me!

Sedap X Klu makan hati?? sakit hati lg ada la kot rasanya…hahaa… tp aku betui2 patah hati sampai xsampai hati nak kata apa2 dah. do as u wish! ikot la kata hati tu.

4. Tetapi di tentukan juga yang nilai Dolar Amerika ialah sebanyak 35 Dollar untuk satu ouns emas. Ini bermakna secara tidak langsung semua matawang dinilai mengikut sekian banyak emas.

5. Di masa itu semua matawang adalah kukuh. Tetapi Britain, pada tahun 1966 telah turunkan nilai Pound British. Malaysia telah rugi banyak kerana simpanan (reserve) kita adalah dalam matawang Pound. Pada satu masa Pound yang bernilai Ringgit Malaysia 8.30 telah turun kepada Ringgit Malaysia 3.60.

6. Kemudian Presiden Richard Nixon membuat keputusan bahawa Dollar Amerika tidak lagi terikat dengan emas. Amerika telah tolak apa yang dipanggil sebagai “Gold Standard”. Amerika juga memutuskan bahawa pasaran akan tentukan nilai Dolar Amerika.

7. Tetapi negara-negara lain masih percaya akan kekuatan ekonomi Amerika dan meneruskan ikatan nilai matawang mereka dengan Dollar.

8. Satu lagi keputusan dunia antarabangsa ialah nilai dagangan antarabangsa ditentukan dengan nilai Dollar Amerika dan bayaran juga dibuat dengan Dollar Amerika. Ini menyebabkan permintaan bagi Dollar Amerika menjadi kuat dan sekali gus menjamin nilai Dollar Amerika tidak jatuh walaupun tidak lagi diukur dengan sekian banyak emas.

9. Pada satu masa dahulu bank besar dibenarkan mencetak dan mengeluarkan “Bank Notes” sebagai wang yang sah dipergunakan. Kemudian pemerintah mengambil alih pengeluaran matawang.

10. Bank mengeluarkan pinjaman daripada modal dan deposit oleh pelanggan. Kadang-kadang jumlah pinjaman melebihi wang yang ada dalam bank. Tetapi ini dihadkan. Walaupun demikian pinjaman yang dikeluarkan kerap kali jauh lebih banyak dari had yang ditentukan.

11. Apabila pendeposit mengeluarkan simpanan mereka beramai-ramai maka bank tidak mampu untuk membayar balik kepada pendeposit kerana semua wang telah diberi pinjam bahkan lebih daripada itu. Dalam keadaan ini bank mesti di selamatkan (bail-out) oleh Kerajaan.

12. Melihat bahawa bank boleh mengeluarkan pinjaman hampir tanpa had (unlimited) maka penyangak pun merancang untuk guna duit bank yang tidak terhad ini untuk meraih keuntungan atas angin. Maka berlakulah dagangan matawang, pinjaman kepada peminjam yang keupayaan membayar tidak terjamin, penjualan pinjaman yang dikeluarkan oleh bank kepada syarikat insurans dan syarikat gadaian (mortgage company) dan lain-lain. Jumlah semua transaksi ini amat besar, bernilai berbilion dolar. Apabila ramai peminjam tidak dapat bayar hutang atau servis hutang, maka mereka yang membeli pinjaman bank dapati mereka akan rugi berbilion dolar.

13. Dan banyak lagilah penyalahgunaan sistem bank Barat yang dilakukan. Demikian Amerika dengan kekayaannya yang besar sekalipun tidak dapat menampung berbilion dolar kerugian oleh bank, syarikat, insuran, syarikat mortgage, hedge funds, merchant dan investment bank dan lain-lain.

14. Sesungguhnya sistem bank dan matawang Barat sudah gagal. Dunia harus kaji untuk menggantinya dengan sistem lain termasuk perbankan Islam dan dagangan dengan matawang khusus seperti Dinar Emas.

15. Tidak seperti duit kertas emas tetap mempunyai nilai dimana-mana dalam dunia. Dinar Emas dicadang hanya untuk menyelesaikan bayaran dagangan antarabangsa.

16. Apakah ada cukup emas dalam dunia untuk dijadikan wang antrabangsa? Sudah tentu tidak.

17. Tetapi kita tidak perlu bayar dengan dinar emas sepenuhnya. Memadai jika kita bayar cuma lebihan antara import-eksport antara dua buah negara.

18. Jika sebuah negara mengeksport 100 juta Dinar kepada sebuah negara lain dan negara itu pula mengeksport kepada negara pertama barangan atau khidmat yang bernilai 110 juta Dinar, maka bayaran yang harus dibuat oleh Bank Negara negara yang pertama hanyalah 10 juta Dinar emas. Jika tidak ada Dinar Emas yang mencukupi maka bayaran boleh dibuat kemudian dengan eksport bernilai 10 juta Dinar.

19. Kita bukan sahaja boleh ada dagangan antara dua buah negara tetapi antara beberapa buah negara. Sebenarnya bank-bank mengguna cara ini untuk menyelesaikan bayaran cheque kepada beberapa bank yang telah terima dan mengeluarkan bayaran berasas kepada cheque lain-lain bank.

20. Sudah tentu akan ada banyak masalah pada permulaan. Tetapi pakar-pakar boleh cari jalan untuk selesaikan atau atasi kelemahan sistem Dinar Emas ini.

21. Bank Negara Malaysia pernah runding dengan sebuah negara lain dan penggunaan Dinar Emas memang boleh dilaksanakan. Tetapi entah kenapa Bank Negara Malaysia tidak dapat menjayakan sistem ini.